Term
| Factors affecting Metamorphism |
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Definition
1. Temperature- geothermal gradient
2. Pressure- directed pressure causes platy minerals and rod shaped minerals to align perpendicular (foliation)
3. Composition of pre-existing rock
4. Fluid phase- helps dissolve unstable minerals releasing ions ions which new minerals need to grow (dehydration reactions) |
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Term
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Definition
Shale---> mica schist (micas, quartz, garnet)
Basalt---> amphibole (amphibole, plagioclase)
Sandstone---> quartzite (recrystallized quartz)
Limestone---> marble (recrystallized calcite) |
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Term
| Metamorphic Process of Shale |
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Definition
| Slate-->phyllite-->schist-->gneiss |
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Term
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Definition
| rocks transitional between metamorphic and igneous rocks. The lowest melting point minerals (quartz and feldspar) melt leaving magic minerals unmelted. This forms quartz and Kspar between layers of unmelted magic minerals |
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Term
| Metamorphic process of basalt |
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Definition
| Serpentine, greenschist, amphibole |
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Term
| Metamorphic process of basalt |
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Definition
| Serpentine, greenschist, amphibole |
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Term
| Non-foliated Metamorphic Rocks |
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Definition
1. Marble (metamorphosed limestone)
2. Quartzite (metamorphosed sandstone)
3. Hornfels (metamorphosed shale) |
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Term
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Definition
-Takes place in thickened crust in the roots of folded mountains during continental collisions
-high T and high P
-Shale and Basalt
-associated with intrusive granites |
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Term
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Definition
-deep ocean trenches
-high p and low t
-blueschist (blue amphibole, green epidote, and aragonite)
-eclogite (forms at very high pressure corresponding to mantle depths, made up of red garnet and green pyroxene) |
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Term
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Definition
-takes place in a metamorphic aureole around a hot igneous intrusion)
-high t and low p
-sandstone, quartzite; limestone, marble; shale, hornfel
-not foliated because of low pressure |
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Term
| Metamorphism in Fault Zones |
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Definition
-caused by shearing
-brittle deformation= fault breccia
-ductile deformation= produces mylonite |
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