Across
- 1. radioactive decay over ____ time
- 3. a fossil that seperates two periods of time
- 5. parts of a layer in another layer
- 7. a line that messes up the law of superposition
- 8. helps find absolute age
- 9. an estimate of the age
Down
- 2. preserved living beings
- 4. has a fault line
- 6. exact age
- 10. a time period with specific fossils