| A | B |
|---|
| plate | A section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of continental and oceanic crust. |
| scientific theory | A well-tested concept that explains a wide range of observations. |
| plate tectonics | The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle. |
| convergent boundary | A plate boundary where two plates move TOWARD each other. |
| transform boundary | A plate boundary where two plates move past each other in OPPOSITE directions. |
| divergent boundary | A plate boundary where two plates move AWAY FROM each other. |
| rift valley | A deep valley that forms where two plates move apart. |
| fault | A break in Earth's crust where slabs of rock slip past each other. |
