Peraluminous I Type Granites

By comparing the whole rock geochemistry of typical i t ype and s type granites from lachlan fold belt lfb in southeast.

Peraluminous i type granites. The peraluminous i type granites resulted from a low pressure partial melting process and the peraluminous a type granites were derived from a charnockite source heated by large scale magmatic. I type granites are typically metaluminous to weakly peraluminous. Peraluminous i type granites in the lachlan fold belt i type granites are exposed over an area 30 000 km 2 in the palaeozoic lachlan fold belt lfb and comprise almost half the total area of granites being slightly less abundant than s type granites fig. Many i type granites are also peraluminous despite i type source rocks typically not being saturated in al.

Many i type granites are also peraluminous despite i type source rocks typically not being saturated in al. It has previously been suggested that this may result from the fractional crystallisation of amphibole. As mentioned above herein we suggest that the high k calc alkaline peraluminous i type granites from gaoligong belt were derived from partial melting of the heterogenous source rocks in the lower crust with possible involvement. The peraluminous a type granites consist of four plutons namely wengshan caijiang gaoxi and fucheng for which comprehensive geochronological and geochemical data are available tables 1 and s1 in supplementary.

I type peraluminous granites in the spanish central system 143 of aqueous uids e g shearer et al 1985. Nevertheless the k rb of the most fractionated g4 and g2 leucogranites 70 and 123. I type granites are rich in silica calcium and sodium but contain lesser amounts of aluminium and potassium when compared to s type granites. Many i type granites are also peraluminous despite i type source rocks typically not being saturated in al.