Across
- 5. the layer on the mantle that the lithosphere floats on
- 6. a split in the lithosphere
- 9. a plate boundary where two plates spread apart
- 11. the landmass that broke apart 25 million years ago
- 12. the cycle that drive sea floor spreading
- 13. a deep canyon in the ocean floor
- 15. the larger of the core layers
- 16. Theory that pieces of the Earth's lithosphere are in motion
- 17. the innermost layer of the Earth
- 18. a plate boundary where two plates slide past each other
- 19. the largest layer of the Earth
Down
- 1. Alfred Wegener's theory that continents drifted apart
- 2. sea floor spreading apart along ridges
- 3. a large ridge in the ocean that seafloor spreads from
- 4. the thinnest layer of the Earth
- 7. the german scientist who developed the theory of plate tectonics
- 8. the brittle layer including the upper mantle and crust
- 10. a convergent boundary where one plate slides under the other
- 12. a boundary where two plates push together
- 14. a deep valley on a divergent boundary