Across
- 5. age based on object
- 7. studies of fossils
- 9. age based on rocks
- 11. leaving of molten rock
- 12. drilled ice
Down
- 1. determining age
- 2. divisions showing time
- 3. putting rocks on each other
- 4. a division of geologic time.
- 6. impression of prehistoric organism
- 8. entry of molten rock
- 10. servel subdivisions