Plate Tectonics

2. The earth's crust being pushed back into the mantle due to new material forming
4. A valley caused by two tectonic plates diverging
6. A deep part of the ocean that pulls down the old seafloor into the mantle
8. A cycle of liquids where the cold liquid sinks, reheats, and then rises to cool back down.
11. A break in the earth's crust that usually results as a center for seismic activity
13. A boundary that consists of pulling away from each other
14. A pocket of magma that forms under the surface to later form a volcano
15. Molten rock (after it reaches surface)
17. The movement of liquid in the earth that drives the plates to move
19. The major circle of volcanoes around the Pacific Ocean
20. A massive chunk of the earths crust that are moved by convection currents
21. A natural event that occurs when two plates collide
22. Molten rock (below the surface)

1. The idea that says that all continents are slowly moving back together
3. A string of islands formed by convergent boundaries
5. The process of the seafloor being replaced by a new layer
7. A split in the sea floor that forms between two plates. They push out new material constantly and are the reason sea floor spreading occurs
9. A boundary that consists of pushing together
10. A pattern of magnetic fields in strips of rock
12. A mountain that forms when magma reaches the su
16. A boundary that consists of sliding against each other horizontally
18. A preserved piece of bone or plant encased in rock or clay
20. A supercontinent originally thought of by Alfred Wegener