metamorphism & metamorphic rocks. the rock that forms depends on: how do metamorphic rocks form?
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Metamorphism & Metamorphism & Metamorphic RocksMetamorphic RocksMetamorphism & Metamorphism &
Metamorphic RocksMetamorphic Rocks
Why Should Why Should YouYou Study Metamorphic Study Metamorphic Rocks?Rocks?
What are the 3 Agents of Metamorphism?What are the 3 Agents of Metamorphism?
Heat Heat ______________________ the the raterate of chemical reactions. of chemical reactions.
Sources of Heat:Sources of Heat:
How does TIME affect transformations?How does TIME affect transformations?
Foliated Meta. Rocks Rock Typical Meta. Features Parent Rock Typical Meta. Features Parent
Name Minerals Grade of Rock RockName Minerals Grade of Rock RockSlateSlate clays, micas, clays, micas, low low fine-grained, shale, fine-grained, shale,
chloritechlorite splits uniformly vol. ash splits uniformly vol. ashPhyllitePhyllite quartz, micas, quartz, micas, low-med fine-gr, glossy shale low-med fine-gr, glossy shale
chloritechlorite “crinkled” “crinkled”
Schist micas, chlorite, med-high distinct foliation shale, talc, garnet visible carbonates, hbl
basalt/gabbroGneiss qtz, feldspar, high light & dark shale, hbl, micas bands sandstone, basalt/gabbro felsic ign.
Amphibolite hbl med-high dark, weak fol. basalt/gabbro
Migmatite qtz, feldspar, very granite streaks felsic ign. & hbl, mica high in gneiss sed. mixed
SCHIST(medium-grained, foliated)
• platy/elongate minerals
• _________________________ metamorphism Schistose foliation
GNEISS
(medium-grained, foliated)
• ______________• ________________________ metamorphism
• Light bands granular minerals. (______________________)
• Dark bands platy/elongate min. (______________________)
AMPHIBOLITE (med-gr, foliated) hornblende & plagioclase (___________________ regional meta.)
MIGMATITES (mixed rocks) • _________________________ metamorphism
• High-grade meta. rx intermix w/ streaks of granite.
Georgian Bay, Ontario, Canada
Nonfoliated Meta. Rocks
Rock Typical Meta. Features Parent Name Minerals Grade of Rock RockMarble calcite, low-high interlocking limestone,
dolomite grains dolostone Quartzite quartz med-high interlocking quartz
grains, hard sandstoneGreenstone chlorite, epidote, low-high fine-grained mafic ign.
hornblende green color
Hornfels micas, garnet, low-med fine-grained, mudrocks quartz hard, dense Anthracite carbon high black, lustrous, coal
subconchoidal fracture
Marble
• ________________________________ metamorphism
• Parent Rock =
How is Marble used?
metamorphism
C
QUARTZITE
• _____________________________________ metamorphism
• Parent Rock = ________________________
• Hard & compact w/ uniform strength [breaks across grains rather than around them]
• used in __________________________________________
metamorphism
Greenstone (____________________ meta)
• Parent rock = ________________________ (green color from chlorite, epidote, & hornblende)
Hornfels (__________________________ meta)
• Parent rock = __________________________
• equidimensional grains
Anthracite
• Parent rock = ___________________________
Does Metamorphism Relate to Plate Tectonics?
Low-temp/high-press _______ part of subducting plate High-temp./high-press _______ part of subducting plate High-temp/low-press _________ meta. follows
Natural Resources Minerals used: talc
graphite garnet kyanite
asbestos
{Chrysotile silky fibers 95% of all asbestos used in the U.S.}
{Crocidolite long, straight fibers This variety presents a health risk. EPA policies
treat all asbestos the same.}
Chrysotile
Ore Deposits
Ore Mineral Formula UsesCopper Bornite Cu5FeS4 transportation,
communications
Iron Hematite Fe2O3 steel manufacturing
Magnetite Fe3O4
Lead Galena PbS batteries, pipes, solder
Tin Cassiterite SnO2 plating, solder, alloys
Tungsten Scheelite CaWO4 metal hardening, Wolframite (Fe,Mn)WO4 carbide manufacturing
Zinc Sphalerite (Zn,Fe)S batteries, brass making, galvanizing iron
(hydrothermal contact meta.)