What Is The Chemical Composition Of Granitic

These are feo feo mgo fe number or feo tot feo tot mgo fe the modified alkali lime index mali na 2 o k 2 o cao and the aluminum saturation index asi al ca 1 67p na k.

What is the chemical composition of granitic.

Both plagioclase feldspar and alkali feldspar are usually abundant in it and their relative abundance has provided the basis for granite classifications. Chemical variation modal composition and classification of granitoids. Sio 2 71 84 tio 2 0 31 al 2 o 3 14 43. Volcanic rock of equivalent chemical composition and mineralogy is called rhyolite.

The principal constituent of granite is feldspar. Strictly speaking granite is an igneous rock with between 20 and 60 quartz by volume and at least 35 of the total feldspar consisting of alkali feldspar although commonly the term granite is used to refer to a wider range of coarse grained igneous rocks containing quartz and feldspar. Major minerals of granite. Orthoclase quartz biotite muscovite and plagioclase which is twinned according to the albite law and oscillatory zoned.

Quartz alkali feldspar which contain alum english. Quartz content can range from 10 60 while the feldspar content typically ranges from 65 95 and biotite content is around 10 15 in most granite. The chemical composition of granite is typically 70 77 silica 11 13 alumina 3 5 potassium oxide 3 5 soda 1 lime 2 3 total iron and less than 1 magnesia and titania. In most granite the ratio of the dominant to the subdominant feldspar is less than two.

Contrasting petrogenetic processes and. This geochemical classification of granitic rocks is based upon three variables. Bernard bonin vojtěch janoušek jean françois moyen. Average chemical composition of granite determined by 2485 chemical analyses of granitic rocks 3 numbers are mass percents recalculated volatile free to total 100.

Chemical variation modal composition and classification of granitoids bernard bonin vojtěch janoušek jean françois moyen to cite this version. Granite is composed mainly of quartz and feldspar with minor amounts of mica amphiboles and other minerals. Chemical composition the resulting granite will likely have been made primarily from quartz different feldspars and biotite however it can also have a variety of other minerals and oxides present. Granite is a hard coarse grained rock making up most of the earth.