Chemical Composition Of Granite And Basalt

Basalt is an igneous rock that contains more than 45 and less than 52 of sio2 and less than five percent of total alkalies k2o na2o 3.

Chemical composition of granite and basalt. Volcanic rock of equivalent chemical composition and mineralogy is called rhyolite. Types of basalt basalt types. A worldwide average of the chemical composition of granite by weight percent based on 2485 analyses. Learn more about the properties and uses of granite in this article.

Granite coarse or medium grained intrusive igneous rock that is rich in quartz and feldspar. Tholeiites vs alkali basalts. A granite containing both muscovite and biotite micas is called a binary or two mica granite. Basalt and granite actually have quite a bit in common.

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. Among other differences the nature of these rocks reveals that basalt is basic in nature whereas granite is acidic in nature. 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. Tholeiitic basalt is relatively rich in silica and poor in sodium.

Two mica granites are typically high in potassium and low in plagioclase and are usually s type granites or a type granites. A magma the earth gets very hot just below the surface and there is lots of liquidrock available. It is the most common plutonic rock of the earth s crust forming by the cooling of magma silicate melt at depth. 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.

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. Both are made up of minerals from the silicate group so both have large amounts of silicon. This composition is as follows. It is defined in the tas diagram shown above.

Included in this category are most basalts of the ocean floor most large oceanic islands and continental flood basalts such as the columbia. Basalt has a strict chemical definition. 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. Average chemical composition of basalt determined by 3594 chemical analyses of basaltic rocks 2 numbers are mass percents recalculated volatile free to total 100.