| A | B |
|---|
| continental shelf | the part of a continent that extends under shallow water from the ocean's edge to a steeper slope. |
| Pangea | A supercontinent, that consisted of all continents put together. |
| Theory of Continental Drift | Theory that all continents were once one land mass and broke apart and moved to their present positions. |
| Theory of Plate Tectonics | Earth's crust and upper mantle are broken into enormous slabs called plates, or tectonic plates. |
| Crust | Earth's outermost solid layer. |
| Mantle | Earth's layer that is between the crust and the core. |
| Plate Boundaries | Places where plates meet and interact. |
| Mid-Ocean Ridge | A continuous ridge of mountains on the ocean floor. |
| Sea Floor Spreading | The process by which new ocean floor is continually added. |
