Plates tectonic

6. currents in the mantle that cause the movement of Earth's plates
7. an underwater chain of mountains.
8. Theory hat the continents were once as one large, single land mass.
11. Type of plate boundary where two plates separate or move apart.
12. a deep valley that forms on land at a divergent boundary where two plates move apart
13. These are formed under water at divergent plate boundaries. They are areas where new ocean crust is formed.
15. This forms on land at divergent plate boundaries. There is a great one in Eastern Africa.
18. When one tectonic plate moves underneath another one, it's called this.
19. the process by which molten material adds new crust to the ocean floor
20. Theory that the lithosphere is divided into tectonic plates that move on the asthenosphere.

1. Type of plate boundary where two plates slide past each other in opposite directions.
2. Rift This place is in Africa and the plates are coming apart.
3. a mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth's crust.
4. Type of plate boundary where two plates collide.
5. Type of crust that is thinner and contains basalt.
9. These form underwater (on the ocean floor) at most convergent boundaries.
10. Layer of earth with the lowest temperature.
14. The cool, outermost layer of Earth that consists of the crust and uppermost part of the mantle.
16. The layer just below the lithosphere.
17. the supercontinent that existed millions of years ago