Intermediate Granite Rocks

Those with between 45 and 55 percent silica are mafic.

Intermediate granite rocks.

The name comes from two related rocks to which granodiorite is an intermediate. For igneous rock the composition is divided into four groups. Typical intermediate rocks include andesite dacite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks. Ultramafic rocks are dominated by olivine and or pyroxene.

Other articles where intermediate rock is discussed. It forms from the slow crystallization of magma below earth s surface. Mafic rocks are dominated by plagioclase and pyroxene even if you can t see them with the naked eye and smaller amounts of olivine. It is usually only exposed at the surface after uplift and erosion have occurred.

Granite is a light colored igneous rock with grains large enough to be visible with the unaided eye. Felsic and mafic rocks. Intermediate rocks are roughly even mixtures of felsic minerals mainly plagioclase and mafic minerals mainly hornblende pyroxene. Felsic intermediate mafic and ultramafic.

These groups refer to differing amounts of silica iron and magnesium found in the minerals that make up the rocks. Syenite diorite and monzonite. Igneous rocks are classified according to their mineral content. 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.

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. Granodiorite is a plutonic igneous rock formed by intrusion of silica rich magma which cools in batholiths or stocks below the earth s surface. Compilations of many rock analyses show that rhyolite and granite are felsic with an average silica content of about 72 percent.