GEOL 11040 Lecture Notes - Lecture 7: Oceanic Crust, Surface Plate, Continental Drift

• School: Kent State University
• Department: Geology
• Course: GEOL 11040
• Professor: Christopher Rowan

Document Summary

A tectonic plate is made up of both crust and rigid mantle lithosphere moving on top of the plastic asthenosphere. Plate boundaries are where the majority of earth"s geological activity occurs including: Most geological activity occurs at plate boundaries because of the concentration of forces affecting the earth"s surface. Ocean basins: cycle material from deep mantle to the surface at ridges and then back down into the mantle at subduction zones. This process takes hundreds of millions of years to complete. An analogy for movement of continents from plate tectonics: A ship becomes trapped in ice and unable to move itself. The ship represents a continent and the ice represents the plates. Focused deformation on a fault creates linear mountain ranges and rift valleys. Mid-ocean ridges are pretty much just long volcanoes. Volcanoes need melted rock, but magma is usually not molten. To generate magma, you need to disrupt the geotherm or change the solidus/melting point.