Transcript Metamorphic Rocks - Classroom Unsquared

CLASSROOM
UNSQUARED
EARTH MATERIALS
EQ:What are metamorphic rocks?
A rock that has changed its mineral
assemblage and texture from a preexiting one due to increases in
temperature and pressure .
Metamorphic Rocks
Metamorphic Rocks
A.
Temperature
Old bedding
planes
Depth of burial
(Avg. geothermal gradient = 20-300C / km)
Proximity to magma
B.
Pressure (Stress)
A. Overburden
Foliation
Metamorphism causes
Recrystallization
Foliation (mineral bands)
Chemical change
Metamorphic grade
(Avg. geopressure gradient = 33 MPa / km)
B. Lateral Compression
Metamorphic Rocks and Parent Rocks
Parent Rock
Metamorphic Rock
Sandstone
Quartzite
Shale
Slate
Limestone
Marble
Granite
Gneiss
Diorite
Gneiss
Slate
Phyllite
Phyllite
Schist
Schist
Gneiss
(Identification Key)
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