REMINDER - CCSFkwiese/content/Classes/IgneousRocksPPT.pdfBrainstorm all igneous rock textures,...
Transcript of REMINDER - CCSFkwiese/content/Classes/IgneousRocksPPT.pdfBrainstorm all igneous rock textures,...
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REMINDER
2 chapters covered next weekSedimentary Rocks
Soils and Weathering (first half)Learn vocabulary for both!
Turn to Neighbor:
Without using your book or notes, try to remember which silicate mineral is made of :
Independent tetrahedra?Single-chains?
Double-chains?Sheets?
3-D Framework?
Which of the above has the most Silica? Least?
What are these large minerals from the Museum of Natural History, NY? (About 4 feet tall!)
MOVIE: Rocks that Originate
Underground5:41 to 12:40
Igneous Rocks are classified by …………..
Porphyritictexture is a subcategory of Aphanitic
Pegmatitictexture is a subcategory
of Phaneritic
Volcanic TuffPumiceObsidianRhyoliteGraniteFelsic
Volcanic TuffPumiceAndesiteDioriteInter-mediate
Volcanic TuffScoriaBasaltGabbroMafic
PeridotiteUltramafic
Pyroclastic or fragmental
Frothy (glassy & vesicular)
GlassyAphaniticPhaneriticComposi-tion
Texture
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> 65% silica
55 – 65% silica
45 – 55% silica
< 45% silica
Extrusive rock names
Intrusive rock names
Mineral composition
NameCompo-sition
Felsic> 65% silica
Interme-diate
55 – 65% silica
Mafic45 – 55% silica
Ultramafic< 45% silica
Extrusive rock names
Intrusive rock names
Mineral composition
NameCompo-sition
Felsic> 65% silica
Interme-diate
55 – 65% silica
Mafic45 – 55% silica
Mostly OlivineMinor PyroxeneMinor Plagioclase
Ultramafic< 45% silica
Extrusive rock names
Intrusive rock names
Mineral composition
NameCompo-sition
Felsic> 65% silica
Interme-diate
55 – 65% silica
PyroxeneCa-rich PlagioclaseMinor OlivineMinor Hornblende
Mafic45 – 55% silica
Mostly OlivineMinor PyroxeneMinor Plagioclase
Ultramafic< 45% silica
Extrusive rock names
Intrusive rock names
Mineral composition
NameCompo-sition
Felsic> 65% silica
HornblendeBiotiteNa-rich PlagioclaseMinor Pyroxene
Interme-diate
55 – 65% silica
PyroxeneCa-rich PlagioclaseMinor OlivineMinor Hornblende
Mafic45 – 55% silica
Mostly OlivineMinor PyroxeneMinor Plagioclase
Ultramafic< 45% silica
Extrusive rock names
Intrusive rock names
Mineral composition
NameCompo-sition
QuartzK-FeldsparMuscoviteMinor BiotiteMinor HornblendeMinor Na-rich Plagiocl.
Felsic> 65% silica
HornblendeBiotiteNa-rich PlagioclaseMinor Pyroxene
Interme-diate
55 – 65% silica
PyroxeneCa-rich PlagioclaseMinor OlivineMinor Hornblende
Mafic45 – 55% silica
Mostly OlivineMinor PyroxeneMinor Plagioclase
Ultramafic< 45% silica
Extrusive rock names
Intrusive rock names
Mineral composition
NameCompo-sition
Rhyolite, Pumice, Tuff, Obsidian
GraniteQuartzK-FeldsparMuscoviteMinor BiotiteMinor HornblendeMinor Na-rich Plagiocl.
Felsic> 65% silica
Andesite, Pumice, Tuff
DioriteHornblendeBiotiteNa-rich PlagioclaseMinor Pyroxene
Interme-diate
55 – 65% silica
Basalt, ScoriaGabbroPyroxeneCa-rich PlagioclaseMinor OlivineMinor Hornblende
Mafic45 – 55% silica
NONE EXIST ON PLANET EARTH
PeridotiteMostly OlivineMinor PyroxeneMinor Plagioclase
Ultramafic< 45% silica
Extrusive rock names
Intrusive rock names
Mineral composition
NameCompo-sition
Porphyritictexture is a subcategory of Aphanitic
Pegmatitictexture is a subcategory
of Phaneritic
Volcanic TuffPumiceObsidianRhyoliteGraniteFelsic
Volcanic TuffPumiceAndesiteDioriteInter-mediate
Volcanic TuffScoriaBasaltGabbroMafic
PeridotiteUltramafic
Pyroclastic or fragmental
Frothy (glassy & vesicular)
GlassyAphaniticPhaneriticComposi-tion
Texture
Phaneritic Phaneritic
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Aphanitic
Pyroclastic Pyroclastic
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Frothy Frothy
Tongariro National Park – Mt. Ngauruhoe
PUMICE FLOATING MOVIE
Glassy
Glassy
Porphyritictexture is a subcategory of Aphanitic
Pegmatitictexture is a subcategory
of Phaneritic
Volcanic TuffPumiceObsidianRhyoliteGraniteFelsic
Volcanic TuffPumiceAndesiteDioriteInter-mediate
Volcanic TuffScoriaBasaltGabbroMafic
PeridotiteUltramafic
Pyroclastic or fragmental
Frothy (glassy & vesicular)
GlassyAphaniticPhaneriticComposi-tion
Texture
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Turn to Neighbor:
Come up with a good definition (no books or notebooks) of VISCOSITY.
Which is more viscous:
Water or Honey?Hot syrup or cold syrup?
DEMO: Oil Viscosity
Highly Viscous Felsic Lava
Low-Viscosity Mafic Lava
Mineral GrowthANIMATION
Phaneritic
Museum of Natural History, NY. – Rare minerals from PegmatitesAs molten granite crystallizes, the melt that remains becoems enriched in water and rare elements such as B, Ta, and Nb. These elements concentrate in the melt because they are not taken up by the minerals crystallizing from it. Eventually, enough water builds up that steam forms. Gem and ore minerals containing rare elements form in
the pockets of steam-and water-rich melt. In the presence of water, minerals can grow to enormous sizes.
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Pegmatite Vein – Filled In – Sierra Nevada Mountains Grand Canyon Pegmatite
(at the bottom!)
Tourmaline Mine Pegmatite San Diego
Glassy Glassy
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Porphyritictexture is a subcategory of Aphanitic
Pegmatitictexture is a subcategory
of Phaneritic
Volcanic TuffPumiceObsidianRhyoliteGraniteFelsic
Volcanic TuffPumiceAndesiteDioriteInter-mediate
Volcanic TuffScoriaBasaltGabbroMafic
PeridotiteUltramafic
Pyroclastic or fragmental
Frothy (glassy & vesicular)
GlassyAphaniticPhaneriticComposi-tion
Texture
Assimilation – Sierra Nevada Mountains – Desolation Wilderness
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1:2QuartzNoneThree dimensional framework of Si-O tetrahedrons with no ionic bonds.
1:2Feldspars2 planes at 90° (square tablets)
Three dimensional framework of Si-O tetrahedrons with ionic bonds filling holes within.
1:2.5Micas1 plane Sheets connected to other sheets by ionic bonds.
1:2.75Hornblende2 planes at 60 and 120° (sheared columns) or hairs/fibers
Double chains connected to other chains by ionic bonds.
1:3Pyroxene2 planes at 90° (square columns) or hairs/fibers
Single chains connected to other chains by ionic bonds.
1:4OlivineNoneSingle Si-O tetrahedron connected to other tetrahedron by ionic bonds.
Si:O ratioExamplesCleavage typeSilicate structure
Plagioclase content
Olivine content
Quartz content
Water content
ViscosityFe, Mg, Ca content
Si, K, Na content
Temper-ature
Moves from Ca-rich to Na-rich
Plagioclase content↓Olivine
content↑Quartz content↑Water
content
↑Viscosity↓Fe, Mg, Ca content ↑Si, K, Na
content↓Temper-ature
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1:2QuartzNoneThree dimensional framework of Si-O tetrahedrons with no ionic bonds.
1:2Feldspars2 planes at 90° (square tablets)
Three dimensional framework of Si-O tetrahedrons with ionic bonds filling holes within.
1:2.5Micas1 plane Sheets connected to other sheets by ionic bonds.
1:2.75Hornblende2 planes at 60 and 120° (sheared columns) or hairs/fibers
Double chains connected to other chains by ionic bonds.
1:3Pyroxene2 planes at 90° (square columns) or hairs/fibers
Single chains connected to other chains by ionic bonds.
1:4OlivineNoneSingle Si-O tetrahedron connected to other tetrahedron by ionic bonds.
Si:O ratioExamplesCleavage typeSilicate structure
Porphyritictexture is a subcategory of Aphanitic
Pegmatitictexture is a subcategory
of Phaneritic
Volcanic TuffPumiceObsidianRhyoliteGraniteFelsic
Volcanic TuffPumiceAndesiteDioriteInter-mediate
Volcanic TuffScoriaBasaltGabbroMafic
PeridotiteUltramafic
Pyroclastic or fragmental
Frothy (glassy & vesicular)
GlassyAphaniticPhaneriticComposi-tion
Texture
Turn to Neighbor:
Brainstorm all igneous rock textures, names, characteristics, etc. that are associated with
Extrusive rocks onlyIntrusive rocks only
(Make two columns on paper and decide where to place each thing so far discussed or read)
Rock names
Textures and features
DefinitionIntrusive or plutonicExtrusive or volcanic
Rock names
Textures and features
Magma that remains underground where it cools
Lava erupted and cooled at surface
DefinitionIntrusive or plutonicExtrusive or volcanic
Rock names
VesiclesAphaniticPorphyriticGlassyFrothyPyroclastic
Textures and features
Magma that remains underground where it cools
Lava erupted and cooled at surface
DefinitionIntrusive or plutonicExtrusive or volcanic
ScoriaPumiceBasaltAndesiteRhyoliteVolcanic TuffObsidian
Rock names
VesiclesAphaniticPorphyriticGlassyFrothyPyroclastic
Textures and features
Magma that remains underground where it cools
Lava erupted and cooled at surface
DefinitionIntrusive or plutonicExtrusive or volcanic
ScoriaPumiceBasaltAndesiteRhyoliteVolcanic TuffObsidian
Rock names
PhaneriticPegmatitic
VesiclesAphaniticPorphyriticGlassyFrothyPyroclastic
Textures and features
Magma that remains underground where it cools
Lava erupted and cooled at surface
DefinitionIntrusive or plutonicExtrusive or volcanic
PeridotiteGabbroDioriteGranite
ScoriaPumiceBasaltAndesiteRhyoliteVolcanic TuffObsidian
Rock names
PhaneriticPegmatitic
VesiclesAphaniticPorphyriticGlassyFrothyPyroclastic
Textures and features
Magma that remains underground where it cools
Lava erupted and cooled at surface
DefinitionIntrusive or plutonicExtrusive or volcanic
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PlutonFormation
ANIMATION
Size
Shape: tabular or massive
Parallel to surrounding bedding (concordant) or cross-cutting (discordant)
BatholithDikeSill
5-30 m thickSize
TabularShape: tabular or massive
ParallelParallel to surrounding bedding (concordant) or cross-cutting (discordant)
BatholithDikeSill
0.5-30 m thick5-30 m thickSize
TabularTabularShape: tabular or massive
Cross-cuttingParallelParallel to surrounding bedding (concordant) or cross-cutting (discordant)
BatholithDikeSill
100s of km wide0.5-30 m thick5-30 m thickSize
MassiveTabularTabularShape: tabular or massive
Cross-cuttingCross-cuttingParallelParallel to surrounding bedding (concordant) or cross-cutting (discordant)
BatholithDikeSill
Basalt Sills – Glacier National Park
Basalt Dike – Mt. Moran – Grand Tetons
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Shiprock Peak in New Mexico Shiprock Peak in New Mexico
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Magma Mixing – Granite and Diorite
Cabo San Lucas, Mexico
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: half of next week’s quiz will contain any question from the question sheet.
Rock ID Activity
Recommend setting samples up into 5 texture columns and 4 compositional rows, just like on naming table. ALSO – set up the Bowens Reaction Series minerals alongside the rocks, so you can see how they match.
There are some duplicate names in the boxes.