105-16 9-30 Absolute rock dating, metamorphic rx

Pressure metamorphism a microscopic view is new

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Unformatted text preview: med during high temperature and relatively high composition of a basalt, butnext. pressure metamorphism. A microscopic view is new minerals) foliation Amphibolitic gneiss thin sect (metabasalt ( polarized light) foliation GRANITE (LEFT) GRANITIC GNEISS (BELOW) foliation Quartz and mica schist (below) — originally a sandstone with clay (to left); polarized light) foliated granoblastic (non-foliated) Porphyroblasts = large met. crystals in a finer-grained matrix Metamorphic rocks and their protoliths garnet porphyroblasts Quartzite -- no foliation. WHY? QUARTZITE — RECRYSTALLIZED QUARTZ SANDSTONE. A MICROSCOPIC VIEW, POLARIZED LIGHT Erosion Metamorphic rocks w/ granitic dikes Migmatitic gneiss, San Gabriel Mtns, California — these gneisses have begun to melt (—> magma)...
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This note was uploaded on 05/11/2013 for the course GEOL 105Lg taught by Professor Davis,platt during the Fall '07 term at USC.

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