Exercises: Dating methods

Explain the difference between relative dating and absolute dating, and give an example of a geological event that can be dated using each type of method.

State the law of superposition of strata and apply it to the quarry sequence in the diagram (layers A, B, and C). Which is the oldest layer and what environmental change does the sequence suggest?

What is an index fossil (or characteristic fossil)? State the three requirements that a good index fossil must meet and explain why human beings cannot serve as such to date ancient rocks.

Define fossil and name three different types of evidence that can become fossilized (hard remains, tracks or ichnites, molds, coprolites, inclusions in amber), explaining what information each type provides.

Explain what the fossilization process consists of (rapid burial, mineralization of the hard parts) and discuss why soft-bodied organisms (jellyfish, worms) rarely appear as fossils.

Explain the principle of faunal identity and how it allows strata from two quarries hundreds of kilometers apart to be correlated, indicating which type of fossils serve best for that task.