SIO 50 Lecture Notes - Lecture 1: Himalayas, San Andreas Fault, Basalt

• School: UCSD
• Department: Scripps Institution of Oceanography
• Course: SIO 50
• Professor: Geoffrey Cook

Document Summary

Plates are composed of the lithosphere (crust and upper mantle) include both continental and oceanic crust sutured together. Some plates are just oceanic crust or continental crust. Ocean crust is denser, sits a little bit lower. Mistake made in the past: number of people he met that islands don"t float on the oceans, rather they are jutting out of the ocean surface (misconceptionn you must deal with) Oceanic crust spreads away from the ride axis, this means that the new crust close to the ride; old crust lies farther away. Oldest crust is around 200 mya, ad reason is that oceanic crust can be sub ducted into the plates. Convection in the mantle causes plates to move. Imagine a lava lamp and it is similar what happens in the mantle. Brings magma up, causes eruptions up in the surface. Because, there"s heat flow, convection in the mantle which causes sea floor spreading and sea floor spreading which causes plate tectonics.