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