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24 Cards in this Set
- Front
- Back
Extrusive |
Form when magma reaches the surface and cools quickly. Have small crystals. - Basalt - Ryholite - Andesite - Obsidian |
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Intrusive |
Forms when magma cools slowly below the surface Have large crystals - Granite - Gabbro - Diorite - Dunite |
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Aphanitic |
Very small, fine-grained crystals |
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Phaneritic |
Very large, visible crystals
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Phenocryst |
Under Aphanitic: Larger crystals |
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Groundmass |
Finer-grained surrounding crystals |
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Glassy |
Smooth, shiny
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Frothy
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Rough, grainy, matte |
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Felsic |
Fledspar + Silica - Quartz - Potassium Felspar - Plagioclase Felspar |
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Intermediate |
52-66% Silica Classified by amount of silica - Diorite (intrusive) - Andesite (extrusive) |
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Mafic |
45-52% Silica Magnesium + Iron - Olivine - Amphibole - Pyroxene |
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Ultramafic |
38-45% Silica Classified by amount of silica - Peridotite (intrusive) - Komatite (extrusive) very rare |
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Intrusive/Extrusive Pairs |
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Magma |
Molten rock beneath earths surface |
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Lava |
Molten rock at earths surface
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Decompression Melting |
Rifting Sea Floor Spreading Upward movement of the earths mantle to an area of lower pressure. Reduction of pressure allows rock to melt, leading to magma formation. |
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Flux Melting |
Occurs when water and other volatile compounds are added to hot solid rock. Travels up and creates volcanic arcs. |
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Heat Transfer |
Heat rises from magma and melts the crust. Direct rise of mafic magma |
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Partial Melting |
Occurs when a portion of the rock melts. A rock containing several different minerals that display as a solid can be different from the bulk composition of the solid. chocolate chip effect |
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Source Rock Melting** |
** |
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Assimilation** |
**
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Magma Mixing |
Different magmas formed in different locations enter a magma chamber |
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Fractional Crystalization** |
One of the most important processes operating with Earths crust. Removal and segregation from a melt of mineral precipitates |
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Bowen's Reaction Series |
Certain minerals found together where some almost never found together. Has to do with how fast certain minerals cool |