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ALKALI GRANITE
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Typical Minerals
QUARTZ > 20%
ORTHOCLASE is greater than
Plagioclase
Mafics - < 10%
Description
     A felsic igneous rock from the bottom of Bowen's Reaction Series. Typically light colored (few mafic minerals) with orthoclase the most obvious mineral (typically pink but also white or greenish), but quartz >20% is essential.
      This rock can be confused with a syenite which appears superficially similar. The amount of quartz is the key: <20% and the rock is "quartz syenite".
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Tectonic Association
     Granite, as with all felsic rocks, is found on continents. It is one of the last fractionation products and typically results from partial melting of the lower crust.
   Tectonic Cross Section - pdf version

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