Composition Of Granite And Basalt

Basalt is mafic while granite is felsic 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.

Composition of granite and basalt.

The temperature of lava is between 1100 to 1250 c when it gets to the surface. Basalt is volcanic or extrusive forming at the surface while granite is plutonic or intrusive forming beneath the surface. Basalt is rich in iron and magnesium and is mainly composed of olivine pyroxene and plagioclase. Granite coarse or medium grained intrusive igneous rock that is rich in quartz and feldspar.

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. Most specimens are compact fine grained and glassy. Rhyolite andesite and basalt form a series that varies in composition from felsic to mafic because of an increasing fraction of iron magnesium rich minerals that darkens the tone.

They can also be porphyritic with phenocrysts of olivine augite or plagioclase. In the upper part of qapf classification of plutonic rocks streckeisen 1976 the granite field is defined by the modal composition of quartz q 20 60 and the p p a ratio between 10 and 65. 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.

The granite field comprises two sub fields. In the simplified classification the intermediate intermediate toned aphanitic crystalline igneous rock is andesite. Holes left by gas bubbles can give basalt a coarsely porous texture. 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.

Grant mason from the byu department of physics and astronomy discusses samples of granite and basalt rock.