Geologic history is divided into eras, periods, and epochs based on the
1. type of rock deposited at different times throughout history
2 half-life of radioactive isotopes found in rocks
inferred movements of Earth's landmasses
4.
fossil evidence found in bedrock
1. type of rock deposited at different times throughout history
2 half-life of radioactive isotopes found in rocks
inferred movements of Earth's landmasses
4.
fossil evidence found in bedrock