| A | B |
|---|
| Continental crust | thicker part of Earth’s crust that forms the large land masses |
| Convergent boundary | two plates coming together |
| Divergent boundary | two plates moving apart |
| Geologic event | a change to the structure of the Earth by tectonic activities |
| Mid-ocean ridge | undersea mountain range formed where two parts of the Earth’s crust are moving apart |
| ocean basin | large bowl shaped depression that holds ocean water; regions of crust below sea level |
| oceanic crust | thinner part of Earth’s crust that lies underneath the ocean basins |
| plate | distinct sections of the lithosphere which make up the outermost layer of the Earth |
| plate boundary | a region where two lithospheric plates meet |
| Sea-floor spreading | formation of new oceanic crust due to the upwelling of magma at mid-ocean ridges |
| Subduction | process where one plate slides under another |
| Tectonics | study of the movement of large masses of rock, known as plates, on the Earth’s surface; includes folds, faults, and plate movement |
| Theory | an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by groups of detached researchers; can be used to explain and predict natural phenomena |
| Theory of plate tectonics | theory that describes plate movement and how it affects Earth’s geologic features |
| Transform boundary | two plates sliding past each other in opposite directions |
