EARTH MATERIALS EQ:What are metamorphic rocks?

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EARTH MATERIALSEQWhat are metamorphic rocks?
A rock that has changed its mineral composition
and/or texture from a pre-existing one due to
increases in temperature and pressure .
Metamorphic Rocks
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Metamorphic Rocks
Temperature Depth of burial (Avg.
geothermal gradient 20-300C / km)
Proximity to magma Pressure (Stress) A.
Overburden (Avg. geopressure gradient
33 MPa / km) B. Lateral Compression
Metamorphism causes Recrystallization
Foliation (mineral bands) Chemical change
Metamorphic grade
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Metamorphic Rocks and Parent Rocks
Parent Rock Sandstone Shale Limestone Granite D
iorite Slate Phyllite Schist
Metamorphic Rock
Quartzite Slate Marble Gneiss Gneiss Phyllite Schi
st Gneiss
(Identification Key)
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Two Kinds of Metamorphism
Regional metamorphism Compression in convergent
plate boundary Covers large area in a region
along a plate boundary Contact
metamorphism Local effect along the margin of a
magma intrusion Location of valuable mineral ores