ERS120H5 Lecture Notes - Lecture 3: South American Plate, Continental Crust, Plate Tectonics
Document Summary
Lithosphere is thin, cool and hard (a shell outside of the planet) Asthenosphere is weak and hot (slippery stuff under the shell that lets it move around) Lithosphere broken into large fragments called plates. Plates more around and interact with each other. The material that makes up the crust is incredibly weak and could not be a plate (it would form mountains if pushed around, not a plate) 1. continental (thick, 35 km, thickest in mountain ranges, low density) 2. oceanic crust (found under oceans, thin, 10 km, high density) Oceanic crust rides lower on planet because it"s thin (creates a low spot that the water could pull in) Lithosphere (crust and upper part of the mantle); dense, strong, not different compositionally from asthenosphere. Lithosphere and asthenosphere differ in temperature (asthenosphere is hotter) What makes up the tectonic plate: a little bit of crust on top and a lot of lithosphere.
