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