Across
- 3. measure of how much material there is
- 4. a boundary where two plates meet and move towards each other
- 6. the hypothesis that states the continents were once connected
- 7. upper layer of Earth's mantle below the lithosphere
- 9. rigid layer that makes up the upper mantle
- 11. the theory that Earth's lithosphere is in constant motion
- 12. where old oceanic lithosphere is pulled back into the mantle
- 14. the movement of a fluid caused by differences in temperature
- 16. the process where new oceanic lithosphere forms
- 18. Molten rock beneath the Earth
- 19. mostly solid rocky part of Earth
- 20. sections of Earth's crust that move due to convection currents
Down
- 1. lower part of the mantle
- 2. the thick part of Earth's crust
- 5. a boundary where two plates meet and pull away from each other
- 8. a boundary where two plates meet and slide past each other
- 10. the central part of the Earth
- 13. thin and solid outermost layer
- 15. layer between the crust and core
- 17. the thin part of Earth's crust