Intermediate Granite Rocks

Granodiorite is a plutonic igneous rock formed by intrusion of silica rich magma which cools in batholiths or stocks below the earth s surface.

Intermediate granite rocks.

Granite is a light colored igneous rock with grains large enough to be visible with the unaided eye. Compilations of many rock analyses show that rhyolite and granite are felsic with an average silica content of about 72 percent. And those with less than 45 percent are ultramafic. Felsic intermediate mafic and ultramafic.

Typical intermediate rocks include andesite dacite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks. 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. The name comes from two related rocks to which granodiorite is an intermediate. Intermediate rocks are roughly even mixtures of felsic minerals mainly plagioclase and mafic minerals mainly hornblende pyroxene.

Mafic rocks are dominated by plagioclase and pyroxene even if you can t see them with the naked eye and smaller amounts of olivine. 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. Syenite diorite and monzonite. Other articles where intermediate rock is discussed.

It is usually only exposed at the surface after uplift and erosion have occurred. Igneous rocks are classified according to their mineral content. Those with between 45 and 55 percent silica are mafic. Felsic and mafic rocks.

Ultramafic rocks are dominated by olivine and or pyroxene. It forms from the slow crystallization of magma below earth s surface. For igneous rock the composition is divided into four groups.