plate tetonics

1. outermost layer of earth
7. name of the hypothetical great continent thought to have split into the landmasses known today
9. theory that continents drift apart
13. boundary between two colliding plates
14. layer between crust and core
15. boundary between two plates moving away from each other
16. a block of lithosphere that consists of the crust and the rigid, outermost part of the mantle
18. liquid layer of the core

1. movement of a fluid because of density differences.
2. the sinking of regions of earth's crust to lower elevations.
3. two plates moving toward each other resulting in both plates pushing upwards.
4. melted rock beneath earth's surface.
5. solid dense center of earth
6. soft layer of the mantle
8. outermost, rigid layer of the earth
10. a break in the Earth's crust
11. imaginary east-west line that circles earth halfway between geographic poles.
12. opening in earth's crust where melted rock reaches earth's surface.
17. large moving section of lithosphere that contains continents and seafloor.