Across
- 2. produced by algae forming calcium carbonate
- 3. evolved in early Paleozoic era
- 6. 3rd layer where temp decreases with height
- 12. cell that lacks a nucleus
- 13. temperature increases;tiny fraction of mass
- 15. 2nd layer of atmosphere from ground
- 16. transfer of heat by molecular activity
- 17. transfer of heat through space by EM waves
Down
- 1. faulted struct of divergent plate boundaries
- 4. 2 sed rocks are sep by erosional surface
- 5. large ancient metamorphic rock within continent
- 7. using radioactive isotopes to det age
- 8. erosional surface sep older rock from young
- 9. the bottom layer of atmosphere
- 10. surface with a break in the rock record
- 11. June 21 or 22
- 14. chronological order of age determined
- 16. transfer of heat by movement of mass