Chemical Composition Of Granite And Basalt

Volcanic rock of equivalent chemical composition and mineralogy is called rhyolite.

Chemical composition of granite and basalt.

A worldwide average of the chemical composition of granite by weight percent based on 2485 analyses. Basalt is mafic while granite is felsic. Basalt is volcanic or extrusive forming at the surface while granite is plutonic or intrusive forming beneath the surface. Sio 2 49 97 tio 2 1 87 al 2 o 3 15 99 fe 2 o 3 3 85 feo 7 24 mno 0 20 mgo 6 84 cao 9 62 na 2 o 2 96 k 2 o 1 12 p 2 o 5 0 35.

Among other differences the nature of these rocks reveals that basalt is basic in nature whereas granite is acidic in nature. It is the most common plutonic rock of the earth s crust forming by the cooling of magma silicate melt at depth. 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. Tholeiites vs alkali basalts.

Of the two basalt is darker and consists of fine grained minerals such as magnesium and iron while granite is lighter and consist of feldspar and quartz. Granite is an intrusive igneous rock which is very hard crystalline and is visibly homogeneous in texture and forms by melting of continental rocks basalt forms when lava reaches the earth s surface near an active volcano. This composition is as follows. Average chemical composition of basalt determined by 3594 chemical analyses of basaltic rocks 2 numbers are mass percents recalculated volatile free to total 100.

It is defined in the tas diagram shown above. Basalt and granite actually have quite a bit in common. Basalt is common on both earth and other solar system bodies such as the moon and mars while granite is only common on earth and rare elsewhere in the solar system. Included in this category are most basalts of the ocean floor most large oceanic islands and continental flood basalts such as the columbia.

Types of basalt basalt types. Basalt has a strict chemical definition. A granite containing both muscovite and biotite micas is called a binary or two mica granite. Tholeiitic basalt is relatively rich in silica and poor in sodium.

Both are made up of minerals from the silicate group so both have large amounts of silicon. A magma the earth gets very hot just below the surface and there is lots of liquidrock available. Two mica granites are typically high in potassium and low in plagioclase and are usually s type granites or a type granites. 70 18 silicon dioxide sio2 14 47 aluminum oxide al2o3 4 11 potassium oxide k2o 3 48 sodium oxide na2o 1 99 calcium oxide cao 1 78 iron ii oxide feo 1 57 iron iii oxide 0 88 magnesium oxide mgo 0 84 water h2o 0 39 titanium dioxide tio2 0 19 diphosphorus pentoxide p2o5 and 0 12 manganese oxide mno.