List 24

2. of superposition / the geologic principle that states that in horizontal layers of sedimentary rock, each layer is older that the one above it
5. tectonics / the theory that explains how large pieces of the lithosphere, called plates move and change shape
6. / the process of one plate going under another
9. / a break in the earth's crust
11. / left alone, not bothered
13. plates / lithospheric plates below the ocean
14. rock / rock formed when layer of sediments harden over million of years. Forms layers
15. / rock formed when exposed to extreme heat and pressure, rock that has changed form
17. boundary / boundary between two colliding plates
18. / rock formed from cooled magma or lava
19. floor spreading / the process by which molten material adds new oceanic crust

1. / scientists who study Earth and the process that have shaped Earth over time
3. / loose materials such as rock fragments, mineral grains, and bits of shell that have moved by wind, water, ice , or gravity
4. boundary / a plate boundary where two plates move past each other in opposite directions
7. drift theory / theory states that the continents have not always been in their present locations buy have "drifted" there over million of years
8. boundary / a plate boundary where two plates move away from each other
10. / the solid part the earth consisting of the crust and the mantle
12. cores / a cylinder that contains ice that has trapped atmospheric gases from years before
16. / the preserved trace, imprints, or remains of a plant or animal