Plate Tectonics

3. The amount of force per unit area.
6. currents Circular movement of a substance due to changes in temperature and density.
7. Convection currents occur in it.
9. Boundary Two plates moving towards each other.
11. When oceanic crust meets continental crust.
14. A trace of an ancient organism that has been preserved in rock.
16. boundary Sliding past each other horizontally.
17. Wegener Credited with the theory of Continental Drift.

1. Tectonics Theory that crust is broken into plates and move around.
2. Occurs when forces act to stretch an object.
4. drift The theory that continents can drift apart from one another.
5. boundary Plates moving away from each other.
6. The central, spherical part of the Earth below the mantle.
8. The thin, outermost layer of the Earth.
10. Shakes the Earth.
11. spreading The process by which new oceanic lithosphere is created at mid-ocean ridges.
12. An ancient super-continent.
13. Breaks in crust.
15. Hess Credited with the theory of Plate Tectonics.
18. valley Formed when two plates pull apart and land falls downard.