Across
- 2. old, stable core of a continent
- 5. flourished during and went extinct at end of Mesozoic
- 7. stable mineral often used to date Precambrian rocks
- 11. signify the end of an era caused by glaciation, meteorites, global warming, supercontinents
- 12. single celled organisms without a nucleus
- 13. these vented water vapor, carbon dioxide and nitrogen gas into atmosphere
- 14. process by which a planet become internally zoned
Down
- 1. modified the atmosphere by adding oxygen (ozone)
- 3. ______ explosion refers to the huge increase in diversity of life on Earth
- 4. result of orogenic events and examples include Rocky, Appalachians, Himalayas
- 6. occurred during Cenozoic era, at height..covered 30% of land
- 8. hydrothermal vents had chemicals and hot water that could produce these building blocks of proteins
- 9. the earth is thought to be 4.6 ____ years old
- 10. movement of shoreline rising