Across
- 3. States that if a fault cuts through a rock it is younger than the rock.
- 7. New layers of rock on old layers.
- 8. Amount of time it takes for half an isotope to decay.
- 9. Estimate of how old something is.
- 10. States that if rock fragments are in another rock, the rock is older.
Down
- 1. Fossils that are used for dating
- 2. Relating to the period before written records.
- 4. Representation of time based on the rock record of Earth.
- 5. Preserved remains of something.
- 6. Exact age of something.