Metamorphic rocks are rocks that have been changed in texture, mineralogy, and
even chemical composition by the application of heat, pressure, chemically active
fluids. Before they became metamorphic rocks, they were other kinds of rocksigneous, sedimentary, or even other metamorphic rocks. The precursor to the
observed metamorphic rock is know as its protolith (to put it in simple words, the
protolith is the rock that got metamorphosed). The key issue concerning metamorphic
rocks is that the metamorphism is usually associated with plate tectonic processes
such as continent- continent collisions (regional metamorphism) and/or contact of
magma or lava (thermal, or contact metamorphism). For the purpose of this course,
metamorphic rocks are classified as either foliated (which means they appear to have
a layered-like structure where minerals are aligned in one direction) or nonfoliated.
Foliated metamosphic rocks are usually formed during regional metamorphism. Nonfoliated metamorphic rocks are usually formed during thermal metamorphism
(although they can be formed during regional metamorphism, too.)
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The original rock (A: Protolith) gets
pressurized and squeezed. It turn into
the metamorphic rock (B). In the
metamorphic rock, we can see some
layer-like trend (Foliation: Red line
on B) due to the pressure. From the
foliation, we can find the direction of
the pressure.
(A) (B)
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- Biotite
Gneiss - Graphite
Schist - Staurolite
Mica Schist - Garnet Mica
Schist - Chlorite
Schist
photo
Type of
Metamorphic
Rock
Foliated or
Non-foliated
Components
Protolith
Notes
Exercise 1a: Identification of Metamorphic Rocks
Identify the metamorphic rocks. Fill in the blanks (1-5).
?Page-3? - Slate 7. Phyllite 8. Talc
(Soapstone) - Quartzite 10.
Serpentinite
photo
Type of
Metamorphic
Rock
Foliated or
Non-foliated
Components
Protolith
Notes
Exercise 1b: Identification of Metamorphic Rocks
Identify the metamorphic rocks. Fill in the blanks (6-10).
?Page-4? - Epidosite 12. Marble 13.
Serpentinte
Marble - Amphibolite 15. Hornfels
photo
Type of
Metamorphic
Rock
Foliated or
Non-foliated
Components
Protolith
Notes
Exercise 1c: Identification of Metamorphic Rocks
Identify the metamorphic rocks. Fill in the blanks (1-5).
Exercise 2a: Fill in the Metamorphic Rock name in the blanks
Exercise 2b: Fill in the Metamorphic Rock name in the blanks
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Exercise 3: Fill in the Metamorphic Rock name in the blanks
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Schist?
Gneiss?