Granodiorite
|
A sample of granodiorite rock |
Granodiorite is an intrusive
igneous rock similar to
granite, but contains more
plagioclase than
potassium feldspar. It usually contains abundant
biotite mica and
hornblende, giving it a darker appearance than true granite. Mica may be present in well-formed hexagonal crystals, and hornblende may appear as needle-like crystals.
On average the upper continental crust has the same composition as granodiorite.
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Grandiorite definition at USGS (public domain source)
