Plate Tectonics

1234567891011121314151617181920
Across
  1. 2. remnant of something that existed long ago; preserved in rock
  2. 6. where the Earth’s crust has broken
  3. 7. supercontinent formed 300 million years ago
  4. 8. measures distance to an object through sound waves
  5. 9. causes the Earth’s plates to move
  6. 12. seperating plates
  7. 14. forms faults
  8. 15. theory of the slow, constant motion of Earth’s plates
  9. 16. forms when crust diverges on land
  10. 17. underwater mountain range
  11. 18. mass divided by volume
  12. 19. theorized that the continents slowly moved over the surface of Earth
  13. 20. outer shell of the lithosphere
Down
  1. 1. higher density crust sinks beneath a deep-ocean trench
  2. 3. new crust pushes old rock further from mid-ocean ridges
  3. 4. when molten material hardens quickly, these form
  4. 5. plates come together
  5. 10. the continents have moved over earth’s surface
  6. 11. where oceanic crust bends downward
  7. 13. 3,000 meters of hot, solid rock