GEOL 106 Lecture Notes - Lecture 19: Silly Putty, Plate Tectonics, Oceanic Crust

• School: Queen's University
• Department: Geological Sciences and Geological Engineering
• Course: GEOL 106
• Professor: John Hanes

Document Summary

Introduction to the rock cycle and the plate tectonic cycle. Not significant for earth, therefore we ignore. Plate tectonic problem: plate tectonics say that the mantle is liquid it convects, but seismic studies say that the mantle is solid s-waves pass through it, both are correct!! The mantle is both solid and liquid: the mantle, although solid convects plastically it behaves like silly putty (cid:498)silly-putty(cid:499) model of the mantle. And while we"re at it, let"s look a little more closely at the nature of the earth"s: with slow stress application over long geologic time, mantle is liquid, flow patterns in metamorphic rock. There are 2 types of crust: (elastico-plastic behaviour: oceanic crust, continental crust. Oceanic crust: 5km thick, 5km ocean water on top, black rocks in colour, (cid:498)mafic(cid:499, mafic= relatively rich in magnesium and iron, ma=magnesium, fi= iron, the iron gives the rock a blackish colour, eg iceland.