Kinawa Granite - an Archean-aged migmatite from Brazil. It formed about 2.72-2.75 billion years ago by metamorphism of an older precursor rock (protolith) that dates to about 3.00-3.38 billion years. This migmatite is quarried in the southern São Francisco Craton of southeastern Brazil. It consists of quartz (gray), feldspar (white), and mafic minerals (black).
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Migmatites are very high grade metamorphic rocks that form by partial melting of gneisses. The felsic minerals have melted, cooled, and recrystallized - they form the light-colored, crystalline-textured bands in the rock. The mafic minerals have higher melting temperatures and still retain their metamorphic foliated character.
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