| A | B |
|---|
| granite | rock that makes up continental crust |
| basalt | rock that makes up oceanic crust |
| convergent boundary | two plates come together |
| divergent boudnary | two plates spreading apart |
| theory of plate tectonics | earth's crust is broken up into plates that float on the lower mantle |
| transform fault boundary | two plates slide past each other |
| convection currents | heat transfer in the mantle that drives plate movement |
| trench | a deep valley in the ocean floor where one plate subducts beneath another |
| rift valley | a deep valley found in the center of the mid-ocean ridge where magma wells up to form new sea floor |
| mid-ocean ridge | mountain range on the ocean floor caused by divergent plate boundaries |
