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Unformatted text preview: University of California, Berkeley Professor Mark Hansen Civil Engineering 93 Engineering Data Analysis Civil Engineering 93 Lecture 4 9/6/07 Igneous Rocks Igneous Processes and Rocks o Igneous Processes magma formation, compostion differentiation o Basic Terms Magma silicate melt below earth surface Lava silicate melt above ground surface Extrusives Magma that reaches the surface and tends to cool fast Intrusives Magma that is trapped underground and cools slowly o What controls rock melting Temperature Closer to the core of earth, the hotter Chemical Composition Pressure Water Content Places of Volcanic Activity o Plate Subduction Oceanic Island Arc o Plate Divergence o Hot Spot o Plate Subduction Continental Volcanic Arc Formation of magma o Mantle provides magma for spreading centers and hot spots o Partial continental rock in subduction zones Crsytal forms in Magma chambers o They fall to the bottom of the viscous magma o Crystal forms at the top of a magma chamber due to cooling o Can fill up the chamber and squeeze magma up veins Creates interesting veins of granite o Country rock is the rock that surrounds the magma chamber...
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This note was uploaded on 04/02/2008 for the course CE 70 taught by Professor Johnson during the Fall '07 term at University of California, Berkeley.
- Fall '07
- Civil Engineering