Tic Tac Know

8. The name of the single landmass that broke apart about 225 million years ago
10. Thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere
12. Theory that pieces of the Earth's lithosphere are in motion,driven by convection currents in the mantle
13. A layer of molten iron and nickel that surrounds the inner core of the Earth
14. A deep valley where two plates move apart
15. The process by which molten material adds new oceanic crust to the ocean floor

1. A plate boundary where two plates move toward each other
2. Cause the plates to move; between the lithosphere and the asthenosphere
3. The undersea mountain mountain chain where new ocean floor is produced; a divergent plate boundary
4. A deep canyon on the ocean floor
5. Alfred Wegener's hypothesis that the continents were once one huge land mass but have since then drifted apart
6. A plate boundary where two plates grind against each other, moving it different directions
7. Dense ball of solid material at the center of the Earth
9. A break or crack in the Earth's lithosphere along which rocks move
11. A plate boundary where two plates move away from each other