GL101 Lecture Notes - Lecture 2: Continental Crust, Plate Tectonics, Oceanic Crust
Document Summary
Divergent boundary involves two plates that are moving apart from each other. Although most divergent boundaries present today are located within oceanic plates, a divergent boundary typically initiates within a continent. It begins with a split, or rift, in the continent is caused by either extensional (stretching) forces within the continent or by the upwelling of hot asthenosphere from the mantle below. Convergent boundary where plates move toward each other. By accommodating the addition of new seafloor at divergent boundaries, the destruction of old seafloor at convergent boundaries ensures the. It is useful to describe convergent boundaries by the character of the plates that are involved: ocean-continent, ocean-ocean and continent- continent. The resulting mountain belt is called a volcanic island arc: continent-continent convergence - if both converging plates are continental, a quite different geological deformation process takes place at the plate boundary. Continental lithosphere is much less dense than the mantle below and, therefore, neither plate subducts.
