Across
- 1. Crust that is dense and made of rock that's rich in iron and magnesium
- 3. Boundary between tectonic plates that slide past each other horiontally
- 7. Chain of volcanic islands
- 9. Crust that has low density and made of rock that's rich in Silica
- 11. Super Continent that formed 300 million years ago that started breaking up 250 million years ago
- 13. Process which they form and break over a million years ago
- 14. New oceanic floor forms as magma rises to Earths surface
- 15. Single, large ocean when there was a super continent
- 16. Peice of lithosphere that has a unique geologic history
- 18. Fossil that lived 270 million years ago
- 19. Narrow valley that forms where plates separate
Down
- 2. Boundary between tectonic plates that are colliding
- 4. Undersea mountain chain that forms as magma rises and creates a new sea floor
- 5. Theory that explains how plates move and change shape
- 6. Study of alignment of magnetic rocks
- 8. Solid, plastic layer of the mantle
- 10. solid, outer layer of Earth
- 12. Hypothesis that states that one land mass broke up into our continents today
- 17. boundary between tectonic plates that move away from each other
- 19. Process by which Earths crust breaks apart