Plate Techtonics

3. The layer that contains Earth’s plates.
4. Any trace of an ancient organism that has been preserved in rock.
7. Where seafloor spreading begins.
8. When 2 plates slip past each other.
13. A fernlike plant that lived 250 million years ago.
14. A German scientist who hypothesized that the continents were once together.
16. Changes in _______ affects the ocean floor.
19. When 2 plates move away from each other.
20. Where the convection current drive Earth’s plates.

1. Breaks in Earth’s crust where rocks have slipped past each other.
2. Adds more crust to the ocean floor and older stripes of rock move outward from either side of the ridge.
5. Forms when to convergent continental crust collide.
6. When 2 plates come together.
9. Where pieces of Earth’s crust diverge on land.
10. Oceanic crust is made up of mostly.
11. What scientist use to discover the ocean floor.
12. 2 plates come together.
15. A supercontinent about 300 million years ago.
17. Occurs when plates slip along the boundary that they form.
18. The process by which the ocean floor sinks beneath a deep ocean trench and back into the mantle again.