S Type Granite Formation

Magma sources and their contribution to the growth of the continental crust.

S type granite formation. Amphibole and pyroxene are more common in i type granitoids. Geological association of canada mineralogical association of. Other articles where s type granite is discussed. Many people recognize granite because it is the most common igneous rock found at earth s surface and because granite is used to make many objects that we encounter in daily life.

Granite is the best known igneous rock. Granitoids with asi values 1 1 chappell 1999 are i type frost et al. A case study from the keivy terrane baltic shield. S type granite this type is of sedimentary origin paraorigin from anatexis of sedimentary rocks with high al2o3 and low sio2 content ex.

Garnet is a very common accessory mineral in this type. Magma type is usually peraluminous magma al2o3 na2o k2o cao. High amounts of na2o and s type granitoids derived from sedimentary protoliths and containing high amounts of al2o3 and relatively low amounts of na2o. Amphibole and pyroxene are more common in i type granitoids while s type granitoids may have garnet cordierite and sillimanite.

The distinction between i and s type granites was primarily made on the basis of their chemical composition reflected in their mineralogy. To improve the understanding of critical factors that control the formation of ree rich granite regolith especially for those related to weathering of the s type granite an investigation of granite and its overlying regolith is conducted in south china s largest s type granite terrain darongshan guangxi. S type granites are over saturated in aluminium with an asi index greater than 1 1 where asi al 2 o 3 cao na 2 o k 2 o in mol percent. Seventh hutton symposium on granites and related rocks p.

2001 and frost and frost 2011 have also provided exhaustive analysis and classification of granitic suites based on a range of major element indices. The anorthosite a type peralkaline granite connection. Hornblende is a typical i type granite mineral which never occurs in s type granite. S type granites are a category of granites first proposed by chappell white.

Granite is an intrusive igneous rock which means it was formed in place during the cooling of molten rock generally the slower the molten rock cooled the larger it s mineral crystals with k feldspar megacrysts forming in special circumstances greater than 5cm. Petrographic features are representative of the chemical. The biotites in i type granites are greener in general than those in s type both in hand sample and in plane polarized light. These include counter tops floor tiles paving stone curbing stair treads building veneer and cemetery monuments.

These result in i type granitoids derived from igneous protoliths and containing moderate amounts of al 2 o 3 and high amounts of na 2 o and s type granitoids derived from sedimentary protoliths and containing high amounts of al 2 o 3 and relatively low amounts of na 2 o.