Science project crossword puzzle

1. Theory that pieces of the Earth's lithosphere are in motion,driven by convection currents in the mantle
6. A break or crack in the Earth's lithosphere along which rocks move
9. A plate boundary where two plates move away from each other
11. The name of the single landmass that broke apart about 225 million years ago
12. Dense ball of solid material at the center of he Earth
13. German Scientist who developed the Theory of the Continental Drift in 1912.
14. Cause the plates to move; between the lithosphere and the asthenosphere
16. A soft layer of the mantle on which the lithosphere floats

2. alfred Wegener's hypothesis that the continents were once one huge land mass but have since then drifted apart
3. A rigid layer made up of the uppermost part of the mantle and the crust
4. Thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere
5. The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary
7. A plate boundary where two plates move toward each other
8. A layer of molten iron and nickel that surrounds the inner core of the Earth
10. Two plate boundaries were two plates grind against each other
15. The layer of rock that forms the Earth's outer surface