Term
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Definition
| A large crystal, >1 mm diameter |
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Term
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Definition
| very fine to fine crystals making up most of the rock, can't be seen by the naked eye |
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Term
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Definition
| very fine, non-crystalline bulk of rock, often made of ash or glass |
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Term
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Definition
explosive eruption, rapidly cooled, typically very fine to no crystals
example: tuff, pumice |
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Term
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Definition
| a trapped gas or fluid bubble |
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Term
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Definition
(texture)
extremely rapid cooling, of viscuos magma, no crystals |
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Term
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Definition
(texture)
rapid cooling, very fine crystals (<1mm crystals) |
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Term
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Definition
(texture)
cooling in stages creates a mix of large and very fine crystals
-the larger crystals are called phenocrysts, the smaller are called matrix or groundmass
-indicates that the rock cooled slowly at first to create large crystals, then more rapidly to form the small crystals |
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Term
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Definition
(texture)
slow to very slow cooling, large crystals that are between 1-10 mm
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Term
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Definition
(texture)
extremely slow cooling, extremely large crystals, fluid-rich, crystals are >1cm |
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Term
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Definition
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Term
Basalt-(low silica)-1200 to 1250
Basaltic Andesite
Andesite
Dacite
Rhyolite-(high silica)-700 to 750
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Definition
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Term
Gabbro-(low silica)-1200 to 1250
Diorite
Tonalite
Granodiorite
Granite-(high silica)-700 to 750 |
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Definition
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Term
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Definition
| molten rock containing liquids, crystals and dissolved gases that cools below ground |
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Term
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Definition
| magma that has erupted onto earth's surface, fine grained rock |
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Term
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Definition
(A factor that determines the violence of an eruption)
-resistance to flow
-the higher the silica content (the more felsic a rock is), the more viscuous it is
-affected by composition, temp, and volatiles |
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Term
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Definition
| Volcanic rocks are defined from each other based on their |
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Term
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Definition
| Plutonic rocks are defined from each other based on their |
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Term
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Definition
Mafic rocks contain a lot of
Ex-basalt, gabbro
-will most likely be dark colored |
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Term
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Definition
Felsic rocks contain alot of...
Ex-rhyolite, granite
-Will most likely be light colored |
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Term
Olivine Ca-rich
Pyroxene Plagioclase
Amphibole
Biotite Na-rich
K-spar
Muscovite
Quartz |
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Definition
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Term
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Definition
Specific diagram of BRS with temperatures and mafic, intermediate, and felsic
(picture) |
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Term
| magma composition and viscosity |
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Definition
| Crystal size can also be influenced by (2 things) |
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Term
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Definition
Color indication
-these rocks tend to be pink, white, or pale grey/brown |
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Term
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Definition
(color indication)
-these rocks tend to be greenish grey to medium grey |
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Term
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Definition
(color indication)
These rocks tend to be green, dark grey, or black |
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Term
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Definition
-Felsic
-0-15% mafic minerals
-High viscosity
-Minerals NOT observed: olivine, pyroxene
-Two textures: aphanitic, porphyritic
-Volcanic
-Rapid cooling
-gas/fluid poor |
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Term
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Definition
-Mafic
-Common minerals: pyroxene, plagioclase
-Most abundant mineral: plagioclase
-texture: phaneritic
-Plutonic
-Slow cooling |
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Term
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Definition
-Intermediate
-Common minerals: pyroxene, hornblende, plagioclase
-Texture: Aphanitic
-Volcanic
-Rapid cooling
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Term
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Definition
-Felsic
-High-viscosity
-gas/fluid poor
-Common mineral: Quartz
-Texture: Glassy
-Volcanic
-Very rapid cooling
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Term
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Definition
-Ultramafic
-Two common minerals: olivine, pyroxene
-Most common mineral: olivine
-Texture: Phaneritic
-Plutonic
-Slow Cooling |
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Term
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Definition
-Intermediate
-Four common minerals: pyroxene, hornblende, plagioclase, quartz
-Two most abundant minerals: plagioclase, hornblende
-Texture: Phaneritic
-Plutonic
-Slow cooling |
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Term
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Definition
-Felsic
-Two common minerals: biotite and quartz
-Three common textures: Glassy, vesicular, pyroclastic
-Volcanic
-Very rapid cooling |
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Term
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Definition
-Mafic
-Common minerals: olivine and plagioclase
-Textures: Aphanitic, vesicular, pyroclastic
-Volcanic
-Rapid cooling
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Term
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Definition
-Felsic
-high viscosity
-gas/fluid poor
-Mineral that is NOT common: olivine
-3 most common minerals: potassium feldspar, quartz, and plagioclase
-Texture: Phaneritic
-Plutonic
-Slow cooling
-~20% plagioclase, ~40% potassium feldspar, ~30% Quartz, ~10% Biotite |
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Term
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Definition
-Mafic
-can be vesicular
-low viscosity
-gas/fluid rich
-3 common minerals: olivine, pyroxene, plagioclase
-Textures: glassy, aphanetic, porphyritic
-Volcanic
-Very Rapid to rapid cooling
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Term
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Definition
-Felsic
-Rocks that are NOT phenocrysts: olivine
-texture: pegmatic
-Plutonic
-very slow cooling |
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Term
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Definition
-Pyroclastic texture
-Volcanic
-Very rapid
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