The flashcards below were created by user
An ordered arrangement of rock layers that is based on the relative ages of the rocks and the the bottom layers are older.
Unit of geologic time that has two periods.
Unit of geologic time that is longer than an epoch but shorter than a era.
A subdivision of geologic time that is longer than a age but shorter than a period.
Process of change by which new species develop from preexisting species over time.