metamorphism and metamorphic rocks •metamorphism process by which rocks undergo changes in...
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METAMORPHISM AND METAMORPHIC ROCKS •Metamorphism process by which rocks undergo changes in mineralogy, texture, or chemical composition. WHERE? in the crust and mantle. Metamorphic Agents : internal heat, weight of rock, horizontal pressures of deformation result in: 1.temperature - PowerPoint PPT PresentationTRANSCRIPT
METAMORPHISM AND
METAMORPHIC ROCKS
• Metamorphism
process by which rocks undergo changes in mineralogy, texture, or chemical composition
WHERE? in the crust and mantle
Metamorphic Agents: internal heat, weight of rock, horizontal pressures of deformation result in:
1. temperature
2. pressure
Metamorphic Agents: (cont.)
2. pressure
i. confining
ii. directed
3. fluids - metasomatism
Types of Metamorphism
1. Contact
i. plate convergence (with subduction)
ii. oceanic and continental hot spots
iii. deformed mountain belts
Types of Metamorphism
2. Regional
i. plate subduction
ii. plate convergence
Types of Metamorphism
3. Hydrothermal - chemical
4. Burial
5. Dynamic or shear (cataclastic)
Classification - Texture and Mineralogy
1. foliated - foliation, schistosity
Classification - Texture and Mineralogy
2. non-foliated
Classification - Texture and Mineralogy
3. porphyroblasts
Grade of Metamorphism
1. Regional vs. Contact
i. low grade to high grade
Grade of Metamorphism
1. Regional vs. Contact
ii. index minerals
Grade of Metamorphism
1. Regional vs. Contact
iii. metamorphic zones and facies
(1) different rocks form from different parent rocks
different rocks form from grades of metamorphism