EESA01H3 Chapter Notes - Chapter 2: Supercontinent Cycle, Metamorphic Rock, Lithification
Document Summary
The earth has many layers: mantle: the layer that surrounds the core. Asthenosphere: the upper mantle that has softer rock. The harder rock above the asthenosphere is the lithosphere (includes the uppermost mantle and the crust) The movement of the heat that is pushed upwards also moves parts of the lithosphere where this movement is called plate tectonics. We have 15 plate tectonics and they help shape the earth. There are three main types of plate boundaries. Divergent plate boundaries: the plates move apart from each other. When this happens magma rises to the surface firing a new crust when it solidifies. Transform plate boundaries: when two plates meet @ a strike-slip fault (a fracture in earth"s crust) and they grind against one another horizontally in the opposite direction. Japan: when two continental collisions happen they do not subduct and so their crusts are forced upwards resulting in mountains.