The average bulk chemical composition of the continental crust is intermediate in silica content, closely approximated by an intermediate igneous rock composition — most commonly cited as andesitic to granodioritic — reflecting the crust's overall mixture of felsic upper crust and more mafic lower crust, rather than the purely felsic composition of rhyolite/granite or the mafic composition of basalt.
Geochemical studies of the continental crust (integrating upper, middle, and lower crustal compositions) consistently find that its average bulk composition is intermediate, most closely matching...
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