Plate tectonics- The theory of the earth being made of plates from the crust.
Continental Drift- Movement of plates throughout time.
Pangaea- The supercontinent that existed millions of years ago.
Asthenosphere- The upper layer of the mantle, below the lithospere.
Lithosphere- The outer part of the earth consisting of the crust and upper mantle.
Mid-Oceanic ridge- An underwater mountain system.
Rift valleys- An enlongated depression that has steep walls because of the downward displacement.
Subduction- When one plate goes under another.