Plate Tectonics
Across
- 6. The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle.
- 9. A deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle.
- 10. A book published by Alfred Wegener.
- 11. The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary.
- 13. A plate boundary where two plates move away from each other.
- 15. A break in Earth's crust along which rocks move.
- 16. Reptile fossil that has been found in places now separated by oceans.
- 18. A plate boundary where two plates move past each other in opposite directions.
- 19. Any trace of an ancient organism that has been preserved in rock.
- 20. A deep valley that forms where two plates move apart.
Down
- 1. A fernlike plant that lived 250 million years ago.
- 2. A plate boundary where to plates move toward each other.
- 3. A section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of continental and oceanic crust.
- 4. The theory that the continents slowly drifted over Earth's surface.
- 5. German scientist who became curious about why some continents look as though they could fit together.
- 7. Mid-Ocean ridges that are continually adding new material to the ocean floor.
- 8. The way scientists mapped mid-ocean ridges in the mid-1900s.
- 12. Another reptile fossil that has been found in places now separated by oceans.
- 14. A supercontinent or single landmass.
- 17. Mountain ranges that run along the middle of some ocean floors.