Across
- 8. A break or crack in the Earth's lithosphere along which rocks move
- 11. Dense ball of solid material at the center of he Earth
- 12. Theory that pieces of the Earth's lithosphere are in motion,driven by convection currents in the mantle
- 13. A deep valley where two plates move apart
- 14. The layer of rock that forms the Earth's outer surface
- 15. A deep canyon on the ocean floor
- 17. The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary
- 19. The undersea mountain mountain chain where new ocean floor is produced; a divergent plate boundary
- 20. German Scientist who developed the Theory of the Continental Drift in 1912.
Down
- 1. The name of the single landmass that broke apart about 225 million years ago
- 2. A plate boundary where two plates move toward each other
- 3. A layer of molten iron and nickel that surrounds the inner core of the Earth
- 4. A plate boundary where two plates grind against each other, moving it different directions
- 5. A soft layer of the mantle on which the lithosphere floats
- 6. Thickest layer of the Earth; it consists of two layers - the lithosphere and the asthenosphere
- 7. A rigid layer made up of the uppermost part of the mantle and the crust
- 9. The process by which molten material adds new oceanic crust to the ocean floor
- 10. Cause the plates to move; between the lithosphere and the asthenosphere
- 16. A plate boundary where two plates move away from each other
- 18. Alfred Wegener's hypothesis that the continents were once one huge land mass but have since then drifted apart