What Is Granitic Magma Like

The supposed divergence here is my acceptance on one hand of the evidence for the existence of s and i type granites and the implications for the nature of their protoliths and on the other hand my doubt in the applicability of the restite unmixing model for chemical variation in granitic magmas.

What is granitic magma like.

A crater is a bowl like depression at the top of the volcano. These different rock types can all be found in the products of a single eruption. It forms from the slow crystallization of magma below earth s surface. These rocks have similar compositions but different cooling conditions.

Granite definition a coarse grained igneous rock composed chiefly of orthoclase and albite feldspars and of quartz usually with lesser amounts of one or more other minerals as mica hornblende or augite. Granite is a light colored igneous rock with grains large enough to be visible with the unaided eye. First i would like to clarify the position of one who is said to hold divergent views. Granitic magma has high levels of potassium and sodium while basaltic magma has very low levels of these minerals.

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. Other articles where granitic magma is discussed. Granite ˈ ɡ r æ n ɪ t is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. When magmas are judged by mineral composition like this they are technically referred to as felsic which is granitic and mafic which is basaltic.

Eruptions of granitic magma can produce rhyolite pumice obsidian or tuff. Figure 2 formation of granitic magma granitic magmas are generated by the partial melting of continental crust. Explosive eruptions produce tuff or pumice. Granites can be predominantly white pink or gray in color depending on their mineralogy the word granite comes from the latin granum a grain in reference to the coarse grained structure of such a completely crystalline rock.

The parental granitic magma underwent the mixing of mantle derived mafic magma and crustal felsic magma coupled with fractional crystallization during magma ascent before emplacement. Partial melting of intermediate rocks can generate felsic granitic magmas. When the heat from the hot basaltic magma partially melts the overlying crustal rocks which are silica rich and have a much lower melting temperature the result can be the production of large quantities of granitic magmas. A basaltic pond of magma becomes trapped below continental crust and partially melts this silica rich crust into a granitic magma.