Across
- 3. how much mass there is in a given amount of volume
- 9. a layer of hot rock
- 10. underwater ocean ranges
- 11. earth's plates that are in slow constant motion
- 13. the uppermost part of the mantle
- 14. breaks in the earth's crust
- 16. plates slip past eachother
- 17. a process where the ocean floor sinks in the mantle
- 18. heat transfer from air currents
- 19. plates come together
- 20. plates collide
Down
- 1. forms when pieces of earth's crust diverge on land
- 2. german scientist who discovered that the continents were together at one point
- 4. a mountain that erupts
- 5. deep underwater canyons
- 6. - an idea that continents slowly move
- 7. a supercontinent that existed 2 million years ago
- 8. pieces of earth separated by cracks
- 12. a process that adds new material to the ocean floor
- 15. any trace of an ancient organism preserved in rock
- 21. a large body of water