Plate Tectonics Review

1. The divergent boundary found in all oceans
4. Form when subduction occurs
7. The rock that is closer to a divergent boundary is __ than rock further away from it
9. What forms (along with a trench) when oceanic-oceanic plates converge
13. States that the youngest rocks of the ocean floor are closest to the divergent boundary, moving outward
15. The type of boundary that occurs when two plates move past each other
18. The theory that states that the lithosphere is broken into plates that are moving due to convection currents underneath them
20. What forms when two continental plates collide
21. The thickest layer of Earth
22. __ and rocks are evidence that continents were together at one time and have moved apart

2. The layer of Earth where convection occurs
3. __ and trenches form a convergent boundary when subduction is involved
5. The mechanism (what causes) plates to move
6. The thinnest layer of Earth
8. The supercontinent that existed about 250 million years ago when all the continents were connected
10. The type of boundary that occurs when two plates are moving toward each other
11. The type of boundary that occurs when two plates are moving away from each other
12. The release of energy buildup when two plates are moving
14. The middle of a divergent boundary on land or in the ocean
16. The location of most geologic activity, like earthquakes and volcanoes
17. The layer of Earth that makes up the plates
19. Pieces of the lithosphere that move
23. When one a denser plate slips underneath a less dense plate