Plate Tectonics

2. Dense ball of solid material at the center of the Earth
3. theory that pieces of the Earth's lithosphere are in motion,driven by convection currents in the mantle
6. A deep valley where two plates move apart
9. alfred Wegener's hypothesis that the continents were once one huge land mass but have since then drifted apart
10. the process by which molten material adds new oceanic crust to the ocean floor
11. A deep canyon on the ocean floor
12. A plate boundary where two plates move toward each other
14. The undersea mountain mountain chain where new ocean floor is produced; a divergent plate boundary
15. Thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere

1. A plate boundary where two plates grind against each other, moving it in different directions
4. A break or crack in the Earth's lithosphere along which rocks move
5. A plate boundary where two plates move away from each other
7. Cause the plates to move; between the lithosphere and the asthenosphere
8. the name of the single landmass that broke apart about 225 million years ago
13. A layer of molten iron and nickel that surrounds the inner core of the Earth