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12 Cards in this Set
- Front
- Back
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How are sedimentary rocks formed
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Solid cohesive mass formed after compaction and cementation - lithification
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How do we classify sedimentary rocks
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less than 1/256 mm = clay
between 1/256 to 1/16 is siltstone between 1/16 to 2 mm is sandstone more than 2 mm is conglomerate |
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How are coquina and coal formed
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Coquina is formed by the combination of organic debris and inorganic precipitates
Coal is plant debris |
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How are metamorphic rocks formed?
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Formed under the influence of heat and/or pressure and/or fluids
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What are the 3 steps of metamorphism
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Recrystallization is when the minerals grow larger
Neomineralization is when growth of new minerals stems from the old minerals Deformation is when the rock is stretched, compressed in solid, or folded in a plastic state |
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What are some sources of Pressure
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Burial applies equal pressure in all directions
Tectonic Differential applies directed stress |
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What are some sources of Temperature
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Thermal gradient which means that the heat will increase by about 20 to 30 C degress every km of depth
Intrustion of magma |
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What is the difference between regional and contact metamorphism
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With contact meta there is a presence of a local source of pressure or temp such as hot magma
With regional meta there is Pressure and/or Temp in a larer scale covering a much wider area, such as mountain building, regional meta rocks are usually characterized by their formation due to directed stress |
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What do minerals with a foliated texture look like
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Minerals arranged in a parallel fashion
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Name some foliated rocks
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slate, phyllite, micaschist, gneiss
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What are the rock sources or parent rocks of quartzite, marble, orthogneiss, amplhibolite
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sandstone for quartzite
limestone for marble granite for orthogneiss basalt for amplhibolite |
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What kind of composition are the oceanic crust and continental crust
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oceanic is basaltic
continental is granite |
