EAS201 Lecture Notes - Lecture 8: Migmatite, Quartzite, Blueschist
20 Sep 2016
School
Department
Course
Professor
Document Summary
Foliation: parallel flakes of mica forming a planar texture. 5 km of depth 50 mpa (10 mpa/km) recrystallization under confining (uniform stress) Small crystals disappear, add their material to the larger crystals. Vertical, some grains dissolve then get reattached at the end have layering/banding of dark and light (material gets reorganized, Ex. ) chlorite cannot survive high grade temps but gives its materials to something like silimanite that appears at high temps. Index minerals: minerals that indicate a metamorphic grade. Relatively large fragments of rock that haven"t melted yet. Solidification to rock due to cooling, and/or pressure decrease and/or degassing (water loss) Fractional crystallization (have seen before) Formation of magma due to heating, and/or pressure increase and/or water uptake. Metasomatic solution go through a process of fractional melting, such that you have metasomatic solutions forming that move out (can be loaded with minerals) Main ore deposits resulting from contact metamorphism: copper, iron, lead,
