Plate Tectonics

3. The process by which molten material adds new oceanic crust to the ocean floor
4. A plate boundary where two plates move away from each other
5. Dense ball of solid material at the center of the Earth
8. German Scientist who developed the Theory of the Continental Drift in 1912.
9. Thickest layer of the Earth
11. A break or crack in the Earth's lithosphere along which rocks move
12. A deep valley where two plates move apart
14. A soft layer of the mantle on which the lithosphere floats

1. causes the plates to move; between the lithosphere and the asthenosphere
2. A plate boundary where two plates move toward each other
6. The name of the single landmass that broke apart long ago
7. The layer of rock that forms the Earth's outer surface
10. A rigid layer made up of the uppermost part of the mantle and the crust
13. undersea mountain mountain chain where new ocean floor is produced; a divergent plate boundary
15. A deep canyon on the ocean floor