What Is A Granitic Magma

Apart from its obvious bearing on the interpretation of the geology and geochemistry of felsic igneous rocks the magma ascent mechanism critically affects any modelling of the metamorphic evolution of the upper lithosphere as well as its rheology.

What is a granitic magma. Other articles where granitic magma is discussed. Emplacement is defined here as the switch from upward to horizontal flow and. 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. Curve representing li f granitic magma and red referring to general granitic magma.

The emplacement of granitic magma within the continental crust marks the final stage in the granite forming process. When magmas are judged by mineral composition like this they are technically referred to as felsic which is granitic and mafic which is basaltic. 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. A good deal of research has shown that dyking is the only viable mechanism by which granitic magmas can be transported vertically through large thicknesses of crust to allow high level emplacement of magma in a largely liquid state clemens and mawer 1992 clemens 1998 petford et al 1993 mcnulty et al 1996 baker 1998 de saint.

The fracture network in granitic magmas consists of through going backbone mafic and silicic composite dykes and smaller dangling granitic dykes locally generated in the magma chamber. Granitic magma must make room for itself or be intruded into other rocks in order to form an intrusion and several mechanisms have been proposed to explain how large batholiths have been emplaced. Granitic magma has high levels of potassium and sodium while basaltic magma has very low levels of these minerals. 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.