Intermediate Granite Rocks

Felsic and mafic rocks.

Intermediate granite rocks.

Those with between 45 and 55 percent silica are mafic. And 65 percent silica are intermediate. It is usually only exposed at the surface after uplift and erosion have occurred. Igneous rocks are classified according to their mineral content.

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 rocks are roughly even mixtures of felsic minerals mainly plagioclase and mafic minerals mainly hornblende pyroxene. For igneous rock the composition is divided into four groups. Mafic rocks are dominated by plagioclase and pyroxene even if you can t see them with the naked eye and smaller amounts of olivine.

Other articles where intermediate rock is discussed. 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. Granite is a light colored igneous rock with grains large enough to be visible with the unaided eye.

Felsic intermediate mafic and ultramafic. The name comes from two related rocks to which granodiorite is an intermediate. It forms from the slow crystallization of magma below earth s surface. 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.

Compilations of many rock analyses show that rhyolite and granite are felsic with an average silica content of about 72 percent. 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. Composition refers to a rock s chemical and mineral make up.