Stratigraphy and Geologic Time Flashcards
1
Q
Q: What is stratigraphy?
A
A: The science of using rock layers’ arrangement and composition to interpret geological history.
2
Q
Q: What is the Principle of Superposition?
A
A: In a sequence of sedimentary rocks, the oldest layers are at the bottom, and the youngest layers are at the top.
3
Q
Q: What are exceptions to the Principle of Superposition?
A
A: Igneous intrusions and mountain-building events can disrupt layer order.
4
Q
Q: What is radiometric dating used for?
A
A: To determine the absolute age of rocks using isotopic decay.
5
Q
Q: Why can’t sedimentary rocks usually be radiometrically dated?
A
A: They are composed of preformed sediments already undergoing radioactive decay.
