Plate Tectonics

1. Theory that pieces of the Earth's lithosphere are in motion,driven by convection currents in the mantle
5. Alfred Wegener's hypothesis that the continents were once one huge land mass but have since then drifted apart
10. A break or crack in the Earth's lithosphere along which rocks move
11. A deep canyon on the ocean floor
12. A deep valley where two plates move apart
13. The undersea mountain mountain chain where new ocean floor is produced; a divergent plate boundary
16. A plate boundary where two plates move toward each other

2. A layer of molten iron and nickel that surrounds the inner core of the Earth
3. thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere
4. Cause the plates to move; between the lithosphere and the asthenosphere
6. A deep valley along the ocean floor through which oceanic crust slowly sinks towards the mantle
7. The process by which molten material adds new oceanic crust to the ocean floor
8. A plate boundary where two plates move away from each other
9. The name of the single landmass that broke apart about 225 million years ago
14. A plate boundary where two plates grind against each other, movie it different directions
15. Dense ball of solid material at the center of the Earth