Geology metamorphic basics

Question	Answer
Geology- Metamorphics	Is the change of rock mineralogy and texture though heat ans pressure in an essentially solid state.
Contact Metamorphism	High heat, low pressure are usually found around igneous intrusions. Index mineral- Andalucite
Dynamic metamorphism	High pressure/ low heat, occurs along thrust faults and along subduction zones
Regional Metamorphism	High heat plus high pressures, occurs along subduction zones and orogenies, All show directional pressure though foliation. Index mineral- Sillimaite
Non foliated textures (no pressure- contact or thermal)	Spotted rocks- produced by partial recrystallization of minerals that form spots. Porphyroblastic- may show foliation but may not as it is large crystals surrounded by smaller ones. Granoblastic- interlocking equal grained crystals Sugary- granoblastic but for marble
Foliated Textures (regional)	Produced by minerals that are platy in shape (e.g micas) and needle shaped (e.g hornblende) and that are under directional pressure. Types are Slatey cleavage, phylilitic texture, Schistose texture, Gneissose texture.

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	Created by holliebishop1996 over 10 years ago