Across
- 1. A layer of rock.
- 4. A law that states that the younger rockisthehighest.
- 7. First life form.
- 8. life: The time it takes for the remaining isotope.
- 9. A law that states that rock that cuts through other rock is the youngest.
- 10. A law that states that rocks inside rocks are older.
Down
- 2. The exact age of something
- 3. The age of something compared to the age of another thing.
- 5. Fossils that help indicate how old a rock is.
- 6. The remains of a dead animal.