Intermediate Granite Rocks

Mafic rocks are dominated by plagioclase and pyroxene even if you can t see them with the naked eye and smaller amounts of olivine.

Intermediate granite rocks.

Granite is composed mainly of quartz and feldspar with minor amounts of mica amphiboles and other minerals this mineral composition usually gives granite a red pink gray or white color with dark mineral. For igneous rock the composition is divided into four groups. Granodiorite is a plutonic igneous rock formed by intrusion of silica rich magma which cools in batholiths or stocks below the earth s surface. And 65 percent silica are intermediate.

It is usually only exposed at the surface after uplift and erosion have occurred. And those with less than 45 percent are ultramafic. Compilations of many rock analyses show that rhyolite and granite are felsic with an average silica content of about 72 percent. Igneous rocks are classified according to their mineral content.

Those with between 45 and 55 percent silica are mafic. Felsic and mafic rocks. Felsic intermediate mafic and ultramafic. In igneous petrology an intermediate composition refers to the chemical composition of a rock that has 52 63 wt sio 2 being an intermediate between felsic and mafic compositions.

It forms from the slow crystallization of magma below earth s surface. Composition refers to a rock s chemical and mineral make up. The name comes from two related rocks to which granodiorite is an intermediate. Ultramafic rocks are dominated by olivine and or pyroxene.

Typical intermediate rocks include andesite dacite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks. Intermediate rocks are roughly even mixtures of felsic minerals mainly plagioclase and mafic minerals mainly hornblende pyroxene. Other articles where intermediate rock is discussed.