Common metamorphic rocksmica schist gneiss slate marble quartzite... Common metamorphic rocks Foliated rocks... Common metamorphic rocks Foliated rocks slate... Very fine-grained, Pl
Trang 1Chapter 8:
Metamorphic rocks
Today’s
Lecture
1) Classification metamorphic rocks
Texture & Composition2) Contact metamorphism
3) Metamorphism along faults
4) Regional metamorphism
5) Metamorphism & plate tectonics
Trang 3Common metamorphic rocks
mica schist
gneiss
slate
marble quartzite
Trang 4Common metamorphic rocks
Foliated rocks
Trang 5Common metamorphic rocks
Foliated rocks slate
Trang 6Fig 8.13
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Trang 7Fig 8.10
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Trang 8Fig 8.09
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Trang 9Very fine-grained,
Platy minerals
(Clays, Micas)
Slate
Common metamorphic rocks
Foliated rocks slate
Trang 10Common metamorphic rocks
Foliated rocks slate
Trang 11Common metamorphic rocks
Foliated rocks slate
Trang 121) Common metamorphic rocks
Foliated rocks
Common metamorphic rocks
Foliated rocks slate
Original
sedimentary
layering
Trang 13Fig 8.12a
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Trang 15Veins developed
in slate
Trang 16Common metamorphic rocks
Foliated rocks phyllite
Slate Phyllite
Fine- to medium-grained
Platy minerals(e.g.
muscovite or chlorite
Trang 17Common metamorphic rocks
Foliated rocks phyllite
Phyllite
Trang 18Biotite Mica
Trang 19Common metamorphic rocks
Foliated rocks phyllite
Original sedimentary
layers
Trang 201) Common metamorphic rocks
Trang 21Common metamorphic rocks
Mica Schist
Rock name:
Composition plus texture
Trang 22Common metamorphic rocks
Trang 23Quartz
Mica
Trang 24Common metamorphic rocks
Segregation
of minerals
into bands
Begins.
Trang 25 Foliated rocks schist
Common metamorphic rocks
Trang 26Fig 8.07a
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Trang 27Fig 8.07b
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Trang 28Foliated Rocks: Schist
Garnet
Trang 291) Common metamorphic rocks
Garnet-Mica Schist
Trang 30Fig 8.08
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Trang 31
1) Common metamorphic rocks
Trang 32Fig 8.11
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Trang 33Fig 8.04
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Trang 34feldspar
biotite
Trang 35Fig 8.03bCourtesy Carlo Giovanella
Metamorphic
minerals
Garnet
Gneiss
Trang 36Common metamorphic rocks
Trang 37 Textural categories and the
Mineral segregation, banding
Metamorphic Textures: Foliated Rocks
Partial melting, formation of magma
Trang 38Migmatites: Formed
by partial melting
Trang 42Calcite
Trang 44Fig 8.17aStephen Marshak
Trang 51 Magma invades pre-existing parent rock
This heating forms a “halo” or zone
of alteration adjacent to contact.
Large magma chamber halo = few km thick)
Dikes, sills halo = few cm thick
Rocks formed are dense, hard and usually
not foliated.
Types of Metamorphism: Contact
Trang 52Fig 8.23
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Trang 56Dynamic Metamorphism Along Faults
Creates fault breccias
Cataclastic textures.
Grinding of rock
In fault zone
Trang 57Fig 08.24
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Trang 58p.218-219c
Trang 60Mylonites Deep fault zone foliated rocks
Trang 61Fig 8.14Stephen Marshak
Trang 64Fig 8.18
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Grades of Metamorphism
Trang 65p.218-219boriginal artwork by Gary Hincks
Textural Grades of Metamorphism
Trang 66Fig 8.22
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Mineral Grades
Trang 67Fig 8.19
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Trang 68Metamorphism and Plate Tectonics
Continental Cratons: Ancient metamorphic environments
Relatively flat expanses of metamorphic rocks &
associated igneous plutons: “shields”
Trang 69Fig 08.29a
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Trang 70Metamorphism and plate tectonics
Most metamorphism associated w/ convergent plate boundaries
Compressional forces deform plate edges
Subduction zones: two linear belts of
Trang 71Metamorphism and plate tectonics
Hydrothermal vents at mid-ocean ridges
Trang 72Fig 08.27
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Trang 73Fig 08.28
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Trang 74p.218-219aoriginal artwork by Gary Hincks
Trang 76Metamorphism and plate tectonics
Subduction zones:
Copper deposits
Trang 77Fig 08.25
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Trang 79Metamorphism and plate tectonics
Subduction zones:
Serpentinite
Trang 82Fig 8.00Stephen Marshak
Trang 83Fig 8.21
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