Comparison of Granites from the Eastern and Western Districts of the Gejiu Ore District in South China: Implication for Petrogenesis and Tin Metallogeny

Late Cretaceous granitoids are developed in the eastern and western districts of Gejiu ore district, but tin deposits mainly occur reasons for difference mineralization between still controversial. Considering main factors controlling granite Sn fertility, whole-rock geochemical characteristics granites on both sides compared. LA-ICP-MS zircon U-Pb analyses yielded two age periods: early phase from 79.2 to 83.3 Ma later 73.8 75.6 Ma. The district have higher εHf(t), CaO/Na2O, Ba, Sr concentrations lower Rb/Sr ratios than granites, indicating that more mantle-derived materials source granites. Results oxygen fugacity show a condition. More depleted Sr, P, Eu Ti with obviously negative anomalies also high low Nb/Ta Zr/Hf ratios, experienced highly magmatic differentiation, attributed volatile F contents can reduce viscosity solidus magma. Combined differences field observations structural styles, whole, fugacities differentiation those not conducive mineralization.