Geological Time

1. the processes of dating rocks and fossils by comparing one rock to another
4. the era where we see the rise of the reptiles
6. the most recent supercontinent that broke up during the mesozoic era
9. the era where the cambrian explosion occured that created a huge diversity of life
11. the law stating that the oldest layers are on the bottom and the newest layers are on top
13. the processes of dating rocks and fossils by measuring the elemental change in a rock
15. the theory that an asteroid the size of mars hit earth and created the moon
17. the current mass extinction that is being caused by human activity
18. The eon that makes up 87% of Earth's history

2. the era where the oceans form and earth develops a crust (cooling)
3. the period of time that summarizes Earth's history
5. The era where Earth and the solar system formed
7. the eon we are currently in now
8. a dominating plant that is non-flowering and has a naked seed during the Mesozoic era
10. organic material that has been solidified into rock
12. the extinction that killed the dinosaurs believed to have happened because of a volcano eruption
14. the era where we see the rise of mammals and the cooling of earth
16. the era where the first life developed creating an oxygen rich atmosphere