We recognize eight types of ferroan granitoid that can be distinguished on the basis of major element chemistry.These include alkalic granitoids that may be metaluminous or peralkaline, alkali-calcic granitoids that may be metaluminous, peraluminous or peralkaline, calc-alkalic granitoids that may be metaluminous or peraluminous, and rare calcic ferroan granitoids. These granitoids may form by ...

Abs t rac t -So lu t ion mechanisms of P in metaluminous to peraluminous quenched, hydrous ( 9 wt% H 2 0 ) and anhydrous glasses in the system CaO-Na20-K20-AI203-SiO2-P205 have been examined with microRaman spectroscopy. The principal aim was to examine relative stability of phosphate complexes as a function of bulk chemical composition. Increasing peraluminosity was accomplished by increasing ...

The diffusion of water in a peralkaline and a peraluminous rhyolitic melt was investigated at temperatures of 714–1,493 K and pressures of 100 and 500 MPa. At temperatures below 923 K dehydration experiments were performed on glasses containing about 2 wt% H2Ot in cold seal pressure vessels. At high temperatures diffusion couples of water-poor (\0.5 wt% H2Ot) and water-rich (*2 wt% H2Ot) melts ...

most skarn deposits are directly related to magmatic activity, and there is a systematic correlation between composition of causative plutons and the metal contents of the related skarns. darreh zerreshk deposit is located in southwest of yazd. petrological and geochemical studies show that darreh zerreshk granitoid ranges in composition from granite through quartz monzodiorite and has subalkal...

Petrology and geochemical characteristics of granitic rocks from South Sulawesi, especially from Polewaliand Masamba area are presented in order to elucidate their origin of magma and geodynamic setting. The granitic rocks in these areas are dominated by granodiorite and granite in composition. Quartz, K-feldspar and plagioclase occur as major phases with hornblende and biotite as major ferroma...

The Proterozoic eon is characterized by an unusual abundance of ferroan feldspathic rocks that range in composition from granite to quartz syenites to feldspathoid-bearing syenites. Three associations of ferroan rocks may be recognized on the basis of major element compositions: (1) metaluminous alkalic to alkali-calcic syenites and granites associated with anorthosites and iron-rich basaltic r...