矿床地球化学国家重点实验室知识库

The Banxi Sb deposit is one of world-class Sb deposits located in the Xiangzhong Sb-Au metallogenic province in southern China. However, the mineralization age of this deposit is still not well constrained due to a lack of suitable minerals for reliable radiometric dating. Since the fluid-inclusion data suggest that the temperature of ore-forming fluids in the Banxi deposit is up to 330 °C, zircon (U-Th)/He thermochronometry with the closure temperature of 160–200 °C was chosen here to elucidate the timing of Sb mineralization of this deposit. Detrital zircons within three samples of altered host rocks in the Banxi deposit yielded (U-Th)/He dates of 132–113 Ma (weighted mean = 121 ± 12 Ma), 132–124 Ma (weighted mean = 129 ± 3 Ma) and 142–113 Ma (weighted mean = 125 ± 10 Ma), respectively, which are broadly consistent with the Rb-Sr and Sm-Nd isochron ages of hydrothermal sulfide minerals (~130 Ma). Combining with the reported ages of adjacent Sb deposits, we propose that Sb mineralization in the Banxi deposit may have primarily taken place during 130–120 Ma.