GEOL 001 Lecture Notes - Lecture 10: Orogeny, Aureola, Magma Chamber
20 Dec 2020
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Document Summary
Marble: coarse, crystalline, parent rock was limestone or dolostone, composed essentially of calcite or dolomite crystals, used as a decorative and monument stone, exhibits a variety of colors. Quartzite: formed from a parent rock of quartz-rich sandstone, quartz grains are fused together. Result from a rise in temperature when magma invades a host rock. The zone of alteration (aureole) forms in the rock surrounding the magma. Most easily recognized when it occurs at or near earth"s surface. Contact: increasing metamorphic grade closer to magma chamber. Chemical alteration caused when hot, ion-rich fluids circulate through fissures and cracks that develop in rock. Most wide-spread along the axis of the mid-ocean ridge system. Produces the greatest quantity of metamorphic rock. Metamorphic grade: mineral isograds (zones of change, index minerals reflect pressure and temperature conditions, groups of 2 to 3 index minerals form an isograd.
