Across
- 3. decay/isotopes
- 5. scientific study
- 6. dating/events or objects
- 8. principle
- 11. time scale/divide earths long history
- 12. fossil/footprint
Down
- 1. rocks
- 2. isotope
- 4. age
- 5. column/arrangement of rock
- 7. created
- 9. dating/event or object in years
- 10. core/ice caps