plate tectonics

4. The deepest parts of the oceans.
9. In this boundary plates slide past each other.
10. Paleontologists noticed that these were the same on different continents even though the continents were separated by oceans.
11. The most outer solid portion of the planet Earth.
13. Plate _____________.
16. alfred Wegener noticed that the coast of South America seemed to fit into the coast of this continent, just like a jigsaw puzzle.
18. The primary force that causes the seafloor to spread and continents to drift.
19. Seafloor ______________.
20. The zone below the lithosphere. It is more 'plastic' than the lithosphere so it is easier to bend and move.
21. The Theory of Continental _____________.

1. The outer part of the Earth's crust. it is composed of solid rock.
2. Places where new seafloor is being created.
3. the process by which Earth's crust breaks apart; can occur within continental crust or oceanic crust
5. The Earth's ______________ field reverses from time to time.
6. the theory that explains how large pieces of the lithosphere, called plates, move and change shape the topography of the earth.
7. Source of heat in the mantle.
8. A _____ boundary creates mountains.
12. Section of the Earth below the crust.
14. ______________ zones. Places where the seafloor is forced under continental plates.
15. A _____ boundary creates new ocean floor.
17. Scientist who first proposed the theory that the continents drifted.