71 Summary — Physical Geology – 2nd Edition

Left: Cross section through the crust for questions 4 to 7.  Right: ¹⁴C decay curve for question 4.

Based on your answer to question 4, what can you say about the age of layer “c” in Figure 8.27.?
What type of unconformity exists between layer “c” and rock “f”?
What about between layer “c” and layer “b”?
We can’t use magnetic chronology to date anything younger than 780,000 years. Why not?
How did William Smith apply the principle of faunal succession to determine the relative ages of the sedimentary rocks of England and Wales?
Access a copy of the geological time scale (International Commission on Stratigraphy). What are the names of the last age (or stage) of the Cretaceous and the first age of the Paleogene? Print out the time scale and stick it on the wall above your desk!