{"id":429,"date":"2021-12-17T21:44:15","date_gmt":"2021-12-17T21:44:15","guid":{"rendered":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/5-weathering-erosion-and-sedimentary-rocks\/"},"modified":"2025-01-21T01:03:28","modified_gmt":"2025-01-21T01:03:28","slug":"5-weathering-erosion-and-sedimentary-rocks","status":"publish","type":"chapter","link":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/5-weathering-erosion-and-sedimentary-rocks\/","title":{"raw":"5 Weathering, Erosion, and Sedimentary Rocks","rendered":"5 Weathering, Erosion, and Sedimentary Rocks"},"content":{"raw":"[caption id=\"attachment_3890\" align=\"aligncenter\" width=\"2560\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/NP3-scaled-1.jpg\"><img class=\"wp-image-332 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1.jpg\" alt=\"The rock has a large cliff.\" width=\"2560\" height=\"1920\"><\/a> Light illuminates the sedimentary rocks of Notch Peak, in the House Range of western Utah.[\/caption]\n<h1>5 Weathering, Erosion, and Sedimentary Rocks<\/h1>\n<b>KEY CONCEPTS<\/b>\n\n<strong>By the end of this chapter, students will be able to:<\/strong>\n<ul>\n \t<li>Describe how water is an integral part of all [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] [pb_glossary id=\"2960\"]formation[\/pb_glossary]<\/li>\n \t<li>Explain how chemical and [pb_glossary id=\"1204\"]mechanical weathering[\/pb_glossary] turn [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] into [pb_glossary id=\"2678\"]sediment[\/pb_glossary]<\/li>\n \t<li>Differentiate the two main categories of sedimentary rocks : [pb_glossary id=\"2825\"]clastic[\/pb_glossary] rock formed from pieces of weathered [pb_glossary id=\"1971\"]bedrock[\/pb_glossary]; and chemical rock that precipitates out of [pb_glossary id=\"2705\"]solution[\/pb_glossary] by organic or inorganic means<\/li>\n \t<li>Explain the importance of sedimentary structures and analysis of [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary], and how they provide insight into the Earth\u2019s history<\/li>\n<\/ul>\n[pb_glossary id=\"2683\"]Sedimentary rock[\/pb_glossary] and the processes that create it, which include [pb_glossary id=\"2676\"]weathering[\/pb_glossary], [pb_glossary id=\"2677\"]erosion[\/pb_glossary], and [pb_glossary id=\"2682\"]lithification[\/pb_glossary], are an integral part of understanding Earth Science. This is because the majority of the Earth\u2019s surface is made up of sedimentary rocks and their common predecessor, [pb_glossary id=\"2678\"]sediments[\/pb_glossary]. Even though sedimentary rocks can form in drastically different ways, their origin and creation have one thing in common, water.\n<h2><span style=\"font-weight: 400\">5.1 The Unique Properties of Water<\/span><\/h2>\n&nbsp;\n\n[caption id=\"attachment_2757\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/H2O_2D_labelled.svg_.png\"><img class=\"size-medium wp-image-145\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2021\/09\/H2O_2D_labelled.svg_-300x131.png\" alt=\"The hydrogen atoms are on one side, about 105\u00b0 apart.\" width=\"300\" height=\"131\"><\/a> A model of a water molecule, showing the bonds between the hydrogen and oxygen.[\/caption]\n\nWater plays a role in the [pb_glossary id=\"2960\"]formation[\/pb_glossary] of most [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary]. It is one of the main agents involved in creating the [pb_glossary id=\"2687\"]minerals[\/pb_glossary] in [pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rock. It also is a [pb_glossary id=\"2676\"]weathering[\/pb_glossary] and [pb_glossary id=\"2677\"]erosion[\/pb_glossary] agent, producing the grains that become [pb_glossary id=\"3363\"]detrital[\/pb_glossary] [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary]. Several special properties make water an especially unique substance, and integral to the production of [pb_glossary id=\"2678\"]sediments[\/pb_glossary] and [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary].\n\nThe water molecule consists of two hydrogen atoms covalently [pb_glossary id=\"2703\"]bonded[\/pb_glossary] to one oxygen atom arranged in a specific and important geometry. The two hydrogen atoms are separated by an angle of about 105 degrees, and both are located to one side of the oxygen atom. This atomic arrangement, with the positively charged hydrogens on one side and negatively charged oxygen on the other side, gives the water molecule a property called <strong>[pb_glossary id=\"2690\"]<strong>polarity<\/strong>[\/pb_glossary]<\/strong>. Resembling a battery or a magnet, the molecule\u2019s positive-negative architecture leads to a whole suite of unique properties.\n\n[caption id=\"attachment_2954\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/05.1_DewSpiderWeb.jpg\"><img class=\"size-medium wp-image-333\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/05.1_DewSpiderWeb-300x225.jpg\" alt=\"The water drops are sticking to a spider's web\" width=\"300\" height=\"225\"><\/a> Dew on a spider's web.[\/caption]\n\n[pb_glossary id=\"2690\"]Polarity[\/pb_glossary] allows water molecules to stick to other substances. This is called <strong>[pb_glossary id=\"2693\"]adhesion[\/pb_glossary]<\/strong>. Water is also attracted to itself, a property called <strong>[pb_glossary id=\"2692\"]cohesion[\/pb_glossary]<\/strong>, which leads to water\u2019s most common form in the air, a droplet. [pb_glossary id=\"2692\"]Cohesion[\/pb_glossary] is responsible for creating surface [pb_glossary id=\"1445\"]tension[\/pb_glossary], which various insects use to walk on water by distributing their weight across the surface.\n\n[caption id=\"attachment_2956\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3D_model_hydrogen_bonds_in_water.svg_.png\"><img class=\"size-medium wp-image-334\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_-300x298.png\" alt=\"The positive side of the water molecule is attracted to the negative side of the water molecule\" width=\"300\" height=\"298\"><\/a> Hydrogen bonding between water molecules.[\/caption]\n\n&nbsp;\n\nThe fact that water is attracted to itself leads to another important property, one that is extremely rare in the natural world\u2014the liquid form is denser than the solid form. The [pb_glossary id=\"2690\"]polarity[\/pb_glossary] of water creates a special type of weak [pb_glossary id=\"2703\"]bonding[\/pb_glossary] called <strong>[pb_glossary id=\"1202\"]hydrogen bonds[\/pb_glossary]<\/strong>. [pb_glossary id=\"1202\"]Hydrogen bonds[\/pb_glossary] allow the molecules in liquid water to sit close together. Water is densest at 4\u00b0C and is less dense above and below that [pb_glossary id=\"2689\"]temperature[\/pb_glossary]. \u00a0As water solidifies into ice, the molecules must move apart in order to fit into the crystal lattice, causing water to expand and become less dense as it freezes. Because of this, ice floats and water at 4<sup>o<\/sup>C sinks, which keeps the oceans liquid and prevents them from freezing solid from the bottom up. This unique property of water keeps Earth, the water planet, habitable.\n\n[caption id=\"attachment_2958\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/NaH2O.svg_.png\"><img class=\"size-medium wp-image-335\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-300x300.png\" alt=\"The negative part of the water molecules surrounds the positively-charged sodium ion.\" width=\"300\" height=\"300\"><\/a> A sodium (Na) ion in solution.[\/caption]\n\nEven more critical for supporting life, water remains liquid over a very large range of temperatures, which is also a result of [pb_glossary id=\"2692\"]cohesion[\/pb_glossary]. Hydrogen [pb_glossary id=\"2703\"]bonding[\/pb_glossary] allows liquid water can absorb high amounts of energy before turning into vapor or gas. The wide range across which water remains a liquid, 0\u00b0C-100\u00b0C (32\u00b0F-212\u00b0F), is rarely exhibited in other substances. Without this high boiling point, liquid water as we know it would be constricted to narrow [pb_glossary id=\"2689\"]temperature[\/pb_glossary] zones on Earth, instead water is found from pole to pole. Further, water is the only substance that exists in all three phases, solid, liquid, and gas in Earth's surface environments.\n\nWater is a <strong>[pb_glossary id=\"2691\"]universal solvent[\/pb_glossary]<\/strong>, meaning it dissolves more substances than any other commonly found, naturally occurring liquid. The water molecules use [pb_glossary id=\"2690\"]polarity[\/pb_glossary] and [pb_glossary id=\"1202\"]hydrogen bonds[\/pb_glossary] to pry ions away from the crystal lattice. Water is such a powerful solvent, it can [pb_glossary id=\"2815\"]dissolve[\/pb_glossary] even the strongest rocks and [pb_glossary id=\"2687\"]minerals[\/pb_glossary] given enough time.\n\n&nbsp;\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"31\"]\n\n[caption id=\"attachment_3999\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.1-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-336\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 5.1 via this QR Code.[\/caption]\n<h2><span style=\"font-weight: 400\">5.2 Weathering and Erosion<\/span><\/h2>\n<strong>[pb_glossary id=\"1971\"]Bedrock[\/pb_glossary]<\/strong> refers to the solid rock that makes up the Earth\u2019s outer [pb_glossary id=\"2580\"]crust[\/pb_glossary]. [pb_glossary id=\"2676\"]Weathering[\/pb_glossary] is a process that turns [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] into smaller particles, called <strong>[pb_glossary id=\"2678\"]sediment[\/pb_glossary]<\/strong>. [pb_glossary id=\"1204\"]Mechanical weathering[\/pb_glossary] includes pressure expansion, [pb_glossary id=\"1207\"]frost wedging[\/pb_glossary], [pb_glossary id=\"1208\"]root wedging[\/pb_glossary], and salt expansion. Chemical <strong>[pb_glossary id=\"2676\"]weathering[\/pb_glossary]<\/strong> includes [pb_glossary id=\"2813\"]carbonic acid[\/pb_glossary] and [pb_glossary id=\"2814\"]hydrolysis[\/pb_glossary], [pb_glossary id=\"2815\"]dissolution[\/pb_glossary], and [pb_glossary id=\"2818\"]oxidation[\/pb_glossary].\n\n[pb_glossary id=\"2677\"]Erosion[\/pb_glossary] is a mechanical process, usually driven by water, wind, gravity, or ice, which transports [pb_glossary id=\"2678\"]sediment[\/pb_glossary] (and [pb_glossary id=\"1203\"]soil[\/pb_glossary]) from the place of [pb_glossary id=\"2676\"]weathering[\/pb_glossary]. Liquid water is the main agent of [pb_glossary id=\"2677\"]erosion[\/pb_glossary]. Gravity and [pb_glossary id=\"3110\"]mass wasting[\/pb_glossary] processes (see Chapter 10, [pb_glossary id=\"3110\"]Mass Wasting[\/pb_glossary]) move rocks and [pb_glossary id=\"2678\"]sediment[\/pb_glossary] to new locations. Gravity and ice, in the form of [pb_glossary id=\"2464\"]glaciers[\/pb_glossary] (see Chapter 14, <a href=\"https:\/\/opengeology.org\/textbook\/14-glaciers\/\">Glaciers<\/a>), move large rock fragments as well as fine [pb_glossary id=\"2678\"]sediment[\/pb_glossary].\n\n[pb_glossary id=\"2677\"]Erosion[\/pb_glossary] resistance is important in the creation of distinctive geological features. This is well-demonstrated in the cliffs of the Grand Canyon. The cliffs are made of rock left standing after less resistant materials have weathered and eroded away. Rocks with different levels of [pb_glossary id=\"2677\"]erosion[\/pb_glossary] resistance also create the unique-looking features called hoodoos in Bryce Canyon National Park and Goblin Valley State Park in Utah.\n<h3><b>5.2.1 Mechanical Weathering<\/b><\/h3>\n<strong>[pb_glossary id=\"1204\"]Mechanical weathering[\/pb_glossary]<\/strong> physically breaks [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] into smaller pieces. \u00a0The usual agents of [pb_glossary id=\"1204\"]mechanical weathering[\/pb_glossary] are pressure, [pb_glossary id=\"2689\"]temperature[\/pb_glossary], freezing\/thawing cycle of water, plant or animal activity, and salt evaporation.\n<h4><span style=\"font-weight: 400\">Pressure Expansion<\/span><\/h4>\n[caption id=\"attachment_2962\" align=\"alignright\" width=\"447\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/GeologicalExfoliationOfGraniteRock.jpg\"><img class=\"wp-image-337\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock.jpg\" alt=\"Granite rock has a relatively thin layer that is peeling away\" width=\"447\" height=\"297\"><\/a> The outer layer of this granite is fractured and eroding away, known as exfoliation[\/caption]\n\n[pb_glossary id=\"1971\"]Bedrock[\/pb_glossary] buried deep within the Earth is under high pressure and [pb_glossary id=\"2689\"]temperature[\/pb_glossary]. When uplift and [pb_glossary id=\"2677\"]erosion[\/pb_glossary] brings [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] to the surface, its [pb_glossary id=\"2689\"]temperature[\/pb_glossary] drops slowly, while its pressure drops immediately. The sudden pressure drop causes the rock to rapidly expand and crack; this is called pressure expansion. Sheeting or <strong>[pb_glossary id=\"1205\"]exfoliation[\/pb_glossary]<\/strong> is when the rock surface spalls off in layers. <strong>[pb_glossary id=\"1206\"]Spheroidal weathering[\/pb_glossary]<\/strong> is a type of [pb_glossary id=\"1205\"]exfoliation[\/pb_glossary] that produces rounded features and is caused when [pb_glossary id=\"2812\"]chemical weathering[\/pb_glossary] moves along [pb_glossary id=\"1934\"]joints[\/pb_glossary] in the [pb_glossary id=\"1971\"]bedrock[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Frost Wedging<\/span><\/h4>\n[caption id=\"attachment_2965\" align=\"alignright\" width=\"500\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Mechanical_weathering.png\"><img class=\"wp-image-338 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Mechanical_weathering.png\" alt=\"A crack in a rock gets progressively bigger as ice freezes, prying the crack open over time.\" width=\"500\" height=\"156\"><\/a> The process of frost wedging[\/caption]\n\n<strong>[pb_glossary id=\"1207\"]Frost wedging[\/pb_glossary]<\/strong>, also called [pb_glossary id=\"1207\"]ice wedging[\/pb_glossary], uses the power of expanding ice to break apart rocks. Water works its way into various cracks, voids, and crevices.\u00a0As the water freezes, it expands with great force, exploiting any weaknesses. When ice melts, the liquid water moves further into the widened spaces. Repeated cycles of freezing and melting eventually pry the rocks apart. The cycles can occur daily when fluctuations of [pb_glossary id=\"2689\"]temperature[\/pb_glossary] between day and night go from freezing to melting.\n<h4><span style=\"font-weight: 400\">Root Wedging<\/span><\/h4>\n[caption id=\"attachment_2967\" align=\"alignright\" width=\"369\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Pine-tree_roots_digging_through_the_asphalt_-_panoramio-scaled.jpg\"><img class=\"wp-image-2967\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Pine-tree_roots_digging_through_the_asphalt_-_panoramio-scaled-1.jpg\" alt=\"The roots of the tree are breaking up the asphalt.\" width=\"369\" height=\"277\"><\/a> The roots of this tree are demonstrating the destructive power of root wedging. Though this picture is a man-made rock (asphalt), it works on typical rock as well.[\/caption]\n\nLike [pb_glossary id=\"1207\"]frost wedging[\/pb_glossary], <strong>[pb_glossary id=\"1208\"]root wedging[\/pb_glossary]<\/strong> happens when plant roots work themselves into cracks, prying the [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] apart as they grow. Occasionally these roots may become fossilized. <strong>[pb_glossary id=\"2809\"]Rhizolith[\/pb_glossary]<\/strong> is the term for these roots preserved in the rock record. Tunneling organisms such as earthworms, termites, and ants are biological agents that induce [pb_glossary id=\"2676\"]weathering[\/pb_glossary] similar to [pb_glossary id=\"1208\"]root wedging[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Salt Expansion<\/span><\/h4>\n[caption id=\"attachment_2968\" align=\"alignright\" width=\"414\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/640px-Tafoni_03.jpg\"><img class=\"wp-image-340\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/640px-Tafoni_03-300x225.jpg\" alt=\"The rock has many holes from the salt erosion.\" width=\"414\" height=\"311\"><\/a> Tafoni from Salt Point, California.[\/caption]\n\nSalt expansion, which works similarly to [pb_glossary id=\"1207\"]frost wedging[\/pb_glossary], occurs in areas of high evaporation or near-[pb_glossary id=\"2883\"]marine[\/pb_glossary] environments. Evaporation causes salts to [pb_glossary id=\"2707\"]precipitate[\/pb_glossary] out of [pb_glossary id=\"2705\"]solution[\/pb_glossary] and grow and expand into cracks in rock. Salt expansion is one of the causes of <strong>[pb_glossary id=\"2810\"]tafoni[\/pb_glossary]<\/strong>, a series of holes in a rock. Tafonis, cracks, and holes are weak points that become susceptible to increased [pb_glossary id=\"2676\"]weathering[\/pb_glossary]. Another phenomena that occurs when salt water evaporates can leave behind a square imprint preserved in a soft [pb_glossary id=\"2678\"]sediment[\/pb_glossary], called a <strong>h<\/strong><strong>opper crystal<\/strong>.\n<h3><b>5.2.2 Chemical Weathering<\/b><\/h3>\n[caption id=\"attachment_2969\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SA2Vratio.png\"><img class=\"wp-image-341 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio-300x138.png\" alt=\"The left side has one large cube, the middle has 8 medium cubes, the right side has 64 small cubes. Each group has the same overall volume.\" width=\"300\" height=\"138\"><\/a> Each of these three groups of cubes has an equal volume. However, their surface areas are vastly different. On the left, the single cube has a length, width, and height of 4 units, giving it a surface area of 6(4x4)=96 and a volume of 4^3=64. The middle eight cubes have a length, width, and height of 2, meaning a surface area of 8(6(2x2))=8x24=192. They also have a volume of 8(2^3)=8x8=64. The 64 cubes on the right have a length, width, and height of 1, leading to a surface area of 64(6(1x1))=64x6=384. The volume remains unchanged, because 64(1^3)=64x1=64. The surface area to volume ratio (SA:V), which is related to the amount of material available for reactions, changes for each as well. On the left, it is 96\/64=0.75 or 3:2. The center has a SA\/V of 192\/64=1.5, or 3:1. On the right, the SA:V is 384\/64=6, or 6:1.[\/caption]\n\n<strong>[pb_glossary id=\"2812\"]Chemical weathering[\/pb_glossary]<\/strong> is the dominate [pb_glossary id=\"2676\"]weathering[\/pb_glossary] process in warm, humid environments. It happens when water, oxygen, and other reactants chemically degrade the [pb_glossary id=\"2687\"]mineral[\/pb_glossary] components of [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] and turn them into water-soluble ions which can then be transported by water. Higher temperatures accelerate [pb_glossary id=\"2812\"]chemical weathering[\/pb_glossary] rates.\n\nChemical and [pb_glossary id=\"1204\"]mechanical weathering[\/pb_glossary] work hand-in-hand via a fundamental concept called surface-area-to-volume ratio. [pb_glossary id=\"2812\"]Chemical weathering[\/pb_glossary] only occurs on rock surfaces because water and reactants cannot penetrate solid rock. [pb_glossary id=\"1204\"]Mechanical weathering[\/pb_glossary] penetrates [pb_glossary id=\"1971\"]bedrock[\/pb_glossary], breaking large rocks into smaller pieces and creating new rock surfaces. This exposes more surface area to [pb_glossary id=\"2812\"]chemical weathering[\/pb_glossary], enhancing its effects. In other words, higher surface-area-to-volume ratios produce higher rates of overall [pb_glossary id=\"2676\"]weathering[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Carbonic Acid and Hydrolysis<\/span><\/h4>\n[caption id=\"attachment_2971\" align=\"aligncenter\" width=\"984\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Hydrolysis.png\"><img class=\"size-full wp-image-342\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Hydrolysis.png\" alt=\"The diagram on the left is before hydrolysis.\" width=\"984\" height=\"168\"><\/a> Generic hydrolysis diagram, where the bonds in mineral in question would represent the left side of the diagram.[\/caption]\n\n<strong>[pb_glossary id=\"2813\"]Carbonic acid[\/pb_glossary]<\/strong> (H<sub>2<\/sub>CO<sub>3<\/sub>) forms when carbon dioxide, the fifth-most abundant gas in the [pb_glossary id=\"2667\"]atmosphere[\/pb_glossary], dissolves in water. This happens naturally in clouds, which is why [pb_glossary id=\"2707\"]precipitation[\/pb_glossary] is normally slightly acidic. [pb_glossary id=\"2813\"]Carbonic acid[\/pb_glossary] is an important agent in two [pb_glossary id=\"2812\"]chemical weathering[\/pb_glossary] reactions, [pb_glossary id=\"2814\"]hydrolysis[\/pb_glossary] and [pb_glossary id=\"2815\"]dissolution[\/pb_glossary].\n\n[pb_glossary id=\"2814\"]Hydrolysis[\/pb_glossary] occurs via two types of reactions. In one reaction, water molecules ionize into positively charged H<sup>+1 <\/sup>and OH<sup>\u22121<\/sup> ions and replace [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2702\"]cations[\/pb_glossary] in the crystal lattice. In another type of [pb_glossary id=\"2814\"]hydrolysis[\/pb_glossary], [pb_glossary id=\"2813\"]carbonic acid[\/pb_glossary] molecules react directly with [pb_glossary id=\"2687\"]minerals[\/pb_glossary], especially those containing silicon and aluminum (i.e. [pb_glossary id=\"1916\"]Feldspars[\/pb_glossary]), to form molecules of clay [pb_glossary id=\"2687\"]minerals[\/pb_glossary].\n\n[pb_glossary id=\"2814\"]Hydrolysis[\/pb_glossary] is the main process that breaks down [pb_glossary id=\"2709\"]silicate[\/pb_glossary] rock and creates clay [pb_glossary id=\"2687\"]minerals[\/pb_glossary]. The following is a [pb_glossary id=\"2814\"]hydrolysis[\/pb_glossary] reaction that occurs when silica-rich [pb_glossary id=\"1916\"]feldspar[\/pb_glossary] encounters [pb_glossary id=\"2813\"]carbonic acid[\/pb_glossary] to produce water-soluble clay and other ions:\n<blockquote><strong>[pb_glossary id=\"1916\"]feldspar[\/pb_glossary]<\/strong> + <strong>[pb_glossary id=\"2813\"]carbonic acid[\/pb_glossary]<\/strong> (in water) \u2192 clay + metal [pb_glossary id=\"2702\"]cations[\/pb_glossary] (Fe<sup>++<\/sup>, Mg<sup>++<\/sup>, Ca<sup>++<\/sup>, Na<sup>+<\/sup>, etc.) + bicarbonate [pb_glossary id=\"2704\"]anions[\/pb_glossary] (HCO<sub>3<\/sub><sup>-1<\/sup>) + silica (SiO<sub>2<\/sub>)<\/blockquote>\nClay [pb_glossary id=\"2687\"]minerals[\/pb_glossary] are platy [pb_glossary id=\"2709\"]silicates[\/pb_glossary] or phyllosilicates (see Chapter 3, [pb_glossary id=\"2687\"]Minerals[\/pb_glossary]) similar to micas, and are the main components of very fine-grained [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. The [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] substances may later [pb_glossary id=\"2707\"]precipitate[\/pb_glossary] into <strong>[pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rocks<\/strong> like [pb_glossary id=\"2842\"]evaporite[\/pb_glossary] and [pb_glossary id=\"2851\"]limestone[\/pb_glossary], as well as amorphous silica or [pb_glossary id=\"2849\"]chert[\/pb_glossary] nodules.\n<h4><span style=\"font-weight: 400\">Dissolution<\/span><\/h4>\n[caption id=\"attachment_2972\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/GoldinPyrite.jpg\"><img class=\"wp-image-343 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite-300x240.jpg\" alt=\"The rock is red.\" width=\"300\" height=\"240\"><\/a> In this rock, a pyrite cube has dissolved (as seen with the negative \"corner\" impression in the rock), leaving behind small specks of gold.[\/caption]\n\n<strong>[pb_glossary id=\"2815\"]Dissolution[\/pb_glossary]<\/strong> is a [pb_glossary id=\"2814\"]hydrolysis[\/pb_glossary] reaction that dissolves [pb_glossary id=\"2687\"]minerals[\/pb_glossary] in [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] and leaves the ions in [pb_glossary id=\"2705\"]solution[\/pb_glossary], usually in water. Some [pb_glossary id=\"2842\"]evaporites[\/pb_glossary] and [pb_glossary id=\"1917\"]carbonates[\/pb_glossary], like salt and [pb_glossary id=\"1918\"]calcite[\/pb_glossary], are more prone to this reaction; however, all [pb_glossary id=\"2687\"]minerals[\/pb_glossary] can be [pb_glossary id=\"2815\"]dissolved[\/pb_glossary]. Non-acidic water, having a neutral pH of 7, will [pb_glossary id=\"2815\"]dissolve[\/pb_glossary] any [pb_glossary id=\"2687\"]mineral[\/pb_glossary], although it may happen very slowly. Water with higher levels of acid, naturally or man-made, dissolves rocks at a higher rate. Liquid water is normally slightly acidic due to the presence of [pb_glossary id=\"2813\"]carbonic acid[\/pb_glossary] and free H+ ions. Natural rainwater can be highly acidic, with pH levels as low as 2. [pb_glossary id=\"2815\"]Dissolution[\/pb_glossary] can be enhanced by a biological agent, such as when organisms like lichen and bacteria release organic acids onto the rocks they are attached to. Regions with high humidity (airborne moisture) and [pb_glossary id=\"2707\"]precipitation[\/pb_glossary] experience more [pb_glossary id=\"2815\"]dissolution[\/pb_glossary] due to greater contact time between rocks and water.\n\n[caption id=\"attachment_2514\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Iddingsite.jpg\"><img class=\"size-medium wp-image-82\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Iddingsite-300x225.jpg\" alt=\"The xenolith sits on top of a basalt rock. It has three sides like a pyramid; one of the sides is more altered to iddingsite.\" width=\"300\" height=\"225\"><\/a> This mantle xenolith containing olivine (green) is chemically weathering by hydrolysis and oxidation into the pseudo-mineral iddingsite, which is a complex of water, clay, and iron oxides. The more altered side of the rock has been exposed to the environment longer.[\/caption]\n\nThe <strong>[pb_glossary id=\"2816\"]Goldich Dissolution Series[\/pb_glossary]<\/strong> shows [pb_glossary id=\"2812\"]chemical weathering[\/pb_glossary] rates are associated to [pb_glossary id=\"2674\"]crystallization[\/pb_glossary] rankings in the [pb_glossary id=\"1174\"]Bowen\u2019s Reaction Series[\/pb_glossary] (see Chapter 4, [pb_glossary id=\"2675\"]Igneous Rock[\/pb_glossary] and [pb_glossary id=\"1181\"]Volcanic[\/pb_glossary] Processes). [pb_glossary id=\"2687\"]Minerals[\/pb_glossary] at the top of the Bowen series crystallize under high temperatures and pressures, and chemically [pb_glossary id=\"1709\"]weather[\/pb_glossary] at a faster rate than [pb_glossary id=\"2687\"]minerals[\/pb_glossary] ranked at the bottom. [pb_glossary id=\"1915\"]Quartz[\/pb_glossary], a [pb_glossary id=\"1954\"]felsic[\/pb_glossary] [pb_glossary id=\"2687\"]mineral[\/pb_glossary] that crystallizes at 700\u00b0C, is very resistant to [pb_glossary id=\"2812\"]chemical weathering[\/pb_glossary]. High [pb_glossary id=\"2674\"]crystallization[\/pb_glossary]-point [pb_glossary id=\"1956\"]mafic[\/pb_glossary] [pb_glossary id=\"2687\"]minerals[\/pb_glossary], such as [pb_glossary id=\"2711\"]olivine[\/pb_glossary] and [pb_glossary id=\"2712\"]pyroxene[\/pb_glossary] (1,250\u00b0C), [pb_glossary id=\"1709\"]weather[\/pb_glossary] relatively rapidly and more completely. [pb_glossary id=\"2711\"]Olivine[\/pb_glossary] and [pb_glossary id=\"2712\"]pyroxene[\/pb_glossary] are rarely found as end products of [pb_glossary id=\"2676\"]weathering[\/pb_glossary] because they tend to break down into elemental ions.\n\n[caption id=\"attachment_2974\" align=\"aligncenter\" width=\"1600\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Karst_minerve.jpg\"><img class=\"wp-image-344 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve.jpg\" alt=\"The rocks in this area are full of holes, formed from karst dissolution.\" width=\"1600\" height=\"625\"><\/a> Eroded karst topography in Minevre, France.[\/caption]\n\n[caption id=\"attachment_2975\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos.jpg\"><img class=\"wp-image-345 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos-300x226.jpg\" alt=\"A heart-shaped formation in Timpanogos Cave\" width=\"300\" height=\"226\"><\/a> A formation called The Great Heart of Timpanogos in Timpanogos Cave National Monument[\/caption]\n\n[pb_glossary id=\"2815\"]Dissolution[\/pb_glossary] is also noteworthy for the special geological features it creates. In places with abundant [pb_glossary id=\"1917\"]carbonate[\/pb_glossary] [pb_glossary id=\"1971\"]bedrock[\/pb_glossary], [pb_glossary id=\"2815\"]dissolution[\/pb_glossary] [pb_glossary id=\"2676\"]weathering[\/pb_glossary] can produce a <strong>[pb_glossary id=\"2817\"]karst[\/pb_glossary] topography<\/strong> characterized by sinkholes or caves (see Chapter 10, [pb_glossary id=\"3110\"]Mass Wasting[\/pb_glossary]).\n\nTimpanogos Cave National Monument in Northern Utah is a well-known [pb_glossary id=\"2815\"]dissolution[\/pb_glossary] feature. The figure shows a cave [pb_glossary id=\"2960\"]formation[\/pb_glossary] created from [pb_glossary id=\"2815\"]dissolution[\/pb_glossary] followed by [pb_glossary id=\"2707\"]precipitation[\/pb_glossary]\u2014[pb_glossary id=\"3129\"]groundwater[\/pb_glossary] [pb_glossary id=\"2706\"]saturated[\/pb_glossary] with [pb_glossary id=\"1918\"]calcite[\/pb_glossary] seeped into the cavern, where evaporation caused the [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] [pb_glossary id=\"2687\"]minerals[\/pb_glossary] to [pb_glossary id=\"2707\"]precipitate[\/pb_glossary] out.\n<h4><span style=\"font-weight: 400\">Oxidation<\/span><\/h4>\n[caption id=\"attachment_2976\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/PyOx.jpg\"><img class=\"wp-image-346 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-300x225.jpg\" alt=\"Goethite is in cubes, though it usually is not. Pyrite is in cubes.\" width=\"300\" height=\"225\"><\/a> Pyrite cubes are oxidized, becoming a new mineral goethite. In this case, goethite is a pseudomorph after pyrite, meaning it has taken the form of another mineral.[\/caption]\n\n<strong>[pb_glossary id=\"2818\"]Oxidation[\/pb_glossary]<\/strong>, the chemical reaction that causes rust in [pb_glossary id=\"3345\"]metallic[\/pb_glossary] iron, occurs geologically when iron atoms in a [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2703\"]bond[\/pb_glossary] with oxygen. Any [pb_glossary id=\"2687\"]minerals[\/pb_glossary] containing iron can be oxidized. The resultant iron [pb_glossary id=\"1919\"]oxides[\/pb_glossary] may permeate a rock if it is rich in iron [pb_glossary id=\"2687\"]minerals[\/pb_glossary]. [pb_glossary id=\"1919\"]Oxides[\/pb_glossary] may also form a coating that covers rocks and grains of [pb_glossary id=\"2678\"]sediment[\/pb_glossary], or lines rock cavities and [pb_glossary id=\"1934\"]fractures[\/pb_glossary]. If the [pb_glossary id=\"1919\"]oxides[\/pb_glossary] are more susceptible to [pb_glossary id=\"2676\"]weathering[\/pb_glossary] than the original [pb_glossary id=\"1971\"]bedrock[\/pb_glossary], they may create void spaces inside the rock mass or hollows on exposed surfaces.\n\nThree commonly found [pb_glossary id=\"2687\"]minerals[\/pb_glossary] are produced by iron-[pb_glossary id=\"2818\"]oxidation[\/pb_glossary] reactions:\u00a0 red or grey <strong>hematite<\/strong>, brown <strong>goethite<\/strong> (pronounced \u201cGUR-tite\u201d), and yellow <strong>limonite<\/strong>. These iron [pb_glossary id=\"1919\"]oxides[\/pb_glossary] coat and bind [pb_glossary id=\"2687\"]mineral[\/pb_glossary] grains together into sedimentary rocks in a process called [pb_glossary id=\"2681\"]cementation[\/pb_glossary], and often give these rocks a dominant color. They color the rock layers of the Colorado Plateau, as well as Zion, Arches, and Grand Canyon National Parks. These [pb_glossary id=\"1919\"]oxides[\/pb_glossary] can permeate a rock that is rich in iron-bearing [pb_glossary id=\"2687\"]minerals[\/pb_glossary] or can be a coating that forms in cavities or [pb_glossary id=\"1934\"]fractures[\/pb_glossary]. When the [pb_glossary id=\"2687\"]minerals[\/pb_glossary] replacing existing [pb_glossary id=\"2687\"]minerals[\/pb_glossary] in [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] are resistant to [pb_glossary id=\"2676\"]weathering[\/pb_glossary], iron concretions may occur in the rock. \u00a0When [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] is replaced by weaker [pb_glossary id=\"1919\"]oxides[\/pb_glossary], this process commonly results in void spaces and weakness throughout the rock mass and often leaves hollows on exposed rock surfaces.\n<h3><b>5.2.3 Erosion<\/b><\/h3>\n[caption id=\"attachment_2980\" align=\"alignleft\" width=\"227\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MB2-scaled.jpg\"><img class=\"wp-image-2980\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/MB2-scaled-1.jpg\" alt=\"The rock is topped by a more resistant.\" width=\"227\" height=\"170\"><\/a> A hoodoo near Moab, Utah[\/caption]\n\n<strong>[pb_glossary id=\"2677\"]Erosion[\/pb_glossary]<\/strong> is a mechanical process, usually driven by water, gravity, (see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/10-mass-wasting\/\">Chapter 10<\/a>), wind, or ice (see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/14-glaciers\/\">Chapter 14<\/a>) that removes [pb_glossary id=\"2678\"]sediment[\/pb_glossary] from the place of [pb_glossary id=\"2676\"]weathering[\/pb_glossary]. Liquid water is the main agent of [pb_glossary id=\"2677\"]erosion[\/pb_glossary].\n\n[caption id=\"attachment_2983\" align=\"alignright\" width=\"379\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Grand_Canyon-Mather_point.jpg\"><img class=\"wp-image-348\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Grand_Canyon-Mather_point-300x225.jpg\" alt=\"The canyon has many cliffs and slopes.\" width=\"379\" height=\"284\"><\/a> Grand Canyon from Mather Point.[\/caption]\n\n[pb_glossary id=\"2677\"]Erosion[\/pb_glossary] <strong>resistance<\/strong> is important in the creation of distinctive geological features. This is well demonstrated in the cliffs of the Grand Canyon. The cliffs are made of rock left standing after less resistant materials have weathered and eroded away. Rocks with different levels [pb_glossary id=\"2677\"]erosion[\/pb_glossary] resistant also create the unique-looking features called hoodoos in Bryce Canyon National Park and Goblin Valley State Park in Utah.\n<h3><b>5.2.4. Soil<\/b><\/h3>\n[caption id=\"attachment_2984\" align=\"alignright\" width=\"318\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SoilStructure.jpg\"><img class=\"wp-image-349\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilStructure-284x300.jpg\" alt=\"The soil is sketched and labeled.\" width=\"318\" height=\"335\"><\/a> Sketch and picture of soil.[\/caption]\n\n<strong>[pb_glossary id=\"1203\"]Soil[\/pb_glossary]<\/strong> is a combination of air, water, [pb_glossary id=\"2687\"]minerals[\/pb_glossary], and organic matter that forms at the transition between [pb_glossary id=\"2669\"]biosphere[\/pb_glossary] and [pb_glossary id=\"2665\"]geosphere[\/pb_glossary]. [pb_glossary id=\"1203\"]Soil[\/pb_glossary] is made when [pb_glossary id=\"2676\"]weathering[\/pb_glossary] breaks down [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] and turns it into [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. \u00a0If [pb_glossary id=\"2677\"]erosion[\/pb_glossary] does not remove the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] significantly, organisms can access the [pb_glossary id=\"2687\"]mineral[\/pb_glossary] content of the [pb_glossary id=\"2678\"]sediments[\/pb_glossary]. \u00a0These organisms turn [pb_glossary id=\"2687\"]minerals[\/pb_glossary], water, and atmospheric gases into organic substances that contribute to the [pb_glossary id=\"1203\"]soil[\/pb_glossary].\n\n[pb_glossary id=\"1203\"]Soil[\/pb_glossary] is an important [pb_glossary id=\"3341\"]reservoir[\/pb_glossary] for organic components necessary for plants, animals, and microorganisms to live. The organic component of [pb_glossary id=\"1203\"]soil[\/pb_glossary], called <strong>[pb_glossary id=\"2819\"]humus[\/pb_glossary]<\/strong>, is a rich source of bioavailable nitrogen. Nitrogen is the most common [pb_glossary id=\"2700\"]element[\/pb_glossary] in the [pb_glossary id=\"2667\"]atmosphere[\/pb_glossary], but it exists in a form most life forms are unable to use. Special bacteria found only in [pb_glossary id=\"1203\"]soil[\/pb_glossary] provide most nitrogen compounds that are usable, bioavailable, by life forms.\n\n[caption id=\"attachment_2986\" align=\"alignleft\" width=\"479\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Nitrogen_Cycle.svg_.png\"><img class=\"wp-image-350\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-1024x768.png\" alt=\"The image shows the way nitrogen can move around, mostly in the soil\" width=\"479\" height=\"359\"><\/a> Schematic of the nitrogen cycle.[\/caption]\n\nThese nitrogen-fixing bacteria absorb nitrogen from the [pb_glossary id=\"2667\"]atmosphere[\/pb_glossary] and convert it into nitrogen compounds. These compounds are absorbed by plants and used to make DNA, amino acids, and enzymes. Animals obtain bioavailable nitrogen by eating plants, and this is the source of most of the nitrogen used by life. That nitrogen is an essential component of proteins and DNA.\u00a0[pb_glossary id=\"1203\"]Soils[\/pb_glossary] range from poor to rich, depending on the amount of [pb_glossary id=\"2819\"]humus[\/pb_glossary] they contain. [pb_glossary id=\"1203\"]Soil[\/pb_glossary] productivity is determined by water and nutrient content. Freshly created [pb_glossary id=\"1181\"]volcanic[\/pb_glossary] [pb_glossary id=\"1203\"]soils[\/pb_glossary], called andisols, and clay-rich [pb_glossary id=\"1203\"]soils[\/pb_glossary] that hold nutrients and water are examples of productive [pb_glossary id=\"1203\"]soils[\/pb_glossary].\n\n[caption id=\"attachment_2987\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/IncaTerrace.jpg\"><img class=\"size-medium wp-image-351\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/IncaTerrace-300x225.jpg\" alt=\"A mountain slope has been made into artificial steps form farming.\" width=\"300\" height=\"225\"><\/a> Agricultural terracing, as made by the Inca culture from the Andes, helps reduce erosion and promote soil formation, leading to better farming practices.[\/caption]\n\nThe nature of the [pb_glossary id=\"1203\"]soil[\/pb_glossary], meaning its characteristics, is determined primarily by five components: 1) the mineralogy of the parent material; 2) topography, 3) [pb_glossary id=\"2676\"]weathering[\/pb_glossary], 4) [pb_glossary id=\"1710\"]climate[\/pb_glossary], and 5) the organisms that inhabit the [pb_glossary id=\"1203\"]soil[\/pb_glossary]. For example, [pb_glossary id=\"1203\"]soil[\/pb_glossary] tends to erode more rapidly on steep slopes so [pb_glossary id=\"1203\"]soil[\/pb_glossary] layers in these areas may be thinner than in flood plains, where it tends to accumulate. The quantity and chemistry of organic matter of [pb_glossary id=\"1203\"]soil[\/pb_glossary] affects how much and what varieties of life it can sustain. [pb_glossary id=\"2689\"]Temperature[\/pb_glossary] and [pb_glossary id=\"2707\"]precipitation[\/pb_glossary], two major [pb_glossary id=\"2676\"]weathering[\/pb_glossary] agents, are dependent on [pb_glossary id=\"1710\"]climate[\/pb_glossary]. Fungi and bacteria contribute organic matter and the ability of [pb_glossary id=\"1203\"]soil[\/pb_glossary] to sustain life, interacting with plant roots to exchange nitrogen and other nutrients.\n\nIn well-formed [pb_glossary id=\"1203\"]soils[\/pb_glossary], there is a discernable arrangement of distinct layers called <strong>[pb_glossary id=\"1203\"]soil[\/pb_glossary]\u00a0horizons<\/strong>. These [pb_glossary id=\"1203\"]soil[\/pb_glossary] horizons can be seen in road cuts that expose the layers at the edge of the cut. [pb_glossary id=\"1203\"]Soil[\/pb_glossary] horizons make up the [pb_glossary id=\"2820\"]soil profile[\/pb_glossary]. Each [pb_glossary id=\"2821\"]soil horizon[\/pb_glossary] reflects [pb_glossary id=\"1710\"]climate[\/pb_glossary], topography, and other [pb_glossary id=\"1203\"]soil[\/pb_glossary]-development factors, as well as its organic material and [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"2831\"]composition[\/pb_glossary]. The horizons are assigned names and letters. Differences in naming schemes depend on the area, [pb_glossary id=\"1203\"]soil[\/pb_glossary] type or research topic. The figure shows a simplified [pb_glossary id=\"2820\"]soil profile[\/pb_glossary] that uses commonly designated names and letters.\n\n[caption id=\"attachment_2989\" align=\"alignright\" width=\"360\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SoilHorizons.gif\"><img class=\"wp-image-352 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilHorizons.gif\" alt=\"The image shows 5 soil layers, ranging from highly altered at the top, to unaltered at the bottom.\" width=\"360\" height=\"415\"><\/a> A simplified soil profile, showing labeled layers.[\/caption]\n<p style=\"padding-left: 30px\"><strong>O Horizon<\/strong>: The top horizon is a thin layer of predominantly organic material, such as leaves, twigs, and other plant parts that are actively decaying into [pb_glossary id=\"2819\"]humus[\/pb_glossary].<\/p>\n<p style=\"padding-left: 30px\"><strong>A Horizon<\/strong>: The next layer, called <strong>[pb_glossary id=\"2822\"]topsoil[\/pb_glossary]<\/strong>, consists of [pb_glossary id=\"2819\"]humus[\/pb_glossary] mixed with [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. As [pb_glossary id=\"2707\"]precipitation[\/pb_glossary] soaks down through this layer, it leaches out soluble chemicals. In wet climates with heavy [pb_glossary id=\"2707\"]precipitation[\/pb_glossary] this leaching out produces a separate layer called horizon E, the leaching or eluviation zone.<\/p>\n<p style=\"padding-left: 30px\"><strong>B Horizon<\/strong>: Also called <strong>[pb_glossary id=\"2823\"]subsoil[\/pb_glossary]<\/strong>, this layer consists of [pb_glossary id=\"2678\"]sediment[\/pb_glossary] mixed with [pb_glossary id=\"2819\"]humus[\/pb_glossary] removed from the upper layers. The [pb_glossary id=\"2823\"]subsoil[\/pb_glossary] is where [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is chemically weathered. The amount of organic material and degree of [pb_glossary id=\"2676\"]weathering[\/pb_glossary] decrease with depth. The upper [pb_glossary id=\"2823\"]subsoil[\/pb_glossary] zone, called <strong>[pb_glossary id=\"3111\"]regolith[\/pb_glossary]<\/strong>, is a porous mixture of [pb_glossary id=\"2819\"]humus[\/pb_glossary] and highly weathered [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. In the lower zone, <strong>saprolite<\/strong>, scant organic material is mixed with largely unaltered [pb_glossary id=\"2688\"]parent rock[\/pb_glossary].<\/p>\n<p style=\"padding-left: 30px\"><strong>C Horizon<\/strong>: This is [pb_glossary id=\"2824\"]substratum[\/pb_glossary] and is a zone of [pb_glossary id=\"1204\"]mechanical weathering[\/pb_glossary]. Here, [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] fragments are physically broken but not chemically altered. This layer contains no organic material.<\/p>\n<p style=\"padding-left: 30px\"><strong>R Horizon<\/strong>: The final layer consists of unweathered, parent <strong>[pb_glossary id=\"1971\"]bedrock[\/pb_glossary]<\/strong> and fragments.<\/p>\n\n\n[caption id=\"attachment_2992\" align=\"alignleft\" width=\"391\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Bauxite_with_unweathered_rock_core._C_021.jpg\"><img class=\"wp-image-353\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021-300x195.jpg\" alt=\"The outside of the rock is tan and weathered, the inside is grey.\" width=\"391\" height=\"254\"><\/a> A sample of bauxite. Note the unweathered igneous rock in the center.[\/caption]\n\nThe United States governing body for agriculture, the USDA, uses a taxonomic classification to identify [pb_glossary id=\"1203\"]soil[\/pb_glossary] types, called [pb_glossary id=\"1203\"]soil[\/pb_glossary] orders. Xoxisols or laterite [pb_glossary id=\"1203\"]soils[\/pb_glossary] are nutrient-poor [pb_glossary id=\"1203\"]soils[\/pb_glossary] found in tropical regions. While poorly suited for growing crops, xosisols are home to most of the world\u2019s mineable aluminum [pb_glossary id=\"3325\"]ore[\/pb_glossary] ([pb_glossary id=\"3357\"]bauxite[\/pb_glossary]). Ardisol forms in dry climates and can develop layers of hardened [pb_glossary id=\"1918\"]calcite[\/pb_glossary], called caliche. Andisols originate from [pb_glossary id=\"1181\"]volcanic[\/pb_glossary] [pb_glossary id=\"1949\"]ash[\/pb_glossary] deposits. Alfisols contain [pb_glossary id=\"2709\"]silicate[\/pb_glossary] clay [pb_glossary id=\"2687\"]minerals[\/pb_glossary]. These two [pb_glossary id=\"1203\"]soil[\/pb_glossary] orders are productive for farming due to their high content of [pb_glossary id=\"2687\"]mineral[\/pb_glossary] nutrients. In general, color can be an important factor in understanding [pb_glossary id=\"1203\"]soil[\/pb_glossary] conditions. Black [pb_glossary id=\"1203\"]soils[\/pb_glossary] tend to be anoxic, red oxygen-rich, and green oxygen-poor (i.e. reduced). This is true for many sedimentary rocks as well.\n\n[caption id=\"attachment_2994\" align=\"alignright\" width=\"484\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Dust-storm-Texas-1935.png\"><img class=\"wp-image-354\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Dust-storm-Texas-1935.png\" alt=\"The black and white photo shows a giant wall of dust.\" width=\"484\" height=\"294\"><\/a> A dust storm approaches Stratford, Texas in 1935.[\/caption]\n\nNot only is [pb_glossary id=\"1203\"]soil[\/pb_glossary] essential to [pb_glossary id=\"2902\"]terrestrial[\/pb_glossary] life in nature, but also human civilization via agriculture. Careless or uninformed human activity can seriously damage [pb_glossary id=\"1203\"]soil[\/pb_glossary]\u2019s life-supporting properties. A prime example is the famous Dust Bowl disaster of the 1930s, which affected the midwestern United States. The damage occurred because of large-scale attempts develop prairieland in southern Kansas, Colorado, western Texas, and Oklahoma into farmland. Poor understanding of the region\u2019s geology, ecology, and [pb_glossary id=\"1710\"]climate[\/pb_glossary] led to farming practices that ruined the [pb_glossary id=\"2820\"]soil profile[\/pb_glossary].\n\nThe prairie [pb_glossary id=\"1203\"]soils[\/pb_glossary] and [pb_glossary id=\"1924\"]native[\/pb_glossary] plants are well adapted to a relatively dry [pb_glossary id=\"1710\"]climate[\/pb_glossary]. With government encouragement, settlers moved in to homestead the region. They plowed vast areas of prairie into long, straight rows and planted grain. The plowing broke up the stable [pb_glossary id=\"2820\"]soil profile[\/pb_glossary] and destroyed the natural grasses and plants, which had long roots that anchored the [pb_glossary id=\"1203\"]soil[\/pb_glossary] layers. The grains they planted had shallower root systems and were plowed up every year, which made the [pb_glossary id=\"1203\"]soil[\/pb_glossary] prone to [pb_glossary id=\"2677\"]erosion[\/pb_glossary]. The plowed furrows were aligned in straight rows running downhill, which favored [pb_glossary id=\"2677\"]erosion[\/pb_glossary] and loss of [pb_glossary id=\"2822\"]topsoil[\/pb_glossary].\n\nThe local [pb_glossary id=\"1710\"]climate[\/pb_glossary] does not produce sufficient [pb_glossary id=\"2707\"]precipitation[\/pb_glossary] to support non-[pb_glossary id=\"1924\"]native[\/pb_glossary] grain crops, so the farmers drilled wells and over-pumped water from the underground [pb_glossary id=\"3166\"]aquifers[\/pb_glossary]. The grain crops failed due to lack of water, leaving bare [pb_glossary id=\"1203\"]soil[\/pb_glossary] that was stripped from the ground by the prairie winds. Particles of midwestern prairie [pb_glossary id=\"1203\"]soil[\/pb_glossary] were deposited along the east [pb_glossary id=\"2890\"]coast[\/pb_glossary] and as far away as Europe. Huge dust storms called black blizzards made life unbearable, and the once-hopeful homesteaders left in droves. The setting for John Steinbeck\u2019s famous novel and John Ford\u2019s film, <em>The Grapes of Wrath,<\/em> is Oklahoma during this time. The lingering question is whether we have learned the lessons of the dust bowl, to avoid creating it again.\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"32\"]\n\n[caption id=\"attachment_3998\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.2-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-355\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 5.2 via this QR Code.[\/caption]\n<h2><span style=\"font-weight: 400\">5.3 Sedimentary rocks<\/span><\/h2>\n[pb_glossary id=\"2683\"]Sedimentary rock[\/pb_glossary] is classified into two main categories: [pb_glossary id=\"2825\"]clastic[\/pb_glossary] and chemical. <strong>[pb_glossary id=\"2825\"]Clastic[\/pb_glossary]<\/strong> or<strong> [pb_glossary id=\"3363\"]detrital[\/pb_glossary]<\/strong> sedimentary rocks are made from pieces of [pb_glossary id=\"1971\"]bedrock[\/pb_glossary], [pb_glossary id=\"2678\"]sediment[\/pb_glossary], derived primarily by [pb_glossary id=\"1204\"]mechanical weathering[\/pb_glossary]. [pb_glossary id=\"2825\"]Clastic[\/pb_glossary] rocks may also include chemically weathered [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. [pb_glossary id=\"2825\"]Clastic[\/pb_glossary] rocks are classified by <strong>grain shape<\/strong>, <strong>[pb_glossary id=\"2828\"]grain size[\/pb_glossary]<\/strong>, and <strong>[pb_glossary id=\"2829\"]sorting[\/pb_glossary]<\/strong>. <strong>Chemical<\/strong> sedimentary rocks are [pb_glossary id=\"2707\"]precipitated[\/pb_glossary] from water [pb_glossary id=\"2706\"]saturated[\/pb_glossary] with [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] [pb_glossary id=\"2687\"]minerals[\/pb_glossary]. Chemical rocks are classified mainly by [pb_glossary id=\"2831\"]composition[\/pb_glossary] of [pb_glossary id=\"2687\"]minerals[\/pb_glossary] in the rock.\n<h3><b>5.3.1 Lithification and Diagenesis<\/b><\/h3>\n<strong><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Siccar_Point_red_capstone_closeup.jpg\"><img class=\"alignright wp-image-356\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-300x225.jpg\" alt=\"\" width=\"445\" height=\"334\"><\/a>[pb_glossary id=\"2682\"]Lithification[\/pb_glossary]<\/strong> turns loose [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains, created by [pb_glossary id=\"2676\"]weathering[\/pb_glossary] and transported by [pb_glossary id=\"2677\"]erosion[\/pb_glossary], into [pb_glossary id=\"2825\"]clastic[\/pb_glossary] [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] via three interconnected steps. <strong>[pb_glossary id=\"2679\"]Deposition[\/pb_glossary]<\/strong> happens when friction and gravity overcome the forces driving [pb_glossary id=\"2678\"]sediment[\/pb_glossary] transport, allowing [pb_glossary id=\"2678\"]sediment[\/pb_glossary] to accumulate. <strong>[pb_glossary id=\"2680\"]Compaction[\/pb_glossary]<\/strong> occurs when material continues to accumulate on top of the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] layer, squeezing the grains together and driving out water. The mechanical [pb_glossary id=\"2680\"]compaction[\/pb_glossary] is aided by weak attractive forces between the smaller grains of [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. [pb_glossary id=\"3129\"]Groundwater[\/pb_glossary] typically carries cementing agents into the [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. These [pb_glossary id=\"2687\"]minerals[\/pb_glossary], such as [pb_glossary id=\"1918\"]calcite[\/pb_glossary], amorphous silica, or [pb_glossary id=\"1919\"]oxides[\/pb_glossary], may have a different [pb_glossary id=\"2831\"]composition[\/pb_glossary] than the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains. <strong>[pb_glossary id=\"2681\"]Cementation[\/pb_glossary]<\/strong> is the process of cementing [pb_glossary id=\"2687\"]minerals[\/pb_glossary] coating the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains and gluing them together into a fused rock.\n\n[caption id=\"attachment_3253\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/07.20_Petrified_forest_log_2_md-1.jpg\"><img class=\"size-medium wp-image-357\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1-300x300.jpg\" alt=\"Photo of log of petrified wood showing structures of the original wood\" width=\"300\" height=\"300\"><\/a> Permineralization in petrified wood[\/caption]\n\n<strong>[pb_glossary id=\"2827\"]Diagenesis[\/pb_glossary]<\/strong> is an accompanying process to [pb_glossary id=\"2682\"]lithification[\/pb_glossary] and is a low-[pb_glossary id=\"2689\"]temperature[\/pb_glossary] form of rock [pb_glossary id=\"2914\"]metamorphism[\/pb_glossary] (see Chapter 6, [pb_glossary id=\"2684\"]Metamorphic Rock[\/pb_glossary]). During [pb_glossary id=\"2827\"]diagenesis[\/pb_glossary], [pb_glossary id=\"2678\"]sediments[\/pb_glossary] are chemically altered by heat and pressure. A classic example is aragonite (CaCO<sub>3<\/sub>), a form of calcium [pb_glossary id=\"1917\"]carbonate[\/pb_glossary] that makes up most organic shells. When lithified aragonite undergoes [pb_glossary id=\"2827\"]diagenesis[\/pb_glossary], the aragonite reverts to [pb_glossary id=\"1918\"]calcite[\/pb_glossary] (CaCO<sub>3<\/sub>), which has the same chemical formula but a different crystalline structure. In [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] containing [pb_glossary id=\"1918\"]calcite[\/pb_glossary] and magnesium (Mg), [pb_glossary id=\"2827\"]diagenesis[\/pb_glossary] may [pb_glossary id=\"2601\"]transform[\/pb_glossary] the two [pb_glossary id=\"2687\"]minerals[\/pb_glossary] into dolomite (CaMg(CO<sub>3<\/sub>)<sub>2<\/sub>). [pb_glossary id=\"2827\"]Diagenesis[\/pb_glossary] may also reduce the [pb_glossary id=\"3116\"]pore[\/pb_glossary] space, or open volume, between [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] grains. The processes of [pb_glossary id=\"2681\"]cementation[\/pb_glossary], [pb_glossary id=\"2680\"]compaction[\/pb_glossary], and ultimately [pb_glossary id=\"2682\"]lithification[\/pb_glossary] occur within the realm of [pb_glossary id=\"2827\"]diagenesis[\/pb_glossary], which includes the processes that turn organic material into [pb_glossary id=\"2176\"]fossils[\/pb_glossary].\n<h3><b>5.3.2 Detrital Sedimentary Rocks (Clastic)<\/b><\/h3>\n<strong>[pb_glossary id=\"3363\"]Detrital[\/pb_glossary]<\/strong> or <strong>[pb_glossary id=\"2825\"]clastic[\/pb_glossary]<\/strong> sedimentary rocks consist of preexisting [pb_glossary id=\"2678\"]sediment[\/pb_glossary] pieces that comes from weathered bedrock. Most of this is mechanically weathered sediment, although some clasts may be pieces of chemical rocks. This creates some overlap between the two categories, since [pb_glossary id=\"2825\"]clastic[\/pb_glossary] sedimentary rocks may include chemical [pb_glossary id=\"2678\"]sediments[\/pb_glossary]. [pb_glossary id=\"3363\"]Detrital[\/pb_glossary] or [pb_glossary id=\"2825\"]clastic[\/pb_glossary] rocks are classified and named based on their [pb_glossary id=\"2828\"]grain size[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Grain Size<\/span><\/h4>\n[caption id=\"attachment_3001\" align=\"aligncenter\" width=\"570\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Wentworth_scaleGrainSize.png\"><img class=\"size-full wp-image-358\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Wentworth_scaleGrainSize.png\" alt=\"Chart with sizes ranging from clay to boulders\" width=\"570\" height=\"768\"><\/a> Size categories of sediments, known as the Wentworth scale.[\/caption]\n\n[pb_glossary id=\"3363\"]Detrital[\/pb_glossary] rock is classified according to [pb_glossary id=\"2678\"]sediment[\/pb_glossary] <strong>[pb_glossary id=\"2828\"]grain size[\/pb_glossary]<\/strong>, which is [pb_glossary id=\"2862\"]graded[\/pb_glossary] from large to small on the Wentworth scale (see figure). [pb_glossary id=\"2828\"]Grain size[\/pb_glossary] is the average diameter of [pb_glossary id=\"2678\"]sediment[\/pb_glossary] fragments in [pb_glossary id=\"2678\"]sediment[\/pb_glossary] or rock. Grain sizes are delineated using a log base 2 scale. For example, the grain sizes in the pebble class are 2.52, 1.26, 0.63, 0.32, 0.16, and 0.08 inches, which correlate respectively to very coarse, coarse, medium, fine, and very fine granules. Large fragments, or clasts, include all grain sizes larger than 2 mm (5\/64 in). These include, boulders, cobbles, granules, and gravel. Sand has a [pb_glossary id=\"2828\"]grain size[\/pb_glossary] between 2 mm and 0.0625 mm, about the lower limit of the naked eye\u2019s resolution. [pb_glossary id=\"2678\"]Sediment[\/pb_glossary] grains smaller than sand are called silt. Silt is unique; the grains can be felt with a finger or as grit between your teeth, but are too small to see with the naked eye.\n<h4><span style=\"font-weight: 400\">Sorting and Rounding<\/span><\/h4>\n[caption id=\"attachment_3002\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Sorting_in_sediment.svg_.png\"><img class=\"size-medium wp-image-359\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Sorting_in_sediment.svg_-300x141.png\" alt=\"The sediment on the left is all about the same size. The sediment on the right is many sizes.\" width=\"300\" height=\"141\"><\/a> A well-sorted sediment (left) and a poorly-sorted sediment (right).[\/caption]\n\n<strong>[pb_glossary id=\"2829\"]Sorting[\/pb_glossary]<\/strong> describes the range of grain sizes within [pb_glossary id=\"2678\"]sediment[\/pb_glossary] or [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary]. Geologists use the term \u201c<strong>well sorted<\/strong>\u201d to describe a narrow range of grain sizes, and \u201cpoorly sorted\u201d for a wide range of grain sizes (see figure). It is important to note that [pb_glossary id=\"1203\"]soil[\/pb_glossary] engineers use similar terms with opposite definitions; well [pb_glossary id=\"2862\"]graded[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] consists of a variety of grain sizes, and poorly [pb_glossary id=\"2862\"]graded[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] has roughly the same grain sizes.\n\nWhen reading the story told by rocks, geologists use [pb_glossary id=\"2829\"]sorting[\/pb_glossary] to interpret [pb_glossary id=\"2677\"]erosion[\/pb_glossary] or transport processes, as well as [pb_glossary id=\"2679\"]deposition[\/pb_glossary] energy. For example, wind-blown sands are typically extremely well sorted, while [pb_glossary id=\"2910\"]glacial[\/pb_glossary] deposits are typically poorly sorted. These characteristics help identify the type of [pb_glossary id=\"2677\"]erosion[\/pb_glossary] process that occurred. Coarse-grained [pb_glossary id=\"2678\"]sediment[\/pb_glossary] and poorly sorted rocks are usually found nearer to the source of [pb_glossary id=\"2678\"]sediment[\/pb_glossary], while fine [pb_glossary id=\"2678\"]sediments[\/pb_glossary] are carried farther away. In a rapidly flowing mountain [pb_glossary id=\"3134\"]stream[\/pb_glossary] you would expect to see boulders and pebbles. In a lake fed by the [pb_glossary id=\"3134\"]stream[\/pb_glossary], there should be sand and silt deposits. If you also find large boulders in the lake, this may indicate the involvement of another [pb_glossary id=\"2678\"]sediment[\/pb_glossary] transport process, such as [pb_glossary id=\"3119\"]rockfall[\/pb_glossary] caused by ice- or root-wedging.\n\n[caption id=\"attachment_3003\" align=\"alignright\" width=\"532\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Rounding__sphericity_EN.svg_.png\"><img class=\"wp-image-360\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Rounding__sphericity_EN.svg_.png\" alt=\"The sediments show various stages of rounding and sphericity, from high to low.\" width=\"532\" height=\"222\"><\/a> Degree of rounding in sediments. Sphericity refers to the spherical nature of an object, a completely different measurement unrelated to rounding.[\/caption]\n\n<strong>[pb_glossary id=\"2830\"]Rounding[\/pb_glossary]<\/strong> is created when angular corners of rock fragments are removed from a piece of [pb_glossary id=\"2678\"]sediment[\/pb_glossary] due to abrasion during transport. Well-rounded [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains are defined as being free of all sharp edges. Very angular [pb_glossary id=\"2678\"]sediment[\/pb_glossary] retains the sharp corners. Most clast fragments start with some sharp edges due to the [pb_glossary id=\"1971\"]bedrock[\/pb_glossary]\u2019s crystalline structure, and those points are worn down during transport. More rounded grains imply a longer [pb_glossary id=\"2677\"]erosion[\/pb_glossary] time or transport distance, or more energetic erosional process. [pb_glossary id=\"2687\"]Mineral[\/pb_glossary] [pb_glossary id=\"1927\"]hardness[\/pb_glossary] is also a factor in [pb_glossary id=\"2830\"]rounding[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Composition and provenance<\/span><\/h4>\n[caption id=\"attachment_3004\" align=\"alignright\" width=\"228\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/VolcnicLithicFragment.jpg\"><img class=\"wp-image-361 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment-228x300.jpg\" alt=\"The grain is round and has vesicles.\" width=\"228\" height=\"300\"><\/a> A sand grain made of basalt, known as a microlitic volcanic lithic fragment. Box is 0.25 mm. Top picture is plane-polarized light, bottom is cross-polarized light.[\/caption]\n\n<strong>[pb_glossary id=\"2831\"]Composition[\/pb_glossary]<\/strong> describes the [pb_glossary id=\"2687\"]mineral[\/pb_glossary] components found in [pb_glossary id=\"2678\"]sediment[\/pb_glossary] or [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] and may be influenced by local geology, like [pb_glossary id=\"3340\"]source rock[\/pb_glossary] and hydrology. Other than clay, most [pb_glossary id=\"2678\"]sediment[\/pb_glossary] components are easily determined by visual inspection (see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/3-minerals\/\">Chapter 3, Minerals<\/a>). The most commonly found [pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"2687\"]mineral[\/pb_glossary] is [pb_glossary id=\"1915\"]quartz[\/pb_glossary] because of its low chemical reactivity and high [pb_glossary id=\"1927\"]hardness[\/pb_glossary], making it resistant to [pb_glossary id=\"2676\"]weathering[\/pb_glossary], and its ubiquitous occurrence in [pb_glossary id=\"2575\"]continental[\/pb_glossary] [pb_glossary id=\"1971\"]bedrock[\/pb_glossary]. Other commonly found [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains include [pb_glossary id=\"1916\"]feldspar[\/pb_glossary] and lithic fragments. Lithic fragments are pieces of fine-grained [pb_glossary id=\"1971\"]bedrock[\/pb_glossary], and include [pb_glossary id=\"2875\"]mud chips[\/pb_glossary], [pb_glossary id=\"1181\"]volcanic[\/pb_glossary] clasts, or pieces of [pb_glossary id=\"2926\"]slate[\/pb_glossary].\n\n[pb_glossary id=\"2676\"]Weathering[\/pb_glossary] of [pb_glossary id=\"1938\"]volcanic rock[\/pb_glossary] produces Hawaii\u2019s famous black ([pb_glossary id=\"1961\"]basalt[\/pb_glossary]) and green ([pb_glossary id=\"2711\"]olivine[\/pb_glossary]) sand beaches, which are rare elsewhere on Earth. This is because the local rock is [pb_glossary id=\"2831\"]composed[\/pb_glossary] almost entirely of [pb_glossary id=\"1961\"]basalt[\/pb_glossary] and provides an abundant source of dark colored clasts loaded with mafic minerals. According to the Goldich Dissolution Series, clasts high in [pb_glossary id=\"1956\"]mafic[\/pb_glossary] [pb_glossary id=\"2687\"]minerals[\/pb_glossary] are more easily destroyed compared to clasts [pb_glossary id=\"2831\"]composed[\/pb_glossary] of [pb_glossary id=\"1954\"]felsic[\/pb_glossary] [pb_glossary id=\"2687\"]minerals[\/pb_glossary] like [pb_glossary id=\"1915\"]quartz[\/pb_glossary].\n\n[caption id=\"attachment_3006\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Green-sand-beach-in-Hawaii.jpg\"><img class=\"wp-image-362 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii-300x215.jpg\" alt=\"Hawiian beach composed of green olivine sand from weathering of nearby basaltic rock.\" width=\"300\" height=\"215\"><\/a> Hawiian beach composed of green olivine sand from weathering of nearby basaltic rock.[\/caption]\n\nGeologists use <strong>[pb_glossary id=\"2832\"]provenance[\/pb_glossary]<\/strong> to discern the original source of [pb_glossary id=\"2678\"]sediment[\/pb_glossary] or [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary]. [pb_glossary id=\"2832\"]Provenance[\/pb_glossary] is determined by analyzing [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2831\"]composition[\/pb_glossary] and types of [pb_glossary id=\"2176\"]fossils[\/pb_glossary] present, as well as textural features like [pb_glossary id=\"2829\"]sorting[\/pb_glossary] and [pb_glossary id=\"2830\"]rounding[\/pb_glossary]. [pb_glossary id=\"2832\"]Provenance[\/pb_glossary] is important for describing [pb_glossary id=\"2576\"]tectonic[\/pb_glossary] history, visualizing paleogeographic [pb_glossary id=\"2960\"]formations[\/pb_glossary], unraveling an area\u2019s geologic history, or reconstructing past [pb_glossary id=\"2623\"]supercontinents[\/pb_glossary].\n\nIn [pb_glossary id=\"1915\"]quartz[\/pb_glossary] [pb_glossary id=\"2834\"]sandstone[\/pb_glossary], sometimes called [pb_glossary id=\"1915\"]quartz[\/pb_glossary] [pb_glossary id=\"2834\"]arenite[\/pb_glossary] (SiO<sub>2<\/sub>), [pb_glossary id=\"2832\"]provenance[\/pb_glossary] may be determined using a rare, durable clast [pb_glossary id=\"2687\"]mineral[\/pb_glossary] called [pb_glossary id=\"2175\"]zircon[\/pb_glossary] (ZrSiO<sub>4<\/sub>). [pb_glossary id=\"2175\"]Zircon[\/pb_glossary], or zirconium [pb_glossary id=\"2709\"]silicate[\/pb_glossary], contains traces of uranium, which can be used for age-dating the source [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] that contributed [pb_glossary id=\"2678\"]sediment[\/pb_glossary] to the lithified [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] rock (see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/7-geologic-time\/\">Chapter 7, Geologic Time<\/a>).\n<h4><span style=\"font-weight: 400\">Classification of Clastic Rocks<\/span><\/h4>\n[caption id=\"attachment_3008\" align=\"alignright\" width=\"395\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Titus_Canyon_Narrows.jpg\"><img class=\"wp-image-363\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Titus_Canyon_Narrows-300x225.jpg\" alt=\"The grey rock is broken and angular within the larger rock.\" width=\"395\" height=\"296\"><\/a> Megabreccia in Titus Canyon, Death Valley National Park, California.[\/caption]\n\n[pb_glossary id=\"2825\"]Clastic[\/pb_glossary] rocks are classified according to the [pb_glossary id=\"2828\"]grain size[\/pb_glossary] of their [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. Coarse-grained rocks contain clasts with a predominant [pb_glossary id=\"2828\"]grain size[\/pb_glossary] larger than sand. Typically, smaller [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains, collectively called [pb_glossary id=\"1959\"]groundmass[\/pb_glossary] or matrix, fill in much of the volume between the larger clasts, and hold the clasts together. <strong>[pb_glossary id=\"2833\"]Conglomerates[\/pb_glossary]<\/strong> are rocks containing coarse rounded clasts, and <strong>breccias<\/strong> contain angular clasts (see figure). Both [pb_glossary id=\"2833\"]conglomerates[\/pb_glossary] and breccias are usually poorly sorted.\n\n[caption id=\"attachment_3504\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1.jpg\"><img class=\"wp-image-364 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1-300x225.jpg\" alt=\"Windblown sand grains showing rounding and frosted surfaces due to transport b wind.\" width=\"300\" height=\"225\"><\/a> Enlarged image of frosted and rounded windblown sand grains[\/caption]\n\nMedium-grained rocks [pb_glossary id=\"2831\"]composed[\/pb_glossary] mainly of sand are called <strong>[pb_glossary id=\"2834\"]sandstone[\/pb_glossary]<\/strong>, or sometimes <strong>[pb_glossary id=\"2834\"]arenite[\/pb_glossary]<\/strong> if well sorted. [pb_glossary id=\"2678\"]Sediment[\/pb_glossary] grains in [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] can having a wide variety of [pb_glossary id=\"2687\"]mineral[\/pb_glossary] compositions, roundness, and [pb_glossary id=\"2829\"]sorting[\/pb_glossary]. Some [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] names indicate the rock\u2019s [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2831\"]composition[\/pb_glossary]. [pb_glossary id=\"1915\"]Quartz[\/pb_glossary] [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] contains predominantly [pb_glossary id=\"1915\"]quartz[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains. <strong>Arkose<\/strong> is [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] with significant amounts of [pb_glossary id=\"1916\"]feldspar[\/pb_glossary], usually greater than 25%. [pb_glossary id=\"2834\"]Sandstone[\/pb_glossary] that contains [pb_glossary id=\"1916\"]feldspar[\/pb_glossary], which weathers more quickly than [pb_glossary id=\"1915\"]quartz[\/pb_glossary], is useful for analyzing the local geologic history. <strong>Greywack<\/strong>e is a term with conflicting definitions. [pb_glossary id=\"2835\"]Greywacke[\/pb_glossary] may refer to [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] with a muddy matrix, or [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] with many lithic fragments (small rock pieces).\n\n[caption id=\"attachment_3013\" align=\"aligncenter\" width=\"636\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Rochester_Shale_Niagara_Gorge.jpg\"><img class=\"wp-image-365\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-1024x685.jpg\" alt=\"The rock breaks apart in very thin layers.\" width=\"636\" height=\"426\"><\/a> The Rochester Shale, New York. Note the thin fissility in the layers.[\/caption]\n\nFine-grained rocks include [pb_glossary id=\"2837\"]mudstone[\/pb_glossary], [pb_glossary id=\"2839\"]shale[\/pb_glossary], [pb_glossary id=\"2840\"]siltstone[\/pb_glossary], and [pb_glossary id=\"2841\"]claystone[\/pb_glossary]. <strong>[pb_glossary id=\"2837\"]Mudstone[\/pb_glossary]<\/strong> is a general term for rocks made of [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains smaller than sand (less than 2 mm). Rocks that are <strong>[pb_glossary id=\"2838\"]fissile[\/pb_glossary]<\/strong>, meaning they separate into thin sheets, are called [pb_glossary id=\"2839\"]shale[\/pb_glossary]. Rocks exclusively [pb_glossary id=\"2831\"]composed[\/pb_glossary] of silt or clay [pb_glossary id=\"2678\"]sediment[\/pb_glossary], are called <strong>[pb_glossary id=\"2840\"]siltstone[\/pb_glossary]<\/strong> or <strong>[pb_glossary id=\"2841\"]claystone[\/pb_glossary]<\/strong>, respectively. These last two rock types are rarer than [pb_glossary id=\"2837\"]mudstone[\/pb_glossary] or [pb_glossary id=\"2839\"]shale[\/pb_glossary].\n\n[caption id=\"attachment_3014\" align=\"alignleft\" width=\"223\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Claystone_GLMsed.jpg\"><img class=\"wp-image-366\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Claystone_GLMsed-300x225.jpg\" alt=\"The light grey layers are very thin.\" width=\"223\" height=\"167\"><\/a> Claystone laminations from Glacial Lake Missoula.[\/caption]\n\nRock types found as a mixture between the main classifications, may be named using the less-common component as a descriptor. For example, a rock containing some silt but mostly rounded sand and gravel is called silty [pb_glossary id=\"2833\"]conglomerate[\/pb_glossary]. Sand-rich rock containing minor amounts of clay is called clayey [pb_glossary id=\"2834\"]sandstone[\/pb_glossary].\n<h3><b>5.3.3. Chemical, Biochemical, and Organic<\/b><\/h3>\n[pb_glossary id=\"2826\"]Chemical sedimentary[\/pb_glossary] rocks are formed by processes that do not directly involve [pb_glossary id=\"1204\"]mechanical weathering[\/pb_glossary] and [pb_glossary id=\"2677\"]erosion[\/pb_glossary]. [pb_glossary id=\"2812\"]Chemical weathering[\/pb_glossary] may contribute the [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] materials in water that ultimately form these rocks. [pb_glossary id=\"2850\"]Biochemical[\/pb_glossary] and organic [pb_glossary id=\"2678\"]sediments[\/pb_glossary] are [pb_glossary id=\"2825\"]clastic[\/pb_glossary] in the sense that they are made from pieces of organic material that is deposited, buried, and lithified; however, they are usually classified as being chemically produced.\n\nInorganic [pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rocks are made of [pb_glossary id=\"2687\"]minerals[\/pb_glossary] [pb_glossary id=\"2707\"]precipitated[\/pb_glossary] from ions [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] in [pb_glossary id=\"2705\"]solution[\/pb_glossary], and created without the aid of living organisms. Inorganic [pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rocks form in environments where [pb_glossary id=\"3371\"]ion[\/pb_glossary] concentration, [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] gasses, temperatures, or pressures are changing, which causes [pb_glossary id=\"2687\"]minerals[\/pb_glossary] to crystallize.\n\n[pb_glossary id=\"2850\"]Biochemical[\/pb_glossary] sedimentary rocks are formed from shells and bodies of underwater organisms. The living organisms extract chemical components from the water and use them to build shells and other body parts. The components include aragonite, a [pb_glossary id=\"2687\"]mineral[\/pb_glossary] similar to and commonly replaced by [pb_glossary id=\"1918\"]calcite[\/pb_glossary], and silica.\n\nOrganic sedimentary rocks come from organic material that has been deposited and lithified, usually underwater. The source materials are plant and animal remains that are transformed through burial and heat, and end up as [pb_glossary id=\"2856\"]coal[\/pb_glossary], [pb_glossary id=\"3338\"]oil[\/pb_glossary], and methane ([pb_glossary id=\"3339\"]natural gas[\/pb_glossary]).\n<h4><span style=\"font-weight: 400\">Inorganic chemical<\/span><\/h4>\n[caption id=\"attachment_3015\" align=\"alignright\" width=\"350\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Bonneville_Salt_Flats_Utah.jpg\"><img class=\"wp-image-367\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-300x200.jpg\" alt=\"The ground is white and flat for a long distance.\" width=\"350\" height=\"233\"><\/a> Salt-covered plain known as the Bonneville Salt Flats, Utah.[\/caption]\n\nInorganic [pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rocks are formed when [pb_glossary id=\"2687\"]minerals[\/pb_glossary] [pb_glossary id=\"2707\"]precipitate[\/pb_glossary] out of an aqueous [pb_glossary id=\"2705\"]solution[\/pb_glossary], usually due to water evaporation. The [pb_glossary id=\"2707\"]precipitate[\/pb_glossary] [pb_glossary id=\"2687\"]minerals[\/pb_glossary] form various salts known as <strong>[pb_glossary id=\"2842\"]evaporites[\/pb_glossary]<\/strong>. For example, the Bonneville Salt Flats in Utah flood with winter rains and dry out every summer, leaving behind salts such as <strong>[pb_glossary id=\"2843\"]gypsum[\/pb_glossary]<\/strong> and <strong>[pb_glossary id=\"2844\"]halite[\/pb_glossary]<\/strong>. The [pb_glossary id=\"2679\"]deposition[\/pb_glossary] order of [pb_glossary id=\"2842\"]evaporites[\/pb_glossary] deposit is opposite to their solubility order, i.e. as water evaporates and increases the [pb_glossary id=\"2687\"]mineral[\/pb_glossary] concentration in [pb_glossary id=\"2705\"]solution[\/pb_glossary], less soluble [pb_glossary id=\"2687\"]minerals[\/pb_glossary] [pb_glossary id=\"2707\"]precipitate[\/pb_glossary] out sooner than the highly soluble [pb_glossary id=\"2687\"]minerals[\/pb_glossary]. The [pb_glossary id=\"2679\"]deposition[\/pb_glossary] order and [pb_glossary id=\"2706\"]saturation[\/pb_glossary] percentages are depicted in the table, bearing in mind the process in nature may vary from laboratory derived values.\n<table>\n<tbody>\n<tr>\n<th><strong>[pb_glossary id=\"2687\"]Mineral[\/pb_glossary] sequence<\/strong><\/th>\n<th><strong>Percent Seawater remaining after evaporation <\/strong><\/th>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"1918\"]Calcite[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">50<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2843\"]Gypsum[\/pb_glossary]\/anhydrite<\/span><\/td>\n<td><span style=\"font-weight: 400\">20<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2844\"]Halite[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">10<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Various potassium and magnesium salts<\/span><\/td>\n<td><span style=\"font-weight: 400\">5<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<em><span style=\"font-weight: 400\">Table after<\/span><span style=\"font-weight: 400\">.<\/span><\/em>\n\n[caption id=\"attachment_3135\" align=\"aligncenter\" width=\"329\"]<a href=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2017\/02\/JoultersCayOoids.jpg\"><img class=\"wp-image-368 \" title=\"&quot;By\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids.jpg\" alt=\"The ooids are very smooth and round\" width=\"329\" height=\"247\"><\/a> Ooids from Joulter's Cay, The Bahamas[\/caption]\n\n[caption id=\"attachment_3018\" align=\"aligncenter\" width=\"367\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Limestone_towers_at_Mono_Lake_California.jpg\"><img class=\"wp-image-369\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_towers_at_Mono_Lake_California-300x225.jpg\" alt=\"The grey limestone towers vertically stick out of the ground.\" width=\"367\" height=\"275\"><\/a> Limestone tufa towers along the shores of Mono Lake, California.[\/caption]\n\nCalcium [pb_glossary id=\"1917\"]carbonate[\/pb_glossary]-[pb_glossary id=\"2706\"]saturated[\/pb_glossary] water precipitates porous masses of [pb_glossary id=\"1918\"]calcite[\/pb_glossary] called <strong>[pb_glossary id=\"2846\"]tufa[\/pb_glossary]<\/strong>. [pb_glossary id=\"2846\"]Tufa[\/pb_glossary] can form near degassing water and in saline lakes. Waterfalls downstream of springs often [pb_glossary id=\"2707\"]precipitate[\/pb_glossary] [pb_glossary id=\"2846\"]tufa[\/pb_glossary] as the turbulent water enhances degassing of carbon dioxide, which makes [pb_glossary id=\"1918\"]calcite[\/pb_glossary] less soluble and causes it to [pb_glossary id=\"2707\"]precipitate[\/pb_glossary]. Saline lakes concentrate calcium [pb_glossary id=\"1917\"]carbonate[\/pb_glossary] from a combination of wave action causing degassing, springs in the lakebed, and evaporation. In salty Mono Lake in California, [pb_glossary id=\"2846\"]tufa[\/pb_glossary] towers were exposed after water was diverted and lowered the lake levels.\n\n[caption id=\"attachment_3019\" align=\"aligncenter\" width=\"556\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Mammoth_Terraces.jpg\"><img class=\"wp-image-370\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-1024x683.jpg\" alt=\"The white and brown natural steps show the formation of travertine.\" width=\"556\" height=\"371\"><\/a> Travertine terraces of Mammoth Hot Springs, Yellowstone National Park, USA[\/caption]\n\nCave deposits like stalactites and stalagmites are another form of chemical [pb_glossary id=\"2707\"]precipitation[\/pb_glossary] of [pb_glossary id=\"1918\"]calcite[\/pb_glossary], in a form called <strong>[pb_glossary id=\"2847\"]travertine[\/pb_glossary]<\/strong>. [pb_glossary id=\"1918\"]Calcite[\/pb_glossary] slowly precipitates from water to form the [pb_glossary id=\"2847\"]travertine[\/pb_glossary], which often shows [pb_glossary id=\"2931\"]banding[\/pb_glossary]. This process is similar to the [pb_glossary id=\"2687\"]mineral[\/pb_glossary] growth on faucets in your home sink or shower that comes from hard ([pb_glossary id=\"2687\"]mineral[\/pb_glossary] rich) water. [pb_glossary id=\"2847\"]Travertine[\/pb_glossary] also forms at hot springs such as Mammoth Hot [pb_glossary id=\"3174\"]Spring[\/pb_glossary] in Yellowstone National Park.\n\n[caption id=\"attachment_3304\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MichiganBIF-1.jpg\"><img class=\"size-medium wp-image-371\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-300x206.jpg\" alt=\"The rock shows red and brown layering.\" width=\"300\" height=\"206\"><\/a> Alternating bands of iron-rich and silica-rich mud, formed as oxygen combined with dissolved iron.[\/caption]\n\n<strong>[pb_glossary id=\"2848\"]Banded iron formation[\/pb_glossary]<\/strong> deposits commonly formed early in Earth\u2019s history, but this type of [pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rock is no longer being created. Oxygenation of the [pb_glossary id=\"2667\"]atmosphere[\/pb_glossary] and oceans caused free iron ions, which are water-soluble, to become oxidized and [pb_glossary id=\"2707\"]precipitate[\/pb_glossary] out of [pb_glossary id=\"2705\"]solution[\/pb_glossary]. The iron [pb_glossary id=\"1919\"]oxide[\/pb_glossary] was deposited, usually in [pb_glossary id=\"2931\"]bands[\/pb_glossary] alternating with layers of [pb_glossary id=\"2849\"]chert[\/pb_glossary].\n\n[caption id=\"attachment_3023\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Flint_with_weathered_crust.jpg\"><img class=\"size-medium wp-image-372\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Flint_with_weathered_crust-300x225.jpg\" alt=\"The flint is dark brown\/grey, and the weathered crust is light tan. The overall shape is blobby.\" width=\"300\" height=\"225\"><\/a> A type of chert, flint, shown with a lighter weathered crust.[\/caption]\n\n<strong>[pb_glossary id=\"2849\"]Chert[\/pb_glossary]<\/strong>, another commonly found [pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rock, is usually produced from silica (SiO<sub>2<\/sub>) [pb_glossary id=\"2707\"]precipitated[\/pb_glossary] from [pb_glossary id=\"3129\"]groundwater[\/pb_glossary]. Silica is highly insoluble on the surface of Earth, which is why [pb_glossary id=\"1915\"]quartz[\/pb_glossary] is so resistant to [pb_glossary id=\"2812\"]chemical weathering[\/pb_glossary]. Water deep underground is subjected to higher pressures and temperatures, which helps [pb_glossary id=\"2815\"]dissolve[\/pb_glossary] silica into an aqueous [pb_glossary id=\"2705\"]solution[\/pb_glossary]. As the [pb_glossary id=\"3129\"]groundwater[\/pb_glossary] rises toward or emerges at the surface the silica precipitates out, often as a cementing agent or into nodules. For example, the bases of the geysers in Yellowstone National Park are surrounded by silica deposits called geyserite or sinter. The silica is [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] in water that is thermally heated by a relatively deep [pb_glossary id=\"2672\"]magma[\/pb_glossary] source. [pb_glossary id=\"2849\"]Chert[\/pb_glossary] can also form biochemically and is discussed in the [pb_glossary id=\"2850\"]Biochemical[\/pb_glossary] subsection. [pb_glossary id=\"2849\"]Chert[\/pb_glossary] has many synonyms, some of which may have gem value such as jasper, flint, onyx, and agate, due to subtle differences in colors, striping, etc., but [pb_glossary id=\"2849\"]chert[\/pb_glossary] is the more general term used by geologists for the entire group.\n\n[caption id=\"attachment_3026\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Oolite.jpg\"><img class=\"size-medium wp-image-373\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite-300x225.jpg\" alt=\"Ooids forming an oolite.\" width=\"300\" height=\"225\"><\/a> Ooids forming an oolite.[\/caption]\n\n<strong>[pb_glossary id=\"2845\"]Oolites[\/pb_glossary]<\/strong> are among the few [pb_glossary id=\"2851\"]limestone[\/pb_glossary] forms created by an inorganic chemical process, similar to what happens in [pb_glossary id=\"2842\"]evaporite[\/pb_glossary] [pb_glossary id=\"2679\"]deposition[\/pb_glossary]. When water is oversaturated with [pb_glossary id=\"1918\"]calcite[\/pb_glossary], the [pb_glossary id=\"2687\"]mineral[\/pb_glossary] precipitates out around a nucleus, a sand grain or shell fragment, and forms little spheres called [pb_glossary id=\"2845\"]ooids[\/pb_glossary] (see figure). As evaporation continues, the [pb_glossary id=\"2845\"]ooids[\/pb_glossary] continue building concentric layers of [pb_glossary id=\"1918\"]calcite[\/pb_glossary] as they roll around in gentle currents.\n<h4><span style=\"font-weight: 400\">Biochemical<\/span><\/h4>\n[caption id=\"attachment_3028\" align=\"alignright\" width=\"450\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Limestone_etched_section_KopeFm_new.jpg\"><img class=\"wp-image-374 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_etched_section_KopeFm_new.jpg\" alt=\"Rock has many fossils throughout\" width=\"450\" height=\"480\"><\/a> Fossiliferous limestone (with brachiopods and bryozoans) from the Kope Formation of Ohio. Lower image is a section of the rock that has been etched with acid to emphasize the fossils.[\/caption]\n\n<strong>[pb_glossary id=\"2850\"]Biochemical[\/pb_glossary]<\/strong> sedimentary rocks are not that different from [pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rocks; they are also formed from ions [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] in [pb_glossary id=\"2705\"]solution[\/pb_glossary]. However, [pb_glossary id=\"2850\"]biochemical[\/pb_glossary] sedimentary rocks rely on biological processes to extract the [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] materials out of the water. Most macroscopic [pb_glossary id=\"2883\"]marine[\/pb_glossary] organisms use [pb_glossary id=\"2815\"]dissolved[\/pb_glossary] [pb_glossary id=\"2687\"]minerals[\/pb_glossary], primarily aragonite (calcium [pb_glossary id=\"1917\"]carbonate[\/pb_glossary]), to build hard parts such as shells. When organisms die the hard parts settle as [pb_glossary id=\"2678\"]sediment[\/pb_glossary], which become buried, compacted and cemented into rock.\n\nThis [pb_glossary id=\"2850\"]biochemical[\/pb_glossary] extraction and secretion is the main process for forming <strong>[pb_glossary id=\"2851\"]limestone[\/pb_glossary]<\/strong>, the most commonly occurring, non-[pb_glossary id=\"2825\"]clastic[\/pb_glossary] [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary]. [pb_glossary id=\"2851\"]Limestone[\/pb_glossary] is mostly made of [pb_glossary id=\"1918\"]calcite[\/pb_glossary] (CaCO<sub>3<\/sub>) and sometimes includes dolomite (CaMgCO<sub>3<\/sub>), a close relative. Solid [pb_glossary id=\"1918\"]calcite[\/pb_glossary] reacts with hydrochloric acid by <strong>effervescing<\/strong> or fizzing. Dolomite only reacts to hydrochloric acid when ground into a powder, which can be done by scratching the rock surface (see Chapter 3, [pb_glossary id=\"2687\"]Minerals[\/pb_glossary]).\n\n[caption id=\"attachment_3031\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/CoquinaClose.jpg\"><img class=\"size-medium wp-image-375\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-300x198.jpg\" alt=\"Rock is broken shells\" width=\"300\" height=\"198\"><\/a> Close-up on coquina.[\/caption]\n\n[pb_glossary id=\"2851\"]Limestone[\/pb_glossary] occurs in many forms, most of which originate from biological processes. Entire coral [pb_glossary id=\"2898\"]reefs[\/pb_glossary] and their ecosystems can be preserved in exquisite detail in [pb_glossary id=\"2851\"]limestone[\/pb_glossary] rock (see figure).\u00a0<strong>[pb_glossary id=\"2852\"]Fossiliferous[\/pb_glossary] [pb_glossary id=\"2851\"]limestone[\/pb_glossary]<\/strong> contains many visible [pb_glossary id=\"2176\"]fossils[\/pb_glossary]. A type of [pb_glossary id=\"2851\"]limestone[\/pb_glossary] called <strong>[pb_glossary id=\"2854\"]coquina[\/pb_glossary]<\/strong> originates from beach sands made predominantly of shells that were then lithified. [pb_glossary id=\"2854\"]Coquina[\/pb_glossary] is [pb_glossary id=\"2831\"]composed[\/pb_glossary] of loosely-cemented shells and shell fragments. You can find beaches like this in modern tropical environments, such as the Bahamas.\u00a0 <strong>[pb_glossary id=\"2855\"]Chalk[\/pb_glossary]<\/strong> contains high concentrations of shells from a microorganism called a coccolithophore. <strong>[pb_glossary id=\"2853\"]Micrite[\/pb_glossary]<\/strong>, also known as microscopic [pb_glossary id=\"1918\"]calcite[\/pb_glossary] mud, is a very fine-grained [pb_glossary id=\"2851\"]limestone[\/pb_glossary] containing microfossils that can only be seen using a microscope.\n\nBiogenetic [pb_glossary id=\"2849\"]chert[\/pb_glossary] forms on the deep [pb_glossary id=\"2885\"]ocean floor[\/pb_glossary], created from [pb_glossary id=\"2850\"]biochemical[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] made of microscopic organic shells. This [pb_glossary id=\"2678\"]sediment[\/pb_glossary], called ooze, may be calcareous (calcium [pb_glossary id=\"1917\"]carbonate[\/pb_glossary] based) or siliceous (silica-based) depending on the type of shells deposited. For example, the shells of radiolarians (zooplankton) and diatoms (phytoplankton) are made of silica, so they produce siliceous ooze.\n<h4><span style=\"font-weight: 400\">Organic<\/span><\/h4>\n[caption id=\"attachment_3033\" align=\"alignright\" width=\"360\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Coal_anthracite.jpg\"><img class=\"wp-image-376 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Coal_anthracite.jpg\" alt=\"It is very black and shiny.\" width=\"360\" height=\"337\"><\/a> Anthracite coal, the highest grade of coal.[\/caption]\n\nUnder the right conditions, intact pieces of organic material or material derived from organic sources, is preserved in the geologic record. Although not derived from [pb_glossary id=\"2678\"]sediment[\/pb_glossary], this lithified organic material is associated with sedimentary [pb_glossary id=\"2857\"]strata[\/pb_glossary] and created by similar processes\u2014burial, [pb_glossary id=\"2680\"]compaction[\/pb_glossary], and [pb_glossary id=\"2827\"]diagenesis[\/pb_glossary]. C Deposits of these fuels develop in areas where organic material collects in large quantities. Lush swamplands can create conditions conducive to [pb_glossary id=\"2856\"]coal[\/pb_glossary] [pb_glossary id=\"2960\"]formation[\/pb_glossary]. Shallow-water, organic material-rich [pb_glossary id=\"2883\"]marine[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] can become highly productive [pb_glossary id=\"3337\"]petroleum[\/pb_glossary] and [pb_glossary id=\"3339\"]natural gas[\/pb_glossary] deposits. See <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/16-energy-and-mineral-resources\/\">Chapter 16, Energy and Mineral Resources,<\/a> for a more in-depth look at these [pb_glossary id=\"2176\"]fossil[\/pb_glossary]-derived energy sources.\n<h4><span style=\"font-weight: 400\">Classification of Chemical Sedimentary Rocks<\/span><\/h4>\n[caption id=\"attachment_3036\" align=\"aligncenter\" width=\"573\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico.jpg\"><img class=\"wp-image-377\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-300x162.jpg\" alt=\"The rock has many light-colored layers.\" width=\"573\" height=\"310\"><\/a> Gyprock, a rock made of the mineral gypsum. From the Castle formation of New Mexico.[\/caption]\n\nIn contrast to [pb_glossary id=\"3363\"]detrital[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary], chemical, [pb_glossary id=\"2850\"]biochemical[\/pb_glossary], and organic sedimentary rocks are classified based on [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2831\"]composition[\/pb_glossary]. Most of these are monomineralic, [pb_glossary id=\"2831\"]composed[\/pb_glossary] of a single [pb_glossary id=\"2687\"]mineral[\/pb_glossary], so the rock name is usually associated with the identifying [pb_glossary id=\"2687\"]mineral[\/pb_glossary]. [pb_glossary id=\"2826\"]Chemical sedimentary[\/pb_glossary] rocks consisting of [pb_glossary id=\"2844\"]halite[\/pb_glossary] are called rock salt. Rocks made of [pb_glossary id=\"2851\"]Limestone[\/pb_glossary] ([pb_glossary id=\"1918\"]calcite[\/pb_glossary]) is an exception, having elaborate subclassifications and even two competing classification methods: Folk Classification and Dunham Classification. The Folk Classification deals with rock grains and usually requires a specialized, petrographic microscope. The Dunham Classification is based on rock [pb_glossary id=\"2919\"]texture[\/pb_glossary], which is visible to the naked eye or using a hand lens and is easier for field applications. Most [pb_glossary id=\"1917\"]carbonate[\/pb_glossary] geologists use the Dunham [pb_glossary id=\"2664\"]system[\/pb_glossary].\n\n[caption id=\"attachment_3038\" align=\"aligncenter\" width=\"791\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SedRx2.png\"><img class=\"size-large wp-image-378\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-791x1024.png\" alt=\"Sedimentary rock identification chart\" width=\"791\" height=\"1024\"><\/a> Sedimentary rock identification chart[\/caption]\n\n&nbsp;\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"33\"]\n\n[caption id=\"attachment_3997\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.3-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-379\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 5.3 via this QR Code.[\/caption]\n<h2><span style=\"font-weight: 400\">5.4 Sedimentary Structures<\/span><\/h2>\nSedimentary structures are visible textures or arrangements of [pb_glossary id=\"2678\"]sediments[\/pb_glossary] within a rock. Geologists use these structures to interpret the processes that made the rock and the environment in which it formed. They use [pb_glossary id=\"2658\"]uniformitarianism[\/pb_glossary] to usually compare sedimentary structures formed in modern environments to lithified counterparts in ancient rocks. Below is a summary discussion of common sedimentary structures that are useful for interpretations in the rock record.\n<h3><b>5.4.1. Bedding Planes<\/b><\/h3>\n[caption id=\"attachment_3042\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/07.4_Horizontal_SEUtahStrat-scaled.jpg\"><img class=\"size-medium wp-image-3042\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/07.4_Horizontal_SEUtahStrat-scaled-1.jpg\" alt=\"Photo of strata in Utah lying horizontal\" width=\"300\" height=\"170\"><\/a> Horizontal strata[\/caption]\n\nThe most basic sedimentary structure is <strong>[pb_glossary id=\"2857\"]bedding[\/pb_glossary] planes<\/strong>, the planes that separate the layers or [pb_glossary id=\"2857\"]strata[\/pb_glossary] in sedimentary and some [pb_glossary id=\"1181\"]volcanic[\/pb_glossary] rocks. Visible in exposed outcroppings, each [pb_glossary id=\"2857\"]bedding[\/pb_glossary] plane indicates a change in [pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"2679\"]deposition[\/pb_glossary] conditions. This change may be subtle. For example, if a section of underlying [pb_glossary id=\"2678\"]sediment[\/pb_glossary] firms up, this may be enough to create a form a layer that is dissimilar from the overlying [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. Each layer is called a [pb_glossary id=\"2858\"]bed[\/pb_glossary], or stratum, the most basic unit of <strong>[pb_glossary id=\"2859\"]stratigraphy[\/pb_glossary]<\/strong>, the study of sedimentary layering.\n\n[caption id=\"attachment_3047\" align=\"alignright\" width=\"257\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/BedOrdOutcropTN.jpg\"><img class=\"wp-image-381 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/BedOrdOutcropTN-257x300.jpg\" alt=\"Two students are looking at the layers of rock.\" width=\"257\" height=\"300\"><\/a> Students from the University of Wooster examine beds of Ordovician limestone in central Tennessee.[\/caption]\n\nAs would be expected, [pb_glossary id=\"2858\"]bed[\/pb_glossary] thickness can indicate [pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"2679\"]deposition[\/pb_glossary] quantity and timing. Technically, a [pb_glossary id=\"2858\"]bed[\/pb_glossary] is a [pb_glossary id=\"2857\"]bedding[\/pb_glossary] plane thicker than 1 cm (0.4 in) and the smallest mappable unit. A layer thinner than 1 cm (0.4 in) is called a <strong>[pb_glossary id=\"2860\"]lamina[\/pb_glossary]<\/strong>. <strong>Varves<\/strong> are [pb_glossary id=\"2857\"]bedding[\/pb_glossary] planes created when [pb_glossary id=\"2860\"]laminae[\/pb_glossary] and [pb_glossary id=\"2858\"]beds[\/pb_glossary] are deposited in repetitive cycles, typically daily or seasonally. Varves are valuable geologic records of climatic histories, especially those found in lakes and [pb_glossary id=\"2910\"]glacial[\/pb_glossary] deposits.\n<h3><b>5.4.2. Graded Bedding<\/b><\/h3>\n[caption id=\"attachment_3049\" align=\"aligncenter\" width=\"613\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA.jpg\"><img class=\"size-full wp-image-382\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA.jpg\" alt=\"Rock shows layers described.\" width=\"613\" height=\"480\"><\/a> Image of the classic Bouma sequence. A=coarse- to fine-grained sandstone, possibly with an erosive base. B=laminated medium- to fine-grained sandstone. C=rippled fine-grained sandstone. D=laminated siltstone grading to mudstone.[\/caption]\n\n<strong>[pb_glossary id=\"2862\"]Graded[\/pb_glossary] [pb_glossary id=\"2857\"]bedding[\/pb_glossary]<\/strong> refers to a sequence of increasingly coarse- or fine-grained [pb_glossary id=\"2678\"]sediment[\/pb_glossary] layers. [pb_glossary id=\"2862\"]Graded[\/pb_glossary] [pb_glossary id=\"2857\"]bedding[\/pb_glossary] often develops when [pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"2679\"]deposition[\/pb_glossary] occurs in an environment of decreasing energy. A <strong>[pb_glossary id=\"2863\"]Bouma sequence[\/pb_glossary]<\/strong> is [pb_glossary id=\"2862\"]graded[\/pb_glossary] [pb_glossary id=\"2857\"]bedding[\/pb_glossary] observed in [pb_glossary id=\"2825\"]clastic[\/pb_glossary] rock called [pb_glossary id=\"2888\"]turbidite[\/pb_glossary]. [pb_glossary id=\"2863\"]Bouma sequence[\/pb_glossary] [pb_glossary id=\"2858\"]beds[\/pb_glossary] are formed by [pb_glossary id=\"3196\"]offshore[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] gravity flows, which are underwater flows of [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. These subsea density flows begin when [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is stirred up by an energetic process and becomes a dense slurry of mixed grains. The [pb_glossary id=\"2678\"]sediment[\/pb_glossary] flow courses downward through submarine channels and canyons due to gravity acting on the density difference between the denser slurry and less dense surrounding seawater. As the flow reaches deeper ocean basins it slows down, loses energy, and deposits [pb_glossary id=\"2678\"]sediment[\/pb_glossary] in a [pb_glossary id=\"2863\"]Bouma sequence[\/pb_glossary] of coarse grains first, followed by increasingly finer grains (see figure).\n<h3><span style=\"font-weight: 400\">5.4.3. Flow Regime and Bedforms<\/span><\/h3>\n[caption id=\"attachment_3051\" align=\"aligncenter\" width=\"1024\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Bedforms_under_various_flow_regimes.pdf.jpg\"><img class=\"size-large wp-image-383\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-1024x713.jpg\" alt=\"There are 7 images of increasing velocity.\" width=\"1024\" height=\"713\"><\/a> Bedforms from under increasing flow velocities.[\/caption]\n\nIn fluid systems, such as moving water or wind, sand is the most easily transported and deposited [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grain. Smaller particles like silt and clay are less movable by fluid systems because the tiny grains are chemically attracted to each other and stick to the underlying [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. Under higher flow rates, the fine silt and clay [pb_glossary id=\"2678\"]sediment[\/pb_glossary] tends to stay in place and the larger sand grains get picked up and moved.\n\n<strong>Bedforms<\/strong> are sedimentary structures created by fluid systems working on sandy [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. [pb_glossary id=\"2828\"]Grain size[\/pb_glossary], flow velocity, and <strong>[pb_glossary id=\"2864\"]flow regime[\/pb_glossary]<\/strong> or pattern interact to produce bedforms having unique, identifiable physical characteristics. Flow regimes are divided into upper and lower regimes, which are further divided into uppermost, upper, lower, and lowermost parts. The table below shows bedforms and their associated flow regimes. For example, the [pb_glossary id=\"2869\"]dunes[\/pb_glossary] [pb_glossary id=\"2865\"]bedform[\/pb_glossary] is created in the upper part of the lower [pb_glossary id=\"2864\"]flow regime[\/pb_glossary].\n<table>\n<tbody>\n<tr>\n<td><strong>[pb_glossary id=\"2864\"]Flow Regime[\/pb_glossary] (part)<\/strong><\/td>\n<td><strong>[pb_glossary id=\"2865\"]Bedform[\/pb_glossary]<\/strong><\/td>\n<td><strong>Description<\/strong><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Lower (lowest)<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2866\"]Plane bed[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">Lower [pb_glossary id=\"2866\"]plane bed[\/pb_glossary], flat [pb_glossary id=\"2860\"]laminations[\/pb_glossary]<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Lower (lower)<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2868\"]Ripples[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">Small (with respect to flow) inclined layers dipping downflow<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Lower (upper)<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2869\"]Dunes[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">Larger inclined cross [pb_glossary id=\"2858\"]beds[\/pb_glossary], \u00b1[pb_glossary id=\"2868\"]ripples[\/pb_glossary], dipping downflow<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Upper (lower)<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2866\"]Plane bed[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">Flat layers, can include lined-up grains ([pb_glossary id=\"2867\"]parting lineations[\/pb_glossary])<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Upper (upper)<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2872\"]Antidunes[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">Hard to preserve reverse [pb_glossary id=\"2869\"]dunes[\/pb_glossary] dipping shallowly upflow<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Upper (uppermost)<\/span><\/td>\n<td><span style=\"font-weight: 400\">Chutes\/pools <\/span><em><span style=\"font-weight: 400\">(rare)<\/span><\/em><\/td>\n<td><span style=\"font-weight: 400\">Erosional, not really a [pb_glossary id=\"2865\"]bedform[\/pb_glossary]; rarely found preserved<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4><span style=\"font-weight: 400\">Plane Beds<\/span><\/h4>\n[caption id=\"attachment_3052\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/PartingLineation.jpg\"><img class=\"wp-image-384 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/PartingLineation-300x200.jpg\" alt=\"There are slight groves in the rock.\" width=\"300\" height=\"200\"><\/a> Subtle lines across this sandstone (trending from the lower left to upper right) are parting lineations.[\/caption]\n\n<strong>Plane [pb_glossary id=\"2858\"]beds[\/pb_glossary]<\/strong> created in the lower [pb_glossary id=\"2864\"]flow regime[\/pb_glossary] are like [pb_glossary id=\"2857\"]bedding[\/pb_glossary] planes, on a smaller scale. The flat, parallel layers form as sandy [pb_glossary id=\"2678\"]sediment[\/pb_glossary] piles and move on top of layers below. Even non-flowing fluid systems, such as lakes, can produce [pb_glossary id=\"2678\"]sediment[\/pb_glossary] plane [pb_glossary id=\"2858\"]beds[\/pb_glossary]. Plane [pb_glossary id=\"2858\"]beds[\/pb_glossary] in the upper [pb_glossary id=\"2864\"]flow regime[\/pb_glossary] are created by fast-flowing fluids. They may look identi\n\n[caption id=\"attachment_3054\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/CurrentRipple.jpg\"><img class=\"wp-image-385 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/CurrentRipple-300x200.jpg\" alt=\"The sand has a steep side on the left of the ripple, and a more gentle slope on the right.\" width=\"300\" height=\"200\"><\/a> Modern current ripple in sand from the Netherlands. The flow creates a steep side down current. In this image, the flow is from right to left.[\/caption]\n\ncal to lower-flow-regime [pb_glossary id=\"2858\"]beds[\/pb_glossary]; however, they typically show <strong>[pb_glossary id=\"2867\"]parting lineations[\/pb_glossary]<\/strong>, slight alignments of grains in rows and swaths, caused by high [pb_glossary id=\"2678\"]sediment[\/pb_glossary] transport rates that only occur in upper flow regimes.\n<h4><span style=\"font-weight: 400\">Ripples<\/span><\/h4>\n<strong>[pb_glossary id=\"2868\"]Ripples[\/pb_glossary]<\/strong> are known by several names: [pb_glossary id=\"2868\"]ripple[\/pb_glossary] marks, [pb_glossary id=\"2868\"]ripple[\/pb_glossary] cross [pb_glossary id=\"2858\"]beds[\/pb_glossary], or [pb_glossary id=\"2868\"]ripple[\/pb_glossary] cross [pb_glossary id=\"2860\"]laminations[\/pb_glossary]. The ridges or undulations in the [pb_glossary id=\"2858\"]bed[\/pb_glossary] are created as [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains pile up on top of the [pb_glossary id=\"2866\"]plane bed[\/pb_glossary]. With the exception of [pb_glossary id=\"2869\"]dunes[\/pb_glossary], the scale of these [pb_glossary id=\"2858\"]beds[\/pb_glossary] is typically measured in centimeters. Occasionally, large flows like [pb_glossary id=\"2910\"]glacial[\/pb_glossary] lake outbursts, can produce [pb_glossary id=\"2868\"]ripples[\/pb_glossary] as tall as 20 m (66 ft).\n\n[caption id=\"attachment_3055\" align=\"alignleft\" width=\"231\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/WaveRipple.jpg\"><img class=\"wp-image-386\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/WaveRipple-300x225.jpg\" alt=\"This brown rock has symmetry in its ripples.\" width=\"231\" height=\"173\"><\/a> A bidirectional flow creates this symmetrical wave ripple. From rocks in Nomgon, Mongolia. Note the crests of the ripples have been eroded away by subsequent flows in places.[\/caption]\n\nFirst scientifically described by Hertha Ayrton, [pb_glossary id=\"2868\"]ripple[\/pb_glossary] shapes are determined by flow type and can be straight-crested, sinuous, or complex. Asymmetrical [pb_glossary id=\"2868\"]ripples[\/pb_glossary] form in a unidirectional flow. Symmetrical [pb_glossary id=\"2868\"]ripples[\/pb_glossary] are the result of an oscillating back-and-forth flow typical of intertidal swash zones. Climbing [pb_glossary id=\"2868\"]ripples[\/pb_glossary] are created from high sedimentation rates and appear as overlapping layers of [pb_glossary id=\"2868\"]ripple[\/pb_glossary] shapes (see figure).\n\n[caption id=\"attachment_3058\" align=\"aligncenter\" width=\"565\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Climbing_ripples.jpg\"><img class=\"wp-image-387\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-300x225.jpg\" alt=\"The ripples are on top, slightly offset, from each other.\" width=\"565\" height=\"424\"><\/a> Climbing ripple deposit from India.[\/caption]\n<h4><span style=\"font-weight: 400\">Dunes<\/span><\/h4>\n[caption id=\"attachment_3060\" align=\"aligncenter\" width=\"1024\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/XBedsZion.jpg\"><img class=\"size-large wp-image-388\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-1024x768.jpg\" alt=\"The mountain has a large variety of angles of beds, resulting from dunes moving in all directions.\" width=\"1024\" height=\"768\"><\/a> Lithified cross-bedded dunes from the high country of Zion National Park, Utah. The complexity of bedding planes results from the three-dimensional network of ancient dune flows.[\/caption]\n\n<strong>[pb_glossary id=\"2869\"]Dunes[\/pb_glossary]<\/strong> are very large and prominent versions of [pb_glossary id=\"2868\"]ripples[\/pb_glossary], and typical examples of large [pb_glossary id=\"2457\"]cross bedding[\/pb_glossary]. [pb_glossary id=\"2457\"]Cross bedding[\/pb_glossary] happens when [pb_glossary id=\"2868\"]ripples[\/pb_glossary] or [pb_glossary id=\"2869\"]dunes[\/pb_glossary] pile atop one another, interrupting, and\/or cutting into the underlying layers. Desert sand [pb_glossary id=\"2869\"]dunes[\/pb_glossary] are probably the first image conjured up by this category of [pb_glossary id=\"2865\"]bedform[\/pb_glossary].\n\nBritish geologist Agnold (1941) considered only Barchan and linear Seif [pb_glossary id=\"2869\"]dunes[\/pb_glossary] as the only true [pb_glossary id=\"2869\"]dune[\/pb_glossary] forms.\u00a0 Other workers have recognized transverse and [pb_glossary id=\"2461\"]star dunes[\/pb_glossary] as well as parabolic and [pb_glossary id=\"2459\"]linear dunes[\/pb_glossary] anchored by plants that are common in coastal areas as other types of [pb_glossary id=\"2869\"]dunes[\/pb_glossary].\n\n[caption id=\"attachment_3063\" align=\"alignleft\" width=\"247\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MoroccoDune.jpg\"><img class=\"wp-image-389\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune-681x1024.jpg\" alt=\"The red dune sand is rippled on one side (the steep side) and smooth on the other.\" width=\"247\" height=\"371\"><\/a> Modern sand dune in Morocco.[\/caption]\n\n[pb_glossary id=\"2869\"]Dunes[\/pb_glossary] are the most common sedimentary structure found within channelized flows of air or water. The biggest difference between [pb_glossary id=\"3134\"]river[\/pb_glossary] [pb_glossary id=\"2869\"]dunes[\/pb_glossary] and air-formed (desert) [pb_glossary id=\"2869\"]dunes[\/pb_glossary] is the depth of fluid [pb_glossary id=\"2664\"]system[\/pb_glossary]. Since the [pb_glossary id=\"2667\"]atmosphere[\/pb_glossary]\u2019s depth is immense when compared to a [pb_glossary id=\"3134\"]river[\/pb_glossary] channel, desert [pb_glossary id=\"2869\"]dunes[\/pb_glossary] are much taller than those found in [pb_glossary id=\"3134\"]rivers[\/pb_glossary]. Some famous air-formed [pb_glossary id=\"2869\"]dune[\/pb_glossary] landscapes include the Sahara Desert, Death Valley, and the Gobi Desert.\n\nAs airflow moves [pb_glossary id=\"2678\"]sediment[\/pb_glossary] along, the grains accumulate on the [pb_glossary id=\"2869\"]dune[\/pb_glossary]\u2019s windward surface (facing the wind). The angle of the windward side is typically shallower than the leeward (downwind) side, which has grains falling down over it. This difference in slopes can be seen in a [pb_glossary id=\"2858\"]bed[\/pb_glossary] cross-section and indicates the direction of the flow in the past. There are typically two styles of [pb_glossary id=\"2869\"]dune[\/pb_glossary] [pb_glossary id=\"2858\"]beds[\/pb_glossary]: the more common [pb_glossary id=\"3183\"]trough[\/pb_glossary] cross [pb_glossary id=\"2858\"]beds[\/pb_glossary] with curved windward surfaces, and rarer planar cross [pb_glossary id=\"2858\"]beds[\/pb_glossary] with flat windward surfaces.\n\nIn tidal locations with strong in-and-out flows, [pb_glossary id=\"2869\"]dunes[\/pb_glossary] can develop in opposite directions. This produces a feature called herringbone [pb_glossary id=\"2457\"]cross bedding[\/pb_glossary].\n\n[caption id=\"attachment_3065\" align=\"aligncenter\" width=\"378\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Herringbone_cross-stratified.jpg\"><img class=\"wp-image-390\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-300x225.jpg\" alt=\"Herringbone_cross-sThe flow is to the left on the bottom, and the right on the top.tratified\" width=\"378\" height=\"284\"><\/a> Herringbone cross-bedding from the Mazomanie Formation, upper Cambrian of Minnesota.[\/caption]\n\n[caption id=\"attachment_3066\" align=\"alignright\" width=\"225\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/HumXSec.jpg\"><img class=\"wp-image-391\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-300x225.jpg\" alt=\"The up and down waves are famous from hummocky-cross stratification.\" width=\"225\" height=\"169\"><\/a> Hummocky-cross stratification, seen as wavy lines throughout the middle of this rock face. Best example is just above the pencil in the center.[\/caption]\n\nAnother [pb_glossary id=\"2869\"]dune[\/pb_glossary] [pb_glossary id=\"2960\"]formation[\/pb_glossary] variant occurs when very strong, hurricane-strength, winds agitate parts of the usually undisturbed seafloor. These [pb_glossary id=\"2858\"]beds[\/pb_glossary] are called <strong>[pb_glossary id=\"2871\"]hummocky cross stratification[\/pb_glossary]<\/strong> and have a 3D architecture of hills and valleys, with inclined and declined layering that matches the [pb_glossary id=\"2869\"]dune[\/pb_glossary] shapes.\n<h4><span style=\"font-weight: 400\">Antidunes<\/span><\/h4>\n[caption id=\"attachment_3069\" align=\"aligncenter\" width=\"356\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Antidunes_Urdaibai_estuary.jpg\"><img class=\"wp-image-392\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-300x225.jpg\" alt=\"The large waves are in place.\" width=\"356\" height=\"267\"><\/a> Antidunes forming in Urdaibai, Spain.[\/caption]\n\n<strong>[pb_glossary id=\"2872\"]Antidunes[\/pb_glossary]<\/strong> are so named because they share similar characteristics with [pb_glossary id=\"2869\"]dunes[\/pb_glossary], but are formed by a different, opposing process. While [pb_glossary id=\"2869\"]dunes[\/pb_glossary] form in lower flow regimes, [pb_glossary id=\"2872\"]antidunes[\/pb_glossary] come from fast-flowing upper flow regimes. In certain conditions of high flow rates, [pb_glossary id=\"2678\"]sediment[\/pb_glossary] accumulates upstream of a subtle [pb_glossary id=\"1454\"]dip[\/pb_glossary] instead of traveling downstream (see figure). [pb_glossary id=\"2872\"]Antidunes[\/pb_glossary] form in phase with the flow; in [pb_glossary id=\"3134\"]rivers[\/pb_glossary] they are marked by rapids in the current. [pb_glossary id=\"2872\"]Antidunes[\/pb_glossary] are rarely preserved in the rock record because the high flow rates needed to produce the [pb_glossary id=\"2858\"]beds[\/pb_glossary] also accelerate [pb_glossary id=\"2677\"]erosion[\/pb_glossary].\n<h3><b>5.4.4. Bioturbation<\/b><\/h3>\n[caption id=\"attachment_3071\" align=\"aligncenter\" width=\"968\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Saluda_bioturbation.jpg\"><img class=\"wp-image-393 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Saluda_bioturbation.jpg\" alt=\"There are several ovals and lines representing places where organisms crawled through the sediment.\" width=\"968\" height=\"297\"><\/a> Bioturbated dolomitic siltstone from Kentucky.[\/caption]\n\n<strong>[pb_glossary id=\"2873\"]Bioturbation[\/pb_glossary]<\/strong> is the result of organisms burrowing through soft [pb_glossary id=\"2678\"]sediment[\/pb_glossary], which disrupts the [pb_glossary id=\"2857\"]bedding[\/pb_glossary] layers. These tunnels are backfilled and eventually preserved when the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] becomes rock. [pb_glossary id=\"2873\"]Bioturbation[\/pb_glossary] happens most commonly in shallow, [pb_glossary id=\"2883\"]marine[\/pb_glossary] environments, and can be used to indicate water depth.\n<h3><b>5.4.5. Mudcracks<\/b><\/h3>\n[caption id=\"attachment_3072\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Mudcracks_roundtop_hill_MD.jpg\"><img class=\"size-medium wp-image-394\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Mudcracks_roundtop_hill_MD-300x214.jpg\" alt=\"The cracks are in several directions, forming squares, triangles, and other polygonal shapes.\" width=\"300\" height=\"214\"><\/a> Lithified mudcracks from Maryland.[\/caption]\n\n<strong>[pb_glossary id=\"2874\"]Mudcracks[\/pb_glossary]<\/strong> occur in clay-rich [pb_glossary id=\"2678\"]sediment[\/pb_glossary] that is submerged underwater and later dries out. Water fills voids in the clay\u2019s crystalline structure, causing the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains to swell. When this waterlogged [pb_glossary id=\"2678\"]sediment[\/pb_glossary] begins to dry out, the clay grains shrink. The [pb_glossary id=\"2678\"]sediment[\/pb_glossary] layer forms deep polygonal cracks with tapered openings toward the surface, which can be seen in profile. The cracks fill with new [pb_glossary id=\"2678\"]sediment[\/pb_glossary] and become visible veins running through the lithified rock. These dried-out clay [pb_glossary id=\"2858\"]beds[\/pb_glossary] are a major source of <strong>[pb_glossary id=\"2875\"]mud chips[\/pb_glossary]<\/strong>, small fragments of mud or [pb_glossary id=\"2839\"]shale[\/pb_glossary], which commonly become [pb_glossary id=\"2958\"]inclusions[\/pb_glossary] in [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] and [pb_glossary id=\"2833\"]conglomerate[\/pb_glossary]. What makes this sedimentary structure so important to geologists, is they only form in certain [pb_glossary id=\"2882\"]depositional\u00a0environments[\/pb_glossary]\u2014such as [pb_glossary id=\"2897\"]tidal flats[\/pb_glossary] that form underwater and are later exposed to air. Syneresis cracks are similar in appearance to [pb_glossary id=\"2874\"]mudcracks[\/pb_glossary] but much rarer; they are formed when subaqueous (underwater) clay [pb_glossary id=\"2678\"]sediment[\/pb_glossary] shrinks<span style=\"font-weight: 400\">.<\/span>\n<h3><b>5.4.6. Sole Marks <\/b><\/h3>\n[caption id=\"attachment_3074\" align=\"alignleft\" width=\"216\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/FluteCast.jpg\"><img class=\"wp-image-395\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-300x225.jpg\" alt=\"The bulge is sticking out of a rock layer above the head of the observer.\" width=\"216\" height=\"162\"><\/a> This flute cast shows a flow direction toward the upper right of the image, as seen by the bulge sticking down out of the layer above. The flute cast would have been scoured into a rock layer below that has been removed by erosion, leaving the sandy layer above to fill in the flute cast.[\/caption]\n\n<strong>[pb_glossary id=\"2876\"]Sole marks[\/pb_glossary]<\/strong> are small features typically found in [pb_glossary id=\"3134\"]river[\/pb_glossary] deposits. They form at the base of a [pb_glossary id=\"2858\"]bed[\/pb_glossary], the sole, and on top of the underlying [pb_glossary id=\"2858\"]bed[\/pb_glossary]. They can indicate several things about the [pb_glossary id=\"2679\"]deposition[\/pb_glossary] conditions, such as flow direction or [pb_glossary id=\"2859\"]stratigraphic[\/pb_glossary] up-direction (see [pb_glossary id=\"2881\"]Geopetal[\/pb_glossary] Structures section). <strong>[pb_glossary id=\"2876\"]Flute casts[\/pb_glossary]<\/strong> or [pb_glossary id=\"2876\"]scour marks[\/pb_glossary] are grooves carved out by the forces of fluid flow and [pb_glossary id=\"2678\"]sediment[\/pb_glossary] loads. The upstream part of the flow creates steep grooves and downstream the grooves are shallower. The grooves subsequently become filled by overlying [pb_glossary id=\"2678\"]sediment[\/pb_glossary], creating a [pb_glossary id=\"2179\"]cast[\/pb_glossary] of the original hollow.\n\n[caption id=\"attachment_3076\" align=\"alignright\" width=\"279\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Groove_casts.jpg\"><img class=\"wp-image-396\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-300x225.jpg\" alt=\"The rock is filled with narrow, parallel ridges.\" width=\"279\" height=\"209\"><\/a> Groove casts at the base of a turbidite deposit in Italy.[\/caption]\n\nFormed similarly to [pb_glossary id=\"2876\"]flute casts[\/pb_glossary] but with a more regular and aligned shape, <strong>[pb_glossary id=\"2876\"]groove casts[\/pb_glossary]<\/strong> are produced by larger clasts or debris carried along in the water that scrape across the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] layer. [pb_glossary id=\"2876\"]Tool marks[\/pb_glossary] come from objects like sticks carried in the fluid downstream or embossed into the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] layer, leaving a depression that later fills with new [pb_glossary id=\"2678\"]sediment[\/pb_glossary].\n\n[caption id=\"attachment_3077\" align=\"alignleft\" width=\"259\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/LoadCast.jpg\"><img class=\"wp-image-397\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/LoadCast-300x225.jpg\" alt=\"The drill core is cylindrical.\" width=\"259\" height=\"194\"><\/a> A drill core showing a load cast showing light-colored sand sticking down into dark mud.[\/caption]\n\n<strong>Load [pb_glossary id=\"2179\"]casts[\/pb_glossary]<\/strong>, an example of <strong>soft-[pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"1448\"]deformation[\/pb_glossary]<\/strong>, are small indentations made by an overlying layer of coarse [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains or clasts intruding into a softer, finer-grained [pb_glossary id=\"2678\"]sediment[\/pb_glossary] layer.\n<h3><b>5.4.7. Raindrop Impressions<\/b><\/h3>\n[caption id=\"attachment_3079\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Raindrop_impressions_mcr1.jpg\"><img class=\"size-medium wp-image-398\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Raindrop_impressions_mcr1-300x200.jpg\" alt=\"This grey rock has round circles left by raindrops\" width=\"300\" height=\"200\"><\/a> Mississippian raindrop impressions over wave ripples from Nova Scotia.[\/caption]\n\nLike their name implies, <strong>[pb_glossary id=\"2878\"]raindrop impressions[\/pb_glossary]<\/strong> are small pits or bumps found in soft [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. While they are generally believed to be created by rainfall, they may be caused by other agents such as escaping gas bubbles<span style=\"font-weight: 400\">.<\/span>\n<h3><b>5.4.8. Imbrication<\/b><\/h3>\n[caption id=\"attachment_3081\" align=\"alignright\" width=\"395\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Imbricated_fabric.jpg\"><img class=\"wp-image-399\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Imbricated_fabric-300x225.jpg\" alt=\"The rocks in this conglomerate are tilted, leaning toward the right.\" width=\"395\" height=\"296\"><\/a> Cobbles in this conglomerate are positioned in a way that they are stacked on each other, which occurred as flow went from left to right.[\/caption]\n\n<strong>[pb_glossary id=\"2879\"]Imbrication[\/pb_glossary]<\/strong> is a [pb_glossary id=\"3213\"]stack[\/pb_glossary] of large and usually flat clasts\u2014cobbles, gravels, [pb_glossary id=\"2875\"]mud chips[\/pb_glossary], etc.\u2014that are aligned in the direction of fluid flow. The clasts may be stacked in rows, with their edges dipping down and flat surfaces aligned to face the flow (see figure). Or their flat surfaces may be parallel to the layer and long axes aligned with flow. Imbrications are useful for analyzing <strong>paleocurrents<\/strong>, or currents found in the geologic past, especially in [pb_glossary id=\"2904\"]alluvial[\/pb_glossary] deposits.\n<h3><b>5.4.9. Geopetal Structures<\/b><\/h3>\n[caption id=\"attachment_3082\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Geopetal.jpg\"><img class=\"wp-image-400 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-300x225.jpg\" alt=\"Line is horizontal in picture as well.\" width=\"300\" height=\"225\"><\/a> This bivalve (clam) fossil was partially filled with tan sediment, partially empty. Later fluids filled in the fossil with white calcite minerals. The line between the sediment and the later calcite is paleo-horizontal.[\/caption]\n\n<strong>[pb_glossary id=\"2881\"]Geopetal[\/pb_glossary] structures<\/strong>, also called up-direction indicators, are used to identify which way was up when the [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] layers were originally formed. This is especially important in places where the rock layers have been deformed, tilted, or overturned. Well preserved [pb_glossary id=\"2874\"]mudcracks[\/pb_glossary], [pb_glossary id=\"2876\"]sole marks[\/pb_glossary], and [pb_glossary id=\"2878\"]raindrop impressions[\/pb_glossary] can be used to determine up direction. Other useful [pb_glossary id=\"2881\"]geopetal[\/pb_glossary] structures include:\n<ul>\n \t<li>\n\n[caption id=\"attachment_3084\" align=\"alignright\" width=\"207\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Eubrontes01.jpg\"><img class=\"size-medium wp-image-401\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01-207x300.jpg\" alt=\"This footprint of a dinosaur is three toes.\" width=\"207\" height=\"300\"><\/a> Eubrontes trace fossil from Utah, showing the geopetal direction is into the image.[\/caption]\n\nVugs: Small voids in the rock that usually become filled during [pb_glossary id=\"2827\"]diagenesis[\/pb_glossary]. If the void is partially filled or filled in stages, it serves as a permanent record of a level bubble, frozen in time.<\/li>\n \t<li>[pb_glossary id=\"2457\"]Cross bedding[\/pb_glossary] \u2013 In places where [pb_glossary id=\"2868\"]ripples[\/pb_glossary] or [pb_glossary id=\"2869\"]dunes[\/pb_glossary] pile on top of one another, where one [pb_glossary id=\"2870\"]cross bed[\/pb_glossary] interrupts and\/or cuts another below, this shows a cross-cutting relationship that indicates up direction.<\/li>\n \t<li>[pb_glossary id=\"2868\"]Ripples[\/pb_glossary], [pb_glossary id=\"2869\"]dunes[\/pb_glossary]: Sometimes the [pb_glossary id=\"2868\"]ripples[\/pb_glossary] are preserved well enough to differentiate between the crests (top) and troughs (bottom).<\/li>\n \t<li>[pb_glossary id=\"2176\"]Fossils[\/pb_glossary]: Body [pb_glossary id=\"2176\"]fossils[\/pb_glossary] in life position, meaning the body parts are not scattered or broken, and [pb_glossary id=\"2183\"]trace fossils[\/pb_glossary] like footprints (see figure) can provide an up direction. Intact fossilized coral [pb_glossary id=\"2898\"]reefs[\/pb_glossary] are excellent up indicators because of their large size and easily distinguishable top and bottom. [pb_glossary id=\"2189\"]Index fossils[\/pb_glossary], such as ammonites, can be used to age date [pb_glossary id=\"2857\"]strata[\/pb_glossary] and determine up direction based on relative rock ages.<\/li>\n \t<li><span style=\"font-weight: 400\">Vesicles - [pb_glossary id=\"2673\"]Lava[\/pb_glossary] flows eliminate gas upwards. An increase of vesicles toward the top of the flow indicates up.<\/span><\/li>\n<\/ul>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"34\"]\n\n[caption id=\"attachment_3996\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.4-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-402\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 5.4 via this QR Code.[\/caption]\n<h2><span style=\"font-weight: 400\">5.5 Depositional Environments<\/span><\/h2>\n[caption id=\"attachment_3085\" align=\"aligncenter\" width=\"1024\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SedimentaryEnvironments.jpg\"><img class=\"wp-image-403 size-large\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments-1024x768.jpg\" alt=\"Many different environments are representative environments from high elevation to deep under water.\" width=\"1024\" height=\"768\"><\/a> A representation of common depositional environments.[\/caption]\n\nThe ultimate goal of many [pb_glossary id=\"2859\"]stratigraphy[\/pb_glossary] studies is to understand the original <strong>[pb_glossary id=\"2882\"]depositional environment[\/pb_glossary]<\/strong>. Knowing where and how a particular [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] was formed can help geologists paint a picture of past environments\u2014such as a mountain [pb_glossary id=\"2464\"]glacier[\/pb_glossary], gentle [pb_glossary id=\"3147\"]floodplain[\/pb_glossary], dry desert, or deep-sea [pb_glossary id=\"2885\"]ocean floor[\/pb_glossary]. The study of [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary] is a complex endeavor; the table shows a simplified version of what to look for in the rock record.\n<table style=\"height: 665px;width: 98.3953%;border-collapse: collapse\" border=\"1\">\n<tbody>\n<tr style=\"height: 28px\">\n<td style=\"width: 19.963%;height: 28px;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>Location<\/strong><\/span><\/td>\n<td style=\"width: 20.8001%;height: 28px;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>[pb_glossary id=\"2678\"]Sediment[\/pb_glossary]<\/strong><\/span><\/td>\n<td style=\"width: 20.8001%;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>Common Rock Types<\/strong><\/span><\/td>\n<td style=\"width: 18.1328%;height: 28px;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>Typical [pb_glossary id=\"2176\"]Fossils[\/pb_glossary]<\/strong><\/span><\/td>\n<td style=\"width: 20.3039%;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>Sedimentary Structures<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 19.963%;height: 28px\">[pb_glossary id=\"2884\"]Abyssal[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%;height: 28px\">very fine muds and oozes, diatomaceous Earth<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2849\"]chert[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%;height: 28px\">diatoms<\/td>\n<td style=\"width: 20.3039%\">few<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 19.963%;height: 28px\">[pb_glossary id=\"2887\"]Submarine fan[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%;height: 28px\">[pb_glossary id=\"2862\"]graded[\/pb_glossary] [pb_glossary id=\"2863\"]Bouma[\/pb_glossary] sequences, alternating sand\/mud<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2825\"]clastic[\/pb_glossary] rocks<\/td>\n<td style=\"width: 18.1328%;height: 28px\">rare<\/td>\n<td style=\"width: 20.3039%\">channels, fan shape<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2892\"]Continental slope[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">mud, possible sand, countourites<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2839\"]shale[\/pb_glossary], [pb_glossary id=\"2840\"]siltstone[\/pb_glossary], [pb_glossary id=\"2851\"]limestone[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">rare<\/td>\n<td style=\"width: 20.3039%\">swaths<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">Lower [pb_glossary id=\"2889\"]shoreface[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">laminated sand<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2834\"]sandstone[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">[pb_glossary id=\"2873\"]bioturbation[\/pb_glossary]<\/td>\n<td style=\"width: 20.3039%\">hummocky cross [pb_glossary id=\"2858\"]beds[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">Upper [pb_glossary id=\"2889\"]shoreface[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">planar sand<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2834\"]sandstone[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">[pb_glossary id=\"2873\"]bioturbation[\/pb_glossary]<\/td>\n<td style=\"width: 20.3039%\">plane [pb_glossary id=\"2858\"]beds[\/pb_glossary], cross [pb_glossary id=\"2858\"]beds[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2896\"]Littoral[\/pb_glossary] (beach)<\/td>\n<td style=\"width: 20.8001%\">very well sorted sand<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2834\"]sandstone[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">[pb_glossary id=\"2873\"]bioturbation[\/pb_glossary]<\/td>\n<td style=\"width: 20.3039%\">few<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2897\"]Tidal Flat[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">mud and sand with channels<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2839\"]shale[\/pb_glossary], [pb_glossary id=\"2837\"]mudstone[\/pb_glossary],[pb_glossary id=\"2840\"]siltstone[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">[pb_glossary id=\"2873\"]bioturbation[\/pb_glossary]<\/td>\n<td style=\"width: 20.3039%\">[pb_glossary id=\"4147\"]mudcracks[\/pb_glossary], symmetric [pb_glossary id=\"2868\"]ripples[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2898\"]Reef[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">lime mud with coral<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2851\"]limestone[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">many, commonly coral<\/td>\n<td style=\"width: 20.3039%\">few<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2900\"]Lagoon[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">laminated mud<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2839\"]shale[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">many, [pb_glossary id=\"2873\"]bioturbation[\/pb_glossary]<\/td>\n<td style=\"width: 20.3039%\">[pb_glossary id=\"2860\"]laminations[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2901\"]Delta[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">channelized sand with mud, \u00b1swamp<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2825\"]clastic[\/pb_glossary] rocks<\/td>\n<td style=\"width: 18.1328%\">many to few<\/td>\n<td style=\"width: 20.3039%\">cross [pb_glossary id=\"2858\"]beds[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2903\"]Fluvial[\/pb_glossary] ([pb_glossary id=\"3134\"]river[\/pb_glossary])<\/td>\n<td style=\"width: 20.8001%\">sand and mud, can have larger [pb_glossary id=\"2678\"]sediments[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2834\"]sandstone[\/pb_glossary], [pb_glossary id=\"2833\"]conglomerate[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">bone [pb_glossary id=\"2858\"]beds[\/pb_glossary] (rare)<\/td>\n<td style=\"width: 20.3039%\">cross [pb_glossary id=\"2858\"]beds[\/pb_glossary], channels, asymmetric [pb_glossary id=\"2868\"]ripples[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2904\"]Alluvial[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">mud to boulders, poorly sorted<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2825\"]clastic[\/pb_glossary] rocks<\/td>\n<td style=\"width: 18.1328%\">rare<\/td>\n<td style=\"width: 20.3039%\">channels, mud cracks<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2905\"]Lacustrine[\/pb_glossary] (lake)<\/td>\n<td style=\"width: 20.8001%\">fine-grained [pb_glossary id=\"2860\"]laminations[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2839\"]shale[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">invertebrates, rare (deep) bone [pb_glossary id=\"2858\"]beds[\/pb_glossary]<\/td>\n<td style=\"width: 20.3039%\">[pb_glossary id=\"2860\"]laminations[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2907\"]Paludal[\/pb_glossary] (swamp)<\/td>\n<td style=\"width: 20.8001%\">plant material<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2856\"]coal[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">plant debris<\/td>\n<td style=\"width: 20.3039%\">rare<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2908\"]Aeolian[\/pb_glossary] ([pb_glossary id=\"2869\"]dunes[\/pb_glossary])<\/td>\n<td style=\"width: 20.8001%\">very well sorted sand and silt<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2834\"]sandstone[\/pb_glossary]<\/td>\n<td style=\"width: 18.1328%\">rare<\/td>\n<td style=\"width: 20.3039%\">cross [pb_glossary id=\"2858\"]beds[\/pb_glossary] (large)<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">[pb_glossary id=\"2910\"]Glacial[\/pb_glossary]<\/td>\n<td style=\"width: 20.8001%\">mud to boulders, poorly sorted<\/td>\n<td style=\"width: 20.8001%\">[pb_glossary id=\"2833\"]conglomerate[\/pb_glossary] ([pb_glossary id=\"2483\"]tillite[\/pb_glossary])<\/td>\n<td style=\"width: 18.1328%\"><\/td>\n<td style=\"width: 20.3039%\">striations, drop stones<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3><b>5.5.1. Marine<\/b><\/h3>\n[pb_glossary id=\"2883\"]Marine[\/pb_glossary] [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary]\u00a0are completely and constantly submerged in seawater. Their depositional characteristics are largely dependent on the depth of water with two notable exceptions, [pb_glossary id=\"2887\"]submarine fans[\/pb_glossary] and [pb_glossary id=\"2888\"]turbidites[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Abyssal<\/span><\/h4>\n[caption id=\"attachment_3087\" align=\"alignleft\" width=\"452\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Marine_sediment_thickness.jpg\"><img class=\"wp-image-404\" title=\"NOAA, public domain\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Marine_sediment_thickness-300x272.jpg\" alt=\"The thickness is low in the abyssal plain.\" width=\"452\" height=\"410\"><\/a> Marine sediment thickness. Note the lack of sediment away from the continents.[\/caption]\n\n<strong>[pb_glossary id=\"2884\"]Abyssal[\/pb_glossary] sedimentary rocks<\/strong> form on the <strong>[pb_glossary id=\"2885\"]abyssal plain[\/pb_glossary]<\/strong>. The plain encompasses relatively flat [pb_glossary id=\"2885\"]ocean floor[\/pb_glossary] with some minor topographical features, called [pb_glossary id=\"2884\"]abyssal[\/pb_glossary] hills. These small seafloor mounts range 100 m to 20 km in diameter, and are possibly created by [pb_glossary id=\"1445\"]extension[\/pb_glossary]. Most [pb_glossary id=\"2884\"]abyssal[\/pb_glossary] plains do not experience significant fluid movement, so [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] formed there are very fine grained.\n\nThere are three categories of [pb_glossary id=\"2884\"]abyssal[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. Calcareous oozes consist of [pb_glossary id=\"1918\"]calcite[\/pb_glossary]-rich plankton shells that have fallen to the [pb_glossary id=\"2885\"]ocean floor[\/pb_glossary]. An example of this type of [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is [pb_glossary id=\"2855\"]chalk[\/pb_glossary]. Siliceous oozes are also made of plankton debris, but these organisms build their shells using silica or hydrated silica. In some cases such as with diatomaceous earth, [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is deposited below the <strong>[pb_glossary id=\"2886\"]calcite compensation depth[\/pb_glossary]<\/strong>, a depth where [pb_glossary id=\"1918\"]calcite[\/pb_glossary] solubility increases. Any [pb_glossary id=\"1918\"]calcite[\/pb_glossary]-based shells are [pb_glossary id=\"2815\"]dissolved[\/pb_glossary], leaving only silica-based shells. [pb_glossary id=\"2849\"]Chert[\/pb_glossary] is another common rock formed from these types of [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. These two types of [pb_glossary id=\"2884\"]abyssal[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] are also classified as [pb_glossary id=\"2850\"]biochemical[\/pb_glossary] in origin. (see [pb_glossary id=\"2850\"]BIOCHEMICAL[\/pb_glossary] section).\n\n[caption id=\"attachment_3090\" align=\"alignright\" width=\"420\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc.jpg\"><img class=\"wp-image-405\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc-300x251.jpg\" alt=\"The rock is powdery and white.\" width=\"420\" height=\"352\"><\/a> Diatomaceous earth[\/caption]\n\nThe third [pb_glossary id=\"2678\"]sediment[\/pb_glossary] type is pelagic clay. Very fine-grained clay particles, typically brown or red, descend through the water column very slowly. Pelagic clay [pb_glossary id=\"2679\"]deposition[\/pb_glossary] occurs in areas of remote open ocean, where there is little plankton accumulation.\n\n[caption id=\"attachment_3092\" align=\"alignleft\" width=\"411\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Turbidite_formation.jpg\"><img class=\"wp-image-406\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-300x209.jpg\" alt=\"The canyon allows stacking of these deposits on the ocean floor.\" width=\"411\" height=\"286\"><\/a> Turbidites inter-deposited within submarine fans.[\/caption]\n\nTwo notable exceptions to the fine-grained nature of [pb_glossary id=\"2884\"]abyssal[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] are <strong>[pb_glossary id=\"2887\"]submarine fan[\/pb_glossary]<\/strong> and <strong>[pb_glossary id=\"2888\"]turbidite[\/pb_glossary]<\/strong> deposits. [pb_glossary id=\"2887\"]Submarine fans[\/pb_glossary] occur [pb_glossary id=\"3196\"]offshore[\/pb_glossary] at the base of large [pb_glossary id=\"3134\"]river[\/pb_glossary] systems. They are initiated during times of low sea level, as strong [pb_glossary id=\"3134\"]river[\/pb_glossary] currents carve [pb_glossary id=\"3224\"]submarine canyons[\/pb_glossary] into the [pb_glossary id=\"2891\"]continental shelf[\/pb_glossary]. When sea levels rise, [pb_glossary id=\"2678\"]sediment[\/pb_glossary] accumulates on the shelf typically forming large, fan-shaped floodplains called deltas. Periodically, the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is disturbed creating dense slurries that flush down the underwater canyons in large gravity-induced events called [pb_glossary id=\"2888\"]turbidites[\/pb_glossary]. The [pb_glossary id=\"2887\"]submarine fan[\/pb_glossary] is formed by a network of [pb_glossary id=\"2888\"]turbidites[\/pb_glossary] that deposit their [pb_glossary id=\"2678\"]sediment[\/pb_glossary] loads as the slope decreases, much like what happens above-water at [pb_glossary id=\"2904\"]alluvial[\/pb_glossary] fans and deltas. This sudden flushing transports coarser [pb_glossary id=\"2678\"]sediment[\/pb_glossary] to the [pb_glossary id=\"2885\"]ocean floor[\/pb_glossary] where they are otherwise uncommon. [pb_glossary id=\"2888\"]Turbidites[\/pb_glossary] are also the typical origin of [pb_glossary id=\"2862\"]graded[\/pb_glossary] [pb_glossary id=\"2863\"]Bouma[\/pb_glossary] sequences. (see Chapter 5, [pb_glossary id=\"2676\"]Weathering[\/pb_glossary], [pb_glossary id=\"2677\"]Erosion[\/pb_glossary], and [pb_glossary id=\"2683\"]Sedimentary Rock[\/pb_glossary]).\n<h4><span style=\"font-weight: 400\">Continental Slope<\/span><\/h4>\n[caption id=\"attachment_3094\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Contourite_sparker_seismic_elongate_drift.png\"><img class=\"wp-image-407 size-medium\" title=\"IODP, 2012\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-300x162.png\" alt=\"The deposit is a large, dipping pile of sediment\" width=\"300\" height=\"162\"><\/a> Contourite drift deposit imaged with seismic waves.[\/caption]\n\n<strong>[pb_glossary id=\"2892\"]Continental slope[\/pb_glossary]<\/strong> deposits are not common in the rock record. The most notable type of [pb_glossary id=\"2892\"]continental slope[\/pb_glossary] deposits are contourites. Contourites form on the slope between the [pb_glossary id=\"2891\"]continental shelf[\/pb_glossary] and deep [pb_glossary id=\"2885\"]ocean floor[\/pb_glossary]. Deep-water ocean currents deposit [pb_glossary id=\"2678\"]sediment[\/pb_glossary] into smooth drifts of various architectures, sometimes interwoven with [pb_glossary id=\"2888\"]turbidites[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Lower shoreface<\/span><\/h4>\n[caption id=\"attachment_3097\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Wavebase.jpg\"><img class=\"wp-image-408 size-medium\" title=\"https:\/\/en.wikipedia.org\/wiki\/File:Wavebase.jpg, by https:\/\/en.wikipedia.org\/wiki\/User:GregBenson\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Wavebase-300x218.jpg\" alt=\"The diagram shows that wavebase is 1\/2 the wavelength of waves of water.\" width=\"300\" height=\"218\"><\/a> Diagram describing wavebase.[\/caption]\n\nThe <strong>lower [pb_glossary id=\"2889\"]shoreface[\/pb_glossary]<\/strong> lies below the normal depth of wave agitation, so the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is not subject to daily winnowing and [pb_glossary id=\"2679\"]deposition[\/pb_glossary]. These [pb_glossary id=\"2678\"]sediment[\/pb_glossary] layers are typically finely laminated, and may contain hummocky cross-stratification. Lower [pb_glossary id=\"2889\"]shoreface[\/pb_glossary] [pb_glossary id=\"2858\"]beds[\/pb_glossary] are affected by larger waves, such those as generated by hurricanes and other large storms.\n<h4><span style=\"font-weight: 400\">Upper shoreface<\/span><\/h4>\n[caption id=\"attachment_3467\" align=\"aligncenter\" width=\"666\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Littoral_Zones-1.jpg\"><img class=\"size-full wp-image-409\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Littoral_Zones-1.jpg\" alt=\"The image shows the many complexities of the shoreline described in the text.\" width=\"666\" height=\"292\"><\/a> Diagram of zones of the shoreline.[\/caption]\n\nThe <strong>upper [pb_glossary id=\"2889\"]shoreface[\/pb_glossary]<\/strong> contains [pb_glossary id=\"2678\"]sediments[\/pb_glossary] within the zone of normal wave action, but still submerged below the beach environment. These [pb_glossary id=\"2678\"]sediments[\/pb_glossary] usually consist of very well sorted, fine sand. The main sedimentary structure is planar [pb_glossary id=\"2857\"]bedding[\/pb_glossary] consistent with the lower part of the upper [pb_glossary id=\"2864\"]flow regime[\/pb_glossary], but it can also contain [pb_glossary id=\"2457\"]cross bedding[\/pb_glossary] created by [pb_glossary id=\"3205\"]longshore currents[\/pb_glossary].\n<h3><b>5.5.2. Transitional coastline\u00a0environments<\/b><\/h3>\n[caption id=\"attachment_3264\" align=\"alignright\" width=\"400\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/TransgressionRegression-1.png\"><img class=\"wp-image-410\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/TransgressionRegression-1-300x199.png\" alt=\"Onlap is sediments moving toward the land. Offlap is moving away.\" width=\"400\" height=\"265\"><\/a> The rising sea levels of transgressions create onlapping sediments, regressions create offlapping.[\/caption]\n\nTransitional environments, more often called [pb_glossary id=\"3195\"]shoreline[\/pb_glossary] or <strong>[pb_glossary id=\"2890\"]coastline[\/pb_glossary] environments<\/strong>, are zones of complex interactions caused by ocean water hitting land. The [pb_glossary id=\"2678\"]sediment[\/pb_glossary] preservation potential is very high in these environments because [pb_glossary id=\"2679\"]deposition[\/pb_glossary] often occurs on the <strong>[pb_glossary id=\"2891\"]continental shelf[\/pb_glossary]<\/strong> and underwater. [pb_glossary id=\"3195\"]Shoreline[\/pb_glossary] environments are an important source of hydrocarbon deposits ([pb_glossary id=\"3337\"]petroleum[\/pb_glossary], [pb_glossary id=\"3339\"]natural gas[\/pb_glossary]).\n\nThe study of [pb_glossary id=\"3195\"]shoreline[\/pb_glossary] [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary] is called <strong>[pb_glossary id=\"2893\"]sequence stratigraphy[\/pb_glossary]<\/strong>. [pb_glossary id=\"2893\"]Sequence stratigraphy[\/pb_glossary]\u00a0examines depositional changes and 3D architectures associated with rising and falling sea levels, which is the main force at work in [pb_glossary id=\"3195\"]shoreline[\/pb_glossary] deposits. These sea-level fluctuations come from the daily tides, as well as [pb_glossary id=\"1710\"]climate[\/pb_glossary] changes and [pb_glossary id=\"2576\"]plate tectonics[\/pb_glossary]. A steady rise in sea level relative to the [pb_glossary id=\"3195\"]shoreline[\/pb_glossary] is called <strong>[pb_glossary id=\"2894\"]transgression[\/pb_glossary]<\/strong>. <strong>[pb_glossary id=\"2895\"]Regression[\/pb_glossary]<\/strong> is the opposite, a relative drop in sea level. Some common components of [pb_glossary id=\"3195\"]shoreline[\/pb_glossary] environments are [pb_glossary id=\"2896\"]littoral[\/pb_glossary] zones, [pb_glossary id=\"2897\"]tidal flats[\/pb_glossary], [pb_glossary id=\"2898\"]reefs[\/pb_glossary], [pb_glossary id=\"2900\"]lagoons[\/pb_glossary], and deltas. For a more in-depth look at these environments, see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/12-shorelines\/\">Chapter 12, Coastlines<\/a>.\n<h4><span style=\"font-weight: 400\">Littoral<\/span><\/h4>\n[caption id=\"attachment_3102\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/HeavyMineralsBeachSand.jpg\"><img class=\"size-medium wp-image-411\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/HeavyMineralsBeachSand-300x205.jpg\" alt=\"The tan rock has dark streaks of minerals.\" width=\"300\" height=\"205\"><\/a> Lithified heavy mineral sand (dark layers) from a beach deposit in India.[\/caption]\n\nThe <strong>[pb_glossary id=\"2896\"]littoral[\/pb_glossary]<\/strong> zone, better known as the beach, consists of highly weathered, homogeneous, well-sorted sand grains made mostly of [pb_glossary id=\"1915\"]quartz[\/pb_glossary]. There are black sand and other types of sand beaches, but they tend to be unique exceptions rather than the rule. Because beach sands, past or present, are so highly evolved, the amount grain [pb_glossary id=\"2676\"]weathering[\/pb_glossary] can be discerned using the [pb_glossary id=\"2687\"]minerals[\/pb_glossary] [pb_glossary id=\"2175\"]zircon[\/pb_glossary], tourmaline, and rutile. This tool is called the ZTR ([pb_glossary id=\"2175\"]zircon[\/pb_glossary], tourmaline, rutile) index. The ZTR index is higher in more weathered beaches, because these relatively rare and [pb_glossary id=\"1709\"]weather[\/pb_glossary]-resistant [pb_glossary id=\"2687\"]minerals[\/pb_glossary] become [pb_glossary id=\"3333\"]concentrated[\/pb_glossary] in older beaches. In some beaches, the ZTR index is so high the sand can be harvested as an economically viable source of these [pb_glossary id=\"2687\"]minerals[\/pb_glossary]. The beach environment has no sedimentary structures, due to the constant bombardment of wave energy delivered by surf action. Beach [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is moved around via multiple processes. Some beaches with high [pb_glossary id=\"2678\"]sediment[\/pb_glossary] supplies develop [pb_glossary id=\"2869\"]dunes[\/pb_glossary] nearby.\n<h4><span style=\"font-weight: 400\">Tidal Flats<\/span><\/h4>\n[caption id=\"attachment_3103\" align=\"aligncenter\" width=\"414\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tidal_flat_general_sketch.png\"><img class=\"wp-image-412\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Tidal_flat_general_sketch-300x225.png\" alt=\"The tidal flat it a network of channels.\" width=\"414\" height=\"311\"><\/a> General diagram of a tidal flat and associated features.[\/caption]\n\n[pb_glossary id=\"2897\"]Tidal flats[\/pb_glossary], or [pb_glossary id=\"2897\"]mud flats[\/pb_glossary], are sedimentary environments that are regularly flooded and drained by ocean tides. [pb_glossary id=\"2897\"]Tidal flats[\/pb_glossary] have large areas of fine-grained [pb_glossary id=\"2678\"]sediment[\/pb_glossary] but may also contain coarser sands. [pb_glossary id=\"2897\"]Tidal flat[\/pb_glossary] deposits typically contain gradational [pb_glossary id=\"2678\"]sediments[\/pb_glossary] and may include multi-directional [pb_glossary id=\"2868\"]ripple[\/pb_glossary] marks. [pb_glossary id=\"2874\"]Mudcracks[\/pb_glossary] are also commonly seen due to the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] being regularly exposed to air during low tides; the combination of [pb_glossary id=\"2874\"]mudcracks[\/pb_glossary] and [pb_glossary id=\"2868\"]ripple[\/pb_glossary] marks is distinctive to [pb_glossary id=\"2897\"]tidal flats[\/pb_glossary].\n\nTidal water carries in [pb_glossary id=\"2678\"]sediment[\/pb_glossary], sometimes focusing the flow through a narrow opening called a tidal inlet. Tidal channels, creek channels influenced by tides, can also [pb_glossary id=\"3080\"]focus[\/pb_glossary] tidally-induced flow. Areas of higher flow like inlets and tidal channels feature coarser grain sizes and larger [pb_glossary id=\"2868\"]ripples[\/pb_glossary], which in some cases can develop into [pb_glossary id=\"2869\"]dunes[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Reefs<\/span><\/h4>\n[caption id=\"attachment_3106\" align=\"aligncenter\" width=\"567\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/CapitolReef-WaterpocketFold.jpg\"><img class=\"wp-image-413\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-300x174.jpg\" alt=\"The fold is a long ridge.\" width=\"567\" height=\"328\"><\/a> Waterpocket fold, Capitol Reef National Park, Utah[\/caption]\n\n[pb_glossary id=\"2898\"]Reefs[\/pb_glossary], which most people would immediately associate with tropical coral [pb_glossary id=\"2898\"]reefs[\/pb_glossary] found in the oceans, are not only made by living things. Natural buildups of sand or rock can also create [pb_glossary id=\"2898\"]reefs[\/pb_glossary], similar to [pb_glossary id=\"3218\"]barrier islands[\/pb_glossary]. Geologically speaking, a <strong>[pb_glossary id=\"2898\"]reef[\/pb_glossary]<\/strong> is any topographically-elevated feature on the [pb_glossary id=\"2891\"]continental shelf[\/pb_glossary], located oceanward of and separate from the beach. The term [pb_glossary id=\"2898\"]reef[\/pb_glossary] can also be applied to [pb_glossary id=\"2902\"]terrestrial[\/pb_glossary] (atop the [pb_glossary id=\"2575\"]continental crust[\/pb_glossary]) features. Capitol [pb_glossary id=\"2898\"]Reef[\/pb_glossary] National Park in Utah contains a topographic barrier, a [pb_glossary id=\"2898\"]reef[\/pb_glossary], called the Waterpocket [pb_glossary id=\"1455\"]Fold[\/pb_glossary].\n\n[caption id=\"attachment_3109\" align=\"alignright\" width=\"272\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Coral_Outcrop_Flynn_Reef.jpg\"><img class=\"wp-image-414\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Coral_Outcrop_Flynn_Reef-300x225.jpg\" alt=\"The reef has many intricacies.\" width=\"272\" height=\"204\"><\/a> A modern coral reef.[\/caption]\n\nMost [pb_glossary id=\"2898\"]reefs[\/pb_glossary], now and in the geologic past, originate from the biological processes of living organisms. The growth habits of coral [pb_glossary id=\"2898\"]reefs[\/pb_glossary] provide geologists important information about the past. The hard structures in coral [pb_glossary id=\"2898\"]reefs[\/pb_glossary] are built by soft-bodied [pb_glossary id=\"2883\"]marine[\/pb_glossary] organisms, which continually add new material and enlarge the [pb_glossary id=\"2898\"]reef[\/pb_glossary] over time. Under certain conditions, when the land beneath a [pb_glossary id=\"2898\"]reef[\/pb_glossary] is subsiding, the coral [pb_glossary id=\"2898\"]reef[\/pb_glossary] may grow around and through existing [pb_glossary id=\"2678\"]sediment[\/pb_glossary], holding the [pb_glossary id=\"2678\"]sediment[\/pb_glossary] in place, and thus preserving the record of environmental and geological condition around it.\n\n[caption id=\"attachment_3110\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Vanatinai_Louisiade_Archipelago.jpg\"><img class=\"size-medium wp-image-415\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Vanatinai_Louisiade_Archipelago-300x200.jpg\" alt=\"The reef is offshore of the island proper.\" width=\"300\" height=\"200\"><\/a> The light blue reef is fringing the island of Vanatinai. As the island erodes away, only the reef will remain, forming a reef-bound seamount.[\/caption]\n\n[pb_glossary id=\"2678\"]Sediment[\/pb_glossary] found in coral [pb_glossary id=\"2898\"]reefs[\/pb_glossary] is typically fine-grained, mostly [pb_glossary id=\"1917\"]carbonate[\/pb_glossary], and tends to deposit between the intact coral skeletons. Water with high levels of silt or clay particles can inhibit the [pb_glossary id=\"2898\"]reef[\/pb_glossary] growth because coral organisms require sunlight to thrive; they host symbiotic algae called zooxanthellae that provide the coral with nourishment via photosynthesis. Inorganic [pb_glossary id=\"2898\"]reef[\/pb_glossary] structures have much more variable compositions. [pb_glossary id=\"2898\"]Reefs[\/pb_glossary] have a big impact on [pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"2679\"]deposition[\/pb_glossary] in [pb_glossary id=\"2900\"]lagoon[\/pb_glossary] environments since they are natural storm breaks, wave and storm buffers, which allows fine grains to settle and accumulate.\n\n[caption id=\"attachment_3113\" align=\"alignright\" width=\"378\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf.jpg\"><img class=\"wp-image-416\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-300x189.jpg\" alt=\"The map shows locations.\" width=\"378\" height=\"238\"><\/a> Seamounts and guyots in the North Pacific.[\/caption]\n\n[pb_glossary id=\"2898\"]Reefs[\/pb_glossary] are found around shorelines and islands; coral [pb_glossary id=\"2898\"]reefs[\/pb_glossary] are particularly common in tropical locations. [pb_glossary id=\"2898\"]Reefs[\/pb_glossary] are also found around features known as <strong>[pb_glossary id=\"2899\"]seamounts[\/pb_glossary]<\/strong>, which is the base of an ocean island left standing underwater after the upper part is eroded away by waves. Examples include the Emperor [pb_glossary id=\"2899\"]Seamounts[\/pb_glossary], formed millions of years ago over the Hawaiian [pb_glossary id=\"2638\"]Hotspot[\/pb_glossary]. [pb_glossary id=\"2898\"]Reefs[\/pb_glossary] live and grow along the upper edge of these flat-topped [pb_glossary id=\"2899\"]seamounts[\/pb_glossary]. If the [pb_glossary id=\"2898\"]reef[\/pb_glossary] builds up above sea level and completely encircles the top of the [pb_glossary id=\"2899\"]seamount[\/pb_glossary], it is called a coral-ringed atoll. If the [pb_glossary id=\"2898\"]reef[\/pb_glossary] is submerged, due to [pb_glossary id=\"2677\"]erosion[\/pb_glossary], [pb_glossary id=\"1464\"]subsidence[\/pb_glossary], or sea level rise, the [pb_glossary id=\"2899\"]seamount[\/pb_glossary]-[pb_glossary id=\"2898\"]reef[\/pb_glossary] structure is called a guyot.\n<h4><span style=\"font-weight: 400\">Lagoon<\/span><\/h4>\n[caption id=\"attachment_3116\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/LaggonKara_bogaz_gol.jpg\"><img class=\"wp-image-417 size-medium\" title=\"Public domain, by NASA\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/LaggonKara_bogaz_gol-300x300.jpg\" alt=\"The lagoon is just inside the coastline.\" width=\"300\" height=\"300\"><\/a> Kara-Bogaz Gol lagoon, Turkmenistan.[\/caption]\n\n<strong>[pb_glossary id=\"2900\"]Lagoons[\/pb_glossary]<\/strong> are small bodies of seawater located inland from the [pb_glossary id=\"3195\"]shore[\/pb_glossary] or isolated by another geographic feature, such as a [pb_glossary id=\"2898\"]reef[\/pb_glossary] or [pb_glossary id=\"3218\"]barrier island[\/pb_glossary]. Because they are protected from the action of tides, currents, and waves, [pb_glossary id=\"2900\"]lagoon[\/pb_glossary] environments typically have very fine grained [pb_glossary id=\"2678\"]sediments[\/pb_glossary]. [pb_glossary id=\"2900\"]Lagoons[\/pb_glossary], as well as [pb_glossary id=\"3219\"]estuaries[\/pb_glossary], are ecosystems with high biological productivity. Rocks from these environments often includes [pb_glossary id=\"2873\"]bioturbation[\/pb_glossary] marks or [pb_glossary id=\"2856\"]coal[\/pb_glossary] deposits. Around [pb_glossary id=\"2900\"]lagoons[\/pb_glossary] where evaporation exceeds water inflow, salt flats, also known as sabkhas, and sand [pb_glossary id=\"2869\"]dune[\/pb_glossary] fields may develop at or above the high [pb_glossary id=\"2428\"]tide[\/pb_glossary] line.\n<h4><span style=\"font-weight: 400\">Deltas<\/span><\/h4>\n[caption id=\"attachment_3118\" align=\"aligncenter\" width=\"496\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/NileDelta-EO.jpg\"><img class=\"size-full wp-image-418\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/NileDelta-EO.jpg\" alt=\"05.5_NileDelta-EO\" width=\"496\" height=\"565\"><\/a> The Nile delta, in Egypt.[\/caption]\n\n[caption id=\"attachment_3120\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Mississippi-birdfoot-delta.jpg\"><img class=\"wp-image-419 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-300x300.jpg\" alt=\"Birdfoot river-dominated delta of the Mississippi River\" width=\"300\" height=\"300\"><\/a> Birdfoot river-dominated delta of the Mississippi River[\/caption]\n\n<strong>Deltas<\/strong> form where [pb_glossary id=\"3134\"]rivers[\/pb_glossary] enter lakes or oceans and are of three basic shapes: [pb_glossary id=\"3134\"]river[\/pb_glossary]-dominated deltas, wave-dominated deltas, and [pb_glossary id=\"2428\"]tide[\/pb_glossary]-dominated deltas. The name [pb_glossary id=\"2901\"]delta[\/pb_glossary] comes from the Greek letter \u0394 ([pb_glossary id=\"2901\"]delta[\/pb_glossary], uppercase), which resembles the triangular shape of the Nile [pb_glossary id=\"3134\"]River[\/pb_glossary] [pb_glossary id=\"2901\"]delta[\/pb_glossary]. The velocity of water flow is dependent on riverbed slope or [pb_glossary id=\"3135\"]gradient[\/pb_glossary], which becomes shallower as the [pb_glossary id=\"3134\"]river[\/pb_glossary] descends from the mountains. At the point where a [pb_glossary id=\"3134\"]river[\/pb_glossary] enters an ocean or lake, its slope angle drops to zero degrees (0\u00b0). The flow velocity quickly drops as well, and [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is deposited, from coarse clasts, to fine sand, and mud to form the [pb_glossary id=\"2901\"]delta[\/pb_glossary]. As one part of the [pb_glossary id=\"2901\"]delta[\/pb_glossary] becomes overwhelmed by [pb_glossary id=\"2678\"]sediment[\/pb_glossary], the slow-moving flow gets diverted back and forth, over and over, and forms a spread out network of smaller distributary channels.\n\n[caption id=\"attachment_3121\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ganges-tide-delta.jpg\"><img class=\"wp-image-420 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta-300x296.jpg\" alt=\"Tidal delta of the Ganges River.\" width=\"300\" height=\"296\"><\/a> Tidal delta of the Ganges River.[\/caption]\n\nDeltas are organized by the dominant process that controls their shape: [pb_glossary id=\"2428\"]tide[\/pb_glossary]-dominated, wave-dominated, or [pb_glossary id=\"3134\"]river[\/pb_glossary]-dominated. Wave-dominated deltas generally have smooth coastlines and beach-ridges on the land that represent previous shorelines. The Nile [pb_glossary id=\"3134\"]River[\/pb_glossary] [pb_glossary id=\"2901\"]delta[\/pb_glossary] is a wave-dominated type. (see figure).\n\nThe Mississippi [pb_glossary id=\"3134\"]River[\/pb_glossary] [pb_glossary id=\"2901\"]delta[\/pb_glossary] is a [pb_glossary id=\"3134\"]river[\/pb_glossary]-dominated [pb_glossary id=\"2901\"]delta[\/pb_glossary]. shaped by levees along the [pb_glossary id=\"3134\"]river[\/pb_glossary] and its distributaries that confine the flow forming a shape called a birdfoot [pb_glossary id=\"2901\"]delta[\/pb_glossary]. Other times the tides or the waves can be a bigger factor, and can reshape the [pb_glossary id=\"2901\"]delta[\/pb_glossary] in various ways.\n\nA [pb_glossary id=\"2428\"]tide[\/pb_glossary]-dominated [pb_glossary id=\"2901\"]delta[\/pb_glossary] is dominated by tidal currents. During flood stages when [pb_glossary id=\"3134\"]rivers[\/pb_glossary] have lots of water available, it develops distributaries that are separated by sand bars and sand ridges. The tidal [pb_glossary id=\"2901\"]delta[\/pb_glossary] of the Ganges [pb_glossary id=\"3134\"]River[\/pb_glossary] is the largest [pb_glossary id=\"3134\"]delta[\/pb_glossary] in the world.\n<h3><b>5.5.3. Terrestrial<\/b><\/h3>\n<strong>[pb_glossary id=\"2902\"]Terrestrial[\/pb_glossary] [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary]<\/strong> are diverse. Water is a major factor in these environments, in liquid or frozen states, or even when it is lacking (arid conditions).\n<h4><span style=\"font-weight: 400\">Fluvial<\/span><\/h4>\n[caption id=\"attachment_3124\" align=\"alignright\" width=\"450\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MeanderingRio-cauto-cuba.jpg\"><img class=\"wp-image-421\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba.jpg\" alt=\"The river wiggles back and forth.\" width=\"450\" height=\"338\"><\/a> The Cauto River in Cuba. Note the sinuosity in the river, which is meandering.[\/caption]\n\n<strong>[pb_glossary id=\"2903\"]Fluvial[\/pb_glossary]<\/strong> ([pb_glossary id=\"3134\"]river[\/pb_glossary]) systems are formed by water flowing in channels over the land. They generally come in two main varieties: [pb_glossary id=\"3153\"]meandering[\/pb_glossary] or [pb_glossary id=\"3152\"]braided[\/pb_glossary]. In [pb_glossary id=\"3153\"]meandering[\/pb_glossary] [pb_glossary id=\"3134\"]streams[\/pb_glossary], the flow carries [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains via a single channel that wanders back and forth across the [pb_glossary id=\"3147\"]floodplain[\/pb_glossary]. The [pb_glossary id=\"3147\"]floodplain[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] away from the channel is mostly fine grained material that only gets deposited during floods.\n\n[caption id=\"attachment_3126\" align=\"alignright\" width=\"443\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/BraidedWaimakariri.jpg\"><img class=\"wp-image-422\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-300x225.jpg\" alt=\"The river has many inter-braided channels.\" width=\"443\" height=\"332\"><\/a> The braided Waimakariri river in New Zealand.[\/caption]\n\n[pb_glossary id=\"3152\"]Braided[\/pb_glossary] [pb_glossary id=\"2903\"]fluvial[\/pb_glossary] systems generally contain coarser [pb_glossary id=\"2678\"]sediment[\/pb_glossary] grains, and form a complicated series of intertwined channels that flow around gravel and sand bars (<a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/11-water\/\">see Chapter 11, Water<\/a>).\n<h4><span style=\"font-weight: 400\">Alluvial<\/span><\/h4>\n[caption id=\"attachment_3129\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/AlluvialPlain.jpg\"><img class=\"wp-image-423 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/AlluvialPlain-300x200.jpg\" alt=\"This broad valley in the desert has alluvial deposition.\" width=\"300\" height=\"200\"><\/a> An alluvial fan spreads out into a broad alluvial plain. From Red Rock Canyon State Park, California.[\/caption]\n\nA distinctive characteristic of <strong>[pb_glossary id=\"2904\"]alluvial[\/pb_glossary]<\/strong> systems is the intermittent flow of water. [pb_glossary id=\"2904\"]Alluvial[\/pb_glossary] deposits are common in arid places with little [pb_glossary id=\"1203\"]soil[\/pb_glossary] development. Lithified [pb_glossary id=\"2904\"]alluvial[\/pb_glossary] [pb_glossary id=\"2858\"]beds[\/pb_glossary] are the primary [pb_glossary id=\"1461\"]basin[\/pb_glossary]-filling rock found throughout the [pb_glossary id=\"2462\"]Basin and Range[\/pb_glossary] region of the western United States. The most distinctive [pb_glossary id=\"2904\"]alluvial[\/pb_glossary] sedimentary deposit is the [pb_glossary id=\"2904\"]alluvial[\/pb_glossary] fan, a large cone of [pb_glossary id=\"2678\"]sediment[\/pb_glossary] formed by [pb_glossary id=\"3134\"]streams[\/pb_glossary] flowing out of dry mountain valleys into a wider and more open dry area. [pb_glossary id=\"2904\"]Alluvial[\/pb_glossary] [pb_glossary id=\"2678\"]sediments[\/pb_glossary] are typically poorly sorted and coarse grained, and often found near [pb_glossary id=\"2906\"]playa[\/pb_glossary] lakes or [pb_glossary id=\"2908\"]aeolian[\/pb_glossary] deposits (<a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/13-deserts\/\">see Chapter 13, Deserts<\/a>).\n<h4><span style=\"font-weight: 400\">Lacustrine<\/span><\/h4>\n[caption id=\"attachment_2479\" align=\"alignright\" width=\"417\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Crater_lake_oregon-1.jpg\"><img class=\"wp-image-45\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Crater_lake_oregon-1-300x200.jpg\" alt=\"The mountain has a large hole in the center that is filled with the lake.\" width=\"417\" height=\"278\"><\/a> Oregon's Crater Lake was formed about 7700 years ago after the eruption of Mount Mazama.[\/caption]\n\nLake systems and deposits, called <strong>[pb_glossary id=\"2905\"]lacustrine[\/pb_glossary]<\/strong>, form via processes somewhat similar to [pb_glossary id=\"2883\"]marine[\/pb_glossary] deposits, but on a much smaller scale. [pb_glossary id=\"2905\"]Lacustrine[\/pb_glossary] deposits are found in lakes in a wide variety of locations. Lake Baikal in southeast Siberia (Russia) is in a [pb_glossary id=\"2576\"]tectonic[\/pb_glossary] [pb_glossary id=\"1461\"]basin[\/pb_glossary]. Crater Lake (Oregon) sits in a [pb_glossary id=\"1181\"]volcanic[\/pb_glossary] [pb_glossary id=\"1188\"]caldera[\/pb_glossary]. The Great Lakes (northern United States) came from glacially carved and deposited [pb_glossary id=\"2678\"]sediment[\/pb_glossary]. Ancient Lake Bonneville (Utah) formed in a\u00a0 pluvial setting that during a [pb_glossary id=\"1710\"]climate[\/pb_glossary] that was relatively wetter and cooler than that of modern Utah. [pb_glossary id=\"3159\"]Oxbow[\/pb_glossary] lakes, named for their curved shape, originated in [pb_glossary id=\"2903\"]fluvial[\/pb_glossary] floodplains. [pb_glossary id=\"2905\"]Lacustrine[\/pb_glossary] [pb_glossary id=\"2678\"]sediment[\/pb_glossary] tends to be very fine grained and thinly laminated, with only minor contributions from wind-blown, current, and tidal deposits. When lakes dry out or evaporation outpaces [pb_glossary id=\"2707\"]precipitation[\/pb_glossary], [pb_glossary id=\"2906\"]playas[\/pb_glossary] form. <strong>[pb_glossary id=\"2906\"]Playa[\/pb_glossary]<\/strong> deposits resemble those of normal lake deposits but contain more [pb_glossary id=\"2842\"]evaporite[\/pb_glossary] [pb_glossary id=\"2687\"]minerals[\/pb_glossary]. Certain [pb_glossary id=\"2897\"]tidal flats[\/pb_glossary] can have [pb_glossary id=\"2906\"]playa[\/pb_glossary]-type deposits as well.\n<h4><span style=\"font-weight: 400\">Paludal<\/span><\/h4>\n<strong>[pb_glossary id=\"2907\"]Paludal[\/pb_glossary]<\/strong> systems include bogs, marshes, swamps, or other wetlands, and usually contain lots of organic matter. [pb_glossary id=\"2907\"]Paludal[\/pb_glossary] systems typically develop in coastal environments, but are common occur in humid, low-lying, low-[pb_glossary id=\"3372\"]latitude[\/pb_glossary], warm zones with large volumes of flowing water. A characteristic [pb_glossary id=\"2907\"]paludal[\/pb_glossary] deposit is a peat bog, a deposit rich in organic matter that can be converted into [pb_glossary id=\"2856\"]coal[\/pb_glossary] when lithified. [pb_glossary id=\"2907\"]Paludal[\/pb_glossary] environments may be associated with tidal, deltaic, [pb_glossary id=\"2905\"]lacustrine[\/pb_glossary], and\/or [pb_glossary id=\"2903\"]fluvial[\/pb_glossary] [pb_glossary id=\"2679\"]deposition[\/pb_glossary].\n<h4><span style=\"font-weight: 400\">Aeolian<\/span><\/h4>\n[caption id=\"attachment_3132\" align=\"alignleft\" width=\"246\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/DuneTypes.jpg\"><img class=\"wp-image-424 size-medium\" title=\"US National Park Service, public domain\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/DuneTypes-246x300.jpg\" alt=\"The chart has the way dunes are made and four dune types.\" width=\"246\" height=\"300\"><\/a> Formation and types of dunes.[\/caption]\n\n<strong>[pb_glossary id=\"2908\"]Aeolian[\/pb_glossary]<\/strong>, sometimes spelled [pb_glossary id=\"2908\"]eolian[\/pb_glossary] or \u0153olian, are deposits of windblown [pb_glossary id=\"2678\"]sediments[\/pb_glossary]. Since wind has a much lower carrying capacity than water, [pb_glossary id=\"2908\"]aeolian[\/pb_glossary] deposits typically consists of clast sizes from fine dust to sand. Fine silt and clay can cross very long distances, even entire oceans suspended in air.\n\nWith sufficient [pb_glossary id=\"2678\"]sediment[\/pb_glossary] influx, [pb_glossary id=\"2908\"]aeolian[\/pb_glossary] systems can potentially form large [pb_glossary id=\"2869\"]dunes[\/pb_glossary] in dry or wet conditions.\u00a0 The figure shows [pb_glossary id=\"2869\"]dune[\/pb_glossary] features and various types. British geologist Ralph A. Bagnold (1896-1990) considered only Barchan and linear Seif [pb_glossary id=\"2869\"]dunes[\/pb_glossary] as the only true [pb_glossary id=\"2869\"]dune[\/pb_glossary] forms. Other scientists recognize transverse, star, parabolic, and [pb_glossary id=\"2459\"]linear dune[\/pb_glossary] types. Parabolic and [pb_glossary id=\"2459\"]linear dunes[\/pb_glossary] grow from sand anchored by plants and are common in coastal areas.\n\n[caption id=\"attachment_3135\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Loess-Plateau-in-China.jpg\"><img class=\"wp-image-425 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-300x199.jpg\" alt=\"Loess Plateau in China. The loess is so highly compacted that buildings and homes have been carved in it.\" width=\"300\" height=\"199\"><\/a> Loess Plateau in China. The loess is so highly compacted that buildings and homes have been carved in it.[\/caption]\n\nCompacted layers of wind-blown [pb_glossary id=\"2678\"]sediment[\/pb_glossary] is known as <strong>[pb_glossary id=\"2909\"]loess[\/pb_glossary]<\/strong>. [pb_glossary id=\"2909\"]Loess[\/pb_glossary] commonly starts as finely ground up rock flour created by [pb_glossary id=\"2464\"]glaciers[\/pb_glossary]. Such deposits cover thousands of square miles in the Midwestern United States. [pb_glossary id=\"2909\"]Loess[\/pb_glossary] may also form in desert regions (<a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/13-deserts\/\">see Chapter 13<\/a>). Silt for the [pb_glossary id=\"2909\"]Loess[\/pb_glossary] Plateau in China came from the Gobi Desert in China and Mongolia.\n<h4><span style=\"font-weight: 400\">Glacial<\/span><\/h4>\n[caption id=\"attachment_3137\" align=\"alignright\" width=\"377\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/GlacierAthabaskaSediments.jpg\"><img class=\"wp-image-426\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-300x199.jpg\" alt=\"Large boulders and smaller sand are seen together.\" width=\"377\" height=\"250\"><\/a> Wide range of sediments near Athabaska Glacier, Jasper National Park, Alberta, Canada.[\/caption]\n\n<strong>[pb_glossary id=\"2910\"]Glacial[\/pb_glossary]<\/strong> sedimentation is very diverse, and generally consists of the most poorly-sorted [pb_glossary id=\"2678\"]sediment[\/pb_glossary] deposits found in nature. The main clast type is called [pb_glossary id=\"2911\"]diamictite[\/pb_glossary], which literally means two sizes, referring to the unsorted mix of large and small rock fragments found in [pb_glossary id=\"2910\"]glacial[\/pb_glossary] deposits. Many [pb_glossary id=\"2910\"]glacial[\/pb_glossary] [pb_glossary id=\"2912\"]tills[\/pb_glossary], glacially derived [pb_glossary id=\"2911\"]diamictites[\/pb_glossary], include very finely-pulverized rock flour along with giant [pb_glossary id=\"1691\"]erratic[\/pb_glossary] boulders. The surfaces of larger clasts typically have striations from the rubbing, scraping, and polishing of surfaces by abrasion during the movement of [pb_glossary id=\"2910\"]glacial[\/pb_glossary] ice. [pb_glossary id=\"2910\"]Glacial[\/pb_glossary] systems are so large and produce so much [pb_glossary id=\"2678\"]sediment[\/pb_glossary], they frequently create multiple, individualized [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary], such as [pb_glossary id=\"2903\"]fluvial[\/pb_glossary], deltaic, [pb_glossary id=\"2905\"]lacustrine[\/pb_glossary], pluvial, [pb_glossary id=\"2904\"]alluvial[\/pb_glossary], and\/or [pb_glossary id=\"2908\"]aeolian[\/pb_glossary] (<a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/14-glaciers\/\">see Chapter 14, Glaciers<\/a>).\n<h3><span style=\"font-weight: 400\">5.5.4. Facies<\/span><\/h3>\nIn addition to [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2831\"]composition[\/pb_glossary] and [pb_glossary id=\"2682\"]lithification[\/pb_glossary] process, geologists also classify [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] by its depositional characteristics, collectively called [pb_glossary id=\"2913\"]facies[\/pb_glossary] or lithofacies. Sedimentary [pb_glossary id=\"2913\"]facies[\/pb_glossary] consist of physical, chemical, and\/or biological properties, including relative changes in these properties in adjacent [pb_glossary id=\"2858\"]beds[\/pb_glossary] of the same layer or geological age. Geologists analyze [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary] [pb_glossary id=\"2913\"]facies[\/pb_glossary] to interpret the original [pb_glossary id=\"2679\"]deposition[\/pb_glossary] environment, as well as disruptive geological events that may have occurred after the rock layers were established.\n\nIt boggles the imagination to think of all the sedimentary [pb_glossary id=\"2679\"]deposition[\/pb_glossary] environments working next to each other, at the same time, in any particular region on Earth. The resulting [pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"2858\"]beds[\/pb_glossary] develop characteristics reflecting contemporaneous conditions at the time of [pb_glossary id=\"2679\"]deposition[\/pb_glossary], which later may become preserved into the rock record. For example in the Grand Canyon, rock [pb_glossary id=\"2857\"]strata[\/pb_glossary] of the same geologic age includes many different [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary]: beach sand, [pb_glossary id=\"2897\"]tidal flat[\/pb_glossary] silt, [pb_glossary id=\"3196\"]offshore[\/pb_glossary] mud, and farther [pb_glossary id=\"3196\"]offshore[\/pb_glossary] [pb_glossary id=\"2851\"]limestone[\/pb_glossary]. In other words, each sedimentary or [pb_glossary id=\"2859\"]stratigraphic[\/pb_glossary] [pb_glossary id=\"2913\"]facies[\/pb_glossary] presents recognizable characteristics that reflect specific, and different, [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary] that were present at the same time.\n\n[pb_glossary id=\"2913\"]Facies[\/pb_glossary] may also reflect depositional changes in the same location over time. During [pb_glossary id=\"2192\"]periods[\/pb_glossary] of rising sea level, called [pb_glossary id=\"2883\"]marine[\/pb_glossary] [pb_glossary id=\"2894\"]transgression[\/pb_glossary], the [pb_glossary id=\"3195\"]shoreline[\/pb_glossary] moves inland as seawater covers what was originally dry land and creates new [pb_glossary id=\"3196\"]offshore[\/pb_glossary] [pb_glossary id=\"2882\"]depositional environments[\/pb_glossary]. When these [pb_glossary id=\"2678\"]sediment[\/pb_glossary] [pb_glossary id=\"2858\"]beds[\/pb_glossary] turn into [pb_glossary id=\"2683\"]sedimentary rock[\/pb_glossary], the vertical [pb_glossary id=\"2859\"]stratigraphy[\/pb_glossary] sequence reveals beach lithofacies buried by [pb_glossary id=\"3196\"]offshore[\/pb_glossary] lithofacies.\n\nBiological [pb_glossary id=\"2913\"]facies[\/pb_glossary] are remnants ([pb_glossary id=\"2856\"]coal[\/pb_glossary], diatomaceous earth) or evidence ([pb_glossary id=\"2176\"]fossils[\/pb_glossary]) of living organisms. [pb_glossary id=\"2189\"]Index fossils[\/pb_glossary], fossilized life forms specific to a particular environment and\/or geologic time [pb_glossary id=\"2192\"]period[\/pb_glossary], are an example of biological [pb_glossary id=\"2913\"]facies[\/pb_glossary]. The horizontal assemblage and vertical distribution of [pb_glossary id=\"2176\"]fossils[\/pb_glossary] are particularly useful for studying species evolution because [pb_glossary id=\"2894\"]transgression[\/pb_glossary], [pb_glossary id=\"2679\"]deposition[\/pb_glossary], burial, and [pb_glossary id=\"2680\"]compaction[\/pb_glossary] processes happen over a considerable geologic time range.\n\n[pb_glossary id=\"2176\"]Fossil[\/pb_glossary] assemblages that show evolutionary changes greatly enhance our interpretation of Earth\u2019s ancient history by illustrating the [pb_glossary id=\"2184\"]correlation[\/pb_glossary] between [pb_glossary id=\"2859\"]stratigraphic[\/pb_glossary] sequence and geologic time scale. During the Middle [pb_glossary id=\"2224\"]Cambrian[\/pb_glossary] [pb_glossary id=\"2192\"]period[\/pb_glossary] (see Chapter 7, Geologic Time), regions around the Grand Canyon experienced [pb_glossary id=\"2883\"]marine[\/pb_glossary] [pb_glossary id=\"2894\"]transgression[\/pb_glossary] in a southeasterly direction (relative to current maps). This shift of the [pb_glossary id=\"3195\"]shoreline[\/pb_glossary] is reflected in the Tapeats [pb_glossary id=\"2834\"]Sandstone[\/pb_glossary] beach [pb_glossary id=\"2913\"]facies[\/pb_glossary], Bright Angle [pb_glossary id=\"2839\"]Shale[\/pb_glossary] near-[pb_glossary id=\"3196\"]offshore[\/pb_glossary] mud [pb_glossary id=\"2913\"]facies[\/pb_glossary], and Muav [pb_glossary id=\"2851\"]Limestone[\/pb_glossary] far-[pb_glossary id=\"3196\"]offshore[\/pb_glossary] [pb_glossary id=\"2913\"]facies[\/pb_glossary]. [pb_glossary id=\"2883\"]Marine[\/pb_glossary] organisms had plenty of time to evolve and adapt to their slowly changing environment; these changes are reflected in the biological [pb_glossary id=\"2913\"]facies[\/pb_glossary], which show older life forms in the western regions of the canyon and younger life forms in the east.\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"35\"]\n\n[caption id=\"attachment_3995\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.5-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-427\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 5.5 via this QR Code.[\/caption]\n<h2>Summary<\/h2>\nSedimentary rocks are grouped into two main categories: [pb_glossary id=\"2825\"]clastic[\/pb_glossary] ([pb_glossary id=\"3363\"]detrital[\/pb_glossary]) and chemical. [pb_glossary id=\"2825\"]Clastic[\/pb_glossary] ([pb_glossary id=\"3363\"]detrital[\/pb_glossary]) rocks are made of [pb_glossary id=\"2687\"]mineral[\/pb_glossary] clasts or [pb_glossary id=\"2678\"]sediment[\/pb_glossary] that lithifies into solid material. [pb_glossary id=\"2678\"]Sediment[\/pb_glossary] is produced by the mechanical or [pb_glossary id=\"2812\"]chemical weathering[\/pb_glossary] of [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] and transported away from the source via [pb_glossary id=\"2677\"]erosion[\/pb_glossary]. [pb_glossary id=\"2678\"]Sediment[\/pb_glossary] that is deposited, buried, compacted, and sometimes cemented becomes [pb_glossary id=\"2825\"]clastic[\/pb_glossary] rock. [pb_glossary id=\"2825\"]Clastic[\/pb_glossary] rocks are classified by [pb_glossary id=\"2828\"]grain size[\/pb_glossary]; for example [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] is made of sand-sized particles. [pb_glossary id=\"2826\"]Chemical sedimentary[\/pb_glossary] rocks comes from [pb_glossary id=\"2687\"]minerals[\/pb_glossary] [pb_glossary id=\"2707\"]precipitated[\/pb_glossary] out an aqueous [pb_glossary id=\"2705\"]solution[\/pb_glossary] and is classified according to [pb_glossary id=\"2687\"]mineral[\/pb_glossary] [pb_glossary id=\"2831\"]composition[\/pb_glossary]. The [pb_glossary id=\"2826\"]chemical sedimentary[\/pb_glossary] rock [pb_glossary id=\"2851\"]limestone[\/pb_glossary] is made of calcium [pb_glossary id=\"1917\"]carbonate[\/pb_glossary]. Sedimentary structures have textures and shapes that give insight on depositional histories. [pb_glossary id=\"2882\"]Depositional environments[\/pb_glossary] depend mainly on fluid transport systems and encompass a wide variety of underwater and above ground conditions. Geologists analyze depositional conditions, sedimentary structures, and rock records to interpret the paleogeographic history of a region.\n<h3>Take this quiz to check your comprehension of this Chapter.<\/h3>\n[h5p id=\"36\"]\n\n[caption id=\"attachment_3994\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/Ch-5-Review-QR-Code.png\"><img class=\"size-thumbnail wp-image-428\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the review quiz for Chapter 5 via this QR Code.[\/caption]\n<h2><b>References<\/b><\/h2>\n<div class=\"csl-bib-body\">\n<ol>\n \t<li class=\"csl-entry\">Affolter, M.D., 2004, On the nature of [pb_glossary id=\"1181\"]volcanic[\/pb_glossary] lithic fragments: Definition source and evolution:<\/li>\n \t<li class=\"csl-entry\">Ashley, G.M., 1990, Classification of large-scale subaqueous bedforms: a new look at an old problem-SEPM bedforms and [pb_glossary id=\"2857\"]bedding[\/pb_glossary] structures: J. [pb_glossary id=\"2678\"]Sediment[\/pb_glossary]. Res., v. 60, no. 1.<\/li>\n \t<li class=\"csl-entry\">Ayrton, H., 1910, The origin and growth of [pb_glossary id=\"2868\"]ripple[\/pb_glossary]-mark: Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, v. 84, no. 571, p. 285\u2013310.<\/li>\n \t<li class=\"csl-entry\">Bagnold, R.A., 1941, The physics of blown sand and desert [pb_glossary id=\"2869\"]dunes[\/pb_glossary]: Methum, London, UK, p. 265.<\/li>\n \t<li class=\"csl-entry\">Blatt, H., Middleton, G.V., and Murray, R., 1980, Origin of Sedimentary Rocks: Prentice-Hall, Inc., Englewood Cliffs, New Jersey, USA.<\/li>\n \t<li class=\"csl-entry\">[pb_glossary id=\"2863\"]Bouma[\/pb_glossary], A.H., Kuenen, P.H., and Shepard, F.P., 1962, Sedimentology of some flysch deposits: a graphic approach to [pb_glossary id=\"2913\"]facies[\/pb_glossary] interpretation: Elsevier Amsterdam.<\/li>\n \t<li class=\"csl-entry\">Cant, D.J., 1982, [pb_glossary id=\"2903\"]Fluvial[\/pb_glossary] [pb_glossary id=\"2913\"]facies[\/pb_glossary] models and their application:<\/li>\n \t<li class=\"csl-entry\">Dickinson, W.R., and Suczek, C.A., 1979, [pb_glossary id=\"2576\"]Plate tectonics[\/pb_glossary] and [pb_glossary id=\"2834\"]sandstone[\/pb_glossary] compositions: AAPG Bull., v. 63, no. 12, p. 2164\u20132182.<\/li>\n \t<li class=\"csl-entry\">Dunham, R.J., 1962, Classification of [pb_glossary id=\"1917\"]carbonate[\/pb_glossary] rocks according to depositional textures:<\/li>\n \t<li class=\"csl-entry\">Eisma, D., 1998, Intertidal deposits: [pb_glossary id=\"3134\"]River[\/pb_glossary] mouths, [pb_glossary id=\"2897\"]tidal flats[\/pb_glossary], and coastal [pb_glossary id=\"2900\"]lagoons[\/pb_glossary]: CRC Marine Science, Taylor &amp; Francis, CRC Marine Science.<\/li>\n \t<li class=\"csl-entry\">Folk, R.L., 1974, Petrography of sedimentary rocks: Univ. Texas, Hemphill, Austin, Tex, v. 182.<\/li>\n \t<li class=\"csl-entry\">Goldich, S.S., 1938, A study in rock-[pb_glossary id=\"2676\"]weathering[\/pb_glossary]: J. Geol., v. 46, no. 1, p. 17\u201358.<\/li>\n \t<li class=\"csl-entry\">Hubert, J.F., 1962, A [pb_glossary id=\"2175\"]zircon[\/pb_glossary]-tourmaline-rutile maturity index and the interdependence of the [pb_glossary id=\"2831\"]composition[\/pb_glossary] of heavy [pb_glossary id=\"2687\"]mineral[\/pb_glossary] assemblages with the gross [pb_glossary id=\"2831\"]composition[\/pb_glossary] and [pb_glossary id=\"2919\"]texture[\/pb_glossary] of [pb_glossary id=\"2834\"]sandstones[\/pb_glossary]: J. Sediment. Res., v. 32, no. 3.<\/li>\n \t<li class=\"csl-entry\">Johnson, C.L., Franseen, E.K., and Goldstein, R.H., 2005, The effects of sea level and palaeotopography on lithofacies distribution and geometries in heterozoan [pb_glossary id=\"1917\"]carbonates[\/pb_glossary], south-eastern Spain: Sedimentology, v. 52, no. 3, p. 513\u2013536., doi: <a href=\"https:\/\/doi.org\/10.1111\/j.1365-3091.2005.00708.x\">10.1111\/j.1365-3091.2005.00708.x<\/a>.<\/li>\n \t<li class=\"csl-entry\">Kar\u00e1tson, D., Sztan\u00f3, O., and Telbisz, T., 2002, Preferred clast orientation in volcaniclastic mass-flow deposits: application of a new photo-statistical method: J. [pb_glossary id=\"2678\"]Sediment[\/pb_glossary]. Res., v. 72, no. 6, p. 823\u2013835.<\/li>\n \t<li class=\"csl-entry\">Klappa, C.F., 1980, Rhizoliths in [pb_glossary id=\"2902\"]terrestrial[\/pb_glossary] [pb_glossary id=\"1917\"]carbonates[\/pb_glossary]: classification, recognition, genesis and significance: Sedimentology, v. 27, no. 6, p. 613\u2013629.<\/li>\n \t<li class=\"csl-entry\">Longman, M.W., 1981, A process approach to recognizing [pb_glossary id=\"2913\"]facies[\/pb_glossary] of [pb_glossary id=\"2898\"]reef[\/pb_glossary] complexes:<\/li>\n \t<li class=\"csl-entry\">Mckee, E.D., and Weir, G.W., 1953, Terminology for stratification and cross-stratification in sedimentary rocks: Geol. Soc. Am. Bull., v. 64, no. 4, p. 381\u2013390.<\/li>\n \t<li class=\"csl-entry\">Metz, R., 1981, Why not [pb_glossary id=\"2878\"]raindrop impressions[\/pb_glossary]? J. [pb_glossary id=\"2678\"]Sediment[\/pb_glossary]. Res., v. 51, no. 1.<\/li>\n \t<li class=\"csl-entry\">Nichols, M.M., Biggs, R.B., and Davies, R.A.Jr., 1985, [pb_glossary id=\"3219\"]Estuaries[\/pb_glossary], <i>in<\/i> Coastal Sedimentary Environments: Springer-Verlag: New York, p. 77\u2013173.<\/li>\n \t<li class=\"csl-entry\">Normark, W.R., 1978, Fan valleys, channels, and depositional lobes on modern submarine fans: characters for recognition of sandy [pb_glossary id=\"2888\"]turbidite[\/pb_glossary] environments: AAPG Bull., v. 62, no. 6, p. 912\u2013931.<\/li>\n \t<li class=\"csl-entry\">Pettijohn, F.J., and Potter, P.E., 2012, Atlas and glossary of primary sedimentary structures:<\/li>\n \t<li class=\"csl-entry\">Plummer, P.S., and Gostin, V.A., 1981, Shrinkage cracks: desiccation or synaeresis? J. [pb_glossary id=\"2678\"]Sediment[\/pb_glossary]. Res., v. 51, no. 4.<\/li>\n \t<li class=\"csl-entry\">Reinson, G.E., 1984, Barrier-island and associated strand-plain systems, <i>in<\/i> Walker, R.G., editor, [pb_glossary id=\"2913\"]Facies[\/pb_glossary] Models: Geoscience Canada Reprint Series 1, p. 119\u2013140.<\/li>\n \t<li class=\"csl-entry\">Stanistreet, I.G., and McCarthy, T.S., 1993, The Okavango Fan and the classification of subaerial fan systems: [pb_glossary id=\"2678\"]Sediment[\/pb_glossary]. Geol., v. 85, no. 1, p. 115\u2013133.<\/li>\n \t<li class=\"csl-entry\">Stow, D.A.V., Faug\u00e8res, J.-C., Viana, A., and Gonthier, E., 1998, [pb_glossary id=\"2176\"]Fossil[\/pb_glossary] contourites: a critical review: [pb_glossary id=\"2678\"]Sediment[\/pb_glossary]. Geol., v. 115, no. 1\u20134, p. 3\u201331.<\/li>\n \t<li class=\"csl-entry\">Stow, D.A.V., and Piper, D.J.W., 1984, Deep-water fine-grained [pb_glossary id=\"2678\"]sediments[\/pb_glossary]: [pb_glossary id=\"2913\"]facies[\/pb_glossary] models: Geological Society, London, Special Publications, v. 15, no. 1, p. 611\u2013646.<\/li>\n \t<li class=\"csl-entry\">Udden, J.A., 1914, Mechanical [pb_glossary id=\"2831\"]composition[\/pb_glossary] of [pb_glossary id=\"2825\"]clastic[\/pb_glossary] [pb_glossary id=\"2678\"]sediments[\/pb_glossary]: Geol. Soc. Am. Bull., v. 25, no. 1, p. 655\u2013744.<\/li>\n \t<li class=\"csl-entry\">Wentworth, C.K., 1922, A scale of [pb_glossary id=\"2938\"]grade[\/pb_glossary] and class terms for [pb_glossary id=\"2825\"]clastic[\/pb_glossary] [pb_glossary id=\"2678\"]sediments[\/pb_glossary]: J. Geol., v. 30, no. 5, p. 377\u2013392.<\/li>\n \t<li class=\"csl-entry\">Yin, D., Peakall, J., Parsons, D., Chen, Z., Averill, H.M., Wignall, P., and Best, J., 2016, [pb_glossary id=\"2865\"]Bedform[\/pb_glossary] genesis in [pb_glossary id=\"1971\"]bedrock[\/pb_glossary] substrates: Insights into formative processes from a new experimental approach and the importance of suspension-dominated abrasion: Geomorphology, v. 255, p. 26\u201338.<\/li>\n<\/ol>\n<\/div>\n<span style=\"font-weight: 400\">\u00a0<\/span>","rendered":"<figure id=\"attachment_3890\" aria-describedby=\"caption-attachment-3890\" style=\"width: 2560px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/NP3-scaled-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-332 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1.jpg\" alt=\"The rock has a large cliff.\" width=\"2560\" height=\"1920\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1.jpg 2560w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1-2048x1536.jpg 2048w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/12\/NP3-scaled-1-350x263.jpg 350w\" sizes=\"auto, (max-width: 2560px) 100vw, 2560px\" \/><\/a><figcaption id=\"caption-attachment-3890\" class=\"wp-caption-text\">Light illuminates the sedimentary rocks of Notch Peak, in the House Range of western Utah.<\/figcaption><\/figure>\n<h1>5 Weathering, Erosion, and Sedimentary Rocks<\/h1>\n<p><b>KEY CONCEPTS<\/b><\/p>\n<p><strong>By the end of this chapter, students will be able to:<\/strong><\/p>\n<ul>\n<li>Describe how water is an integral part of all <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2960\">formation<\/a><\/li>\n<li>Explain how chemical and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">mechanical weathering<\/a> turn <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a><\/li>\n<li>Differentiate the two main categories of sedimentary rocks : <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> rock formed from pieces of weathered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>; and chemical rock that precipitates out of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a> by organic or inorganic means<\/li>\n<li>Explain the importance of sedimentary structures and analysis of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a>, and how they provide insight into the Earth\u2019s history<\/li>\n<\/ul>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">Sedimentary rock<\/a> and the processes that create it, which include <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2682\">lithification<\/a>, are an integral part of understanding Earth Science. This is because the majority of the Earth\u2019s surface is made up of sedimentary rocks and their common predecessor, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a>. Even though sedimentary rocks can form in drastically different ways, their origin and creation have one thing in common, water.<\/p>\n<h2><span style=\"font-weight: 400\">5.1 The Unique Properties of Water<\/span><\/h2>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2757\" aria-describedby=\"caption-attachment-2757\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/H2O_2D_labelled.svg_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-145\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2021\/09\/H2O_2D_labelled.svg_-300x131.png\" alt=\"The hydrogen atoms are on one side, about 105\u00b0 apart.\" width=\"300\" height=\"131\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/09\/H2O_2D_labelled.svg_-300x131.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/09\/H2O_2D_labelled.svg_-768x336.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/09\/H2O_2D_labelled.svg_-65x28.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/09\/H2O_2D_labelled.svg_-225x98.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/09\/H2O_2D_labelled.svg_-350x153.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2021\/09\/H2O_2D_labelled.svg_.png 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2757\" class=\"wp-caption-text\">A model of a water molecule, showing the bonds between the hydrogen and oxygen.<\/figcaption><\/figure>\n<p>Water plays a role in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2960\">formation<\/a> of most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a>. It is one of the main agents involved in creating the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rock. It also is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> agent, producing the grains that become <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3363\">detrital<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a>. Several special properties make water an especially unique substance, and integral to the production of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a>.<\/p>\n<p>The water molecule consists of two hydrogen atoms covalently <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2703\">bonded<\/a> to one oxygen atom arranged in a specific and important geometry. The two hydrogen atoms are separated by an angle of about 105 degrees, and both are located to one side of the oxygen atom. This atomic arrangement, with the positively charged hydrogens on one side and negatively charged oxygen on the other side, gives the water molecule a property called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2690\"><strong>polarity<\/strong><\/a><\/strong>. Resembling a battery or a magnet, the molecule\u2019s positive-negative architecture leads to a whole suite of unique properties.<\/p>\n<figure id=\"attachment_2954\" aria-describedby=\"caption-attachment-2954\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/05.1_DewSpiderWeb.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-333\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/05.1_DewSpiderWeb-300x225.jpg\" alt=\"The water drops are sticking to a spider's web\" width=\"300\" height=\"225\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/05.1_DewSpiderWeb-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/05.1_DewSpiderWeb-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/05.1_DewSpiderWeb-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/05.1_DewSpiderWeb-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/05.1_DewSpiderWeb.jpg 639w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2954\" class=\"wp-caption-text\">Dew on a spider&#8217;s web.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2690\">Polarity<\/a> allows water molecules to stick to other substances. This is called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2693\">adhesion<\/a><\/strong>. Water is also attracted to itself, a property called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2692\">cohesion<\/a><\/strong>, which leads to water\u2019s most common form in the air, a droplet. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2692\">Cohesion<\/a> is responsible for creating surface <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1445\">tension<\/a>, which various insects use to walk on water by distributing their weight across the surface.<\/p>\n<figure id=\"attachment_2956\" aria-describedby=\"caption-attachment-2956\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3D_model_hydrogen_bonds_in_water.svg_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-334\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_-300x298.png\" alt=\"The positive side of the water molecule is attracted to the negative side of the water molecule\" width=\"300\" height=\"298\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_-300x298.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_-150x150.png 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_-768x762.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_-65x65.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_-225x223.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_-350x347.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/3D_model_hydrogen_bonds_in_water.svg_.png 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2956\" class=\"wp-caption-text\">Hydrogen bonding between water molecules.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The fact that water is attracted to itself leads to another important property, one that is extremely rare in the natural world\u2014the liquid form is denser than the solid form. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2690\">polarity<\/a> of water creates a special type of weak <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2703\">bonding<\/a> called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1202\">hydrogen bonds<\/a><\/strong>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1202\">Hydrogen bonds<\/a> allow the molecules in liquid water to sit close together. Water is densest at 4\u00b0C and is less dense above and below that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2689\">temperature<\/a>. \u00a0As water solidifies into ice, the molecules must move apart in order to fit into the crystal lattice, causing water to expand and become less dense as it freezes. Because of this, ice floats and water at 4<sup>o<\/sup>C sinks, which keeps the oceans liquid and prevents them from freezing solid from the bottom up. This unique property of water keeps Earth, the water planet, habitable.<\/p>\n<figure id=\"attachment_2958\" aria-describedby=\"caption-attachment-2958\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/NaH2O.svg_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-335\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-300x300.png\" alt=\"The negative part of the water molecules surrounds the positively-charged sodium ion.\" width=\"300\" height=\"300\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-300x300.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-1024x1024.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-150x150.png 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-768x768.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-65x65.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-225x225.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_-350x350.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NaH2O.svg_.png 1346w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2958\" class=\"wp-caption-text\">A sodium (Na) ion in solution.<\/figcaption><\/figure>\n<p>Even more critical for supporting life, water remains liquid over a very large range of temperatures, which is also a result of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2692\">cohesion<\/a>. Hydrogen <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2703\">bonding<\/a> allows liquid water can absorb high amounts of energy before turning into vapor or gas. The wide range across which water remains a liquid, 0\u00b0C-100\u00b0C (32\u00b0F-212\u00b0F), is rarely exhibited in other substances. Without this high boiling point, liquid water as we know it would be constricted to narrow <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2689\">temperature<\/a> zones on Earth, instead water is found from pole to pole. Further, water is the only substance that exists in all three phases, solid, liquid, and gas in Earth&#8217;s surface environments.<\/p>\n<p>Water is a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2691\">universal solvent<\/a><\/strong>, meaning it dissolves more substances than any other commonly found, naturally occurring liquid. The water molecules use <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2690\">polarity<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1202\">hydrogen bonds<\/a> to pry ions away from the crystal lattice. Water is such a powerful solvent, it can <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolve<\/a> even the strongest rocks and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> given enough time.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-31\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-31\" class=\"h5p-iframe\" data-content-id=\"31\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"5.1 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3999\" aria-describedby=\"caption-attachment-3999\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.1-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-336\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.1-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3999\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 5.1 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">5.2 Weathering and Erosion<\/span><\/h2>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">Bedrock<\/a><\/strong> refers to the solid rock that makes up the Earth\u2019s outer <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2580\">crust<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">Weathering<\/a> is a process that turns <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> into smaller particles, called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a><\/strong>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">Mechanical weathering<\/a> includes pressure expansion, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1207\">frost wedging<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1208\">root wedging<\/a>, and salt expansion. Chemical <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a><\/strong> includes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2813\">carbonic acid<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2814\">hydrolysis<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolution<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2818\">oxidation<\/a>.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">Erosion<\/a> is a mechanical process, usually driven by water, wind, gravity, or ice, which transports <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> (and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a>) from the place of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>. Liquid water is the main agent of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>. Gravity and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3110\">mass wasting<\/a> processes (see Chapter 10, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3110\">Mass Wasting<\/a>) move rocks and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> to new locations. Gravity and ice, in the form of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2464\">glaciers<\/a> (see Chapter 14, <a href=\"https:\/\/opengeology.org\/textbook\/14-glaciers\/\">Glaciers<\/a>), move large rock fragments as well as fine <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">Erosion<\/a> resistance is important in the creation of distinctive geological features. This is well-demonstrated in the cliffs of the Grand Canyon. The cliffs are made of rock left standing after less resistant materials have weathered and eroded away. Rocks with different levels of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> resistance also create the unique-looking features called hoodoos in Bryce Canyon National Park and Goblin Valley State Park in Utah.<\/p>\n<h3><b>5.2.1 Mechanical Weathering<\/b><\/h3>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">Mechanical weathering<\/a><\/strong> physically breaks <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> into smaller pieces. \u00a0The usual agents of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">mechanical weathering<\/a> are pressure, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2689\">temperature<\/a>, freezing\/thawing cycle of water, plant or animal activity, and salt evaporation.<\/p>\n<h4><span style=\"font-weight: 400\">Pressure Expansion<\/span><\/h4>\n<figure id=\"attachment_2962\" aria-describedby=\"caption-attachment-2962\" style=\"width: 447px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/GeologicalExfoliationOfGraniteRock.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-337\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock.jpg\" alt=\"Granite rock has a relatively thin layer that is peeling away\" width=\"447\" height=\"297\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock.jpg 1599w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock-300x199.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock-1024x680.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock-768x510.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock-1536x1020.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock-225x149.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GeologicalExfoliationOfGraniteRock-350x232.jpg 350w\" sizes=\"auto, (max-width: 447px) 100vw, 447px\" \/><\/a><figcaption id=\"caption-attachment-2962\" class=\"wp-caption-text\">The outer layer of this granite is fractured and eroding away, known as exfoliation<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">Bedrock<\/a> buried deep within the Earth is under high pressure and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2689\">temperature<\/a>. When uplift and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> brings <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> to the surface, its <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2689\">temperature<\/a> drops slowly, while its pressure drops immediately. The sudden pressure drop causes the rock to rapidly expand and crack; this is called pressure expansion. Sheeting or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1205\">exfoliation<\/a><\/strong> is when the rock surface spalls off in layers. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1206\">Spheroidal weathering<\/a><\/strong> is a type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1205\">exfoliation<\/a> that produces rounded features and is caused when <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">chemical weathering<\/a> moves along <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1934\">joints<\/a> in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Frost Wedging<\/span><\/h4>\n<figure id=\"attachment_2965\" aria-describedby=\"caption-attachment-2965\" style=\"width: 500px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Mechanical_weathering.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-338 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Mechanical_weathering.png\" alt=\"A crack in a rock gets progressively bigger as ice freezes, prying the crack open over time.\" width=\"500\" height=\"156\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mechanical_weathering.png 500w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mechanical_weathering-300x94.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mechanical_weathering-65x20.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mechanical_weathering-225x70.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mechanical_weathering-350x109.png 350w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><figcaption id=\"caption-attachment-2965\" class=\"wp-caption-text\">The process of frost wedging<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1207\">Frost wedging<\/a><\/strong>, also called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1207\">ice wedging<\/a>, uses the power of expanding ice to break apart rocks. Water works its way into various cracks, voids, and crevices.\u00a0As the water freezes, it expands with great force, exploiting any weaknesses. When ice melts, the liquid water moves further into the widened spaces. Repeated cycles of freezing and melting eventually pry the rocks apart. The cycles can occur daily when fluctuations of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2689\">temperature<\/a> between day and night go from freezing to melting.<\/p>\n<h4><span style=\"font-weight: 400\">Root Wedging<\/span><\/h4>\n<figure id=\"attachment_2967\" aria-describedby=\"caption-attachment-2967\" style=\"width: 369px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Pine-tree_roots_digging_through_the_asphalt_-_panoramio-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2967\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Pine-tree_roots_digging_through_the_asphalt_-_panoramio-scaled-1.jpg\" alt=\"The roots of the tree are breaking up the asphalt.\" width=\"369\" height=\"277\" \/><\/a><figcaption id=\"caption-attachment-2967\" class=\"wp-caption-text\">The roots of this tree are demonstrating the destructive power of root wedging. Though this picture is a man-made rock (asphalt), it works on typical rock as well.<\/figcaption><\/figure>\n<p>Like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1207\">frost wedging<\/a>, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1208\">root wedging<\/a><\/strong> happens when plant roots work themselves into cracks, prying the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> apart as they grow. Occasionally these roots may become fossilized. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2809\">Rhizolith<\/a><\/strong> is the term for these roots preserved in the rock record. Tunneling organisms such as earthworms, termites, and ants are biological agents that induce <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> similar to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1208\">root wedging<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Salt Expansion<\/span><\/h4>\n<figure id=\"attachment_2968\" aria-describedby=\"caption-attachment-2968\" style=\"width: 414px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/640px-Tafoni_03.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-340\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/640px-Tafoni_03-300x225.jpg\" alt=\"The rock has many holes from the salt erosion.\" width=\"414\" height=\"311\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/640px-Tafoni_03-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/640px-Tafoni_03-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/640px-Tafoni_03-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/640px-Tafoni_03-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/640px-Tafoni_03.jpg 640w\" sizes=\"auto, (max-width: 414px) 100vw, 414px\" \/><\/a><figcaption id=\"caption-attachment-2968\" class=\"wp-caption-text\">Tafoni from Salt Point, California.<\/figcaption><\/figure>\n<p>Salt expansion, which works similarly to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1207\">frost wedging<\/a>, occurs in areas of high evaporation or near-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">marine<\/a> environments. Evaporation causes salts to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a> out of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a> and grow and expand into cracks in rock. Salt expansion is one of the causes of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2810\">tafoni<\/a><\/strong>, a series of holes in a rock. Tafonis, cracks, and holes are weak points that become susceptible to increased <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>. Another phenomena that occurs when salt water evaporates can leave behind a square imprint preserved in a soft <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, called a <strong>h<\/strong><strong>opper crystal<\/strong>.<\/p>\n<h3><b>5.2.2 Chemical Weathering<\/b><\/h3>\n<figure id=\"attachment_2969\" aria-describedby=\"caption-attachment-2969\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SA2Vratio.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-341 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio-300x138.png\" alt=\"The left side has one large cube, the middle has 8 medium cubes, the right side has 64 small cubes. Each group has the same overall volume.\" width=\"300\" height=\"138\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio-300x138.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio-1024x470.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio-768x352.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio-65x30.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio-225x103.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio-350x160.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SA2Vratio.png 1086w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2969\" class=\"wp-caption-text\">Each of these three groups of cubes has an equal volume. However, their surface areas are vastly different. On the left, the single cube has a length, width, and height of 4 units, giving it a surface area of 6(4&#215;4)=96 and a volume of 4^3=64. The middle eight cubes have a length, width, and height of 2, meaning a surface area of 8(6(2&#215;2))=8&#215;24=192. They also have a volume of 8(2^3)=8&#215;8=64. The 64 cubes on the right have a length, width, and height of 1, leading to a surface area of 64(6(1&#215;1))=64&#215;6=384. The volume remains unchanged, because 64(1^3)=64&#215;1=64. The surface area to volume ratio (SA:V), which is related to the amount of material available for reactions, changes for each as well. On the left, it is 96\/64=0.75 or 3:2. The center has a SA\/V of 192\/64=1.5, or 3:1. On the right, the SA:V is 384\/64=6, or 6:1.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">Chemical weathering<\/a><\/strong> is the dominate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> process in warm, humid environments. It happens when water, oxygen, and other reactants chemically degrade the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> components of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> and turn them into water-soluble ions which can then be transported by water. Higher temperatures accelerate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">chemical weathering<\/a> rates.<\/p>\n<p>Chemical and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">mechanical weathering<\/a> work hand-in-hand via a fundamental concept called surface-area-to-volume ratio. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">Chemical weathering<\/a> only occurs on rock surfaces because water and reactants cannot penetrate solid rock. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">Mechanical weathering<\/a> penetrates <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>, breaking large rocks into smaller pieces and creating new rock surfaces. This exposes more surface area to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">chemical weathering<\/a>, enhancing its effects. In other words, higher surface-area-to-volume ratios produce higher rates of overall <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Carbonic Acid and Hydrolysis<\/span><\/h4>\n<figure id=\"attachment_2971\" aria-describedby=\"caption-attachment-2971\" style=\"width: 984px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Hydrolysis.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-342\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Hydrolysis.png\" alt=\"The diagram on the left is before hydrolysis.\" width=\"984\" height=\"168\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Hydrolysis.png 984w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Hydrolysis-300x51.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Hydrolysis-768x131.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Hydrolysis-65x11.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Hydrolysis-225x38.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Hydrolysis-350x60.png 350w\" sizes=\"auto, (max-width: 984px) 100vw, 984px\" \/><\/a><figcaption id=\"caption-attachment-2971\" class=\"wp-caption-text\">Generic hydrolysis diagram, where the bonds in mineral in question would represent the left side of the diagram.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2813\">Carbonic acid<\/a><\/strong> (H<sub>2<\/sub>CO<sub>3<\/sub>) forms when carbon dioxide, the fifth-most abundant gas in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2667\">atmosphere<\/a>, dissolves in water. This happens naturally in clouds, which is why <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a> is normally slightly acidic. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2813\">Carbonic acid<\/a> is an important agent in two <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">chemical weathering<\/a> reactions, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2814\">hydrolysis<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolution<\/a>.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2814\">Hydrolysis<\/a> occurs via two types of reactions. In one reaction, water molecules ionize into positively charged H<sup>+1 <\/sup>and OH<sup>\u22121<\/sup> ions and replace <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2702\">cations<\/a> in the crystal lattice. In another type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2814\">hydrolysis<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2813\">carbonic acid<\/a> molecules react directly with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>, especially those containing silicon and aluminum (i.e. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1916\">Feldspars<\/a>), to form molecules of clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2814\">Hydrolysis<\/a> is the main process that breaks down <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2709\">silicate<\/a> rock and creates clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>. The following is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2814\">hydrolysis<\/a> reaction that occurs when silica-rich <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1916\">feldspar<\/a> encounters <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2813\">carbonic acid<\/a> to produce water-soluble clay and other ions:<\/p>\n<blockquote><p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1916\">feldspar<\/a><\/strong> + <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2813\">carbonic acid<\/a><\/strong> (in water) \u2192 clay + metal <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2702\">cations<\/a> (Fe<sup>++<\/sup>, Mg<sup>++<\/sup>, Ca<sup>++<\/sup>, Na<sup>+<\/sup>, etc.) + bicarbonate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2704\">anions<\/a> (HCO<sub>3<\/sub><sup>-1<\/sup>) + silica (SiO<sub>2<\/sub>)<\/p><\/blockquote>\n<p>Clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> are platy <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2709\">silicates<\/a> or phyllosilicates (see Chapter 3, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">Minerals<\/a>) similar to micas, and are the main components of very fine-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> substances may later <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a> into <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rocks<\/strong> like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2842\">evaporite<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a>, as well as amorphous silica or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">chert<\/a> nodules.<\/p>\n<h4><span style=\"font-weight: 400\">Dissolution<\/span><\/h4>\n<figure id=\"attachment_2972\" aria-describedby=\"caption-attachment-2972\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/GoldinPyrite.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-343 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite-300x240.jpg\" alt=\"The rock is red.\" width=\"300\" height=\"240\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite-300x240.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite-1024x819.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite-768x614.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite-65x52.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite-225x180.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite-350x280.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GoldinPyrite.jpg 1471w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2972\" class=\"wp-caption-text\">In this rock, a pyrite cube has dissolved (as seen with the negative &#8220;corner&#8221; impression in the rock), leaving behind small specks of gold.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">Dissolution<\/a><\/strong> is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2814\">hydrolysis<\/a> reaction that dissolves <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> and leaves the ions in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a>, usually in water. Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2842\">evaporites<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonates<\/a>, like salt and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>, are more prone to this reaction; however, all <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> can be <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a>. Non-acidic water, having a neutral pH of 7, will <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolve<\/a> any <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a>, although it may happen very slowly. Water with higher levels of acid, naturally or man-made, dissolves rocks at a higher rate. Liquid water is normally slightly acidic due to the presence of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2813\">carbonic acid<\/a> and free H+ ions. Natural rainwater can be highly acidic, with pH levels as low as 2. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">Dissolution<\/a> can be enhanced by a biological agent, such as when organisms like lichen and bacteria release organic acids onto the rocks they are attached to. Regions with high humidity (airborne moisture) and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a> experience more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolution<\/a> due to greater contact time between rocks and water.<\/p>\n<figure id=\"attachment_2514\" aria-describedby=\"caption-attachment-2514\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Iddingsite.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-82\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Iddingsite-300x225.jpg\" alt=\"The xenolith sits on top of a basalt rock. It has three sides like a pyramid; one of the sides is more altered to iddingsite.\" width=\"300\" height=\"225\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Iddingsite-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Iddingsite-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Iddingsite-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Iddingsite-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Iddingsite.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2514\" class=\"wp-caption-text\">This mantle xenolith containing olivine (green) is chemically weathering by hydrolysis and oxidation into the pseudo-mineral iddingsite, which is a complex of water, clay, and iron oxides. The more altered side of the rock has been exposed to the environment longer.<\/figcaption><\/figure>\n<p>The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2816\">Goldich Dissolution Series<\/a><\/strong> shows <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">chemical weathering<\/a> rates are associated to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2674\">crystallization<\/a> rankings in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1174\">Bowen\u2019s Reaction Series<\/a> (see Chapter 4, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2675\">Igneous Rock<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1181\">Volcanic<\/a> Processes). <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">Minerals<\/a> at the top of the Bowen series crystallize under high temperatures and pressures, and chemically <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1709\">weather<\/a> at a faster rate than <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> ranked at the bottom. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">Quartz<\/a>, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1954\">felsic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> that crystallizes at 700\u00b0C, is very resistant to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">chemical weathering<\/a>. High <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2674\">crystallization<\/a>-point <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1956\">mafic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2711\">olivine<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2712\">pyroxene<\/a> (1,250\u00b0C), <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1709\">weather<\/a> relatively rapidly and more completely. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2711\">Olivine<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2712\">pyroxene<\/a> are rarely found as end products of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> because they tend to break down into elemental ions.<\/p>\n<figure id=\"attachment_2974\" aria-describedby=\"caption-attachment-2974\" style=\"width: 1600px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Karst_minerve.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-344 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve.jpg\" alt=\"The rocks in this area are full of holes, formed from karst dissolution.\" width=\"1600\" height=\"625\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve.jpg 1600w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve-300x117.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve-1024x400.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve-768x300.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve-1536x600.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve-65x25.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve-225x88.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Karst_minerve-350x137.jpg 350w\" sizes=\"auto, (max-width: 1600px) 100vw, 1600px\" \/><\/a><figcaption id=\"caption-attachment-2974\" class=\"wp-caption-text\">Eroded karst topography in Minevre, France.<\/figcaption><\/figure>\n<figure id=\"attachment_2975\" aria-describedby=\"caption-attachment-2975\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-345 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos-300x226.jpg\" alt=\"A heart-shaped formation in Timpanogos Cave\" width=\"300\" height=\"226\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos-300x226.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos-1024x771.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos-768x579.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos-225x170.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos-350x264.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Timpanogos-Cave-the-Great-Heart-of-Timpanogos.jpg 1411w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2975\" class=\"wp-caption-text\">A formation called The Great Heart of Timpanogos in Timpanogos Cave National Monument<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">Dissolution<\/a> is also noteworthy for the special geological features it creates. In places with abundant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolution<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> can produce a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2817\">karst<\/a> topography<\/strong> characterized by sinkholes or caves (see Chapter 10, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3110\">Mass Wasting<\/a>).<\/p>\n<p>Timpanogos Cave National Monument in Northern Utah is a well-known <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolution<\/a> feature. The figure shows a cave <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2960\">formation<\/a> created from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolution<\/a> followed by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a>\u2014<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3129\">groundwater<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2706\">saturated<\/a> with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> seeped into the cavern, where evaporation caused the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a> out.<\/p>\n<h4><span style=\"font-weight: 400\">Oxidation<\/span><\/h4>\n<figure id=\"attachment_2976\" aria-describedby=\"caption-attachment-2976\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/PyOx.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-346 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-300x225.jpg\" alt=\"Goethite is in cubes, though it usually is not. Pyrite is in cubes.\" width=\"300\" height=\"225\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PyOx.jpg 1600w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2976\" class=\"wp-caption-text\">Pyrite cubes are oxidized, becoming a new mineral goethite. In this case, goethite is a pseudomorph after pyrite, meaning it has taken the form of another mineral.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2818\">Oxidation<\/a><\/strong>, the chemical reaction that causes rust in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3345\">metallic<\/a> iron, occurs geologically when iron atoms in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2703\">bond<\/a> with oxygen. Any <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> containing iron can be oxidized. The resultant iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1919\">oxides<\/a> may permeate a rock if it is rich in iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1919\">Oxides<\/a> may also form a coating that covers rocks and grains of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, or lines rock cavities and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1934\">fractures<\/a>. If the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1919\">oxides<\/a> are more susceptible to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> than the original <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>, they may create void spaces inside the rock mass or hollows on exposed surfaces.<\/p>\n<p>Three commonly found <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> are produced by iron-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2818\">oxidation<\/a> reactions:\u00a0 red or grey <strong>hematite<\/strong>, brown <strong>goethite<\/strong> (pronounced \u201cGUR-tite\u201d), and yellow <strong>limonite<\/strong>. These iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1919\">oxides<\/a> coat and bind <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> grains together into sedimentary rocks in a process called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2681\">cementation<\/a>, and often give these rocks a dominant color. They color the rock layers of the Colorado Plateau, as well as Zion, Arches, and Grand Canyon National Parks. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1919\">oxides<\/a> can permeate a rock that is rich in iron-bearing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> or can be a coating that forms in cavities or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1934\">fractures<\/a>. When the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> replacing existing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> are resistant to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>, iron concretions may occur in the rock. \u00a0When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> is replaced by weaker <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1919\">oxides<\/a>, this process commonly results in void spaces and weakness throughout the rock mass and often leaves hollows on exposed rock surfaces.<\/p>\n<h3><b>5.2.3 Erosion<\/b><\/h3>\n<figure id=\"attachment_2980\" aria-describedby=\"caption-attachment-2980\" style=\"width: 227px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MB2-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2980\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/MB2-scaled-1.jpg\" alt=\"The rock is topped by a more resistant.\" width=\"227\" height=\"170\" \/><\/a><figcaption id=\"caption-attachment-2980\" class=\"wp-caption-text\">A hoodoo near Moab, Utah<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">Erosion<\/a><\/strong> is a mechanical process, usually driven by water, gravity, (see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/10-mass-wasting\/\">Chapter 10<\/a>), wind, or ice (see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/14-glaciers\/\">Chapter 14<\/a>) that removes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> from the place of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>. Liquid water is the main agent of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>.<\/p>\n<figure id=\"attachment_2983\" aria-describedby=\"caption-attachment-2983\" style=\"width: 379px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Grand_Canyon-Mather_point.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-348\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Grand_Canyon-Mather_point-300x225.jpg\" alt=\"The canyon has many cliffs and slopes.\" width=\"379\" height=\"284\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Grand_Canyon-Mather_point-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Grand_Canyon-Mather_point-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Grand_Canyon-Mather_point-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Grand_Canyon-Mather_point-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Grand_Canyon-Mather_point-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Grand_Canyon-Mather_point.jpg 1024w\" sizes=\"auto, (max-width: 379px) 100vw, 379px\" \/><\/a><figcaption id=\"caption-attachment-2983\" class=\"wp-caption-text\">Grand Canyon from Mather Point.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">Erosion<\/a> <strong>resistance<\/strong> is important in the creation of distinctive geological features. This is well demonstrated in the cliffs of the Grand Canyon. The cliffs are made of rock left standing after less resistant materials have weathered and eroded away. Rocks with different levels <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> resistant also create the unique-looking features called hoodoos in Bryce Canyon National Park and Goblin Valley State Park in Utah.<\/p>\n<h3><b>5.2.4. Soil<\/b><\/h3>\n<figure id=\"attachment_2984\" aria-describedby=\"caption-attachment-2984\" style=\"width: 318px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SoilStructure.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-349\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilStructure-284x300.jpg\" alt=\"The soil is sketched and labeled.\" width=\"318\" height=\"335\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilStructure-284x300.jpg 284w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilStructure-65x69.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilStructure-225x237.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilStructure-350x369.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilStructure.jpg 513w\" sizes=\"auto, (max-width: 318px) 100vw, 318px\" \/><\/a><figcaption id=\"caption-attachment-2984\" class=\"wp-caption-text\">Sketch and picture of soil.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">Soil<\/a><\/strong> is a combination of air, water, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>, and organic matter that forms at the transition between <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2669\">biosphere<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2665\">geosphere<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">Soil<\/a> is made when <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> breaks down <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> and turns it into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. \u00a0If <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> does not remove the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> significantly, organisms can access the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> content of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a>. \u00a0These organisms turn <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>, water, and atmospheric gases into organic substances that contribute to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a>.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">Soil<\/a> is an important <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3341\">reservoir<\/a> for organic components necessary for plants, animals, and microorganisms to live. The organic component of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a>, called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2819\">humus<\/a><\/strong>, is a rich source of bioavailable nitrogen. Nitrogen is the most common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2700\">element<\/a> in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2667\">atmosphere<\/a>, but it exists in a form most life forms are unable to use. Special bacteria found only in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> provide most nitrogen compounds that are usable, bioavailable, by life forms.<\/p>\n<figure id=\"attachment_2986\" aria-describedby=\"caption-attachment-2986\" style=\"width: 479px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Nitrogen_Cycle.svg_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-350\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-1024x768.png\" alt=\"The image shows the way nitrogen can move around, mostly in the soil\" width=\"479\" height=\"359\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-1024x768.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-300x225.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-768x576.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-1536x1152.png 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-65x49.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-225x169.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_-350x263.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Nitrogen_Cycle.svg_.png 1600w\" sizes=\"auto, (max-width: 479px) 100vw, 479px\" \/><\/a><figcaption id=\"caption-attachment-2986\" class=\"wp-caption-text\">Schematic of the nitrogen cycle.<\/figcaption><\/figure>\n<p>These nitrogen-fixing bacteria absorb nitrogen from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2667\">atmosphere<\/a> and convert it into nitrogen compounds. These compounds are absorbed by plants and used to make DNA, amino acids, and enzymes. Animals obtain bioavailable nitrogen by eating plants, and this is the source of most of the nitrogen used by life. That nitrogen is an essential component of proteins and DNA.\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">Soils<\/a> range from poor to rich, depending on the amount of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2819\">humus<\/a> they contain. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">Soil<\/a> productivity is determined by water and nutrient content. Freshly created <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1181\">volcanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soils<\/a>, called andisols, and clay-rich <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soils<\/a> that hold nutrients and water are examples of productive <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soils<\/a>.<\/p>\n<figure id=\"attachment_2987\" aria-describedby=\"caption-attachment-2987\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/IncaTerrace.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-351\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/IncaTerrace-300x225.jpg\" alt=\"A mountain slope has been made into artificial steps form farming.\" width=\"300\" height=\"225\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/IncaTerrace-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/IncaTerrace-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/IncaTerrace-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/IncaTerrace-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/IncaTerrace.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2987\" class=\"wp-caption-text\">Agricultural terracing, as made by the Inca culture from the Andes, helps reduce erosion and promote soil formation, leading to better farming practices.<\/figcaption><\/figure>\n<p>The nature of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a>, meaning its characteristics, is determined primarily by five components: 1) the mineralogy of the parent material; 2) topography, 3) <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>, 4) <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1710\">climate<\/a>, and 5) the organisms that inhabit the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a>. For example, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> tends to erode more rapidly on steep slopes so <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> layers in these areas may be thinner than in flood plains, where it tends to accumulate. The quantity and chemistry of organic matter of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> affects how much and what varieties of life it can sustain. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2689\">Temperature<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a>, two major <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> agents, are dependent on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1710\">climate<\/a>. Fungi and bacteria contribute organic matter and the ability of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> to sustain life, interacting with plant roots to exchange nitrogen and other nutrients.<\/p>\n<p>In well-formed <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soils<\/a>, there is a discernable arrangement of distinct layers called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a>\u00a0horizons<\/strong>. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> horizons can be seen in road cuts that expose the layers at the edge of the cut. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">Soil<\/a> horizons make up the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2820\">soil profile<\/a>. Each <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2821\">soil horizon<\/a> reflects <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1710\">climate<\/a>, topography, and other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a>-development factors, as well as its organic material and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a>. The horizons are assigned names and letters. Differences in naming schemes depend on the area, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> type or research topic. The figure shows a simplified <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2820\">soil profile<\/a> that uses commonly designated names and letters.<\/p>\n<figure id=\"attachment_2989\" aria-describedby=\"caption-attachment-2989\" style=\"width: 360px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SoilHorizons.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-352 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SoilHorizons.gif\" alt=\"The image shows 5 soil layers, ranging from highly altered at the top, to unaltered at the bottom.\" width=\"360\" height=\"415\" \/><\/a><figcaption id=\"caption-attachment-2989\" class=\"wp-caption-text\">A simplified soil profile, showing labeled layers.<\/figcaption><\/figure>\n<p style=\"padding-left: 30px\"><strong>O Horizon<\/strong>: The top horizon is a thin layer of predominantly organic material, such as leaves, twigs, and other plant parts that are actively decaying into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2819\">humus<\/a>.<\/p>\n<p style=\"padding-left: 30px\"><strong>A Horizon<\/strong>: The next layer, called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2822\">topsoil<\/a><\/strong>, consists of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2819\">humus<\/a> mixed with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. As <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a> soaks down through this layer, it leaches out soluble chemicals. In wet climates with heavy <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a> this leaching out produces a separate layer called horizon E, the leaching or eluviation zone.<\/p>\n<p style=\"padding-left: 30px\"><strong>B Horizon<\/strong>: Also called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2823\">subsoil<\/a><\/strong>, this layer consists of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> mixed with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2819\">humus<\/a> removed from the upper layers. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2823\">subsoil<\/a> is where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is chemically weathered. The amount of organic material and degree of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> decrease with depth. The upper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2823\">subsoil<\/a> zone, called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3111\">regolith<\/a><\/strong>, is a porous mixture of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2819\">humus<\/a> and highly weathered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. In the lower zone, <strong>saprolite<\/strong>, scant organic material is mixed with largely unaltered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2688\">parent rock<\/a>.<\/p>\n<p style=\"padding-left: 30px\"><strong>C Horizon<\/strong>: This is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2824\">substratum<\/a> and is a zone of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">mechanical weathering<\/a>. Here, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> fragments are physically broken but not chemically altered. This layer contains no organic material.<\/p>\n<p style=\"padding-left: 30px\"><strong>R Horizon<\/strong>: The final layer consists of unweathered, parent <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a><\/strong> and fragments.<\/p>\n<figure id=\"attachment_2992\" aria-describedby=\"caption-attachment-2992\" style=\"width: 391px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Bauxite_with_unweathered_rock_core._C_021.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-353\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021-300x195.jpg\" alt=\"The outside of the rock is tan and weathered, the inside is grey.\" width=\"391\" height=\"254\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021-300x195.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021-1024x664.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021-768x498.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021-65x42.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021-225x146.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021-350x227.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bauxite_with_unweathered_rock_core._C_021.jpg 1492w\" sizes=\"auto, (max-width: 391px) 100vw, 391px\" \/><\/a><figcaption id=\"caption-attachment-2992\" class=\"wp-caption-text\">A sample of bauxite. Note the unweathered igneous rock in the center.<\/figcaption><\/figure>\n<p>The United States governing body for agriculture, the USDA, uses a taxonomic classification to identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> types, called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> orders. Xoxisols or laterite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soils<\/a> are nutrient-poor <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soils<\/a> found in tropical regions. While poorly suited for growing crops, xosisols are home to most of the world\u2019s mineable aluminum <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3325\">ore<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3357\">bauxite<\/a>). Ardisol forms in dry climates and can develop layers of hardened <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>, called caliche. Andisols originate from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1181\">volcanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1949\">ash<\/a> deposits. Alfisols contain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2709\">silicate<\/a> clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>. These two <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> orders are productive for farming due to their high content of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> nutrients. In general, color can be an important factor in understanding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> conditions. Black <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soils<\/a> tend to be anoxic, red oxygen-rich, and green oxygen-poor (i.e. reduced). This is true for many sedimentary rocks as well.<\/p>\n<figure id=\"attachment_2994\" aria-describedby=\"caption-attachment-2994\" style=\"width: 484px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Dust-storm-Texas-1935.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-354\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Dust-storm-Texas-1935.png\" alt=\"The black and white photo shows a giant wall of dust.\" width=\"484\" height=\"294\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Dust-storm-Texas-1935.png 640w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Dust-storm-Texas-1935-300x182.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Dust-storm-Texas-1935-65x40.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Dust-storm-Texas-1935-225x137.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Dust-storm-Texas-1935-350x213.png 350w\" sizes=\"auto, (max-width: 484px) 100vw, 484px\" \/><\/a><figcaption id=\"caption-attachment-2994\" class=\"wp-caption-text\">A dust storm approaches Stratford, Texas in 1935.<\/figcaption><\/figure>\n<p>Not only is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> essential to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2902\">terrestrial<\/a> life in nature, but also human civilization via agriculture. Careless or uninformed human activity can seriously damage <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a>\u2019s life-supporting properties. A prime example is the famous Dust Bowl disaster of the 1930s, which affected the midwestern United States. The damage occurred because of large-scale attempts develop prairieland in southern Kansas, Colorado, western Texas, and Oklahoma into farmland. Poor understanding of the region\u2019s geology, ecology, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1710\">climate<\/a> led to farming practices that ruined the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2820\">soil profile<\/a>.<\/p>\n<p>The prairie <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soils<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1924\">native<\/a> plants are well adapted to a relatively dry <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1710\">climate<\/a>. With government encouragement, settlers moved in to homestead the region. They plowed vast areas of prairie into long, straight rows and planted grain. The plowing broke up the stable <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2820\">soil profile<\/a> and destroyed the natural grasses and plants, which had long roots that anchored the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> layers. The grains they planted had shallower root systems and were plowed up every year, which made the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> prone to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>. The plowed furrows were aligned in straight rows running downhill, which favored <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> and loss of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2822\">topsoil<\/a>.<\/p>\n<p>The local <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1710\">climate<\/a> does not produce sufficient <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a> to support non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1924\">native<\/a> grain crops, so the farmers drilled wells and over-pumped water from the underground <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3166\">aquifers<\/a>. The grain crops failed due to lack of water, leaving bare <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> that was stripped from the ground by the prairie winds. Particles of midwestern prairie <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> were deposited along the east <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2890\">coast<\/a> and as far away as Europe. Huge dust storms called black blizzards made life unbearable, and the once-hopeful homesteaders left in droves. The setting for John Steinbeck\u2019s famous novel and John Ford\u2019s film, <em>The Grapes of Wrath,<\/em> is Oklahoma during this time. The lingering question is whether we have learned the lessons of the dust bowl, to avoid creating it again.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-32\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-32\" class=\"h5p-iframe\" data-content-id=\"32\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"5.2 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3998\" aria-describedby=\"caption-attachment-3998\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.2-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-355\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.2-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3998\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 5.2 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">5.3 Sedimentary rocks<\/span><\/h2>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">Sedimentary rock<\/a> is classified into two main categories: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> and chemical. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">Clastic<\/a><\/strong> or<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3363\">detrital<\/a><\/strong> sedimentary rocks are made from pieces of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, derived primarily by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">mechanical weathering<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">Clastic<\/a> rocks may also include chemically weathered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">Clastic<\/a> rocks are classified by <strong>grain shape<\/strong>, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">grain size<\/a><\/strong>, and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2829\">sorting<\/a><\/strong>. <strong>Chemical<\/strong> sedimentary rocks are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitated<\/a> from water <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2706\">saturated<\/a> with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>. Chemical rocks are classified mainly by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> in the rock.<\/p>\n<h3><b>5.3.1 Lithification and Diagenesis<\/b><\/h3>\n<p><strong><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Siccar_Point_red_capstone_closeup.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-356\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-300x225.jpg\" alt=\"\" width=\"445\" height=\"334\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Siccar_Point_red_capstone_closeup.jpg 2048w\" sizes=\"auto, (max-width: 445px) 100vw, 445px\" \/><\/a><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2682\">Lithification<\/a><\/strong> turns loose <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains, created by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> and transported by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>, into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> via three interconnected steps. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">Deposition<\/a><\/strong> happens when friction and gravity overcome the forces driving <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> transport, allowing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> to accumulate. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2680\">Compaction<\/a><\/strong> occurs when material continues to accumulate on top of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> layer, squeezing the grains together and driving out water. The mechanical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2680\">compaction<\/a> is aided by weak attractive forces between the smaller grains of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3129\">Groundwater<\/a> typically carries cementing agents into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>, amorphous silica, or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1919\">oxides<\/a>, may have a different <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a> than the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2681\">Cementation<\/a><\/strong> is the process of cementing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> coating the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains and gluing them together into a fused rock.<\/p>\n<figure id=\"attachment_3253\" aria-describedby=\"caption-attachment-3253\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/07.20_Petrified_forest_log_2_md-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-357\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1-300x300.jpg\" alt=\"Photo of log of petrified wood showing structures of the original wood\" width=\"300\" height=\"300\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1-300x300.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1-150x150.jpg 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1-768x768.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1-65x65.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1-225x225.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1-350x350.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/07.20_Petrified_forest_log_2_md-1.jpg 1009w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3253\" class=\"wp-caption-text\">Permineralization in petrified wood<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2827\">Diagenesis<\/a><\/strong> is an accompanying process to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2682\">lithification<\/a> and is a low-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2689\">temperature<\/a> form of rock <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2914\">metamorphism<\/a> (see Chapter 6, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2684\">Metamorphic Rock<\/a>). During <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2827\">diagenesis<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> are chemically altered by heat and pressure. A classic example is aragonite (CaCO<sub>3<\/sub>), a form of calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a> that makes up most organic shells. When lithified aragonite undergoes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2827\">diagenesis<\/a>, the aragonite reverts to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> (CaCO<sub>3<\/sub>), which has the same chemical formula but a different crystalline structure. In <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> containing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> and magnesium (Mg), <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2827\">diagenesis<\/a> may <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2601\">transform<\/a> the two <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> into dolomite (CaMg(CO<sub>3<\/sub>)<sub>2<\/sub>). <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2827\">Diagenesis<\/a> may also reduce the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3116\">pore<\/a> space, or open volume, between <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> grains. The processes of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2681\">cementation<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2680\">compaction<\/a>, and ultimately <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2682\">lithification<\/a> occur within the realm of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2827\">diagenesis<\/a>, which includes the processes that turn organic material into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">fossils<\/a>.<\/p>\n<h3><b>5.3.2 Detrital Sedimentary Rocks (Clastic)<\/b><\/h3>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3363\">Detrital<\/a><\/strong> or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a><\/strong> sedimentary rocks consist of preexisting <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> pieces that comes from weathered bedrock. Most of this is mechanically weathered sediment, although some clasts may be pieces of chemical rocks. This creates some overlap between the two categories, since <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> sedimentary rocks may include chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3363\">Detrital<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> rocks are classified and named based on their <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">grain size<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Grain Size<\/span><\/h4>\n<figure id=\"attachment_3001\" aria-describedby=\"caption-attachment-3001\" style=\"width: 570px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Wentworth_scaleGrainSize.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-358\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Wentworth_scaleGrainSize.png\" alt=\"Chart with sizes ranging from clay to boulders\" width=\"570\" height=\"768\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wentworth_scaleGrainSize.png 570w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wentworth_scaleGrainSize-223x300.png 223w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wentworth_scaleGrainSize-65x88.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wentworth_scaleGrainSize-225x303.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wentworth_scaleGrainSize-350x472.png 350w\" sizes=\"auto, (max-width: 570px) 100vw, 570px\" \/><\/a><figcaption id=\"caption-attachment-3001\" class=\"wp-caption-text\">Size categories of sediments, known as the Wentworth scale.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3363\">Detrital<\/a> rock is classified according to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">grain size<\/a><\/strong>, which is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2862\">graded<\/a> from large to small on the Wentworth scale (see figure). <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">Grain size<\/a> is the average diameter of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> fragments in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> or rock. Grain sizes are delineated using a log base 2 scale. For example, the grain sizes in the pebble class are 2.52, 1.26, 0.63, 0.32, 0.16, and 0.08 inches, which correlate respectively to very coarse, coarse, medium, fine, and very fine granules. Large fragments, or clasts, include all grain sizes larger than 2 mm (5\/64 in). These include, boulders, cobbles, granules, and gravel. Sand has a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">grain size<\/a> between 2 mm and 0.0625 mm, about the lower limit of the naked eye\u2019s resolution. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a> grains smaller than sand are called silt. Silt is unique; the grains can be felt with a finger or as grit between your teeth, but are too small to see with the naked eye.<\/p>\n<h4><span style=\"font-weight: 400\">Sorting and Rounding<\/span><\/h4>\n<figure id=\"attachment_3002\" aria-describedby=\"caption-attachment-3002\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Sorting_in_sediment.svg_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-359\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Sorting_in_sediment.svg_-300x141.png\" alt=\"The sediment on the left is all about the same size. The sediment on the right is many sizes.\" width=\"300\" height=\"141\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Sorting_in_sediment.svg_-300x141.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Sorting_in_sediment.svg_-65x30.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Sorting_in_sediment.svg_-225x105.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Sorting_in_sediment.svg_.png 320w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3002\" class=\"wp-caption-text\">A well-sorted sediment (left) and a poorly-sorted sediment (right).<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2829\">Sorting<\/a><\/strong> describes the range of grain sizes within <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a>. Geologists use the term \u201c<strong>well sorted<\/strong>\u201d to describe a narrow range of grain sizes, and \u201cpoorly sorted\u201d for a wide range of grain sizes (see figure). It is important to note that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> engineers use similar terms with opposite definitions; well <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2862\">graded<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> consists of a variety of grain sizes, and poorly <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2862\">graded<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> has roughly the same grain sizes.<\/p>\n<p>When reading the story told by rocks, geologists use <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2829\">sorting<\/a> to interpret <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> or transport processes, as well as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> energy. For example, wind-blown sands are typically extremely well sorted, while <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">glacial<\/a> deposits are typically poorly sorted. These characteristics help identify the type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> process that occurred. Coarse-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> and poorly sorted rocks are usually found nearer to the source of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, while fine <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> are carried farther away. In a rapidly flowing mountain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">stream<\/a> you would expect to see boulders and pebbles. In a lake fed by the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">stream<\/a>, there should be sand and silt deposits. If you also find large boulders in the lake, this may indicate the involvement of another <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> transport process, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3119\">rockfall<\/a> caused by ice- or root-wedging.<\/p>\n<figure id=\"attachment_3003\" aria-describedby=\"caption-attachment-3003\" style=\"width: 532px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Rounding__sphericity_EN.svg_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-360\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Rounding__sphericity_EN.svg_.png\" alt=\"The sediments show various stages of rounding and sphericity, from high to low.\" width=\"532\" height=\"222\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rounding__sphericity_EN.svg_.png 640w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rounding__sphericity_EN.svg_-300x125.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rounding__sphericity_EN.svg_-65x27.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rounding__sphericity_EN.svg_-225x94.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rounding__sphericity_EN.svg_-350x146.png 350w\" sizes=\"auto, (max-width: 532px) 100vw, 532px\" \/><\/a><figcaption id=\"caption-attachment-3003\" class=\"wp-caption-text\">Degree of rounding in sediments. Sphericity refers to the spherical nature of an object, a completely different measurement unrelated to rounding.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2830\">Rounding<\/a><\/strong> is created when angular corners of rock fragments are removed from a piece of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> due to abrasion during transport. Well-rounded <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains are defined as being free of all sharp edges. Very angular <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> retains the sharp corners. Most clast fragments start with some sharp edges due to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>\u2019s crystalline structure, and those points are worn down during transport. More rounded grains imply a longer <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a> time or transport distance, or more energetic erosional process. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">Mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1927\">hardness<\/a> is also a factor in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2830\">rounding<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Composition and provenance<\/span><\/h4>\n<figure id=\"attachment_3004\" aria-describedby=\"caption-attachment-3004\" style=\"width: 228px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/VolcnicLithicFragment.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-361 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment-228x300.jpg\" alt=\"The grain is round and has vesicles.\" width=\"228\" height=\"300\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment-228x300.jpg 228w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment-778x1024.jpg 778w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment-768x1010.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment-65x86.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment-225x296.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment-350x460.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/VolcnicLithicFragment.jpg 1166w\" sizes=\"auto, (max-width: 228px) 100vw, 228px\" \/><\/a><figcaption id=\"caption-attachment-3004\" class=\"wp-caption-text\">A sand grain made of basalt, known as a microlitic volcanic lithic fragment. Box is 0.25 mm. Top picture is plane-polarized light, bottom is cross-polarized light.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">Composition<\/a><\/strong> describes the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> components found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> and may be influenced by local geology, like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3340\">source rock<\/a> and hydrology. Other than clay, most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> components are easily determined by visual inspection (see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/3-minerals\/\">Chapter 3, Minerals<\/a>). The most commonly found <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">quartz<\/a> because of its low chemical reactivity and high <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1927\">hardness<\/a>, making it resistant to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>, and its ubiquitous occurrence in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2575\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>. Other commonly found <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains include <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1916\">feldspar<\/a> and lithic fragments. Lithic fragments are pieces of fine-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a>, and include <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2875\">mud chips<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1181\">volcanic<\/a> clasts, or pieces of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2926\">slate<\/a>.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">Weathering<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1938\">volcanic rock<\/a> produces Hawaii\u2019s famous black (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1961\">basalt<\/a>) and green (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2711\">olivine<\/a>) sand beaches, which are rare elsewhere on Earth. This is because the local rock is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composed<\/a> almost entirely of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1961\">basalt<\/a> and provides an abundant source of dark colored clasts loaded with mafic minerals. According to the Goldich Dissolution Series, clasts high in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1956\">mafic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> are more easily destroyed compared to clasts <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composed<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1954\">felsic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">quartz<\/a>.<\/p>\n<figure id=\"attachment_3006\" aria-describedby=\"caption-attachment-3006\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Green-sand-beach-in-Hawaii.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-362 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii-300x215.jpg\" alt=\"Hawiian beach composed of green olivine sand from weathering of nearby basaltic rock.\" width=\"300\" height=\"215\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii-300x215.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii-1024x732.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii-768x549.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii-65x46.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii-225x161.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii-350x250.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Green-sand-beach-in-Hawaii.jpg 1383w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3006\" class=\"wp-caption-text\">Hawiian beach composed of green olivine sand from weathering of nearby basaltic rock.<\/figcaption><\/figure>\n<p>Geologists use <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2832\">provenance<\/a><\/strong> to discern the original source of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2832\">Provenance<\/a> is determined by analyzing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a> and types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">fossils<\/a> present, as well as textural features like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2829\">sorting<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2830\">rounding<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2832\">Provenance<\/a> is important for describing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2576\">tectonic<\/a> history, visualizing paleogeographic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2960\">formations<\/a>, unraveling an area\u2019s geologic history, or reconstructing past <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2623\">supercontinents<\/a>.<\/p>\n<p>In <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">quartz<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a>, sometimes called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">quartz<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">arenite<\/a> (SiO<sub>2<\/sub>), <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2832\">provenance<\/a> may be determined using a rare, durable clast <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2175\">zircon<\/a> (ZrSiO<sub>4<\/sub>). <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2175\">Zircon<\/a>, or zirconium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2709\">silicate<\/a>, contains traces of uranium, which can be used for age-dating the source <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> that contributed <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> to the lithified <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> rock (see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/7-geologic-time\/\">Chapter 7, Geologic Time<\/a>).<\/p>\n<h4><span style=\"font-weight: 400\">Classification of Clastic Rocks<\/span><\/h4>\n<figure id=\"attachment_3008\" aria-describedby=\"caption-attachment-3008\" style=\"width: 395px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Titus_Canyon_Narrows.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-363\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Titus_Canyon_Narrows-300x225.jpg\" alt=\"The grey rock is broken and angular within the larger rock.\" width=\"395\" height=\"296\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Titus_Canyon_Narrows-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Titus_Canyon_Narrows-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Titus_Canyon_Narrows-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Titus_Canyon_Narrows-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Titus_Canyon_Narrows-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Titus_Canyon_Narrows.jpg 1024w\" sizes=\"auto, (max-width: 395px) 100vw, 395px\" \/><\/a><figcaption id=\"caption-attachment-3008\" class=\"wp-caption-text\">Megabreccia in Titus Canyon, Death Valley National Park, California.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">Clastic<\/a> rocks are classified according to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">grain size<\/a> of their <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. Coarse-grained rocks contain clasts with a predominant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">grain size<\/a> larger than sand. Typically, smaller <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains, collectively called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1959\">groundmass<\/a> or matrix, fill in much of the volume between the larger clasts, and hold the clasts together. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2833\">Conglomerates<\/a><\/strong> are rocks containing coarse rounded clasts, and <strong>breccias<\/strong> contain angular clasts (see figure). Both <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2833\">conglomerates<\/a> and breccias are usually poorly sorted.<\/p>\n<figure id=\"attachment_3504\" aria-describedby=\"caption-attachment-3504\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-364 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1-300x225.jpg\" alt=\"Windblown sand grains showing rounding and frosted surfaces due to transport b wind.\" width=\"300\" height=\"225\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/13.19_Windblown_sand_grains_CoralPinkSandDunesSand-1.jpg 1500w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3504\" class=\"wp-caption-text\">Enlarged image of frosted and rounded windblown sand grains<\/figcaption><\/figure>\n<p>Medium-grained rocks <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composed<\/a> mainly of sand are called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a><\/strong>, or sometimes <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">arenite<\/a><\/strong> if well sorted. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a> grains in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> can having a wide variety of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> compositions, roundness, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2829\">sorting<\/a>. Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> names indicate the rock\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">Quartz<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> contains predominantly <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">quartz<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains. <strong>Arkose<\/strong> is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> with significant amounts of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1916\">feldspar<\/a>, usually greater than 25%. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">Sandstone<\/a> that contains <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1916\">feldspar<\/a>, which weathers more quickly than <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">quartz<\/a>, is useful for analyzing the local geologic history. <strong>Greywack<\/strong>e is a term with conflicting definitions. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2835\">Greywacke<\/a> may refer to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> with a muddy matrix, or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> with many lithic fragments (small rock pieces).<\/p>\n<figure id=\"attachment_3013\" aria-describedby=\"caption-attachment-3013\" style=\"width: 636px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Rochester_Shale_Niagara_Gorge.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-365\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-1024x685.jpg\" alt=\"The rock breaks apart in very thin layers.\" width=\"636\" height=\"426\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-1024x685.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-300x201.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-768x514.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-1536x1028.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-65x44.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-225x151.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge-350x234.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Rochester_Shale_Niagara_Gorge.jpg 1600w\" sizes=\"auto, (max-width: 636px) 100vw, 636px\" \/><\/a><figcaption id=\"caption-attachment-3013\" class=\"wp-caption-text\">The Rochester Shale, New York. Note the thin fissility in the layers.<\/figcaption><\/figure>\n<p>Fine-grained rocks include <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2837\">mudstone<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">shale<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2840\">siltstone<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2841\">claystone<\/a>. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2837\">Mudstone<\/a><\/strong> is a general term for rocks made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains smaller than sand (less than 2 mm). Rocks that are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2838\">fissile<\/a><\/strong>, meaning they separate into thin sheets, are called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">shale<\/a>. Rocks exclusively <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composed<\/a> of silt or clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, are called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2840\">siltstone<\/a><\/strong> or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2841\">claystone<\/a><\/strong>, respectively. These last two rock types are rarer than <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2837\">mudstone<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">shale<\/a>.<\/p>\n<figure id=\"attachment_3014\" aria-describedby=\"caption-attachment-3014\" style=\"width: 223px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Claystone_GLMsed.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-366\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Claystone_GLMsed-300x225.jpg\" alt=\"The light grey layers are very thin.\" width=\"223\" height=\"167\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Claystone_GLMsed-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Claystone_GLMsed-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Claystone_GLMsed-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Claystone_GLMsed-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Claystone_GLMsed.jpg 640w\" sizes=\"auto, (max-width: 223px) 100vw, 223px\" \/><\/a><figcaption id=\"caption-attachment-3014\" class=\"wp-caption-text\">Claystone laminations from Glacial Lake Missoula.<\/figcaption><\/figure>\n<p>Rock types found as a mixture between the main classifications, may be named using the less-common component as a descriptor. For example, a rock containing some silt but mostly rounded sand and gravel is called silty <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2833\">conglomerate<\/a>. Sand-rich rock containing minor amounts of clay is called clayey <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a>.<\/p>\n<h3><b>5.3.3. Chemical, Biochemical, and Organic<\/b><\/h3>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">Chemical sedimentary<\/a> rocks are formed by processes that do not directly involve <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1204\">mechanical weathering<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">Chemical weathering<\/a> may contribute the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> materials in water that ultimately form these rocks. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">Biochemical<\/a> and organic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> in the sense that they are made from pieces of organic material that is deposited, buried, and lithified; however, they are usually classified as being chemically produced.<\/p>\n<p>Inorganic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rocks are made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitated<\/a> from ions <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a>, and created without the aid of living organisms. Inorganic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rocks form in environments where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3371\">ion<\/a> concentration, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> gasses, temperatures, or pressures are changing, which causes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> to crystallize.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">Biochemical<\/a> sedimentary rocks are formed from shells and bodies of underwater organisms. The living organisms extract chemical components from the water and use them to build shells and other body parts. The components include aragonite, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> similar to and commonly replaced by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>, and silica.<\/p>\n<p>Organic sedimentary rocks come from organic material that has been deposited and lithified, usually underwater. The source materials are plant and animal remains that are transformed through burial and heat, and end up as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2856\">coal<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3338\">oil<\/a>, and methane (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3339\">natural gas<\/a>).<\/p>\n<h4><span style=\"font-weight: 400\">Inorganic chemical<\/span><\/h4>\n<figure id=\"attachment_3015\" aria-describedby=\"caption-attachment-3015\" style=\"width: 350px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Bonneville_Salt_Flats_Utah.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-367\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-300x200.jpg\" alt=\"The ground is white and flat for a long distance.\" width=\"350\" height=\"233\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-300x200.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-1024x683.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-768x512.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-1536x1024.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-225x150.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah-350x233.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bonneville_Salt_Flats_Utah.jpg 1599w\" sizes=\"auto, (max-width: 350px) 100vw, 350px\" \/><\/a><figcaption id=\"caption-attachment-3015\" class=\"wp-caption-text\">Salt-covered plain known as the Bonneville Salt Flats, Utah.<\/figcaption><\/figure>\n<p>Inorganic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rocks are formed when <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a> out of an aqueous <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a>, usually due to water evaporation. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> form various salts known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2842\">evaporites<\/a><\/strong>. For example, the Bonneville Salt Flats in Utah flood with winter rains and dry out every summer, leaving behind salts such as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2843\">gypsum<\/a><\/strong> and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2844\">halite<\/a><\/strong>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> order of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2842\">evaporites<\/a> deposit is opposite to their solubility order, i.e. as water evaporates and increases the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> concentration in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a>, less soluble <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a> out sooner than the highly soluble <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> order and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2706\">saturation<\/a> percentages are depicted in the table, bearing in mind the process in nature may vary from laboratory derived values.<\/p>\n<table>\n<tbody>\n<tr>\n<th><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">Mineral<\/a> sequence<\/strong><\/th>\n<th><strong>Percent Seawater remaining after evaporation <\/strong><\/th>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">Calcite<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">50<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2843\">Gypsum<\/a>\/anhydrite<\/span><\/td>\n<td><span style=\"font-weight: 400\">20<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2844\">Halite<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">10<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Various potassium and magnesium salts<\/span><\/td>\n<td><span style=\"font-weight: 400\">5<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em><span style=\"font-weight: 400\">Table after<\/span><span style=\"font-weight: 400\">.<\/span><\/em><\/p>\n<figure id=\"attachment_3135\" aria-describedby=\"caption-attachment-3135\" style=\"width: 329px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2017\/02\/JoultersCayOoids.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-368\" title=\"&quot;By\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids.jpg\" alt=\"The ooids are very smooth and round\" width=\"329\" height=\"247\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids.jpg 1600w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/JoultersCayOoids-350x263.jpg 350w\" sizes=\"auto, (max-width: 329px) 100vw, 329px\" \/><\/a><figcaption id=\"caption-attachment-3135\" class=\"wp-caption-text\">Ooids from Joulter&#8217;s Cay, The Bahamas<\/figcaption><\/figure>\n<figure id=\"attachment_3018\" aria-describedby=\"caption-attachment-3018\" style=\"width: 367px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Limestone_towers_at_Mono_Lake_California.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-369\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_towers_at_Mono_Lake_California-300x225.jpg\" alt=\"The grey limestone towers vertically stick out of the ground.\" width=\"367\" height=\"275\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_towers_at_Mono_Lake_California-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_towers_at_Mono_Lake_California-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_towers_at_Mono_Lake_California-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_towers_at_Mono_Lake_California-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_towers_at_Mono_Lake_California.jpg 640w\" sizes=\"auto, (max-width: 367px) 100vw, 367px\" \/><\/a><figcaption id=\"caption-attachment-3018\" class=\"wp-caption-text\">Limestone tufa towers along the shores of Mono Lake, California.<\/figcaption><\/figure>\n<p>Calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a>&#8211;<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2706\">saturated<\/a> water precipitates porous masses of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2846\">tufa<\/a><\/strong>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2846\">Tufa<\/a> can form near degassing water and in saline lakes. Waterfalls downstream of springs often <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2846\">tufa<\/a> as the turbulent water enhances degassing of carbon dioxide, which makes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> less soluble and causes it to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a>. Saline lakes concentrate calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a> from a combination of wave action causing degassing, springs in the lakebed, and evaporation. In salty Mono Lake in California, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2846\">tufa<\/a> towers were exposed after water was diverted and lowered the lake levels.<\/p>\n<figure id=\"attachment_3019\" aria-describedby=\"caption-attachment-3019\" style=\"width: 556px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Mammoth_Terraces.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-370\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-1024x683.jpg\" alt=\"The white and brown natural steps show the formation of travertine.\" width=\"556\" height=\"371\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-1024x683.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-300x200.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-768x512.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-1536x1024.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-225x150.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces-350x233.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mammoth_Terraces.jpg 1599w\" sizes=\"auto, (max-width: 556px) 100vw, 556px\" \/><\/a><figcaption id=\"caption-attachment-3019\" class=\"wp-caption-text\">Travertine terraces of Mammoth Hot Springs, Yellowstone National Park, USA<\/figcaption><\/figure>\n<p>Cave deposits like stalactites and stalagmites are another form of chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>, in a form called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2847\">travertine<\/a><\/strong>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">Calcite<\/a> slowly precipitates from water to form the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2847\">travertine<\/a>, which often shows <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2931\">banding<\/a>. This process is similar to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> growth on faucets in your home sink or shower that comes from hard (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> rich) water. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2847\">Travertine<\/a> also forms at hot springs such as Mammoth Hot <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3174\">Spring<\/a> in Yellowstone National Park.<\/p>\n<figure id=\"attachment_3304\" aria-describedby=\"caption-attachment-3304\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MichiganBIF-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-371\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-300x206.jpg\" alt=\"The rock shows red and brown layering.\" width=\"300\" height=\"206\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-300x206.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-1024x704.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-768x528.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-1536x1057.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-65x45.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-225x155.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1-350x241.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MichiganBIF-1.jpg 1599w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3304\" class=\"wp-caption-text\">Alternating bands of iron-rich and silica-rich mud, formed as oxygen combined with dissolved iron.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2848\">Banded iron formation<\/a><\/strong> deposits commonly formed early in Earth\u2019s history, but this type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rock is no longer being created. Oxygenation of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2667\">atmosphere<\/a> and oceans caused free iron ions, which are water-soluble, to become oxidized and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitate<\/a> out of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a>. The iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1919\">oxide<\/a> was deposited, usually in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2931\">bands<\/a> alternating with layers of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">chert<\/a>.<\/p>\n<figure id=\"attachment_3023\" aria-describedby=\"caption-attachment-3023\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Flint_with_weathered_crust.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-372\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Flint_with_weathered_crust-300x225.jpg\" alt=\"The flint is dark brown\/grey, and the weathered crust is light tan. The overall shape is blobby.\" width=\"300\" height=\"225\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Flint_with_weathered_crust-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Flint_with_weathered_crust-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Flint_with_weathered_crust-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Flint_with_weathered_crust-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Flint_with_weathered_crust.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3023\" class=\"wp-caption-text\">A type of chert, flint, shown with a lighter weathered crust.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">Chert<\/a><\/strong>, another commonly found <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rock, is usually produced from silica (SiO<sub>2<\/sub>) <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitated<\/a> from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3129\">groundwater<\/a>. Silica is highly insoluble on the surface of Earth, which is why <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">quartz<\/a> is so resistant to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">chemical weathering<\/a>. Water deep underground is subjected to higher pressures and temperatures, which helps <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolve<\/a> silica into an aqueous <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a>. As the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3129\">groundwater<\/a> rises toward or emerges at the surface the silica precipitates out, often as a cementing agent or into nodules. For example, the bases of the geysers in Yellowstone National Park are surrounded by silica deposits called geyserite or sinter. The silica is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> in water that is thermally heated by a relatively deep <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2672\">magma<\/a> source. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">Chert<\/a> can also form biochemically and is discussed in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">Biochemical<\/a> subsection. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">Chert<\/a> has many synonyms, some of which may have gem value such as jasper, flint, onyx, and agate, due to subtle differences in colors, striping, etc., but <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">chert<\/a> is the more general term used by geologists for the entire group.<\/p>\n<figure id=\"attachment_3026\" aria-describedby=\"caption-attachment-3026\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Oolite.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-373\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite-300x225.jpg\" alt=\"Ooids forming an oolite.\" width=\"300\" height=\"225\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite-1024x766.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite-768x575.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite-225x168.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite-350x262.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Oolite.jpg 1391w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3026\" class=\"wp-caption-text\">Ooids forming an oolite.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2845\">Oolites<\/a><\/strong> are among the few <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a> forms created by an inorganic chemical process, similar to what happens in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2842\">evaporite<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a>. When water is oversaturated with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> precipitates out around a nucleus, a sand grain or shell fragment, and forms little spheres called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2845\">ooids<\/a> (see figure). As evaporation continues, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2845\">ooids<\/a> continue building concentric layers of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> as they roll around in gentle currents.<\/p>\n<h4><span style=\"font-weight: 400\">Biochemical<\/span><\/h4>\n<figure id=\"attachment_3028\" aria-describedby=\"caption-attachment-3028\" style=\"width: 450px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Limestone_etched_section_KopeFm_new.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-374 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_etched_section_KopeFm_new.jpg\" alt=\"Rock has many fossils throughout\" width=\"450\" height=\"480\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_etched_section_KopeFm_new.jpg 450w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_etched_section_KopeFm_new-281x300.jpg 281w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_etched_section_KopeFm_new-65x69.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_etched_section_KopeFm_new-225x240.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Limestone_etched_section_KopeFm_new-350x373.jpg 350w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><\/a><figcaption id=\"caption-attachment-3028\" class=\"wp-caption-text\">Fossiliferous limestone (with brachiopods and bryozoans) from the Kope Formation of Ohio. Lower image is a section of the rock that has been etched with acid to emphasize the fossils.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">Biochemical<\/a><\/strong> sedimentary rocks are not that different from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rocks; they are also formed from ions <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a>. However, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">biochemical<\/a> sedimentary rocks rely on biological processes to extract the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> materials out of the water. Most macroscopic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">marine<\/a> organisms use <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>, primarily aragonite (calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a>), to build hard parts such as shells. When organisms die the hard parts settle as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, which become buried, compacted and cemented into rock.<\/p>\n<p>This <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">biochemical<\/a> extraction and secretion is the main process for forming <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a><\/strong>, the most commonly occurring, non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">Limestone<\/a> is mostly made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> (CaCO<sub>3<\/sub>) and sometimes includes dolomite (CaMgCO<sub>3<\/sub>), a close relative. Solid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> reacts with hydrochloric acid by <strong>effervescing<\/strong> or fizzing. Dolomite only reacts to hydrochloric acid when ground into a powder, which can be done by scratching the rock surface (see Chapter 3, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">Minerals<\/a>).<\/p>\n<figure id=\"attachment_3031\" aria-describedby=\"caption-attachment-3031\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/CoquinaClose.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-375\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-300x198.jpg\" alt=\"Rock is broken shells\" width=\"300\" height=\"198\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-300x198.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-1024x675.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-768x506.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-1536x1012.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-225x148.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose-350x231.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CoquinaClose.jpg 1584w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3031\" class=\"wp-caption-text\">Close-up on coquina.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">Limestone<\/a> occurs in many forms, most of which originate from biological processes. Entire coral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a> and their ecosystems can be preserved in exquisite detail in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a> rock (see figure).\u00a0<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2852\">Fossiliferous<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a><\/strong> contains many visible <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">fossils<\/a>. A type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a> called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2854\">coquina<\/a><\/strong> originates from beach sands made predominantly of shells that were then lithified. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2854\">Coquina<\/a> is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composed<\/a> of loosely-cemented shells and shell fragments. You can find beaches like this in modern tropical environments, such as the Bahamas.\u00a0 <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2855\">Chalk<\/a><\/strong> contains high concentrations of shells from a microorganism called a coccolithophore. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2853\">Micrite<\/a><\/strong>, also known as microscopic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> mud, is a very fine-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a> containing microfossils that can only be seen using a microscope.<\/p>\n<p>Biogenetic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">chert<\/a> forms on the deep <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2885\">ocean floor<\/a>, created from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">biochemical<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> made of microscopic organic shells. This <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, called ooze, may be calcareous (calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a> based) or siliceous (silica-based) depending on the type of shells deposited. For example, the shells of radiolarians (zooplankton) and diatoms (phytoplankton) are made of silica, so they produce siliceous ooze.<\/p>\n<h4><span style=\"font-weight: 400\">Organic<\/span><\/h4>\n<figure id=\"attachment_3033\" aria-describedby=\"caption-attachment-3033\" style=\"width: 360px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Coal_anthracite.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-376 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Coal_anthracite.jpg\" alt=\"It is very black and shiny.\" width=\"360\" height=\"337\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coal_anthracite.jpg 360w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coal_anthracite-300x281.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coal_anthracite-65x61.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coal_anthracite-225x211.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coal_anthracite-350x328.jpg 350w\" sizes=\"auto, (max-width: 360px) 100vw, 360px\" \/><\/a><figcaption id=\"caption-attachment-3033\" class=\"wp-caption-text\">Anthracite coal, the highest grade of coal.<\/figcaption><\/figure>\n<p>Under the right conditions, intact pieces of organic material or material derived from organic sources, is preserved in the geologic record. Although not derived from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, this lithified organic material is associated with sedimentary <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">strata<\/a> and created by similar processes\u2014burial, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2680\">compaction<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2827\">diagenesis<\/a>. C Deposits of these fuels develop in areas where organic material collects in large quantities. Lush swamplands can create conditions conducive to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2856\">coal<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2960\">formation<\/a>. Shallow-water, organic material-rich <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">marine<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> can become highly productive <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3337\">petroleum<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3339\">natural gas<\/a> deposits. See <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/16-energy-and-mineral-resources\/\">Chapter 16, Energy and Mineral Resources,<\/a> for a more in-depth look at these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">fossil<\/a>-derived energy sources.<\/p>\n<h4><span style=\"font-weight: 400\">Classification of Chemical Sedimentary Rocks<\/span><\/h4>\n<figure id=\"attachment_3036\" aria-describedby=\"caption-attachment-3036\" style=\"width: 573px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-377\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-300x162.jpg\" alt=\"The rock has many light-colored layers.\" width=\"573\" height=\"310\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-300x162.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-1024x555.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-768x416.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-1536x832.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-65x35.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-225x122.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico-350x190.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Gyprock_Castile_Formation_Upper_Permian_Eddy_County_New_Mexico.jpg 1599w\" sizes=\"auto, (max-width: 573px) 100vw, 573px\" \/><\/a><figcaption id=\"caption-attachment-3036\" class=\"wp-caption-text\">Gyprock, a rock made of the mineral gypsum. From the Castle formation of New Mexico.<\/figcaption><\/figure>\n<p>In contrast to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3363\">detrital<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, chemical, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">biochemical<\/a>, and organic sedimentary rocks are classified based on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a>. Most of these are monomineralic, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composed<\/a> of a single <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a>, so the rock name is usually associated with the identifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">Chemical sedimentary<\/a> rocks consisting of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2844\">halite<\/a> are called rock salt. Rocks made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">Limestone<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>) is an exception, having elaborate subclassifications and even two competing classification methods: Folk Classification and Dunham Classification. The Folk Classification deals with rock grains and usually requires a specialized, petrographic microscope. The Dunham Classification is based on rock <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2919\">texture<\/a>, which is visible to the naked eye or using a hand lens and is easier for field applications. Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a> geologists use the Dunham <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2664\">system<\/a>.<\/p>\n<figure id=\"attachment_3038\" aria-describedby=\"caption-attachment-3038\" style=\"width: 791px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SedRx2.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-large wp-image-378\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-791x1024.png\" alt=\"Sedimentary rock identification chart\" width=\"791\" height=\"1024\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-791x1024.png 791w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-232x300.png 232w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-768x994.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-1187x1536.png 1187w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-1583x2048.png 1583w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-65x84.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-225x291.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2-350x453.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedRx2.png 1700w\" sizes=\"auto, (max-width: 791px) 100vw, 791px\" \/><\/a><figcaption id=\"caption-attachment-3038\" class=\"wp-caption-text\">Sedimentary rock identification chart<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-33\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-33\" class=\"h5p-iframe\" data-content-id=\"33\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"5.3 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3997\" aria-describedby=\"caption-attachment-3997\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.3-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-379\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.3-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3997\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 5.3 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">5.4 Sedimentary Structures<\/span><\/h2>\n<p>Sedimentary structures are visible textures or arrangements of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> within a rock. Geologists use these structures to interpret the processes that made the rock and the environment in which it formed. They use <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2658\">uniformitarianism<\/a> to usually compare sedimentary structures formed in modern environments to lithified counterparts in ancient rocks. Below is a summary discussion of common sedimentary structures that are useful for interpretations in the rock record.<\/p>\n<h3><b>5.4.1. Bedding Planes<\/b><\/h3>\n<figure id=\"attachment_3042\" aria-describedby=\"caption-attachment-3042\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/07.4_Horizontal_SEUtahStrat-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-3042\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/07.4_Horizontal_SEUtahStrat-scaled-1.jpg\" alt=\"Photo of strata in Utah lying horizontal\" width=\"300\" height=\"170\" \/><\/a><figcaption id=\"caption-attachment-3042\" class=\"wp-caption-text\">Horizontal strata<\/figcaption><\/figure>\n<p>The most basic sedimentary structure is <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> planes<\/strong>, the planes that separate the layers or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">strata<\/a> in sedimentary and some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1181\">volcanic<\/a> rocks. Visible in exposed outcroppings, each <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> plane indicates a change in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> conditions. This change may be subtle. For example, if a section of underlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> firms up, this may be enough to create a form a layer that is dissimilar from the overlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. Each layer is called a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">bed<\/a>, or stratum, the most basic unit of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2859\">stratigraphy<\/a><\/strong>, the study of sedimentary layering.<\/p>\n<figure id=\"attachment_3047\" aria-describedby=\"caption-attachment-3047\" style=\"width: 257px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/BedOrdOutcropTN.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-381 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/BedOrdOutcropTN-257x300.jpg\" alt=\"Two students are looking at the layers of rock.\" width=\"257\" height=\"300\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BedOrdOutcropTN-257x300.jpg 257w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BedOrdOutcropTN-65x76.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BedOrdOutcropTN-225x263.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BedOrdOutcropTN-350x409.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BedOrdOutcropTN.jpg 700w\" sizes=\"auto, (max-width: 257px) 100vw, 257px\" \/><\/a><figcaption id=\"caption-attachment-3047\" class=\"wp-caption-text\">Students from the University of Wooster examine beds of Ordovician limestone in central Tennessee.<\/figcaption><\/figure>\n<p>As would be expected, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">bed<\/a> thickness can indicate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> quantity and timing. Technically, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">bed<\/a> is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> plane thicker than 1 cm (0.4 in) and the smallest mappable unit. A layer thinner than 1 cm (0.4 in) is called a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2860\">lamina<\/a><\/strong>. <strong>Varves<\/strong> are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> planes created when <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2860\">laminae<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> are deposited in repetitive cycles, typically daily or seasonally. Varves are valuable geologic records of climatic histories, especially those found in lakes and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">glacial<\/a> deposits.<\/p>\n<h3><b>5.4.2. Graded Bedding<\/b><\/h3>\n<figure id=\"attachment_3049\" aria-describedby=\"caption-attachment-3049\" style=\"width: 613px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-382\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA.jpg\" alt=\"Rock shows layers described.\" width=\"613\" height=\"480\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA.jpg 613w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA-300x235.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA-65x51.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA-225x176.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_from_Pigeon_Pt_Fm_at_Pescadero_Beach_CA-350x274.jpg 350w\" sizes=\"auto, (max-width: 613px) 100vw, 613px\" \/><\/a><figcaption id=\"caption-attachment-3049\" class=\"wp-caption-text\">Image of the classic Bouma sequence. A=coarse- to fine-grained sandstone, possibly with an erosive base. B=laminated medium- to fine-grained sandstone. C=rippled fine-grained sandstone. D=laminated siltstone grading to mudstone.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2862\">Graded<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a><\/strong> refers to a sequence of increasingly coarse- or fine-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> layers. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2862\">Graded<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> often develops when <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> occurs in an environment of decreasing energy. A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2863\">Bouma sequence<\/a><\/strong> is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2862\">graded<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> observed in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> rock called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2888\">turbidite<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2863\">Bouma sequence<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> are formed by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3196\">offshore<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> gravity flows, which are underwater flows of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. These subsea density flows begin when <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is stirred up by an energetic process and becomes a dense slurry of mixed grains. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> flow courses downward through submarine channels and canyons due to gravity acting on the density difference between the denser slurry and less dense surrounding seawater. As the flow reaches deeper ocean basins it slows down, loses energy, and deposits <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2863\">Bouma sequence<\/a> of coarse grains first, followed by increasingly finer grains (see figure).<\/p>\n<h3><span style=\"font-weight: 400\">5.4.3. Flow Regime and Bedforms<\/span><\/h3>\n<figure id=\"attachment_3051\" aria-describedby=\"caption-attachment-3051\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Bedforms_under_various_flow_regimes.pdf.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-large wp-image-383\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-1024x713.jpg\" alt=\"There are 7 images of increasing velocity.\" width=\"1024\" height=\"713\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-1024x713.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-300x209.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-768x535.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-1536x1070.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-65x45.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-225x157.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf-350x244.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Bedforms_under_various_flow_regimes.pdf.jpg 2048w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption id=\"caption-attachment-3051\" class=\"wp-caption-text\">Bedforms from under increasing flow velocities.<\/figcaption><\/figure>\n<p>In fluid systems, such as moving water or wind, sand is the most easily transported and deposited <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grain. Smaller particles like silt and clay are less movable by fluid systems because the tiny grains are chemically attracted to each other and stick to the underlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. Under higher flow rates, the fine silt and clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> tends to stay in place and the larger sand grains get picked up and moved.<\/p>\n<p><strong>Bedforms<\/strong> are sedimentary structures created by fluid systems working on sandy <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">Grain size<\/a>, flow velocity, and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2864\">flow regime<\/a><\/strong> or pattern interact to produce bedforms having unique, identifiable physical characteristics. Flow regimes are divided into upper and lower regimes, which are further divided into uppermost, upper, lower, and lowermost parts. The table below shows bedforms and their associated flow regimes. For example, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2865\">bedform<\/a> is created in the upper part of the lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2864\">flow regime<\/a>.<\/p>\n<table>\n<tbody>\n<tr>\n<td><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2864\">Flow Regime<\/a> (part)<\/strong><\/td>\n<td><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2865\">Bedform<\/a><\/strong><\/td>\n<td><strong>Description<\/strong><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Lower (lowest)<\/span><\/td>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2866\">Plane bed<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">Lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2866\">plane bed<\/a>, flat <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2860\">laminations<\/a><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Lower (lower)<\/span><\/td>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">Ripples<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">Small (with respect to flow) inclined layers dipping downflow<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Lower (upper)<\/span><\/td>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">Dunes<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">Larger inclined cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a>, \u00b1<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a>, dipping downflow<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Upper (lower)<\/span><\/td>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2866\">Plane bed<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">Flat layers, can include lined-up grains (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2867\">parting lineations<\/a>)<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Upper (upper)<\/span><\/td>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2872\">Antidunes<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">Hard to preserve reverse <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> dipping shallowly upflow<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Upper (uppermost)<\/span><\/td>\n<td><span style=\"font-weight: 400\">Chutes\/pools <\/span><em><span style=\"font-weight: 400\">(rare)<\/span><\/em><\/td>\n<td><span style=\"font-weight: 400\">Erosional, not really a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2865\">bedform<\/a>; rarely found preserved<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h4><span style=\"font-weight: 400\">Plane Beds<\/span><\/h4>\n<figure id=\"attachment_3052\" aria-describedby=\"caption-attachment-3052\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/PartingLineation.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-384 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/PartingLineation-300x200.jpg\" alt=\"There are slight groves in the rock.\" width=\"300\" height=\"200\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PartingLineation-300x200.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PartingLineation-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PartingLineation-225x150.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PartingLineation-350x234.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/PartingLineation.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3052\" class=\"wp-caption-text\">Subtle lines across this sandstone (trending from the lower left to upper right) are parting lineations.<\/figcaption><\/figure>\n<p><strong>Plane <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a><\/strong> created in the lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2864\">flow regime<\/a> are like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> planes, on a smaller scale. The flat, parallel layers form as sandy <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> piles and move on top of layers below. Even non-flowing fluid systems, such as lakes, can produce <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> plane <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a>. Plane <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> in the upper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2864\">flow regime<\/a> are created by fast-flowing fluids. They may look identi<\/p>\n<figure id=\"attachment_3054\" aria-describedby=\"caption-attachment-3054\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/CurrentRipple.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-385 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/CurrentRipple-300x200.jpg\" alt=\"The sand has a steep side on the left of the ripple, and a more gentle slope on the right.\" width=\"300\" height=\"200\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CurrentRipple-300x200.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CurrentRipple-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CurrentRipple-225x150.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CurrentRipple-350x234.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CurrentRipple.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3054\" class=\"wp-caption-text\">Modern current ripple in sand from the Netherlands. The flow creates a steep side down current. In this image, the flow is from right to left.<\/figcaption><\/figure>\n<p>cal to lower-flow-regime <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a>; however, they typically show <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2867\">parting lineations<\/a><\/strong>, slight alignments of grains in rows and swaths, caused by high <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> transport rates that only occur in upper flow regimes.<\/p>\n<h4><span style=\"font-weight: 400\">Ripples<\/span><\/h4>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">Ripples<\/a><\/strong> are known by several names: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripple<\/a> marks, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripple<\/a> cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a>, or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripple<\/a> cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2860\">laminations<\/a>. The ridges or undulations in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">bed<\/a> are created as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains pile up on top of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2866\">plane bed<\/a>. With the exception of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a>, the scale of these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> is typically measured in centimeters. Occasionally, large flows like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">glacial<\/a> lake outbursts, can produce <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a> as tall as 20 m (66 ft).<\/p>\n<figure id=\"attachment_3055\" aria-describedby=\"caption-attachment-3055\" style=\"width: 231px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/WaveRipple.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-386\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/WaveRipple-300x225.jpg\" alt=\"This brown rock has symmetry in its ripples.\" width=\"231\" height=\"173\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/WaveRipple-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/WaveRipple-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/WaveRipple-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/WaveRipple-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/WaveRipple.jpg 640w\" sizes=\"auto, (max-width: 231px) 100vw, 231px\" \/><\/a><figcaption id=\"caption-attachment-3055\" class=\"wp-caption-text\">A bidirectional flow creates this symmetrical wave ripple. From rocks in Nomgon, Mongolia. Note the crests of the ripples have been eroded away by subsequent flows in places.<\/figcaption><\/figure>\n<p>First scientifically described by Hertha Ayrton, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripple<\/a> shapes are determined by flow type and can be straight-crested, sinuous, or complex. Asymmetrical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a> form in a unidirectional flow. Symmetrical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a> are the result of an oscillating back-and-forth flow typical of intertidal swash zones. Climbing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a> are created from high sedimentation rates and appear as overlapping layers of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripple<\/a> shapes (see figure).<\/p>\n<figure id=\"attachment_3058\" aria-describedby=\"caption-attachment-3058\" style=\"width: 565px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Climbing_ripples.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-387\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-300x225.jpg\" alt=\"The ripples are on top, slightly offset, from each other.\" width=\"565\" height=\"424\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Climbing_ripples.jpg 2048w\" sizes=\"auto, (max-width: 565px) 100vw, 565px\" \/><\/a><figcaption id=\"caption-attachment-3058\" class=\"wp-caption-text\">Climbing ripple deposit from India.<\/figcaption><\/figure>\n<h4><span style=\"font-weight: 400\">Dunes<\/span><\/h4>\n<figure id=\"attachment_3060\" aria-describedby=\"caption-attachment-3060\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/XBedsZion.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-large wp-image-388\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-1024x768.jpg\" alt=\"The mountain has a large variety of angles of beds, resulting from dunes moving in all directions.\" width=\"1024\" height=\"768\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/XBedsZion.jpg 1600w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption id=\"caption-attachment-3060\" class=\"wp-caption-text\">Lithified cross-bedded dunes from the high country of Zion National Park, Utah. The complexity of bedding planes results from the three-dimensional network of ancient dune flows.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">Dunes<\/a><\/strong> are very large and prominent versions of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a>, and typical examples of large <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2457\">cross bedding<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2457\">Cross bedding<\/a> happens when <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> pile atop one another, interrupting, and\/or cutting into the underlying layers. Desert sand <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> are probably the first image conjured up by this category of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2865\">bedform<\/a>.<\/p>\n<p>British geologist Agnold (1941) considered only Barchan and linear Seif <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> as the only true <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a> forms.\u00a0 Other workers have recognized transverse and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2461\">star dunes<\/a> as well as parabolic and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2459\">linear dunes<\/a> anchored by plants that are common in coastal areas as other types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a>.<\/p>\n<figure id=\"attachment_3063\" aria-describedby=\"caption-attachment-3063\" style=\"width: 247px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MoroccoDune.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-389\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune-681x1024.jpg\" alt=\"The red dune sand is rippled on one side (the steep side) and smooth on the other.\" width=\"247\" height=\"371\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune-681x1024.jpg 681w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune-199x300.jpg 199w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune-768x1155.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune-65x98.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune-225x338.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune-350x526.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MoroccoDune.jpg 796w\" sizes=\"auto, (max-width: 247px) 100vw, 247px\" \/><\/a><figcaption id=\"caption-attachment-3063\" class=\"wp-caption-text\">Modern sand dune in Morocco.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">Dunes<\/a> are the most common sedimentary structure found within channelized flows of air or water. The biggest difference between <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> and air-formed (desert) <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> is the depth of fluid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2664\">system<\/a>. Since the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2667\">atmosphere<\/a>\u2019s depth is immense when compared to a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a> channel, desert <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> are much taller than those found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">rivers<\/a>. Some famous air-formed <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a> landscapes include the Sahara Desert, Death Valley, and the Gobi Desert.<\/p>\n<p>As airflow moves <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> along, the grains accumulate on the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a>\u2019s windward surface (facing the wind). The angle of the windward side is typically shallower than the leeward (downwind) side, which has grains falling down over it. This difference in slopes can be seen in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">bed<\/a> cross-section and indicates the direction of the flow in the past. There are typically two styles of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a>: the more common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3183\">trough<\/a> cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> with curved windward surfaces, and rarer planar cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> with flat windward surfaces.<\/p>\n<p>In tidal locations with strong in-and-out flows, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> can develop in opposite directions. This produces a feature called herringbone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2457\">cross bedding<\/a>.<\/p>\n<figure id=\"attachment_3065\" aria-describedby=\"caption-attachment-3065\" style=\"width: 378px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Herringbone_cross-stratified.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-390\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-300x225.jpg\" alt=\"Herringbone_cross-sThe flow is to the left on the bottom, and the right on the top.tratified\" width=\"378\" height=\"284\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Herringbone_cross-stratified.jpg 1600w\" sizes=\"auto, (max-width: 378px) 100vw, 378px\" \/><\/a><figcaption id=\"caption-attachment-3065\" class=\"wp-caption-text\">Herringbone cross-bedding from the Mazomanie Formation, upper Cambrian of Minnesota.<\/figcaption><\/figure>\n<figure id=\"attachment_3066\" aria-describedby=\"caption-attachment-3066\" style=\"width: 225px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/HumXSec.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-391\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-300x225.jpg\" alt=\"The up and down waves are famous from hummocky-cross stratification.\" width=\"225\" height=\"169\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HumXSec.jpg 1600w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" \/><\/a><figcaption id=\"caption-attachment-3066\" class=\"wp-caption-text\">Hummocky-cross stratification, seen as wavy lines throughout the middle of this rock face. Best example is just above the pencil in the center.<\/figcaption><\/figure>\n<p>Another <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2960\">formation<\/a> variant occurs when very strong, hurricane-strength, winds agitate parts of the usually undisturbed seafloor. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> are called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2871\">hummocky cross stratification<\/a><\/strong> and have a 3D architecture of hills and valleys, with inclined and declined layering that matches the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a> shapes.<\/p>\n<h4><span style=\"font-weight: 400\">Antidunes<\/span><\/h4>\n<figure id=\"attachment_3069\" aria-describedby=\"caption-attachment-3069\" style=\"width: 356px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Antidunes_Urdaibai_estuary.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-392\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-300x225.jpg\" alt=\"The large waves are in place.\" width=\"356\" height=\"267\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Antidunes_Urdaibai_estuary.jpg 1600w\" sizes=\"auto, (max-width: 356px) 100vw, 356px\" \/><\/a><figcaption id=\"caption-attachment-3069\" class=\"wp-caption-text\">Antidunes forming in Urdaibai, Spain.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2872\">Antidunes<\/a><\/strong> are so named because they share similar characteristics with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a>, but are formed by a different, opposing process. While <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> form in lower flow regimes, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2872\">antidunes<\/a> come from fast-flowing upper flow regimes. In certain conditions of high flow rates, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> accumulates upstream of a subtle <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1454\">dip<\/a> instead of traveling downstream (see figure). <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2872\">Antidunes<\/a> form in phase with the flow; in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">rivers<\/a> they are marked by rapids in the current. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2872\">Antidunes<\/a> are rarely preserved in the rock record because the high flow rates needed to produce the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> also accelerate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>.<\/p>\n<h3><b>5.4.4. Bioturbation<\/b><\/h3>\n<figure id=\"attachment_3071\" aria-describedby=\"caption-attachment-3071\" style=\"width: 968px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Saluda_bioturbation.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-393 size-full\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Saluda_bioturbation.jpg\" alt=\"There are several ovals and lines representing places where organisms crawled through the sediment.\" width=\"968\" height=\"297\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Saluda_bioturbation.jpg 968w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Saluda_bioturbation-300x92.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Saluda_bioturbation-768x236.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Saluda_bioturbation-65x20.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Saluda_bioturbation-225x69.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Saluda_bioturbation-350x107.jpg 350w\" sizes=\"auto, (max-width: 968px) 100vw, 968px\" \/><\/a><figcaption id=\"caption-attachment-3071\" class=\"wp-caption-text\">Bioturbated dolomitic siltstone from Kentucky.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2873\">Bioturbation<\/a><\/strong> is the result of organisms burrowing through soft <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, which disrupts the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> layers. These tunnels are backfilled and eventually preserved when the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> becomes rock. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2873\">Bioturbation<\/a> happens most commonly in shallow, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">marine<\/a> environments, and can be used to indicate water depth.<\/p>\n<h3><b>5.4.5. Mudcracks<\/b><\/h3>\n<figure id=\"attachment_3072\" aria-describedby=\"caption-attachment-3072\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Mudcracks_roundtop_hill_MD.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-394\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Mudcracks_roundtop_hill_MD-300x214.jpg\" alt=\"The cracks are in several directions, forming squares, triangles, and other polygonal shapes.\" width=\"300\" height=\"214\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mudcracks_roundtop_hill_MD-300x214.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mudcracks_roundtop_hill_MD-65x46.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mudcracks_roundtop_hill_MD-225x161.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mudcracks_roundtop_hill_MD-350x250.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mudcracks_roundtop_hill_MD.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3072\" class=\"wp-caption-text\">Lithified mudcracks from Maryland.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2874\">Mudcracks<\/a><\/strong> occur in clay-rich <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> that is submerged underwater and later dries out. Water fills voids in the clay\u2019s crystalline structure, causing the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains to swell. When this waterlogged <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> begins to dry out, the clay grains shrink. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> layer forms deep polygonal cracks with tapered openings toward the surface, which can be seen in profile. The cracks fill with new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> and become visible veins running through the lithified rock. These dried-out clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> are a major source of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2875\">mud chips<\/a><\/strong>, small fragments of mud or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">shale<\/a>, which commonly become <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2958\">inclusions<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2833\">conglomerate<\/a>. What makes this sedimentary structure so important to geologists, is they only form in certain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional\u00a0environments<\/a>\u2014such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">tidal flats<\/a> that form underwater and are later exposed to air. Syneresis cracks are similar in appearance to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2874\">mudcracks<\/a> but much rarer; they are formed when subaqueous (underwater) clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> shrinks<span style=\"font-weight: 400\">.<\/span><\/p>\n<h3><b>5.4.6. Sole Marks <\/b><\/h3>\n<figure id=\"attachment_3074\" aria-describedby=\"caption-attachment-3074\" style=\"width: 216px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/FluteCast.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-395\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-300x225.jpg\" alt=\"The bulge is sticking out of a rock layer above the head of the observer.\" width=\"216\" height=\"162\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/FluteCast.jpg 1600w\" sizes=\"auto, (max-width: 216px) 100vw, 216px\" \/><\/a><figcaption id=\"caption-attachment-3074\" class=\"wp-caption-text\">This flute cast shows a flow direction toward the upper right of the image, as seen by the bulge sticking down out of the layer above. The flute cast would have been scoured into a rock layer below that has been removed by erosion, leaving the sandy layer above to fill in the flute cast.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2876\">Sole marks<\/a><\/strong> are small features typically found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a> deposits. They form at the base of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">bed<\/a>, the sole, and on top of the underlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">bed<\/a>. They can indicate several things about the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> conditions, such as flow direction or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2859\">stratigraphic<\/a> up-direction (see <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2881\">Geopetal<\/a> Structures section). <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2876\">Flute casts<\/a><\/strong> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2876\">scour marks<\/a> are grooves carved out by the forces of fluid flow and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> loads. The upstream part of the flow creates steep grooves and downstream the grooves are shallower. The grooves subsequently become filled by overlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, creating a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2179\">cast<\/a> of the original hollow.<\/p>\n<figure id=\"attachment_3076\" aria-describedby=\"caption-attachment-3076\" style=\"width: 279px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Groove_casts.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-396\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-300x225.jpg\" alt=\"The rock is filled with narrow, parallel ridges.\" width=\"279\" height=\"209\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Groove_casts.jpg 1600w\" sizes=\"auto, (max-width: 279px) 100vw, 279px\" \/><\/a><figcaption id=\"caption-attachment-3076\" class=\"wp-caption-text\">Groove casts at the base of a turbidite deposit in Italy.<\/figcaption><\/figure>\n<p>Formed similarly to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2876\">flute casts<\/a> but with a more regular and aligned shape, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2876\">groove casts<\/a><\/strong> are produced by larger clasts or debris carried along in the water that scrape across the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> layer. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2876\">Tool marks<\/a> come from objects like sticks carried in the fluid downstream or embossed into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> layer, leaving a depression that later fills with new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>.<\/p>\n<figure id=\"attachment_3077\" aria-describedby=\"caption-attachment-3077\" style=\"width: 259px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/LoadCast.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-397\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/LoadCast-300x225.jpg\" alt=\"The drill core is cylindrical.\" width=\"259\" height=\"194\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LoadCast-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LoadCast-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LoadCast-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LoadCast-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LoadCast.jpg 640w\" sizes=\"auto, (max-width: 259px) 100vw, 259px\" \/><\/a><figcaption id=\"caption-attachment-3077\" class=\"wp-caption-text\">A drill core showing a load cast showing light-colored sand sticking down into dark mud.<\/figcaption><\/figure>\n<p><strong>Load <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2179\">casts<\/a><\/strong>, an example of <strong>soft-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1448\">deformation<\/a><\/strong>, are small indentations made by an overlying layer of coarse <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains or clasts intruding into a softer, finer-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> layer.<\/p>\n<h3><b>5.4.7. Raindrop Impressions<\/b><\/h3>\n<figure id=\"attachment_3079\" aria-describedby=\"caption-attachment-3079\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Raindrop_impressions_mcr1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-398\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Raindrop_impressions_mcr1-300x200.jpg\" alt=\"This grey rock has round circles left by raindrops\" width=\"300\" height=\"200\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Raindrop_impressions_mcr1-300x200.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Raindrop_impressions_mcr1-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Raindrop_impressions_mcr1-225x150.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Raindrop_impressions_mcr1-350x234.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Raindrop_impressions_mcr1.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3079\" class=\"wp-caption-text\">Mississippian raindrop impressions over wave ripples from Nova Scotia.<\/figcaption><\/figure>\n<p>Like their name implies, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2878\">raindrop impressions<\/a><\/strong> are small pits or bumps found in soft <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. While they are generally believed to be created by rainfall, they may be caused by other agents such as escaping gas bubbles<span style=\"font-weight: 400\">.<\/span><\/p>\n<h3><b>5.4.8. Imbrication<\/b><\/h3>\n<figure id=\"attachment_3081\" aria-describedby=\"caption-attachment-3081\" style=\"width: 395px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Imbricated_fabric.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-399\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Imbricated_fabric-300x225.jpg\" alt=\"The rocks in this conglomerate are tilted, leaning toward the right.\" width=\"395\" height=\"296\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Imbricated_fabric-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Imbricated_fabric-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Imbricated_fabric-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Imbricated_fabric-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Imbricated_fabric.jpg 640w\" sizes=\"auto, (max-width: 395px) 100vw, 395px\" \/><\/a><figcaption id=\"caption-attachment-3081\" class=\"wp-caption-text\">Cobbles in this conglomerate are positioned in a way that they are stacked on each other, which occurred as flow went from left to right.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2879\">Imbrication<\/a><\/strong> is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3213\">stack<\/a> of large and usually flat clasts\u2014cobbles, gravels, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2875\">mud chips<\/a>, etc.\u2014that are aligned in the direction of fluid flow. The clasts may be stacked in rows, with their edges dipping down and flat surfaces aligned to face the flow (see figure). Or their flat surfaces may be parallel to the layer and long axes aligned with flow. Imbrications are useful for analyzing <strong>paleocurrents<\/strong>, or currents found in the geologic past, especially in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">alluvial<\/a> deposits.<\/p>\n<h3><b>5.4.9. Geopetal Structures<\/b><\/h3>\n<figure id=\"attachment_3082\" aria-describedby=\"caption-attachment-3082\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Geopetal.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-400 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-300x225.jpg\" alt=\"Line is horizontal in picture as well.\" width=\"300\" height=\"225\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Geopetal.jpg 1600w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3082\" class=\"wp-caption-text\">This bivalve (clam) fossil was partially filled with tan sediment, partially empty. Later fluids filled in the fossil with white calcite minerals. The line between the sediment and the later calcite is paleo-horizontal.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2881\">Geopetal<\/a> structures<\/strong>, also called up-direction indicators, are used to identify which way was up when the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> layers were originally formed. This is especially important in places where the rock layers have been deformed, tilted, or overturned. Well preserved <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2874\">mudcracks<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2876\">sole marks<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2878\">raindrop impressions<\/a> can be used to determine up direction. Other useful <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2881\">geopetal<\/a> structures include:<\/p>\n<ul>\n<li>\n<figure id=\"attachment_3084\" aria-describedby=\"caption-attachment-3084\" style=\"width: 207px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Eubrontes01.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-401\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01-207x300.jpg\" alt=\"This footprint of a dinosaur is three toes.\" width=\"207\" height=\"300\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01-207x300.jpg 207w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01-706x1024.jpg 706w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01-768x1114.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01-65x94.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01-225x326.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01-350x508.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Eubrontes01.jpg 826w\" sizes=\"auto, (max-width: 207px) 100vw, 207px\" \/><\/a><figcaption id=\"caption-attachment-3084\" class=\"wp-caption-text\">Eubrontes trace fossil from Utah, showing the geopetal direction is into the image.<\/figcaption><\/figure>\n<p>Vugs: Small voids in the rock that usually become filled during <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2827\">diagenesis<\/a>. If the void is partially filled or filled in stages, it serves as a permanent record of a level bubble, frozen in time.<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2457\">Cross bedding<\/a> \u2013 In places where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> pile on top of one another, where one <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2870\">cross bed<\/a> interrupts and\/or cuts another below, this shows a cross-cutting relationship that indicates up direction.<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">Ripples<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a>: Sometimes the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a> are preserved well enough to differentiate between the crests (top) and troughs (bottom).<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">Fossils<\/a>: Body <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">fossils<\/a> in life position, meaning the body parts are not scattered or broken, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2183\">trace fossils<\/a> like footprints (see figure) can provide an up direction. Intact fossilized coral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a> are excellent up indicators because of their large size and easily distinguishable top and bottom. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2189\">Index fossils<\/a>, such as ammonites, can be used to age date <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">strata<\/a> and determine up direction based on relative rock ages.<\/li>\n<li><span style=\"font-weight: 400\">Vesicles &#8211; <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2673\">Lava<\/a> flows eliminate gas upwards. An increase of vesicles toward the top of the flow indicates up.<\/span><\/li>\n<\/ul>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-34\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-34\" class=\"h5p-iframe\" data-content-id=\"34\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"5.4 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3996\" aria-describedby=\"caption-attachment-3996\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.4-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-402\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.4-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3996\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 5.4 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">5.5 Depositional Environments<\/span><\/h2>\n<figure id=\"attachment_3085\" aria-describedby=\"caption-attachment-3085\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/SedimentaryEnvironments.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-403 size-large\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments-1024x768.jpg\" alt=\"Many different environments are representative environments from high elevation to deep under water.\" width=\"1024\" height=\"768\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/SedimentaryEnvironments.jpg 1400w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption id=\"caption-attachment-3085\" class=\"wp-caption-text\">A representation of common depositional environments.<\/figcaption><\/figure>\n<p>The ultimate goal of many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2859\">stratigraphy<\/a> studies is to understand the original <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environment<\/a><\/strong>. Knowing where and how a particular <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> was formed can help geologists paint a picture of past environments\u2014such as a mountain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2464\">glacier<\/a>, gentle <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3147\">floodplain<\/a>, dry desert, or deep-sea <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2885\">ocean floor<\/a>. The study of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a> is a complex endeavor; the table shows a simplified version of what to look for in the rock record.<\/p>\n<table style=\"height: 665px;width: 98.3953%;border-collapse: collapse\">\n<tbody>\n<tr style=\"height: 28px\">\n<td style=\"width: 19.963%;height: 28px;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>Location<\/strong><\/span><\/td>\n<td style=\"width: 20.8001%;height: 28px;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a><\/strong><\/span><\/td>\n<td style=\"width: 20.8001%;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>Common Rock Types<\/strong><\/span><\/td>\n<td style=\"width: 18.1328%;height: 28px;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>Typical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">Fossils<\/a><\/strong><\/span><\/td>\n<td style=\"width: 20.3039%;border-style: double;text-align: center\"><span style=\"text-decoration: underline\"><strong>Sedimentary Structures<\/strong><\/span><\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 19.963%;height: 28px\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2884\">Abyssal<\/a><\/td>\n<td style=\"width: 20.8001%;height: 28px\">very fine muds and oozes, diatomaceous Earth<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">chert<\/a><\/td>\n<td style=\"width: 18.1328%;height: 28px\">diatoms<\/td>\n<td style=\"width: 20.3039%\">few<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 19.963%;height: 28px\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2887\">Submarine fan<\/a><\/td>\n<td style=\"width: 20.8001%;height: 28px\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2862\">graded<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2863\">Bouma<\/a> sequences, alternating sand\/mud<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> rocks<\/td>\n<td style=\"width: 18.1328%;height: 28px\">rare<\/td>\n<td style=\"width: 20.3039%\">channels, fan shape<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2892\">Continental slope<\/a><\/td>\n<td style=\"width: 20.8001%\">mud, possible sand, countourites<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">shale<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2840\">siltstone<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a><\/td>\n<td style=\"width: 18.1328%\">rare<\/td>\n<td style=\"width: 20.3039%\">swaths<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">Lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2889\">shoreface<\/a><\/td>\n<td style=\"width: 20.8001%\">laminated sand<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a><\/td>\n<td style=\"width: 18.1328%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2873\">bioturbation<\/a><\/td>\n<td style=\"width: 20.3039%\">hummocky cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\">Upper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2889\">shoreface<\/a><\/td>\n<td style=\"width: 20.8001%\">planar sand<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a><\/td>\n<td style=\"width: 18.1328%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2873\">bioturbation<\/a><\/td>\n<td style=\"width: 20.3039%\">plane <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a>, cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2896\">Littoral<\/a> (beach)<\/td>\n<td style=\"width: 20.8001%\">very well sorted sand<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a><\/td>\n<td style=\"width: 18.1328%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2873\">bioturbation<\/a><\/td>\n<td style=\"width: 20.3039%\">few<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">Tidal Flat<\/a><\/td>\n<td style=\"width: 20.8001%\">mud and sand with channels<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">shale<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2837\">mudstone<\/a>,<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2840\">siltstone<\/a><\/td>\n<td style=\"width: 18.1328%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2873\">bioturbation<\/a><\/td>\n<td style=\"width: 20.3039%\">mudcracks, symmetric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">Reef<\/a><\/td>\n<td style=\"width: 20.8001%\">lime mud with coral<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a><\/td>\n<td style=\"width: 18.1328%\">many, commonly coral<\/td>\n<td style=\"width: 20.3039%\">few<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2900\">Lagoon<\/a><\/td>\n<td style=\"width: 20.8001%\">laminated mud<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">shale<\/a><\/td>\n<td style=\"width: 18.1328%\">many, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2873\">bioturbation<\/a><\/td>\n<td style=\"width: 20.3039%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2860\">laminations<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">Delta<\/a><\/td>\n<td style=\"width: 20.8001%\">channelized sand with mud, \u00b1swamp<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> rocks<\/td>\n<td style=\"width: 18.1328%\">many to few<\/td>\n<td style=\"width: 20.3039%\">cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2903\">Fluvial<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a>)<\/td>\n<td style=\"width: 20.8001%\">sand and mud, can have larger <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a><\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2833\">conglomerate<\/a><\/td>\n<td style=\"width: 18.1328%\">bone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> (rare)<\/td>\n<td style=\"width: 20.3039%\">cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a>, channels, asymmetric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">Alluvial<\/a><\/td>\n<td style=\"width: 20.8001%\">mud to boulders, poorly sorted<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> rocks<\/td>\n<td style=\"width: 18.1328%\">rare<\/td>\n<td style=\"width: 20.3039%\">channels, mud cracks<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2905\">Lacustrine<\/a> (lake)<\/td>\n<td style=\"width: 20.8001%\">fine-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2860\">laminations<\/a><\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">shale<\/a><\/td>\n<td style=\"width: 18.1328%\">invertebrates, rare (deep) bone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a><\/td>\n<td style=\"width: 20.3039%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2860\">laminations<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2907\">Paludal<\/a> (swamp)<\/td>\n<td style=\"width: 20.8001%\">plant material<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2856\">coal<\/a><\/td>\n<td style=\"width: 18.1328%\">plant debris<\/td>\n<td style=\"width: 20.3039%\">rare<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2908\">Aeolian<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a>)<\/td>\n<td style=\"width: 20.8001%\">very well sorted sand and silt<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a><\/td>\n<td style=\"width: 18.1328%\">rare<\/td>\n<td style=\"width: 20.3039%\">cross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> (large)<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 19.963%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">Glacial<\/a><\/td>\n<td style=\"width: 20.8001%\">mud to boulders, poorly sorted<\/td>\n<td style=\"width: 20.8001%\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2833\">conglomerate<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2483\">tillite<\/a>)<\/td>\n<td style=\"width: 18.1328%\"><\/td>\n<td style=\"width: 20.3039%\">striations, drop stones<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3><b>5.5.1. Marine<\/b><\/h3>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">Marine<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a>\u00a0are completely and constantly submerged in seawater. Their depositional characteristics are largely dependent on the depth of water with two notable exceptions, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2887\">submarine fans<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2888\">turbidites<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Abyssal<\/span><\/h4>\n<figure id=\"attachment_3087\" aria-describedby=\"caption-attachment-3087\" style=\"width: 452px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Marine_sediment_thickness.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-404\" title=\"NOAA, public domain\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Marine_sediment_thickness-300x272.jpg\" alt=\"The thickness is low in the abyssal plain.\" width=\"452\" height=\"410\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Marine_sediment_thickness-300x272.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Marine_sediment_thickness-768x697.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Marine_sediment_thickness-65x59.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Marine_sediment_thickness-225x204.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Marine_sediment_thickness-350x318.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Marine_sediment_thickness.jpg 857w\" sizes=\"auto, (max-width: 452px) 100vw, 452px\" \/><\/a><figcaption id=\"caption-attachment-3087\" class=\"wp-caption-text\">Marine sediment thickness. Note the lack of sediment away from the continents.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2884\">Abyssal<\/a> sedimentary rocks<\/strong> form on the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2885\">abyssal plain<\/a><\/strong>. The plain encompasses relatively flat <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2885\">ocean floor<\/a> with some minor topographical features, called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2884\">abyssal<\/a> hills. These small seafloor mounts range 100 m to 20 km in diameter, and are possibly created by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1445\">extension<\/a>. Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2884\">abyssal<\/a> plains do not experience significant fluid movement, so <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> formed there are very fine grained.<\/p>\n<p>There are three categories of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2884\">abyssal<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. Calcareous oozes consist of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>-rich plankton shells that have fallen to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2885\">ocean floor<\/a>. An example of this type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2855\">chalk<\/a>. Siliceous oozes are also made of plankton debris, but these organisms build their shells using silica or hydrated silica. In some cases such as with diatomaceous earth, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is deposited below the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2886\">calcite compensation depth<\/a><\/strong>, a depth where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a> solubility increases. Any <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1918\">calcite<\/a>-based shells are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2815\">dissolved<\/a>, leaving only silica-based shells. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2849\">Chert<\/a> is another common rock formed from these types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. These two types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2884\">abyssal<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> are also classified as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">biochemical<\/a> in origin. (see <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2850\">BIOCHEMICAL<\/a> section).<\/p>\n<figure id=\"attachment_3090\" aria-describedby=\"caption-attachment-3090\" style=\"width: 420px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-405\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc-300x251.jpg\" alt=\"The rock is powdery and white.\" width=\"420\" height=\"352\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc-300x251.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc-768x643.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc-65x54.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc-225x188.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc-350x293.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Diatomite_diatomaceous_earth_Monterey_Formation_at_a_diatomite_quarry_just_south_of_Lompoc.jpg 1023w\" sizes=\"auto, (max-width: 420px) 100vw, 420px\" \/><\/a><figcaption id=\"caption-attachment-3090\" class=\"wp-caption-text\">Diatomaceous earth<\/figcaption><\/figure>\n<p>The third <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> type is pelagic clay. Very fine-grained clay particles, typically brown or red, descend through the water column very slowly. Pelagic clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> occurs in areas of remote open ocean, where there is little plankton accumulation.<\/p>\n<figure id=\"attachment_3092\" aria-describedby=\"caption-attachment-3092\" style=\"width: 411px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Turbidite_formation.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-406\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-300x209.jpg\" alt=\"The canyon allows stacking of these deposits on the ocean floor.\" width=\"411\" height=\"286\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-300x209.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-1024x714.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-768x535.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-1536x1070.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-65x45.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-225x157.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation-350x244.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Turbidite_formation.jpg 1600w\" sizes=\"auto, (max-width: 411px) 100vw, 411px\" \/><\/a><figcaption id=\"caption-attachment-3092\" class=\"wp-caption-text\">Turbidites inter-deposited within submarine fans.<\/figcaption><\/figure>\n<p>Two notable exceptions to the fine-grained nature of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2884\">abyssal<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> are <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2887\">submarine fan<\/a><\/strong> and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2888\">turbidite<\/a><\/strong> deposits. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2887\">Submarine fans<\/a> occur <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3196\">offshore<\/a> at the base of large <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a> systems. They are initiated during times of low sea level, as strong <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a> currents carve <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3224\">submarine canyons<\/a> into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2891\">continental shelf<\/a>. When sea levels rise, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> accumulates on the shelf typically forming large, fan-shaped floodplains called deltas. Periodically, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is disturbed creating dense slurries that flush down the underwater canyons in large gravity-induced events called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2888\">turbidites<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2887\">submarine fan<\/a> is formed by a network of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2888\">turbidites<\/a> that deposit their <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> loads as the slope decreases, much like what happens above-water at <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">alluvial<\/a> fans and deltas. This sudden flushing transports coarser <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2885\">ocean floor<\/a> where they are otherwise uncommon. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2888\">Turbidites<\/a> are also the typical origin of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2862\">graded<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2863\">Bouma<\/a> sequences. (see Chapter 5, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">Weathering<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">Erosion<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">Sedimentary Rock<\/a>).<\/p>\n<h4><span style=\"font-weight: 400\">Continental Slope<\/span><\/h4>\n<figure id=\"attachment_3094\" aria-describedby=\"caption-attachment-3094\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Contourite_sparker_seismic_elongate_drift.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-407 size-medium\" title=\"IODP, 2012\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-300x162.png\" alt=\"The deposit is a large, dipping pile of sediment\" width=\"300\" height=\"162\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-300x162.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-1024x553.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-768x414.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-1536x829.png 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-65x35.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-225x121.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift-350x189.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Contourite_sparker_seismic_elongate_drift.png 2048w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3094\" class=\"wp-caption-text\">Contourite drift deposit imaged with seismic waves.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2892\">Continental slope<\/a><\/strong> deposits are not common in the rock record. The most notable type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2892\">continental slope<\/a> deposits are contourites. Contourites form on the slope between the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2891\">continental shelf<\/a> and deep <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2885\">ocean floor<\/a>. Deep-water ocean currents deposit <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> into smooth drifts of various architectures, sometimes interwoven with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2888\">turbidites<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Lower shoreface<\/span><\/h4>\n<figure id=\"attachment_3097\" aria-describedby=\"caption-attachment-3097\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Wavebase.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-408 size-medium\" title=\"https:\/\/en.wikipedia.org\/wiki\/File:Wavebase.jpg, by https:\/\/en.wikipedia.org\/wiki\/User:GregBenson\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Wavebase-300x218.jpg\" alt=\"The diagram shows that wavebase is 1\/2 the wavelength of waves of water.\" width=\"300\" height=\"218\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wavebase-300x218.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wavebase-65x47.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wavebase-225x164.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wavebase-350x255.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Wavebase.jpg 400w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3097\" class=\"wp-caption-text\">Diagram describing wavebase.<\/figcaption><\/figure>\n<p>The <strong>lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2889\">shoreface<\/a><\/strong> lies below the normal depth of wave agitation, so the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is not subject to daily winnowing and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a>. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> layers are typically finely laminated, and may contain hummocky cross-stratification. Lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2889\">shoreface<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> are affected by larger waves, such those as generated by hurricanes and other large storms.<\/p>\n<h4><span style=\"font-weight: 400\">Upper shoreface<\/span><\/h4>\n<figure id=\"attachment_3467\" aria-describedby=\"caption-attachment-3467\" style=\"width: 666px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Littoral_Zones-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-409\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Littoral_Zones-1.jpg\" alt=\"The image shows the many complexities of the shoreline described in the text.\" width=\"666\" height=\"292\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Littoral_Zones-1.jpg 666w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Littoral_Zones-1-300x132.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Littoral_Zones-1-65x28.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Littoral_Zones-1-225x99.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Littoral_Zones-1-350x153.jpg 350w\" sizes=\"auto, (max-width: 666px) 100vw, 666px\" \/><\/a><figcaption id=\"caption-attachment-3467\" class=\"wp-caption-text\">Diagram of zones of the shoreline.<\/figcaption><\/figure>\n<p>The <strong>upper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2889\">shoreface<\/a><\/strong> contains <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> within the zone of normal wave action, but still submerged below the beach environment. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> usually consist of very well sorted, fine sand. The main sedimentary structure is planar <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> consistent with the lower part of the upper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2864\">flow regime<\/a>, but it can also contain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2457\">cross bedding<\/a> created by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3205\">longshore currents<\/a>.<\/p>\n<h3><b>5.5.2. Transitional coastline\u00a0environments<\/b><\/h3>\n<figure id=\"attachment_3264\" aria-describedby=\"caption-attachment-3264\" style=\"width: 400px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/TransgressionRegression-1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-410\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/TransgressionRegression-1-300x199.png\" alt=\"Onlap is sediments moving toward the land. Offlap is moving away.\" width=\"400\" height=\"265\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/TransgressionRegression-1-300x199.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/TransgressionRegression-1-65x43.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/TransgressionRegression-1-225x149.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/TransgressionRegression-1-350x232.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/TransgressionRegression-1.png 500w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/a><figcaption id=\"caption-attachment-3264\" class=\"wp-caption-text\">The rising sea levels of transgressions create onlapping sediments, regressions create offlapping.<\/figcaption><\/figure>\n<p>Transitional environments, more often called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">shoreline<\/a> or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2890\">coastline<\/a> environments<\/strong>, are zones of complex interactions caused by ocean water hitting land. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> preservation potential is very high in these environments because <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> often occurs on the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2891\">continental shelf<\/a><\/strong> and underwater. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">Shoreline<\/a> environments are an important source of hydrocarbon deposits (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3337\">petroleum<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3339\">natural gas<\/a>).<\/p>\n<p>The study of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">shoreline<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a> is called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2893\">sequence stratigraphy<\/a><\/strong>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2893\">Sequence stratigraphy<\/a>\u00a0examines depositional changes and 3D architectures associated with rising and falling sea levels, which is the main force at work in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">shoreline<\/a> deposits. These sea-level fluctuations come from the daily tides, as well as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1710\">climate<\/a> changes and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2576\">plate tectonics<\/a>. A steady rise in sea level relative to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">shoreline<\/a> is called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2894\">transgression<\/a><\/strong>. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2895\">Regression<\/a><\/strong> is the opposite, a relative drop in sea level. Some common components of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">shoreline<\/a> environments are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2896\">littoral<\/a> zones, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">tidal flats<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2900\">lagoons<\/a>, and deltas. For a more in-depth look at these environments, see <a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/12-shorelines\/\">Chapter 12, Coastlines<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Littoral<\/span><\/h4>\n<figure id=\"attachment_3102\" aria-describedby=\"caption-attachment-3102\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/HeavyMineralsBeachSand.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-411\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/HeavyMineralsBeachSand-300x205.jpg\" alt=\"The tan rock has dark streaks of minerals.\" width=\"300\" height=\"205\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HeavyMineralsBeachSand-300x205.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HeavyMineralsBeachSand-65x44.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HeavyMineralsBeachSand-225x154.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HeavyMineralsBeachSand-350x240.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/HeavyMineralsBeachSand.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3102\" class=\"wp-caption-text\">Lithified heavy mineral sand (dark layers) from a beach deposit in India.<\/figcaption><\/figure>\n<p>The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2896\">littoral<\/a><\/strong> zone, better known as the beach, consists of highly weathered, homogeneous, well-sorted sand grains made mostly of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1915\">quartz<\/a>. There are black sand and other types of sand beaches, but they tend to be unique exceptions rather than the rule. Because beach sands, past or present, are so highly evolved, the amount grain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a> can be discerned using the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2175\">zircon<\/a>, tourmaline, and rutile. This tool is called the ZTR (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2175\">zircon<\/a>, tourmaline, rutile) index. The ZTR index is higher in more weathered beaches, because these relatively rare and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1709\">weather<\/a>-resistant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> become <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3333\">concentrated<\/a> in older beaches. In some beaches, the ZTR index is so high the sand can be harvested as an economically viable source of these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>. The beach environment has no sedimentary structures, due to the constant bombardment of wave energy delivered by surf action. Beach <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is moved around via multiple processes. Some beaches with high <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> supplies develop <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> nearby.<\/p>\n<h4><span style=\"font-weight: 400\">Tidal Flats<\/span><\/h4>\n<figure id=\"attachment_3103\" aria-describedby=\"caption-attachment-3103\" style=\"width: 414px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tidal_flat_general_sketch.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-412\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Tidal_flat_general_sketch-300x225.png\" alt=\"The tidal flat it a network of channels.\" width=\"414\" height=\"311\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Tidal_flat_general_sketch-300x225.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Tidal_flat_general_sketch-768x576.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Tidal_flat_general_sketch-65x49.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Tidal_flat_general_sketch-225x169.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Tidal_flat_general_sketch-350x263.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Tidal_flat_general_sketch.png 960w\" sizes=\"auto, (max-width: 414px) 100vw, 414px\" \/><\/a><figcaption id=\"caption-attachment-3103\" class=\"wp-caption-text\">General diagram of a tidal flat and associated features.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">Tidal flats<\/a>, or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">mud flats<\/a>, are sedimentary environments that are regularly flooded and drained by ocean tides. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">Tidal flats<\/a> have large areas of fine-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> but may also contain coarser sands. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">Tidal flat<\/a> deposits typically contain gradational <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> and may include multi-directional <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripple<\/a> marks. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2874\">Mudcracks<\/a> are also commonly seen due to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> being regularly exposed to air during low tides; the combination of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2874\">mudcracks<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripple<\/a> marks is distinctive to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">tidal flats<\/a>.<\/p>\n<p>Tidal water carries in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, sometimes focusing the flow through a narrow opening called a tidal inlet. Tidal channels, creek channels influenced by tides, can also <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3080\">focus<\/a> tidally-induced flow. Areas of higher flow like inlets and tidal channels feature coarser grain sizes and larger <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripples<\/a>, which in some cases can develop into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Reefs<\/span><\/h4>\n<figure id=\"attachment_3106\" aria-describedby=\"caption-attachment-3106\" style=\"width: 567px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/CapitolReef-WaterpocketFold.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-413\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-300x174.jpg\" alt=\"The fold is a long ridge.\" width=\"567\" height=\"328\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-300x174.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-1024x593.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-768x445.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-1536x890.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-65x38.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-225x130.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold-350x203.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/CapitolReef-WaterpocketFold.jpg 1599w\" sizes=\"auto, (max-width: 567px) 100vw, 567px\" \/><\/a><figcaption id=\"caption-attachment-3106\" class=\"wp-caption-text\">Waterpocket fold, Capitol Reef National Park, Utah<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">Reefs<\/a>, which most people would immediately associate with tropical coral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a> found in the oceans, are not only made by living things. Natural buildups of sand or rock can also create <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a>, similar to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3218\">barrier islands<\/a>. Geologically speaking, a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a><\/strong> is any topographically-elevated feature on the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2891\">continental shelf<\/a>, located oceanward of and separate from the beach. The term <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> can also be applied to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2902\">terrestrial<\/a> (atop the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2575\">continental crust<\/a>) features. Capitol <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">Reef<\/a> National Park in Utah contains a topographic barrier, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a>, called the Waterpocket <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1455\">Fold<\/a>.<\/p>\n<figure id=\"attachment_3109\" aria-describedby=\"caption-attachment-3109\" style=\"width: 272px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Coral_Outcrop_Flynn_Reef.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-414\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Coral_Outcrop_Flynn_Reef-300x225.jpg\" alt=\"The reef has many intricacies.\" width=\"272\" height=\"204\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coral_Outcrop_Flynn_Reef-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coral_Outcrop_Flynn_Reef-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coral_Outcrop_Flynn_Reef-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coral_Outcrop_Flynn_Reef-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Coral_Outcrop_Flynn_Reef.jpg 640w\" sizes=\"auto, (max-width: 272px) 100vw, 272px\" \/><\/a><figcaption id=\"caption-attachment-3109\" class=\"wp-caption-text\">A modern coral reef.<\/figcaption><\/figure>\n<p>Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a>, now and in the geologic past, originate from the biological processes of living organisms. The growth habits of coral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a> provide geologists important information about the past. The hard structures in coral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a> are built by soft-bodied <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">marine<\/a> organisms, which continually add new material and enlarge the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> over time. Under certain conditions, when the land beneath a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> is subsiding, the coral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> may grow around and through existing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, holding the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> in place, and thus preserving the record of environmental and geological condition around it.<\/p>\n<figure id=\"attachment_3110\" aria-describedby=\"caption-attachment-3110\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Vanatinai_Louisiade_Archipelago.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-415\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Vanatinai_Louisiade_Archipelago-300x200.jpg\" alt=\"The reef is offshore of the island proper.\" width=\"300\" height=\"200\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Vanatinai_Louisiade_Archipelago-300x200.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Vanatinai_Louisiade_Archipelago-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Vanatinai_Louisiade_Archipelago-225x150.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Vanatinai_Louisiade_Archipelago-350x234.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Vanatinai_Louisiade_Archipelago.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3110\" class=\"wp-caption-text\">The light blue reef is fringing the island of Vanatinai. As the island erodes away, only the reef will remain, forming a reef-bound seamount.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a> found in coral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a> is typically fine-grained, mostly <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a>, and tends to deposit between the intact coral skeletons. Water with high levels of silt or clay particles can inhibit the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> growth because coral organisms require sunlight to thrive; they host symbiotic algae called zooxanthellae that provide the coral with nourishment via photosynthesis. Inorganic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> structures have much more variable compositions. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">Reefs<\/a> have a big impact on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2900\">lagoon<\/a> environments since they are natural storm breaks, wave and storm buffers, which allows fine grains to settle and accumulate.<\/p>\n<figure id=\"attachment_3113\" aria-describedby=\"caption-attachment-3113\" style=\"width: 378px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-416\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-300x189.jpg\" alt=\"The map shows locations.\" width=\"378\" height=\"238\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-300x189.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-1024x645.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-768x483.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-1536x967.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-65x41.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-225x142.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf-350x220.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Distribution_of_seamounts_and_guyots_in_the_North_Pacific.pdf.jpg 2048w\" sizes=\"auto, (max-width: 378px) 100vw, 378px\" \/><\/a><figcaption id=\"caption-attachment-3113\" class=\"wp-caption-text\">Seamounts and guyots in the North Pacific.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">Reefs<\/a> are found around shorelines and islands; coral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reefs<\/a> are particularly common in tropical locations. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">Reefs<\/a> are also found around features known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2899\">seamounts<\/a><\/strong>, which is the base of an ocean island left standing underwater after the upper part is eroded away by waves. Examples include the Emperor <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2899\">Seamounts<\/a>, formed millions of years ago over the Hawaiian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2638\">Hotspot<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">Reefs<\/a> live and grow along the upper edge of these flat-topped <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2899\">seamounts<\/a>. If the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> builds up above sea level and completely encircles the top of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2899\">seamount<\/a>, it is called a coral-ringed atoll. If the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> is submerged, due to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1464\">subsidence<\/a>, or sea level rise, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2899\">seamount<\/a>&#8211;<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> structure is called a guyot.<\/p>\n<h4><span style=\"font-weight: 400\">Lagoon<\/span><\/h4>\n<figure id=\"attachment_3116\" aria-describedby=\"caption-attachment-3116\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/LaggonKara_bogaz_gol.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-417 size-medium\" title=\"Public domain, by NASA\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/LaggonKara_bogaz_gol-300x300.jpg\" alt=\"The lagoon is just inside the coastline.\" width=\"300\" height=\"300\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LaggonKara_bogaz_gol-300x300.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LaggonKara_bogaz_gol-150x150.jpg 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LaggonKara_bogaz_gol-65x65.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LaggonKara_bogaz_gol-225x225.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LaggonKara_bogaz_gol-350x350.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/LaggonKara_bogaz_gol.jpg 639w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3116\" class=\"wp-caption-text\">Kara-Bogaz Gol lagoon, Turkmenistan.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2900\">Lagoons<\/a><\/strong> are small bodies of seawater located inland from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">shore<\/a> or isolated by another geographic feature, such as a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3218\">barrier island<\/a>. Because they are protected from the action of tides, currents, and waves, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2900\">lagoon<\/a> environments typically have very fine grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2900\">Lagoons<\/a>, as well as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3219\">estuaries<\/a>, are ecosystems with high biological productivity. Rocks from these environments often includes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2873\">bioturbation<\/a> marks or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2856\">coal<\/a> deposits. Around <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2900\">lagoons<\/a> where evaporation exceeds water inflow, salt flats, also known as sabkhas, and sand <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a> fields may develop at or above the high <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2428\">tide<\/a> line.<\/p>\n<h4><span style=\"font-weight: 400\">Deltas<\/span><\/h4>\n<figure id=\"attachment_3118\" aria-describedby=\"caption-attachment-3118\" style=\"width: 496px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/NileDelta-EO.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-418\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/NileDelta-EO.jpg\" alt=\"05.5_NileDelta-EO\" width=\"496\" height=\"565\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NileDelta-EO.jpg 496w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NileDelta-EO-263x300.jpg 263w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NileDelta-EO-65x74.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NileDelta-EO-225x256.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/NileDelta-EO-350x399.jpg 350w\" sizes=\"auto, (max-width: 496px) 100vw, 496px\" \/><\/a><figcaption id=\"caption-attachment-3118\" class=\"wp-caption-text\">The Nile delta, in Egypt.<\/figcaption><\/figure>\n<figure id=\"attachment_3120\" aria-describedby=\"caption-attachment-3120\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Mississippi-birdfoot-delta.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-419 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-300x300.jpg\" alt=\"Birdfoot river-dominated delta of the Mississippi River\" width=\"300\" height=\"300\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-300x300.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-1024x1022.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-150x150.jpg 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-768x767.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-65x65.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-225x225.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta-350x349.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Mississippi-birdfoot-delta.jpg 1061w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3120\" class=\"wp-caption-text\">Birdfoot river-dominated delta of the Mississippi River<\/figcaption><\/figure>\n<p><strong>Deltas<\/strong> form where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">rivers<\/a> enter lakes or oceans and are of three basic shapes: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a>-dominated deltas, wave-dominated deltas, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2428\">tide<\/a>-dominated deltas. The name <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a> comes from the Greek letter \u0394 (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a>, uppercase), which resembles the triangular shape of the Nile <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">River<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a>. The velocity of water flow is dependent on riverbed slope or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3135\">gradient<\/a>, which becomes shallower as the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a> descends from the mountains. At the point where a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a> enters an ocean or lake, its slope angle drops to zero degrees (0\u00b0). The flow velocity quickly drops as well, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is deposited, from coarse clasts, to fine sand, and mud to form the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a>. As one part of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a> becomes overwhelmed by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, the slow-moving flow gets diverted back and forth, over and over, and forms a spread out network of smaller distributary channels.<\/p>\n<figure id=\"attachment_3121\" aria-describedby=\"caption-attachment-3121\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ganges-tide-delta.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-420 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta-300x296.jpg\" alt=\"Tidal delta of the Ganges River.\" width=\"300\" height=\"296\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta-300x296.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta-1024x1009.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta-768x757.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta-65x64.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta-225x222.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta-350x345.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ganges-tide-delta.jpg 1055w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3121\" class=\"wp-caption-text\">Tidal delta of the Ganges River.<\/figcaption><\/figure>\n<p>Deltas are organized by the dominant process that controls their shape: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2428\">tide<\/a>-dominated, wave-dominated, or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a>-dominated. Wave-dominated deltas generally have smooth coastlines and beach-ridges on the land that represent previous shorelines. The Nile <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">River<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a> is a wave-dominated type. (see figure).<\/p>\n<p>The Mississippi <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">River<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a> is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a>-dominated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a>. shaped by levees along the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a> and its distributaries that confine the flow forming a shape called a birdfoot <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a>. Other times the tides or the waves can be a bigger factor, and can reshape the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a> in various ways.<\/p>\n<p>A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2428\">tide<\/a>-dominated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a> is dominated by tidal currents. During flood stages when <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">rivers<\/a> have lots of water available, it develops distributaries that are separated by sand bars and sand ridges. The tidal <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2901\">delta<\/a> of the Ganges <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">River<\/a> is the largest <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">delta<\/a> in the world.<\/p>\n<h3><b>5.5.3. Terrestrial<\/b><\/h3>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2902\">Terrestrial<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a><\/strong> are diverse. Water is a major factor in these environments, in liquid or frozen states, or even when it is lacking (arid conditions).<\/p>\n<h4><span style=\"font-weight: 400\">Fluvial<\/span><\/h4>\n<figure id=\"attachment_3124\" aria-describedby=\"caption-attachment-3124\" style=\"width: 450px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MeanderingRio-cauto-cuba.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-421\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba.jpg\" alt=\"The river wiggles back and forth.\" width=\"450\" height=\"338\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba.jpg 1600w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/MeanderingRio-cauto-cuba-350x263.jpg 350w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><\/a><figcaption id=\"caption-attachment-3124\" class=\"wp-caption-text\">The Cauto River in Cuba. Note the sinuosity in the river, which is meandering.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2903\">Fluvial<\/a><\/strong> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">river<\/a>) systems are formed by water flowing in channels over the land. They generally come in two main varieties: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3153\">meandering<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3152\">braided<\/a>. In <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3153\">meandering<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">streams<\/a>, the flow carries <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains via a single channel that wanders back and forth across the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3147\">floodplain<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3147\">floodplain<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> away from the channel is mostly fine grained material that only gets deposited during floods.<\/p>\n<figure id=\"attachment_3126\" aria-describedby=\"caption-attachment-3126\" style=\"width: 443px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/BraidedWaimakariri.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-422\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-300x225.jpg\" alt=\"The river has many inter-braided channels.\" width=\"443\" height=\"332\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-300x225.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-1024x768.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-768x576.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-1536x1152.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-65x49.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-225x169.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri-350x263.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/BraidedWaimakariri.jpg 1600w\" sizes=\"auto, (max-width: 443px) 100vw, 443px\" \/><\/a><figcaption id=\"caption-attachment-3126\" class=\"wp-caption-text\">The braided Waimakariri river in New Zealand.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3152\">Braided<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2903\">fluvial<\/a> systems generally contain coarser <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> grains, and form a complicated series of intertwined channels that flow around gravel and sand bars (<a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/11-water\/\">see Chapter 11, Water<\/a>).<\/p>\n<h4><span style=\"font-weight: 400\">Alluvial<\/span><\/h4>\n<figure id=\"attachment_3129\" aria-describedby=\"caption-attachment-3129\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/AlluvialPlain.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-423 size-medium\" title=\"By Matt Affolter\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/AlluvialPlain-300x200.jpg\" alt=\"This broad valley in the desert has alluvial deposition.\" width=\"300\" height=\"200\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/AlluvialPlain-300x200.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/AlluvialPlain-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/AlluvialPlain-225x150.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/AlluvialPlain-350x234.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/AlluvialPlain.jpg 640w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3129\" class=\"wp-caption-text\">An alluvial fan spreads out into a broad alluvial plain. From Red Rock Canyon State Park, California.<\/figcaption><\/figure>\n<p>A distinctive characteristic of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">alluvial<\/a><\/strong> systems is the intermittent flow of water. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">Alluvial<\/a> deposits are common in arid places with little <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1203\">soil<\/a> development. Lithified <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">alluvial<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> are the primary <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1461\">basin<\/a>-filling rock found throughout the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2462\">Basin and Range<\/a> region of the western United States. The most distinctive <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">alluvial<\/a> sedimentary deposit is the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">alluvial<\/a> fan, a large cone of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> formed by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">streams<\/a> flowing out of dry mountain valleys into a wider and more open dry area. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">Alluvial<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a> are typically poorly sorted and coarse grained, and often found near <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2906\">playa<\/a> lakes or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2908\">aeolian<\/a> deposits (<a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/13-deserts\/\">see Chapter 13, Deserts<\/a>).<\/p>\n<h4><span style=\"font-weight: 400\">Lacustrine<\/span><\/h4>\n<figure id=\"attachment_2479\" aria-describedby=\"caption-attachment-2479\" style=\"width: 417px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Crater_lake_oregon-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-45\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Crater_lake_oregon-1-300x200.jpg\" alt=\"The mountain has a large hole in the center that is filled with the lake.\" width=\"417\" height=\"278\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Crater_lake_oregon-1-300x200.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Crater_lake_oregon-1-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Crater_lake_oregon-1-225x150.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Crater_lake_oregon-1-350x233.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Crater_lake_oregon-1.jpg 623w\" sizes=\"auto, (max-width: 417px) 100vw, 417px\" \/><\/a><figcaption id=\"caption-attachment-2479\" class=\"wp-caption-text\">Oregon&#8217;s Crater Lake was formed about 7700 years ago after the eruption of Mount Mazama.<\/figcaption><\/figure>\n<p>Lake systems and deposits, called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2905\">lacustrine<\/a><\/strong>, form via processes somewhat similar to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">marine<\/a> deposits, but on a much smaller scale. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2905\">Lacustrine<\/a> deposits are found in lakes in a wide variety of locations. Lake Baikal in southeast Siberia (Russia) is in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2576\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1461\">basin<\/a>. Crater Lake (Oregon) sits in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1181\">volcanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1188\">caldera<\/a>. The Great Lakes (northern United States) came from glacially carved and deposited <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>. Ancient Lake Bonneville (Utah) formed in a\u00a0 pluvial setting that during a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1710\">climate<\/a> that was relatively wetter and cooler than that of modern Utah. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3159\">Oxbow<\/a> lakes, named for their curved shape, originated in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2903\">fluvial<\/a> floodplains. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2905\">Lacustrine<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> tends to be very fine grained and thinly laminated, with only minor contributions from wind-blown, current, and tidal deposits. When lakes dry out or evaporation outpaces <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitation<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2906\">playas<\/a> form. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2906\">Playa<\/a><\/strong> deposits resemble those of normal lake deposits but contain more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2842\">evaporite<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a>. Certain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">tidal flats<\/a> can have <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2906\">playa<\/a>-type deposits as well.<\/p>\n<h4><span style=\"font-weight: 400\">Paludal<\/span><\/h4>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2907\">Paludal<\/a><\/strong> systems include bogs, marshes, swamps, or other wetlands, and usually contain lots of organic matter. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2907\">Paludal<\/a> systems typically develop in coastal environments, but are common occur in humid, low-lying, low-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3372\">latitude<\/a>, warm zones with large volumes of flowing water. A characteristic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2907\">paludal<\/a> deposit is a peat bog, a deposit rich in organic matter that can be converted into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2856\">coal<\/a> when lithified. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2907\">Paludal<\/a> environments may be associated with tidal, deltaic, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2905\">lacustrine<\/a>, and\/or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2903\">fluvial<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Aeolian<\/span><\/h4>\n<figure id=\"attachment_3132\" aria-describedby=\"caption-attachment-3132\" style=\"width: 246px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/DuneTypes.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-424 size-medium\" title=\"US National Park Service, public domain\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/DuneTypes-246x300.jpg\" alt=\"The chart has the way dunes are made and four dune types.\" width=\"246\" height=\"300\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/DuneTypes-246x300.jpg 246w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/DuneTypes-65x79.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/DuneTypes-225x275.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/DuneTypes-350x427.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/DuneTypes.jpg 750w\" sizes=\"auto, (max-width: 246px) 100vw, 246px\" \/><\/a><figcaption id=\"caption-attachment-3132\" class=\"wp-caption-text\">Formation and types of dunes.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2908\">Aeolian<\/a><\/strong>, sometimes spelled <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2908\">eolian<\/a> or \u0153olian, are deposits of windblown <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a>. Since wind has a much lower carrying capacity than water, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2908\">aeolian<\/a> deposits typically consists of clast sizes from fine dust to sand. Fine silt and clay can cross very long distances, even entire oceans suspended in air.<\/p>\n<p>With sufficient <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> influx, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2908\">aeolian<\/a> systems can potentially form large <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> in dry or wet conditions.\u00a0 The figure shows <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a> features and various types. British geologist Ralph A. Bagnold (1896-1990) considered only Barchan and linear Seif <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a> as the only true <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dune<\/a> forms. Other scientists recognize transverse, star, parabolic, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2459\">linear dune<\/a> types. Parabolic and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2459\">linear dunes<\/a> grow from sand anchored by plants and are common in coastal areas.<\/p>\n<figure id=\"attachment_3135\" aria-describedby=\"caption-attachment-3135\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Loess-Plateau-in-China.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-425 size-medium\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-300x199.jpg\" alt=\"Loess Plateau in China. The loess is so highly compacted that buildings and homes have been carved in it.\" width=\"300\" height=\"199\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-300x199.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-1024x679.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-768x509.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-1536x1018.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-225x149.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China-350x232.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Loess-Plateau-in-China.jpg 1565w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-3135\" class=\"wp-caption-text\">Loess Plateau in China. The loess is so highly compacted that buildings and homes have been carved in it.<\/figcaption><\/figure>\n<p>Compacted layers of wind-blown <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> is known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2909\">loess<\/a><\/strong>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2909\">Loess<\/a> commonly starts as finely ground up rock flour created by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2464\">glaciers<\/a>. Such deposits cover thousands of square miles in the Midwestern United States. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2909\">Loess<\/a> may also form in desert regions (<a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/13-deserts\/\">see Chapter 13<\/a>). Silt for the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2909\">Loess<\/a> Plateau in China came from the Gobi Desert in China and Mongolia.<\/p>\n<h4><span style=\"font-weight: 400\">Glacial<\/span><\/h4>\n<figure id=\"attachment_3137\" aria-describedby=\"caption-attachment-3137\" style=\"width: 377px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/GlacierAthabaskaSediments.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-426\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-300x199.jpg\" alt=\"Large boulders and smaller sand are seen together.\" width=\"377\" height=\"250\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-300x199.jpg 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-1024x680.jpg 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-768x510.jpg 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-1536x1020.jpg 1536w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-65x43.jpg 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-225x149.jpg 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments-350x232.jpg 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/GlacierAthabaskaSediments.jpg 1599w\" sizes=\"auto, (max-width: 377px) 100vw, 377px\" \/><\/a><figcaption id=\"caption-attachment-3137\" class=\"wp-caption-text\">Wide range of sediments near Athabaska Glacier, Jasper National Park, Alberta, Canada.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">Glacial<\/a><\/strong> sedimentation is very diverse, and generally consists of the most poorly-sorted <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> deposits found in nature. The main clast type is called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2911\">diamictite<\/a>, which literally means two sizes, referring to the unsorted mix of large and small rock fragments found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">glacial<\/a> deposits. Many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">glacial<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2912\">tills<\/a>, glacially derived <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2911\">diamictites<\/a>, include very finely-pulverized rock flour along with giant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1691\">erratic<\/a> boulders. The surfaces of larger clasts typically have striations from the rubbing, scraping, and polishing of surfaces by abrasion during the movement of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">glacial<\/a> ice. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2910\">Glacial<\/a> systems are so large and produce so much <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a>, they frequently create multiple, individualized <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a>, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2903\">fluvial<\/a>, deltaic, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2905\">lacustrine<\/a>, pluvial, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2904\">alluvial<\/a>, and\/or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2908\">aeolian<\/a> (<a href=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/chapter\/14-glaciers\/\">see Chapter 14, Glaciers<\/a>).<\/p>\n<h3><span style=\"font-weight: 400\">5.5.4. Facies<\/span><\/h3>\n<p>In addition to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2682\">lithification<\/a> process, geologists also classify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> by its depositional characteristics, collectively called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> or lithofacies. Sedimentary <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> consist of physical, chemical, and\/or biological properties, including relative changes in these properties in adjacent <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> of the same layer or geological age. Geologists analyze <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> to interpret the original <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> environment, as well as disruptive geological events that may have occurred after the rock layers were established.<\/p>\n<p>It boggles the imagination to think of all the sedimentary <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a> environments working next to each other, at the same time, in any particular region on Earth. The resulting <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> develop characteristics reflecting contemporaneous conditions at the time of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a>, which later may become preserved into the rock record. For example in the Grand Canyon, rock <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">strata<\/a> of the same geologic age includes many different <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a>: beach sand, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">tidal flat<\/a> silt, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3196\">offshore<\/a> mud, and farther <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3196\">offshore<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a>. In other words, each sedimentary or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2859\">stratigraphic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> presents recognizable characteristics that reflect specific, and different, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a> that were present at the same time.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">Facies<\/a> may also reflect depositional changes in the same location over time. During <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2192\">periods<\/a> of rising sea level, called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">marine<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2894\">transgression<\/a>, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">shoreline<\/a> moves inland as seawater covers what was originally dry land and creates new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3196\">offshore<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">depositional environments<\/a>. When these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2858\">beds<\/a> turn into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2683\">sedimentary rock<\/a>, the vertical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2859\">stratigraphy<\/a> sequence reveals beach lithofacies buried by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3196\">offshore<\/a> lithofacies.<\/p>\n<p>Biological <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> are remnants (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2856\">coal<\/a>, diatomaceous earth) or evidence (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">fossils<\/a>) of living organisms. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2189\">Index fossils<\/a>, fossilized life forms specific to a particular environment and\/or geologic time <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2192\">period<\/a>, are an example of biological <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a>. The horizontal assemblage and vertical distribution of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">fossils<\/a> are particularly useful for studying species evolution because <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2894\">transgression<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2679\">deposition<\/a>, burial, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2680\">compaction<\/a> processes happen over a considerable geologic time range.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">Fossil<\/a> assemblages that show evolutionary changes greatly enhance our interpretation of Earth\u2019s ancient history by illustrating the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2184\">correlation<\/a> between <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2859\">stratigraphic<\/a> sequence and geologic time scale. During the Middle <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2224\">Cambrian<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2192\">period<\/a> (see Chapter 7, Geologic Time), regions around the Grand Canyon experienced <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">marine<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2894\">transgression<\/a> in a southeasterly direction (relative to current maps). This shift of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3195\">shoreline<\/a> is reflected in the Tapeats <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">Sandstone<\/a> beach <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a>, Bright Angle <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2839\">Shale<\/a> near-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3196\">offshore<\/a> mud <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a>, and Muav <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">Limestone<\/a> far-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3196\">offshore<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2883\">Marine<\/a> organisms had plenty of time to evolve and adapt to their slowly changing environment; these changes are reflected in the biological <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a>, which show older life forms in the western regions of the canyon and younger life forms in the east.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-35\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-35\" class=\"h5p-iframe\" data-content-id=\"35\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"5.5 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3995\" aria-describedby=\"caption-attachment-3995\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/5.5-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-427\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/5.5-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3995\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 5.5 via this QR Code.<\/figcaption><\/figure>\n<h2>Summary<\/h2>\n<p>Sedimentary rocks are grouped into two main categories: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3363\">detrital<\/a>) and chemical. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">Clastic<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3363\">detrital<\/a>) rocks are made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> clasts or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediment<\/a> that lithifies into solid material. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a> is produced by the mechanical or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2812\">chemical weathering<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> and transported away from the source via <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2677\">erosion<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a> that is deposited, buried, compacted, and sometimes cemented becomes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> rock. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">Clastic<\/a> rocks are classified by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2828\">grain size<\/a>; for example <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> is made of sand-sized particles. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">Chemical sedimentary<\/a> rocks comes from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">minerals<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2707\">precipitated<\/a> out an aqueous <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2705\">solution<\/a> and is classified according to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2826\">chemical sedimentary<\/a> rock <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2851\">limestone<\/a> is made of calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a>. Sedimentary structures have textures and shapes that give insight on depositional histories. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2882\">Depositional environments<\/a> depend mainly on fluid transport systems and encompass a wide variety of underwater and above ground conditions. Geologists analyze depositional conditions, sedimentary structures, and rock records to interpret the paleogeographic history of a region.<\/p>\n<h3>Take this quiz to check your comprehension of this Chapter.<\/h3>\n<div id=\"h5p-36\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-36\" class=\"h5p-iframe\" data-content-id=\"36\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Chapter 5 Review\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3994\" aria-describedby=\"caption-attachment-3994\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/01\/Ch-5-Review-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-428\" src=\"https:\/\/pressbooks.ccconline.org\/accdigitalmarketing\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-150x150.png 150w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-300x300.png 300w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-1024x1024.png 1024w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-768x768.png 768w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-65x65.png 65w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-225x225.png 225w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code-350x350.png 350w, https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-content\/uploads\/sites\/222\/2025\/01\/Ch-5-Review-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3994\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the review quiz for Chapter 5 via this QR Code.<\/figcaption><\/figure>\n<h2><b>References<\/b><\/h2>\n<div class=\"csl-bib-body\">\n<ol>\n<li class=\"csl-entry\">Affolter, M.D., 2004, On the nature of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1181\">volcanic<\/a> lithic fragments: Definition source and evolution:<\/li>\n<li class=\"csl-entry\">Ashley, G.M., 1990, Classification of large-scale subaqueous bedforms: a new look at an old problem-SEPM bedforms and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2857\">bedding<\/a> structures: J. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a>. Res., v. 60, no. 1.<\/li>\n<li class=\"csl-entry\">Ayrton, H., 1910, The origin and growth of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2868\">ripple<\/a>-mark: Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, v. 84, no. 571, p. 285\u2013310.<\/li>\n<li class=\"csl-entry\">Bagnold, R.A., 1941, The physics of blown sand and desert <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2869\">dunes<\/a>: Methum, London, UK, p. 265.<\/li>\n<li class=\"csl-entry\">Blatt, H., Middleton, G.V., and Murray, R., 1980, Origin of Sedimentary Rocks: Prentice-Hall, Inc., Englewood Cliffs, New Jersey, USA.<\/li>\n<li class=\"csl-entry\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2863\">Bouma<\/a>, A.H., Kuenen, P.H., and Shepard, F.P., 1962, Sedimentology of some flysch deposits: a graphic approach to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> interpretation: Elsevier Amsterdam.<\/li>\n<li class=\"csl-entry\">Cant, D.J., 1982, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2903\">Fluvial<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> models and their application:<\/li>\n<li class=\"csl-entry\">Dickinson, W.R., and Suczek, C.A., 1979, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2576\">Plate tectonics<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstone<\/a> compositions: AAPG Bull., v. 63, no. 12, p. 2164\u20132182.<\/li>\n<li class=\"csl-entry\">Dunham, R.J., 1962, Classification of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonate<\/a> rocks according to depositional textures:<\/li>\n<li class=\"csl-entry\">Eisma, D., 1998, Intertidal deposits: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3134\">River<\/a> mouths, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2897\">tidal flats<\/a>, and coastal <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2900\">lagoons<\/a>: CRC Marine Science, Taylor &amp; Francis, CRC Marine Science.<\/li>\n<li class=\"csl-entry\">Folk, R.L., 1974, Petrography of sedimentary rocks: Univ. Texas, Hemphill, Austin, Tex, v. 182.<\/li>\n<li class=\"csl-entry\">Goldich, S.S., 1938, A study in rock-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2676\">weathering<\/a>: J. Geol., v. 46, no. 1, p. 17\u201358.<\/li>\n<li class=\"csl-entry\">Hubert, J.F., 1962, A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2175\">zircon<\/a>-tourmaline-rutile maturity index and the interdependence of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a> of heavy <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2687\">mineral<\/a> assemblages with the gross <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2919\">texture<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2834\">sandstones<\/a>: J. Sediment. Res., v. 32, no. 3.<\/li>\n<li class=\"csl-entry\">Johnson, C.L., Franseen, E.K., and Goldstein, R.H., 2005, The effects of sea level and palaeotopography on lithofacies distribution and geometries in heterozoan <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonates<\/a>, south-eastern Spain: Sedimentology, v. 52, no. 3, p. 513\u2013536., doi: <a href=\"https:\/\/doi.org\/10.1111\/j.1365-3091.2005.00708.x\">10.1111\/j.1365-3091.2005.00708.x<\/a>.<\/li>\n<li class=\"csl-entry\">Kar\u00e1tson, D., Sztan\u00f3, O., and Telbisz, T., 2002, Preferred clast orientation in volcaniclastic mass-flow deposits: application of a new photo-statistical method: J. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a>. Res., v. 72, no. 6, p. 823\u2013835.<\/li>\n<li class=\"csl-entry\">Klappa, C.F., 1980, Rhizoliths in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2902\">terrestrial<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1917\">carbonates<\/a>: classification, recognition, genesis and significance: Sedimentology, v. 27, no. 6, p. 613\u2013629.<\/li>\n<li class=\"csl-entry\">Longman, M.W., 1981, A process approach to recognizing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2898\">reef<\/a> complexes:<\/li>\n<li class=\"csl-entry\">Mckee, E.D., and Weir, G.W., 1953, Terminology for stratification and cross-stratification in sedimentary rocks: Geol. Soc. Am. Bull., v. 64, no. 4, p. 381\u2013390.<\/li>\n<li class=\"csl-entry\">Metz, R., 1981, Why not <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2878\">raindrop impressions<\/a>? J. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a>. Res., v. 51, no. 1.<\/li>\n<li class=\"csl-entry\">Nichols, M.M., Biggs, R.B., and Davies, R.A.Jr., 1985, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_3219\">Estuaries<\/a>, <i>in<\/i> Coastal Sedimentary Environments: Springer-Verlag: New York, p. 77\u2013173.<\/li>\n<li class=\"csl-entry\">Normark, W.R., 1978, Fan valleys, channels, and depositional lobes on modern submarine fans: characters for recognition of sandy <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2888\">turbidite<\/a> environments: AAPG Bull., v. 62, no. 6, p. 912\u2013931.<\/li>\n<li class=\"csl-entry\">Pettijohn, F.J., and Potter, P.E., 2012, Atlas and glossary of primary sedimentary structures:<\/li>\n<li class=\"csl-entry\">Plummer, P.S., and Gostin, V.A., 1981, Shrinkage cracks: desiccation or synaeresis? J. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a>. Res., v. 51, no. 4.<\/li>\n<li class=\"csl-entry\">Reinson, G.E., 1984, Barrier-island and associated strand-plain systems, <i>in<\/i> Walker, R.G., editor, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">Facies<\/a> Models: Geoscience Canada Reprint Series 1, p. 119\u2013140.<\/li>\n<li class=\"csl-entry\">Stanistreet, I.G., and McCarthy, T.S., 1993, The Okavango Fan and the classification of subaerial fan systems: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a>. Geol., v. 85, no. 1, p. 115\u2013133.<\/li>\n<li class=\"csl-entry\">Stow, D.A.V., Faug\u00e8res, J.-C., Viana, A., and Gonthier, E., 1998, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2176\">Fossil<\/a> contourites: a critical review: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">Sediment<\/a>. Geol., v. 115, no. 1\u20134, p. 3\u201331.<\/li>\n<li class=\"csl-entry\">Stow, D.A.V., and Piper, D.J.W., 1984, Deep-water fine-grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a>: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2913\">facies<\/a> models: Geological Society, London, Special Publications, v. 15, no. 1, p. 611\u2013646.<\/li>\n<li class=\"csl-entry\">Udden, J.A., 1914, Mechanical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2831\">composition<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a>: Geol. Soc. Am. Bull., v. 25, no. 1, p. 655\u2013744.<\/li>\n<li class=\"csl-entry\">Wentworth, C.K., 1922, A scale of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2938\">grade<\/a> and class terms for <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2825\">clastic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2678\">sediments<\/a>: J. Geol., v. 30, no. 5, p. 377\u2013392.<\/li>\n<li class=\"csl-entry\">Yin, D., Peakall, J., Parsons, D., Chen, Z., Averill, H.M., Wignall, P., and Best, J., 2016, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_2865\">Bedform<\/a> genesis in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_429_1971\">bedrock<\/a> substrates: Insights into formative processes from a new experimental approach and the importance of suspension-dominated abrasion: Geomorphology, v. 255, p. 26\u201338.<\/li>\n<\/ol>\n<\/div>\n<p><span style=\"font-weight: 400\">\u00a0<\/span><\/p>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_429_2683\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2683\"><div tabindex=\"-1\"><p>Rocks that are formed by sedimentary processes, including sediments lithifying and precipitation from solution.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2960\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2960\"><div tabindex=\"-1\"><p>An extensive, distinct, and mapped set of geologic layers.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1204\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1204\"><div tabindex=\"-1\"><p>The physical breakdown (weathering) of bedrock by processes such as pressure, ice expansion, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1971\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1971\"><div tabindex=\"-1\"><p>Term for the underlying lithified rocks that make up the geologic record in an area. This term can sometimes refer to only the deeper, crystalline (non-layered) rocks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2678\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2678\"><div tabindex=\"-1\"><p>Pieces of rock that have been weathered and possibly eroded.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2825\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2825\"><div tabindex=\"-1\"><p>Sedimentary rocks that are made of sediment, weathered pieces of bedrock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2705\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2705\"><div tabindex=\"-1\"><p>The act of taking a solid and dissolving it into a liquid. This commonly occurs with salts and other minerals in water.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2882\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2882\"><div tabindex=\"-1\"><p>An interpretation of the rock record which describes the cause of sedimentation (i.e. ancient beach, river, swamp, etc.).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2676\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2676\"><div tabindex=\"-1\"><p>Breaking down rocks into small pieces by chemical or mechanical means.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2677\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2677\"><div tabindex=\"-1\"><p>The transport and movement of weathered sediments.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2682\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2682\"><div tabindex=\"-1\"><p>The process of turning sediment into a sedimentary rocks, including deposition, compaction, and cementation.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2687\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2687\"><div tabindex=\"-1\"><p>A natural substance that is typically solid, has a crystalline structure, and is typically formed by inorganic processes. Minerals are the building blocks of most rocks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2826\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2826\"><div tabindex=\"-1\"><p>Sedimentary rocks that are precipitated, from solution.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3363\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3363\"><div tabindex=\"-1\"><p>Sedimentary rocks made of mineral grains weathered as mechanical detritus of previous rocks, e.g. sand, gravel, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2703\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2703\"><div tabindex=\"-1\"><p>Two or more atoms or ions that are connected chemically.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2690\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2690\"><div tabindex=\"-1\"><p>A molecule (like water) which has a positive side and a negative side.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2693\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2693\"><div tabindex=\"-1\"><p>Forces that cause one substance to stick to another.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2692\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2692\"><div tabindex=\"-1\"><p>Forces that hold a substance together.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1445\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1445\"><div tabindex=\"-1\"><p>Stresses that pull objects apart into a larger surface area or volume; stretching forces.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1202\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1202\"><div tabindex=\"-1\"><p>A weak chemical bond which attracts hydrogen to a negative part of a molecule. Many of water's properties are due to hydrogen bonds.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2689\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2689\"><div tabindex=\"-1\"><p>The measure of the vibrational (kinetic) energy of a substance.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2691\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2691\"><div tabindex=\"-1\"><p>A chemical that can dissolve a wide range of other chemicals.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2815\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2815\"><div tabindex=\"-1\"><p>The process in which solids (like minerals) are disassociated and the ionic components are dispersed in a liquid (usually water).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2580\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2580\"><div tabindex=\"-1\"><p>The outermost chemical layer of the Earth, defined by its low density and higher concentrations of lighter elements. The crust has two types: <strong>continental<\/strong>, which is the thick, more ductile, and lowest density, and <strong>oceanic<\/strong>, which is higher density, more brittle, and thinner.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1207\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1207\"><div tabindex=\"-1\"><p>A process where water freezes inside cracks in rocks, causing expansion and mechanical weathering.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1208\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1208\"><div tabindex=\"-1\"><p>A process where plants and their roots wedge into cracks in bedrock, and widen them.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2813\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2813\"><div tabindex=\"-1\"><p>An acid that forms from carbon dioxide and water. It is a large contributor to chemical weathering.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2814\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2814\"><div tabindex=\"-1\"><p>Water breaking into ions and replacing ions in minerals; a major type of chemical weathering in silicates.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2818\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2818\"><div tabindex=\"-1\"><p>Certain metallic elements (like iron) take in oxygen, causing reactions like rust.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1203\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1203\"><div tabindex=\"-1\"><p>A type of non-eroded sediment mixed with organic matter, used by plants. Many essential elements for life, like nitrogen, are delivered to organisms via the soil.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3110\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3110\"><div tabindex=\"-1\"><p>Any downhill movement of material, caused by gravity.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2464\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2464\"><div tabindex=\"-1\"><p>A body of ice that moves downhill under its own mass.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1205\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1205\"><div tabindex=\"-1\"><p>A type of mechanical weathering in which outer layers of rock, approximately parallel to the surface, fracture off.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1206\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1206\"><div tabindex=\"-1\"><p>A type of exfoliation where homogenous rocks weather into round shapes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2812\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2812\"><div tabindex=\"-1\"><p>Breaking down of mineral material via chemical methods, like dissolution and oxidation.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1934\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1934\"><div tabindex=\"-1\"><p>A break within a rock that has no relative movement between the sides. Caused by cooling, pressure release, tectonic forces, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2809\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2809\"><div tabindex=\"-1\"><p>Root systems preserved in rocks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2883\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2883\"><div tabindex=\"-1\"><p>Places that are under ocean water at all times.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2707\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2707\"><div tabindex=\"-1\"><p>The act of a solid coming out of solution, typically resulting from a drop in temperature or a decrease of the dissolving material.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2810\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2810\"><div tabindex=\"-1\"><p>Rounded cavities within rocks that form in various ways, including mineral growth, mainly salt.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2667\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2667\"><div tabindex=\"-1\"><p>The gases that are part of the Earth, which are mainly nitrogen and oxygen.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2702\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2702\"><div tabindex=\"-1\"><p>A positively-charged ion. In geology, this commonly includes ions of the elements Ca+2, Na+1, K+1, Fe+2,+3, Al+3, and Mg+2.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1916\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1916\"><div tabindex=\"-1\"><p>Consisting of three end members:&nbsp;potassium feldspar (K-spar, KAlSi3O8), plagioclase with calcium (CaAl2Si2O8, called anorthite), and plagioclase with sodium (NaAlSi3O8, called albite). Commonly blocky, with two cleavages as ~90\u00b0. Plagioclase is typically more dull white and grey, and K-spar is more vibrant white, orange, or red. The most common mineral found within the crust, and a major component of almost all igneous rocks, some sedimentary rocks, and some metamorphic rocks. Structure is a three-dimensional framework of silica tetrahedra, with locations open for cations (K, Na, Ca).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2709\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2709\"><div tabindex=\"-1\"><p>Mineral group in which the silica tetrahedra, SiO4-4, is the building block.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2704\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2704\"><div tabindex=\"-1\"><p>A negatively-charged ion. In geology, this commonly includes elements and molecules like SiO4-4, S-2, SO4-4, and O-2.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2842\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2842\"><div tabindex=\"-1\"><p>A chemical sedimentary rock that forms as water evaporates.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2851\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2851\"><div tabindex=\"-1\"><p>A chemical or biochemical rock made of mainly calcite.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2849\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2849\"><div tabindex=\"-1\"><p>A very fine grained version of silica deposited with or without microfossils.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1917\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1917\"><div tabindex=\"-1\"><p>Mineral group in which the carbonate ion, CO3-2, is the building block. This can also refer to the rocks that are made from these minerals, namely limestone and dolomite (dolostone).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1918\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1918\"><div tabindex=\"-1\"><p>CaCO3. Pure form is clear, but can take on many different colors with impurities. It is soft, fizzes in acid, and has three cleavages that are not at 90\u00b0. Thus, it can form slanted blocks, though it is visually common to be without any structure. Found in many sedimentary rocks from marine settings, rarely in igneous rocks, in the metamorphic rock marble, but is common as a secondary mineral throughout surface rocks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2816\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2816\"><div tabindex=\"-1\"><p>Working opposite of Bowen's reaction series, it states that minerals that are formed at conditions more dissimilar to the surface are more quickly prone to chemical weathering.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2674\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2674\"><div tabindex=\"-1\"><p>The process of liquid rock freezing into solid rock. Because liquid rock is made of many components, the process is complex as different components freeze at different temperatures.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1174\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1174\"><div tabindex=\"-1\"><p>A series of mineral formation temperatures that can explain the minerals that form in specific igneous rocks. For example, pyroxene will form with olivine and amphibole, but not quartz.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2675\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2675\"><div tabindex=\"-1\"><p>Rocks that are formed from liquid rock, i.e. from volcanic processes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1181\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1181\"><div tabindex=\"-1\"><p>Place where lava is erupted at the surface.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1709\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1709\"><div tabindex=\"-1\"><p>Current conditions within the atmosphere.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1915\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1915\"><div tabindex=\"-1\"><p>SiO2. Transparent, but can be any color imaginable with impurities. No cleavage, hard, and commonly forms equant masses. Perfect crystals are hexagonal prisms topped with pyramidal shapes. One of the most common minerals, and is found in many different geologic settings, including the dominant component of sand on the surface of Earth. Structure is a three-dimensional network of silica tetrahedra, connected as much as possible to each other.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1954\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1954\"><div tabindex=\"-1\"><p>Can refer to a volcanic rock with higher silica composition, or the minerals that make up those rocks, namely quartz, feldspar (both potassium feldspar and plagioclase feldspar), and muscovite mica. Felsic rocks are lighter in color and contain more minerals that are light in color, but can contain some biotite and amphibole. Primary felsic rocks are rhyolite (extrusive) and granite (intrusive).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1956\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1956\"><div tabindex=\"-1\"><p>Can refer to a volcanic rock with lower silica composition, or the minerals that make up those rocks, namely olivine, pyroxene, amphibole, and biotite. Mafic rocks are darker in color and contain more minerals that are dark in color, but can contain some plagioclase feldspar. Primary mafic rocks are basalt (extrusive) and gabbro (intrusive).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2711\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2711\"><div tabindex=\"-1\"><p>(Fe,Mg)2SiO4.&nbsp;Typically translucent olive green and equant, with no cleavage. Common in mafic igneous rocks and in the mantle, but easily weathered in surface conditions. Structure is isolated silica tetrahedra. Known as peridot when a gem.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2712\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2712\"><div tabindex=\"-1\"><p>XY(Al,Si)2O6, in which X typically equals Na, Ca, Mg, or Fe and Y typically equals Mg, Fe, or Al. Typically black to dark green, blocky, with two cleavages at ~90\u00b0. Common in mafic igneous rocks and some metamorphic rocks. Structure is a single chain of silica tetrahedra.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2817\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2817\"><div tabindex=\"-1\"><p>Carbonate rocks which dissolve, leaving behind caverns and holes which affect the landscape.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3129\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3129\"><div tabindex=\"-1\"><p>Water that is below the surface.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2706\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2706\"><div tabindex=\"-1\"><p>A solution that has the maximum allowed dissolved component, and is unable to dissolve more.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3345\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3345\"><div tabindex=\"-1\"><p>Minerals with a luster similar to metal and contain metals, including valuable elements like lead, zinc, copper, tin, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1919\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1919\"><div tabindex=\"-1\"><p>Minerals in which ions are bonded to oxygen, such as in ice, H2O.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2681\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2681\"><div tabindex=\"-1\"><p>Sediment being \"glued\" together via mineralization, typically calcite and quartz from groundwater fluids.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2669\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2669\"><div tabindex=\"-1\"><p>The living things that inhabit the Earth.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2665\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2665\"><div tabindex=\"-1\"><p>The solid, rocky parts of the Earth, including the crust, mantle, and core.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3341\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3341\"><div tabindex=\"-1\"><p>Rocks which allow petroleum resources to collect or move.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2819\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2819\"><div tabindex=\"-1\"><p>Organic rich material found in soil.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2700\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2700\"><div tabindex=\"-1\"><p>A group of all atoms with a specific number of protons, having specific, universal, and unique properties.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1710\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1710\"><div tabindex=\"-1\"><p>Long term averages and variations within the conditions of the atmosphere.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2820\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2820\"><div tabindex=\"-1\"><p>A hypothetical or real section cut through soil, showing the different layers (horizons) that exist.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2821\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2821\"><div tabindex=\"-1\"><p>Specific layers within a soil profile with specific properties.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2831\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2831\"><div tabindex=\"-1\"><p>The mineral make up of a rock, i.e. which minerals are found within a rock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2822\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2822\"><div tabindex=\"-1\"><p>Upper layer of soil, made mainly out of organic material.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2823\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2823\"><div tabindex=\"-1\"><p>Lower layer of the soil (B) which is a mixture of weathered bedrock, leeched materials, and organic material. Has two sublayers: the upper part, or regolith (with more organic materials), and the lower part, saprolite, which is only slightly weathered bedrock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3111\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3111\"><div tabindex=\"-1\"><p>Loose material that is a mixture of soil components and weathered bedrock sediments.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2688\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2688\"><div tabindex=\"-1\"><p>The rocks that existed before the changes that lead to a metamorphic rock, i.e. what rock would exist if the metamorphism was reversed.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2824\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2824\"><div tabindex=\"-1\"><p>Lowest layer of the soil (C), which is mechanically weathered (not chemically weathered) bedrock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3325\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3325\"><div tabindex=\"-1\"><p>Valuable material in the Earth, typically used for metallic mineral resources.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3357\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3357\"><div tabindex=\"-1\"><p>A highly weathered soil deposit that consists of aluminum ores.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1949\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1949\"><div tabindex=\"-1\"><p>Volcanic tephra that is less than 2 mm in diameter.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2902\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2902\"><div tabindex=\"-1\"><p>Depositional environments that are on land.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1924\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1924\"><div tabindex=\"-1\"><p>Minerals made from just a single element, bonded to itself. Examples include gold, silver, copper, and diamond, which is a native version of carbon.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3166\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3166\"><div tabindex=\"-1\"><p>A rock or sediment that has good permeability and porosity, and allows water to move easily, making it possible to get water for human use.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2890\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2890\"><div tabindex=\"-1\"><p>The entire area which is related to land-sea interactions.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2828\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2828\"><div tabindex=\"-1\"><p>The average diameter of a grain of sediment, ranging from small, also known as fine-grained (e.g. clay, silt) to large, also known as coarse-grained (e.g. boulder).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2829\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2829\"><div tabindex=\"-1\"><p>The range of sediment sizes within a sediment or sediment within sedimentary rocks. Well sorted means the sediment has the same sizes, poorly sorted means many different sizes are present.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2679\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2679\"><div tabindex=\"-1\"><p>Sediment gathering together and collecting, typically in a topographic low point.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2680\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2680\"><div tabindex=\"-1\"><p>Sediment being squeezed together into a coherent mass.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2827\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2827\"><div tabindex=\"-1\"><p>Changes in sedimentary rocks due to increased (but low when compared to metamorphism) temperatures and pressures. This can include deposition of new minerals (e.g. limestone converting to dolomite) or dissolution of existing minerals.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2914\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2914\"><div tabindex=\"-1\"><p>Rocks and minerals that change within the Earth are called metamorphic, changed by heat and pressure. Metamorphism is the name of the process.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2684\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2684\"><div tabindex=\"-1\"><p>Rocks formed via heat and pressure which change the minerals within the rock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2601\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2601\"><div tabindex=\"-1\"><p>Place where two plates slide past each other, creating strike slip faults.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3116\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3116\"><div tabindex=\"-1\"><p>Empty space in a geologic material, either within sediments, or within rocks. Can be filled by air, water, or hydrocarbons.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2176\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2176\"><div tabindex=\"-1\"><p>Any evidence of ancient life.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2862\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2862\"><div tabindex=\"-1\"><p>A sequence of layers in which the sediment changes linearly in size, either getting coarser or finer.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2910\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2910\"><div tabindex=\"-1\"><p>Deposition and erosion tied to glacier movement.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3134\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3134\"><div tabindex=\"-1\"><p>A channelled body of water.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3119\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3119\"><div tabindex=\"-1\"><p>Detached, free-falling rocks from very steep slopes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2830\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2830\"><div tabindex=\"-1\"><p>How smooth or rough the edges are within a sediment.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1927\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1927\"><div tabindex=\"-1\"><p>The ease or difficulty in scratching a mineral, measured by the qualitative Mohs hardness scale, which ranges from soft talc (#1 on the scale) to hard diamond (#10 on the scale).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3340\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3340\"><div tabindex=\"-1\"><p>A rock that contains material which can be turned into petroleum resources. Organic-rich muds form good source rocks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2575\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2575\"><div tabindex=\"-1\"><p>The layers of igneous, sedimentary, and metamorphic rocks that form the continents. Continental crust is much thicker than oceanic crust. Continental crust is defined as having higher concentrations of&nbsp;very light elements like K, Na, and Ca, and is the lowest density rocky layer of Earth. Its average composition is similar to granite.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2875\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2875\"><div tabindex=\"-1\"><p>Pieces of mudcracks that are incorporated into a sedimentary rock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2926\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2926\"><div tabindex=\"-1\"><p>Metamorphic rock with a strong foliation but no visible minerals, derived from mudstones or shales.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1938\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1938\"><div tabindex=\"-1\"><p>Igneous rock cooling, and thus forming, outside of the Earth, i.e. on the surface.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1961\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1961\"><div tabindex=\"-1\"><p>General name of a mafic rock that is extrusive. Generally has a black groundmass color.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2832\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2832\"><div tabindex=\"-1\"><p>The study of the components of a rock, mainly sedimentary rocks, and the information that can be obtained by understanding the origin of the components.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2576\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2576\"><div tabindex=\"-1\"><p>The theory that the outer layer of the Earth (the lithosphere) is broken in several plates, and these plates move relative to one another, causing the major topographic features of Earth (e.g. mountains, oceans) and most earthquakes and volcanoes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2623\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2623\"><div tabindex=\"-1\"><p>An arrangement of many continental masses collided together into one larger mass. According to the Wilson Cycle, this occurs every half billion years or so.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2834\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2834\"><div tabindex=\"-1\"><p>A rock primarily made of sand.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2175\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2175\"><div tabindex=\"-1\"><p>ZrSiO4.&nbsp;Relatively chemically inert with a hardness of 8.5. Common accessory mineral in igneous and metamorphic rocks, as well as detrital sediments. Uranium can substitute for zirconium, making zircon a valuable mineral in radiometric dating.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1959\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1959\"><div tabindex=\"-1\"><p>General term from the fine-grained, not discernible part of a rock. In igneous rocks, this is the part of the rock that is not phenocrysts, and can help in determining the composition of extrusive rocks. In sedimentary rocks, it typically refers to the fine-grained components, namely mud. In metamorphic rocks, it is usually referring to material between porphyroblasts or a low-grade rock with only microscopic mineralization.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2833\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2833\"><div tabindex=\"-1\"><p>A sedimentary rock with rounded, larger (\u22652 mm) clasts.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2835\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2835\"><div tabindex=\"-1\"><p>A sandstone with a significant mud component OR a sandstone with a significant lithic fragment component.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2837\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2837\"><div tabindex=\"-1\"><p>A rock made of primarily mud, i.e. particles smaller than sand (\u22640.064 mm).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2839\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2839\"><div tabindex=\"-1\"><p>A very fine-grained rock with very thin layering (fissile).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2840\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2840\"><div tabindex=\"-1\"><p>A rock made of primarily silt.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2841\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2841\"><div tabindex=\"-1\"><p>A rock made primarily of clay.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2838\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2838\"><div tabindex=\"-1\"><p>Extremely thin bedding in mudstones, a characteristic of shale.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2850\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2850\"><div tabindex=\"-1\"><p>Chemical sedimentary rocks that have a biologic component to their origin. Many limestones are biochemical.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3371\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3371\"><div tabindex=\"-1\"><p>An atom or molecule that has a charge (positive or negative) due to the loss or gain of electrons.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2856\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2856\"><div tabindex=\"-1\"><p>Former swamp-derived (plant) material that is part of the rock record.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3338\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3338\"><div tabindex=\"-1\"><p>A dark liquid fossil fuel derived from petroleum.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3339\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3339\"><div tabindex=\"-1\"><p>Gaseous fossil fuel derived from petroleum, mostly made of methane.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2843\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2843\"><div tabindex=\"-1\"><p>An evaporite mineral, CaSo4\u20222H2O. Has one cleavage, hardness of 2. Typically clear or white.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2844\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2844\"><div tabindex=\"-1\"><p>Also known as rock salt, or table salt. 3 cleavages at 90\u00b0, cubic crystal habit. Typically clear or white, hardness of 3.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2846\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2846\"><div tabindex=\"-1\"><p>Porous variety of carbonate that form in relatively unheated water, sometimes as towers and spires.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2847\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2847\"><div tabindex=\"-1\"><p>Porous, concentric, or layered variety of carbonate that forms with often heated water in springs and\/or caves.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2931\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2931\"><div tabindex=\"-1\"><p>A separation of light (felsic) and dark (mafic) minerals in higher grade metamorphic rocks like gneiss.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3174\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3174\"><div tabindex=\"-1\"><p>A place where pressurized groundwater flows onto the surface.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2848\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2848\"><div tabindex=\"-1\"><p>A sedimentary rock that formed long ago as free oxygen changed the solubility of iron, causing layers of iron rich and iron-poor sediments to form in thin layers, or bands.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2672\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2672\"><div tabindex=\"-1\"><p>Liquid rock within the Earth.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2845\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2845\"><div tabindex=\"-1\"><p>Spheres of calcite that form in saline waters with slight wave agitation. Ooid refers to the sphere, oolite the rock with the spheres.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2898\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2898\"><div tabindex=\"-1\"><p>A topographic high found away from the beach in deeper water, but still on the continental shelf. Typically, these are formed in tropical areas by organisms such as corals.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2852\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2852\"><div tabindex=\"-1\"><p>Adjective for a rock filled with fossils, most commonly with limestones.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2854\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2854\"><div tabindex=\"-1\"><p>Limestone made of shell fragments cemented together.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2855\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2855\"><div tabindex=\"-1\"><p>A limestone made of&nbsp;coccolithophore shells, a type of single-celled algae.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2853\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2853\"><div tabindex=\"-1\"><p>Limestone made of primarily fine-grained calcite mud. Microscopic fossils are commonly present.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2885\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2885\"><div tabindex=\"-1\"><p>Relatively flat ocean floor, which accumulates very fine grained detrital and chemical sediments.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2857\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2857\"><div tabindex=\"-1\"><p>Discernible layers of rock, typically from a sedimentary rock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3337\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3337\"><div tabindex=\"-1\"><p>A fossil fuel derived from shallow marine rocks. Consists of oil and natural gas.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2919\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2919\"><div tabindex=\"-1\"><p>Arrangement of minerals within a rock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2664\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2664\"><div tabindex=\"-1\"><p>An interconnected set of parts that combine and make up a whole.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2658\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2658\"><div tabindex=\"-1\"><p>Idea championed by James Hutton that the present is the key to the past, meaning the physical laws and processes that existed and operate in the past still exist and operate today.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2858\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2858\"><div tabindex=\"-1\"><p>A specific layer of rock with identifiable properties.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2859\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2859\"><div tabindex=\"-1\"><p>The study of rock layers and their relationships to each other within a specific area.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2860\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2860\"><div tabindex=\"-1\"><p>Thin (less than 1 cm) beds of rock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2863\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2863\"><div tabindex=\"-1\"><p>Predictable sequence of fining upward sediments, caused by turbidity flows.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2888\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2888\"><div tabindex=\"-1\"><p>Turbidite is the rock that forms from a turbidity flow, a relatively coarse and dense sediment transported to the abyssal plain.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3196\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3196\"><div tabindex=\"-1\"><p>The part of the coastline which is below any wave base action.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2864\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2864\"><div tabindex=\"-1\"><p>A qualitative measure of the speed of a fluid flow, with different amounts of flow corresponding to different sedimentary structures, called bedforms. Typically, it is split into upper and lower flow regimes, with upper being a more rapid flow.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2869\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2869\"><div tabindex=\"-1\"><p>A large pile of sediment, deposited perpendicular to flow. Internal bedding in dunes dips toward flow direction (i.e. cross bedding). Formed in the upper part of the lower flow regime.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2865\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2865\"><div tabindex=\"-1\"><p>A specific type of sedimentary structure (ripples, plane beds, etc.) linked to a specific flow regime.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2866\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2866\"><div tabindex=\"-1\"><p>A specific layer of rock formed by flowing fluid, either in the lowest part of the lower flow regime or lower part of the upper flow regime.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2868\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2868\"><div tabindex=\"-1\"><p>Ridges of sediment that form perpendicular to flow in the lower part of the lower flow regime.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2867\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2867\"><div tabindex=\"-1\"><p>Subtle ridges formed in the upper flow regime on top of plane beds in the direction of flow.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2872\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2872\"><div tabindex=\"-1\"><p>Similar to dunes, in that they are ridges of sand that form perpendicular to flow, but internally, the sediments dip up stream. Forms in the upper part of the upper flow regime.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2457\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2457\"><div tabindex=\"-1\"><p>A sedimentary structure that has inclined layers within an overall layer. Forms commonly in dunes, larger in eolian dunes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2461\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2461\"><div tabindex=\"-1\"><p>Dunes that form from many different wind directions.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2459\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2459\"><div tabindex=\"-1\"><p>Dunes that are much longer than wide, forming from wind that varies in two opposite directions.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3183\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3183\"><div tabindex=\"-1\"><p>Bottommost part of a wave.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2871\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2871\"><div tabindex=\"-1\"><p>A special type of cross bedding that forms when strong storms produce mounds and divots of cross-bedded sand in deeper water.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1454\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1454\"><div tabindex=\"-1\"><p>A measure of a plane's (maximum) angle with respect to horizontal, where a perfectly horizontal plane has a dip of zero and a vertical plane has a dip of 90\u00b0.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2873\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2873\"><div tabindex=\"-1\"><p>Sedimentary layering disturbed by movement of organisms.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2874\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2874\"><div tabindex=\"-1\"><p>Polygonal cracking that occurs with shrinking clays. Indicative of mud submerged underwater and then exposed to air.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2958\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2958\"><div tabindex=\"-1\"><p>A piece of a rock that is caught up inside of another rock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2897\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2897\"><div tabindex=\"-1\"><p>Wide and flat area of land covered by ocean water during high tide, but exposed to air by low tide.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2876\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2876\"><div tabindex=\"-1\"><p>A series of sedimentary structures formed on the base of a flow, eroding into underlying sediment. Examples include scour marks, flute casts, groove casts, and tool marks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2881\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2881\"><div tabindex=\"-1\"><p>A feature in a rock that allows the observer to determine which direction was up in the past.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2179\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2179\"><div tabindex=\"-1\"><p>Material filling in a cavity left by a organism that has dissolved away.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1448\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1448\"><div tabindex=\"-1\"><p>A strain that occurs in a substance in which the item changes shape due to a stress.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2878\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2878\"><div tabindex=\"-1\"><p>Small circular pits formed by raindrops impacting soft sediments.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2879\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2879\"><div tabindex=\"-1\"><p>Stacked cobbles in the direction of flow.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3213\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3213\"><div tabindex=\"-1\"><p>Rock spire that is offshore and a remnant of a rock layer.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2904\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2904\"><div tabindex=\"-1\"><p>Depositional environments that are involved with rarely-flowing water.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2870\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2870\"><div tabindex=\"-1\"><p>A sedimentary structure that forms in the lower flow regime, where ridges of sediment form perpendicular to flow direction, but within the ridges, sediment layers and dips toward flow direction. Found in ripples and dunes. Can be tabular, sinuous, or trough shaped.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2183\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2183\"><div tabindex=\"-1\"><p>Evidence of biologic activity that is preserved in the fossil record, but it not the organism itself. Examples include footprints and burrows. Ichnology is the study of trace fossils.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2189\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2189\"><div tabindex=\"-1\"><p>A fossil with a wide reach but short span used to match a rock later to a specific time period of rocks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2673\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2673\"><div tabindex=\"-1\"><p>Liquid rock on the surface of the Earth.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3147\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3147\"><div tabindex=\"-1\"><p>Flat area around a river channel that is filled with water during flooding events.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2884\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2884\"><div tabindex=\"-1\"><p>The deep, flat part of the ocean. Also known as the ocean floor.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2887\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2887\"><div tabindex=\"-1\"><p>Broad cone of coarse sediment deposited from a submarine flow or turbidity flow.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2892\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2892\"><div tabindex=\"-1\"><p>Steep part of an ocean basin that is the transition between the continental mass and the ocean floor.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2889\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2889\"><div tabindex=\"-1\"><p>Part of the coastal depositional environment, near the tidal zone but below. Lower shoreface is the part of the coastline which is only disturbed by storm waves, upper shoreface is disturbed by typical, daily wave action.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2896\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2896\"><div tabindex=\"-1\"><p>The beach (shoreline) zone, where waves are crashing.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_4147\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_4147\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2900\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2900\"><div tabindex=\"-1\"><p>Interior body of ocean water, at least partially cut off from the main ocean water.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2901\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2901\"><div tabindex=\"-1\"><p>Place where rivers enter a large body of water, forming a triangular shape as the river deposits sediment and switches course.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2903\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2903\"><div tabindex=\"-1\"><p>Deposition that has to so with rivers.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2905\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2905\"><div tabindex=\"-1\"><p>Deposition in and around lakes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2907\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2907\"><div tabindex=\"-1\"><p>Deposition in swamps.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2908\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2908\"><div tabindex=\"-1\"><p>Deposition with wind-blown sediment<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2483\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2483\"><div tabindex=\"-1\"><p>Term for a rock made definitively of glacial till.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2886\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2886\"><div tabindex=\"-1\"><p>Also known as the CCD, it is the point in the depths of the ocean where calcite start to dissolve, leaving only siliceous ooze behind.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3224\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3224\"><div tabindex=\"-1\"><p>Canyon carved into a continental shelf.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2891\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2891\"><div tabindex=\"-1\"><p>Submerged part of the continental mass, with a gentle slope.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3205\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3205\"><div tabindex=\"-1\"><p>A net movement that occurs as waves intersect the shoreline at non-perpendicular angles.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3195\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3195\"><div tabindex=\"-1\"><p>The part of the coastline which is directly related to water-land interaction, specifically the tidal zone and the range of wave base.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2893\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2893\"><div tabindex=\"-1\"><p>The study of changes in the rock record caused by changing sea level over time.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2894\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2894\"><div tabindex=\"-1\"><p>Sea level rise over time.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2895\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2895\"><div tabindex=\"-1\"><p>Sea level fall over time.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3333\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3333\"><div tabindex=\"-1\"><p>A mechanical process which takes ore and separates it from gangue material.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3080\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3080\"><div tabindex=\"-1\"><p>Initiation point of an earthquake or fault movement.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3218\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3218\"><div tabindex=\"-1\"><p>Ridges of sand, made from former beach sediments, that form parallel to the shoreline.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1455\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1455\"><div tabindex=\"-1\"><p>A rock layer that has been bent in a ductile way instead of breaking (as with faulting).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2899\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2899\"><div tabindex=\"-1\"><p>An eroded island. Since wave and weather action does not extend deep into the ocean, the root of the island is preserved as a seamount. Reefs can grow around seamounts.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2638\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2638\"><div tabindex=\"-1\"><p>Rising stationary magma, forming a succession of volcanism. This is reflected as islands on oceanic plates, and volcanic mountains or craters on land.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1464\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1464\"><div tabindex=\"-1\"><p>The act of the land surface down-warping, typically referred to when discussing sedimentation or with rapid groundwater removal.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3219\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3219\"><div tabindex=\"-1\"><p>Lagoon with brackish water, typically with abundant biologic factors.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2428\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2428\"><div tabindex=\"-1\"><p>Movements of water (rising and falling) due to the gravity of the moon and sun. This is most often seen in marine settings.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3135\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3135\"><div tabindex=\"-1\"><p>Slope of a stream channel.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3153\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3153\"><div tabindex=\"-1\"><p>Low-gradient channel where rivers sweep across broad flood plains.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3152\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3152\"><div tabindex=\"-1\"><p>Channel type with many switching channels, common with large sediment volumes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1461\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1461\"><div tabindex=\"-1\"><p>A down-warped feature in the crust.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2462\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2462\"><div tabindex=\"-1\"><p>Term for the extensional tectonic province that extends from California's Sierra Nevada Mountains in the west, to Utah's Wasatch Mountains to the east, to southern Oregon and Idaho to the north, to northern Mexico to the south. Known as a wide rift, as each graben 'basin,' bounded by horst 'ranges.' Each set of horsts with a graben has some individual extension, adding up to the overall rifting.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2906\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2906\"><div tabindex=\"-1\"><p>A dry lake bed in a desert valley.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1188\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1188\"><div tabindex=\"-1\"><p>Hole left behind after a large volume of material erupts out of a volcano. This depression is often tuned into a valley or lake after the eruption is over.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3159\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3159\"><div tabindex=\"-1\"><p>Abandoned meanders that are cut off from the main channel.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_3372\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_3372\"><div tabindex=\"-1\"><p>The measure of degrees north or south from the equator, which has a latitude of 0 degrees.&nbsp; The Earth's north and south poles have latitudes of 90 degrees north and south, respectively.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2909\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2909\"><div tabindex=\"-1\"><p>Wind-blown silt, mainly formed from glacial processes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2911\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2911\"><div tabindex=\"-1\"><p>A sedimentary rock containing two distinct grain sizes, typically cobbles (or larger) mixed with mud.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2912\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2912\"><div tabindex=\"-1\"><p>General term for very poorly sorted sediment that is of glacial origin.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_1691\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_1691\"><div tabindex=\"-1\"><p>Large sediment (e.g. boulder) carried and then dropped by a glacier.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2913\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2913\"><div tabindex=\"-1\"><p>A specific set of features that are tied together in an interpretive group. Facies can be based on mineralogy, biologic factors, fossils, rock types, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2192\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2192\"><div tabindex=\"-1\"><p>The third largest span of time recognized by geologists; smaller than a era, larger than a epoch. We are currently in the Quaternary period. Rocks of a specific period are called systems.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2184\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2184\"><div tabindex=\"-1\"><p>Matching rocks of similar ages, types, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2224\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2224\"><div tabindex=\"-1\"><p>The first period of the Paleozoic, 541 million years ago-485 million years ago.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_429_2938\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_429_2938\"><div tabindex=\"-1\"><p>A qualitative measure of the amount of metamorphism that has occurred or the amount of a resource present in an ore.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":83,"menu_order":5,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[48],"contributor":[],"license":[],"class_list":["post-429","chapter","type-chapter","status-publish","hentry","chapter-type-numberless"],"part":19,"_links":{"self":[{"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/pressbooks\/v2\/chapters\/429","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/wp\/v2\/users\/83"}],"version-history":[{"count":3,"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/pressbooks\/v2\/chapters\/429\/revisions"}],"predecessor-version":[{"id":3406,"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/pressbooks\/v2\/chapters\/429\/revisions\/3406"}],"part":[{"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/pressbooks\/v2\/parts\/19"}],"metadata":[{"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/pressbooks\/v2\/chapters\/429\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/wp\/v2\/media?parent=429"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/pressbooks\/v2\/chapter-type?post=429"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/wp\/v2\/contributor?post=429"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/accintrogeology\/wp-json\/wp\/v2\/license?post=429"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}