plate tectonics

3. parallel pattern of rock material found at identical locations across the Mid-Atlantic Ridge
6. the amount of matter in a given space or volume
7. when a denser plate is pushed down and beneath a less dense plate
9. solid fragments of weathered rock are eroded and then dropped into a new place
12. when two tectonic plates move toward each other and collide
15. mechanical or chemical processes that break rocks into smaller pieces
16. process by which water, ice, wind, and gravity remove and transport sediments
19. tectonic plates that lie under surface land masses
20. seafloor mountain system formed by divergent boundaries

1. 1st theory describing the history of Earth's Surface
2. Supercontinentat that incorporated most all of the landmasses on Earth
4. long crack in the surface of the Earth
5. 2nd theory describing the history of the Earth's surface
8. when two plates move away from each other
10. photos or images taken of Earth from space
11. circular movement of fluids caused by the rising of hotter, less dense fluid and the falling of cooler, denser fluid
13. huge pieces of lithosphere that slowly move on the asthenosphere
14. Tectonic plates that are at the bottom of the ocean
17. distance above sea level
18. when twon plates slide past each other