Hornblende Kaolinite (clay) - City College of San Francisco · 5 Density separation during sand...
Transcript of Hornblende Kaolinite (clay) - City College of San Francisco · 5 Density separation during sand...
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Hornblende(Ca,Na)2-3(Fe,Mg,Al)5Si6(Si,Al)2O22(OH)2
Kaolinite (clay)Al2Si2O5(OH)4
Foliation ANIMATION
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Why?How does texture change as grade increases?
Grains and crystals pack closer together under confining pressure
Density increases (volume shrinks)
Why?How does texture change as grade increases?
Grains and crystals pack closer together under confining pressure
Density increases (volume shrinks)
Minerals align when under directed pressure
Foliation increases
Why?How does texture change as grade increases?
Grains and crystals pack closer together under confining pressure
Density increases (volume shrinks)
Grain boundaries migrate, enlarging crystal size as pressure (any kind) placed on crystal boundaries.
Crystal size increases
Minerals align when under directed pressure
Foliation increases
Why?How does texture change as grade increases?
Migmatitictexture
Very high
Gneissic texture
High
SchistosityMed to high
Phyllitictexture
Low to med
Rock or slatycleavage
Low
Description (+ picture)Foliation typeGrade
4
Microscopic, aligned mica minerals. Planar cleavage. No visible minerals. Dense.
Rock or slatycleavage
Low
Description (+ picture)FoliationGrade
Mostly microscopic, aligned mica minerals. Only a few visible, isolated minerals peeking out of satiny background. Foliation is undulating.
Phyllitictexture
Low to med
Microscopic, aligned mica minerals. Planar cleavage. No visible minerals. Dense.
Rock or slatycleavage
Low
Description (+ picture)FoliationGrade
Mostly visible biotite minerals – all aligned, giving rock a scaly look, like a fish. Foliation is undulating and fine. Some large porphyroblasts may peek out.
SchistosityMed to high
Mostly microscopic, aligned mica minerals. Only a few visible, isolated minerals peeking out of satiny background. Foliation is undulating.
Phyllitictexture
Low to med
Microscopic, aligned mica minerals. Planar cleavage. No visible minerals. Dense.
Rock or slatycleavage
Low
Description (+ picture)FoliationGrade
5
Density separation during sand deposition (from hour glass)
All visible, interlocking crystals, separated into alternating dark- and light-colored layers.
Gneissic texture
High
Description (+ picture)Foliation type
Grade
6
Gneissic texture where ½ melted, and the high temperatures caused folding of the layers.
Migmatitictexture
Very high
All visible, interlocking crystals, separated into alternating dark- and light-colored layers.
Gneissic texture
High
Description (+ picture)Foliation type
Grade
---------------Pyroxene--------------------------------Hornblende-----------------
----------------------------Garnet-----------------------------------------------------------------------------Biotite------------------------------
-------------------------------Muscovite-----------------------------------------------------------------------------------------Calcite-------------------------------------------------------------------------------------------------------------------------Feldspar----------------------------------------------------------------------------------------------------------------------Quartz-----------------------------------------------------------
Low Medium HighGeneral mineral grade stability
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Core Mountain Garnet – from the Adirondack Mountains, NY – Museum of Natural History, NY. Garnet-bearing amphibolite – shows how metamorphism changes texture. Originally this rock was a GABBRO with olivine, pyroxene, and plagioclase. Under high T and P, water seeped into rock and reacted with original minerals to form hornblende and garnet. Water allowed for the large crystal size.
Chemically active fluids
TPMetamorphic setting
High – from magma and from heated surface waters
High: increasing toward magma
LowContact metamorphism (C)
Chemically active fluidsTPMetamorphic setting
Low – liberated from hydrous minerals and small amounts in cracks/pores
High: steadily increasing with depth
High: steadily increasing with depth
Regional metamorphism: Deep burial (B)
High – from magma and from heated surface waters
High: increasing toward magma
LowContact metamorphism (C)
Chemically active fluidsTPMetamorphic setting
Low – liberated from hydrous minerals and small amounts in cracks/pores
Low to medium: increasing with depth
High: increasing with depth
Regional metamorphism: Converging continents (R)
Low – liberated from hydrous minerals and small amounts in cracks/pores
High: steadily increasing with depth
High: steadily increasing with depth
Regional metamorphism: Deep burial (B)
High – from magma and from heated surface waters
High: increasing toward magma
LowContact metamorphism (C)
Chemically active fluidsTPMetamorphic setting
High – from hydrous minerals in hydrothermally altered ocean crust and water trapped in pores/cracks
Low: slowly increasing with depth
HighSubduction zone metamorphism (S)
Low – liberated from hydrous minerals and small amounts in cracks/pores
Low to medium: increasing with depth
High: increasing with depth
Regional metamorphism: Converging continents (R)
Low – liberated from hydrous minerals and small amounts in cracks/pores
High: steadily increasing with depth
High: steadily increasing with depth
Regional metamorphism: Deep burial (B)
High – from magma and from heated surface waters
High: increasing toward magma
LowContact metamorphism (C)
Chemically active fluidsTPMetamorphic setting
High – from magmas and from circulating seawater
High because occurs at the Moho.
LowHydrothermal (H) circulation at spreading centers
High – from hydrous minerals in hydrothermally altered ocean crust and water trapped in pores/cracks
Low: slowly increasing with depth
HighSubduction zone metamorphism (S)
Low – liberated from hydrous minerals and small amounts in cracks/pores
Low to medium: increasing with depth
High: increasing with depth
Regional metamorphism: Converging continents (R)
Low – liberated from hydrous minerals and small amounts in cracks/pores
High: steadily increasing with depth
High: steadily increasing with depth
Regional metamorphism: Deep burial (B)
High – from magma and from heated surface waters
High: increasing toward magma
LowContact metamorphism (C)
Chemically active fluidsTPMetamorphic setting
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Eroding Metamorphic RocksANIMATION
Review Display Samples
Review Metamorphic Rock Chart
Metamorphic Rocks Activity
There are some duplicate names in the boxes.
Metamorphic Rocks in North America Formulas You Need To Know
CaCO3
Mineral:
Sedimentary rock:
Metamorphic rock:
SiO2
Mineral:
Sedimentary rock:
Metamorphic rock:
CaCO3Mineral: Calcite
Sedimentary rock:
Metamorphic rock:
SiO2Mineral: Quartz
Sedimentary rock:
Metamorphic rock:
CaCO3Mineral: Calcite
Sedimentary rock:Chalk, Limestone
(including coquina, calcarenite)
Metamorphic rock:
SiO2Mineral: Quartz
Sedimentary rock:Quartz Sandstone,
Chert, Diatomite
Metamorphic rock:
CaCO3Mineral: Calcite
Sedimentary rock:Chalk, Limestone
(including coquina, calcarenite)
Metamorphic rock:Marble
SiO2Mineral: Quartz
Sedimentary rock:Quartz Sandstone,
Chert, Diatomite
Metamorphic rock:Quartzite
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GRADE:LowLow - MedMed - HighHighVery High
Limestone(CaCO3)
Chert (SiO2)BasaltGraniteShaleParent rock
B, R, SB, R, SSB, R, SB, R, SMetamorphic settings
GRADE:LowLow - MedMed - HighHighVery High
Mantle rock (Peridotite)
BasaltShaleMixture of minerals
Limestone(CaCO3)
Chert(SiO2)
Parent rock
HCCCCCMetamorphic settings
SlatePhylliteSchistGneissMigmatite
GRADE:LowLow - MedMed - HighHighVery High
Limestone(CaCO3)
Chert (SiO2)BasaltGraniteShaleParent rock
B, R, SB, R, SSB, R, SB, R, SMetamorphic settings
GneissMigmatite
SlatePhylliteSchistGneissMigmatite
GRADE:LowLow - MedMed - HighHighVery High
Limestone(CaCO3)
Chert (SiO2)BasaltGraniteShaleParent rock
B, R, SB, R, SSB, R, SB, R, SMetamorphic settings
Greenstone
BlueschistEclogiteGneiss
Migmatite
SlatePhylliteSchistGneissMigmatite
GRADE:LowLow - MedMed - HighHighVery High
Limestone(CaCO3)
Chert (SiO2)BasaltGraniteShaleParent rock
B, R, SB, R, SSB, R, SB, R, SMetamorphic settings
Quartzite (crystals grow larger)
Greenstone
BlueschistEclogiteGneiss
Migmatite
SlatePhylliteSchistGneissMigmatite
GRADE:LowLow - MedMed - HighHighVery High
Limestone(CaCO3)
Chert (SiO2)BasaltGraniteShaleParent rock
B, R, SB, R, SSB, R, SB, R, SMetamorphic settings
Marble (crystals grow larger)
Quartzite (crystals grow larger)
Greenstone
BlueschistEclogiteGneiss
Migmatite
SlatePhylliteSchistGneissMigmatite
GRADE:LowLow - MedMed - HighHighVery High
Limestone(CaCO3)
Chert (SiO2)BasaltGraniteShaleParent rock
B, R, SB, R, SSB, R, SB, R, SMetamorphic settings
Quartzite (crystals grow larger)
GRADE:LowLow - MedMed - HighHighVery High
Mantle rock (Peridotite)
BasaltShaleMixture of minerals
Limestone(CaCO3)
Chert(SiO2)
Parent rock
HCCCCCMetamorphic settings
Marble (crystals grow larger)
Quartzite (crystals grow larger)
GRADE:LowLow - MedMed - HighHighVery High
Mantle rock (Peridotite)
BasaltShaleMixture of minerals
Limestone(CaCO3)
Chert(SiO2)
Parent rock
HCCCCCMetamorphic settings
Skarn(crystals grow larger; form new minerals)
Marble (crystals grow larger)
Quartzite (crystals grow larger)
GRADE:LowLow - MedMed - HighHighVery High
Mantle rock (Peridotite)
BasaltShaleMixture of minerals
Limestone(CaCO3)
Chert(SiO2)
Parent rock
HCCCCCMetamorphic settings
HornfelsHornfelsSkarn(crystals grow larger; form new minerals)
Marble (crystals grow larger)
Quartzite (crystals grow larger)
GRADE:LowLow - MedMed - HighHighVery High
Mantle rock (Peridotite)
BasaltShaleMixture of minerals
Limestone(CaCO3)
Chert(SiO2)
Parent rock
HCCCCCMetamorphic settings
SerpentiniteHornfelsHornfelsSkarn(crystals grow larger; form new minerals)
Marble (crystals grow larger)
Quartzite (crystals grow larger)
GRADE:LowLow - MedMed - HighHighVery High
Mantle rock (Peridotite)
BasaltShaleMixture of minerals
Limestone(CaCO3)
Chert(SiO2)
Parent rock
HCCCCCMetamorphic settings
Serpentinite – Mt Diablo
Soils derived from serpentine are toxic to many plants, because of high levels of nickel, chromium, and cobalt; growth of many plants is also inhibited by low levels of potassiumand phosphorusand a low ratio of calcium/magnesium.
We have now completed this week’s question sheet.
On your own, review each question again. I recommend that you write out your answers
(synthesize your thoughts and notes and put the answers into your own words).
If something doesn’t make sense or to just get some feedback, come see the tutors or me during my office
hours.
Remember: The exam will contain ANY question from ANY question sheet for this section.
ROCK/MINERAL REVIEW