Geochemical characterization of some tin-mineralizing granites of New South Wales

The granites of three areas of Sn mineralization in the New England Area of New South Wales have been analysed to determine whether geochemical discriminants may be used to distinguish between granites which produce Sn mineralization, and those which do not. Neutron activation analyses of Sn are consistent with reports elsewhere that Sn-mineralizing granites have Sn concentrations of 15–30 μg/g, whereas granites which do not produce mineralization typically have about 5 μg/g Sn. Furthermore, Sn-mineralizing granites form compact groups, distinct from granites not responsible for mineralization, when plotted on ternary diagrams of SiO₂CaO+MgO+FeONa₂O+K₂O+Al₂O₃, Na + KFeMg and CaNaK. We conclude that the Sn-mineralizing granites can be geochemically characterized.