Intermediate Granite Rocks

Felsic and mafic rocks.

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. And those with less than 45 percent are ultramafic. These groups refer to differing amounts of silica iron and magnesium found in the minerals that make up the 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. Composition refers to a rock s chemical and mineral make up. Granodiorite is a plutonic igneous rock formed by intrusion of silica rich magma which cools in batholiths or stocks below the earth s surface. Those with between 45 and 55 percent silica are mafic.

And 65 percent silica are intermediate. Syenite diorite and monzonite. It forms from the slow crystallization of magma below earth s surface. Felsic intermediate mafic and ultramafic.

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. 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. Typical intermediate rocks include andesite dacite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks.

Other articles where intermediate rock is discussed. Ultramafic rocks are dominated by olivine and or pyroxene. Igneous rocks are classified according to their mineral content.