| A | B |
|---|
| asthenoshpere | upper part of matle on which the plates move |
| compression | stress that squeezes rock until it folds or breaks |
| convergent plate boundary | boundary between two colliding plates often associated with mountain building ocean trenches and volcanic islands (compression) |
| crust | the layer of rock that forms the Earths outer surface |
| divergent plate boundary | boundary between tectonic plates in which the two plates move away from each other, and new crust is created between them (tension) |
| geology | the study of the solid Earth |
| inner core | a dense sphere of solid iron and nickel at the center of the Earth |
| lithosphere | the rigid layer of earth, including the crust and upper mantle |
| magma | the molten mixture of rock forming substances, gases, and water that makes up part of Earth's mantle |
| mantle | the layer of hot, solid material between Earth's crust and core |
| outer core | a layer of molten iron and nickel that surrounds the Earth's inner core |
| Pangea | large ancient land mass that was composed of all the continents joined together |
| plate boundaries | a crack in the lithosphere where two of Earth's plates meet |
| plate tectonics | the theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle |
| plates | a section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of continental and oceanic crust |
| shearing | stress that pushes a mass of rock in opposite directions |
| tension | stress that stretches rock so that it becomes thinner in the middle |
| transform plate boundary | boundar between two plates that are sliding past each other (shearing) |
