Relative Dating Review Answers
1. What is Uniformitarianism and give an example? Who came up with the theory?
Processes that shape the earth, like erosion and deposition, remain the same over time. James
Hutton
2. What is Catastrophism and give an example? The earth changes due to drastic and sudden events
like meteor impacts, volcanoes, earthquakes, and tsunamis.
3. What is relative dating? The determination of which event is younger or older than another.
4. What is the principal of superposition? Oldest rock layers lie beneath younger rock layers in
undisturbed rock layers.
5. What is the geologic column? An idealized sequence of rock layers that contains all the known
fossils and rock formations on earth, arranged from oldest to youngest.
6. What is horizontal origin and cross cutting? Horizontal origin states that most rock layers form in
horizontal bands and if the rocks are arranged in any other way then there had to be some force
that acted on the rocks. Cross cutting states that a fault or igneous intrusion is younger than the
rocks the cut across.
7. What are unconformities? Missing rock layers that cause a break in the sequence of rock layers.
8. Name and describe three types of unconformities. Disconformity-most common, a missing sequence
in parallel rock layers; Nonconformity- older sedimentary rock layers lie on top of eroded igneous
or metamorphic rock; Angular unconformity- found between horizontal layers of sedimentary rock
and layers that have been tilted or folded.
9.
sequence these rock layers from oldest to youngest
Oldest ------------------------------------------------------------------ Youngest
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