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