Dating fossils based on the rock layer in which they are found uses which dating method?

• A. Relative dating
• B. Absolute dating
• C. Uniformitarianism
• D. Evidence

Answer: (A)

Dating fossils by the rock layer is an example of relative dating. The idea is that in undisturbed sedimentary layers, the oldest rocks sit at the bottom and younger rocks pile on top, so fossils in higher layers are newer than those in lower layers. This lets scientists compare the order of events without assigning exact ages in years. The method often uses index fossils—species known to have existed for a limited time and found in many places—to help match layers across different locations and tighten the sequence.

Absolute dating would give numeric ages, not just order, by using methods like radiometric dating. Uniformitarianism is a broad principle about how geological processes operate across time, not a dating method. “Evidence” isn’t a dating method either.