| A | B |
|---|
| plate tectonincs theory | crust is made of several huge plates "floating" on mantle |
| plate tectonics theory | movement of plates causes earthquakes, volcanoes, mountain ranges, and trenches |
| continental drift theory | continents together 200 million years ago -- pangea -- slowly moving since then |
| tectonic plate | huge section of Earth's crust, slowly moving -- float on mantle |
| trench | formed as one plate slides under another plate |
| Marianas Trench | deepest ocean trench in world -- one plate slides under another |
| San Andreas fault | American plate and Pacific plate slide past one another |
| Himalayan Mountains | formed by folding of crust where two continental plates move together -- India into Asia |
| Alps Mountains | 2 continental plates moving together -- Italy into Europe |
| mid-Atlantic ridge | crustal plates moving apart -- mantle material moves up forming mountain range |
| convection current | circular movement of material because some places are hotter than others |
| Pangea | name for ancient "super continent" -- from Greek meaning "all-earth" |
| fault | break in crust |
| fault | earthquakes occur along these, most volcanoes occur here too |
| Alfred Wegner | propsed version of Continental Drift Theory currently accepted |
