GEO 1111 Lecture Notes - Lecture 9: Turbidity, Olivine, Sediment Gravity Flow

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: Donald Cummings

Document Summary

Forms from crystallization of molten (magma, lava) rock. Magma is below the surface, lava is above. There are crystals and gas in the magma. Magma and igneous rocks are made at hotspots, spreading ridges and subduction zones. The only part of the earth that is liquid is outer core. Geothermal gradient does not intercept the rocks melting point. Flux melting by introducing water from subduction creates partial melting (changed the phase boundary) Less dense than rock, therefore will move upwards. Lava crystallizes to form extrusive(volcanic) rock- fine, if magma crystalizes before reaching the surface then it is intrusive (plutonic) rock- large. Classification of igneous of rock is based on grain size-texture and chem composition. Volcanic rock cools rapidly, thus having fine grains or are glassy. Plutonic rocks are coarse grained since the crystals had more time and room to grow. Composition is based on silica content *right side of chart shows mineral comp.