Plate Tectonics

1234567891011121314151617181920
Across
  1. 2. The layer of Earth under the crust
  2. 6. Solid but bendable metal
  3. 7. A measure of how much mass there is in a given volume of water
  4. 8. Plates collide
  5. 11. This forms where pieces of Earth’s crust diverge on land
  6. 13. Wegener’s idea that the continents slowly moved over Earth’s surface
  7. 15. This begins at a mid-ocean ridge
  8. 19. Supercontinent about 300 million years ago
  9. 20. Plates slip past each other
Down
  1. 1. This forms long chains of mountains that rise up from the ocean floor
  2. 3. A deep underwater canyon
  3. 4. The theory of this states that Earth’s plates are in slow, constant motion, driven by convection currents in the mantle
  4. 5. Layer of rock that forms Earth’s outer skin
  5. 9. Plates divide
  6. 10. The crust and uppermost mantle
  7. 12. Any trace of an ancient organism that has been preserved in rock
  8. 14. Breaks in Earth’s crust where rocks have slipped past each other
  9. 16. When the ocean floor sinks beneath a deep-ocean trench and back into the mantle again
  10. 17. Caused at a transform boundary
  11. 18. These are broken into pieces separated by cracks