What Is Granitic Magma Like

Partial melting of intermediate rocks can generate felsic granitic magmas.

What is granitic magma like. 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. When magmas are judged by mineral composition like this they are technically referred to as felsic which is granitic and mafic which is basaltic. Other articles where granitic magma is discussed. A crater is a bowl like depression at the top of the volcano.

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. Effusive eruptions produce rhyolite or obsidian if the lava cools rapidly. 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.

Eruptions of granitic magma can produce rhyolite pumice obsidian or tuff. A basaltic pond of magma becomes trapped below continental crust and partially melts this silica rich crust into a granitic magma. 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. Explosive eruptions produce tuff or pumice.

These rocks have similar compositions but different cooling conditions. Strictly speaking granite is an. 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. 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.

Granitic magma has high levels of potassium and sodium while basaltic magma has very low levels of these minerals. Granite ˈ ɡ r æ n ɪ t is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. 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. Granitic or rhyolitic magmas and andesitic magmas are generated at convergent plate boundaries where the oceanic lithosphere the outer layer of earth composed of the crust and upper mantle is subducted so that its edge is positioned below the edge of the continental plate or.