Geological Time
Across
- 1. Eras are subdivided into unit in geological time
- 4. New rock layers meet a much older rock surface beneath them
- 6. All atoms are the same
- 8. An extremely thin coat of carbon on a rock
- 12. Scientists who study fossil
- 13. A break in earth crust
- 15. Group of hard-shelled animals that evoled in shallow sea more then 500 mya
- 16. Gradual changes in living things over long periods of time
- 17. If ti no longer exists and will never live again on earth
- 19. All matter, tiny particles
Down
- 1. Fossil in which minerals replace all or some parts of an organism
- 2. Continents moved into a great landmass
- 3. continents moving slowly over earths surface because of forces inside earth
- 5. Preserved remains or traces of living things
- 7. Rock's age compared with the other rock's age
- 9. Number of year since rock formed
- 10. Hollow ares in sediment in the shape of an organism
- 11. Another name for the Mesozoic Era
- 14. Solid copy of the shapes organism
- 18. Earth cooled; during the Quaternary Period