The mineralization age of the Banxi Sb deposit in Xiangzhong metallogenic province in southern China

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 degrees C, zircon (U-Th)/He thermochronometry with the closure temperature of 160-200 degrees 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 (similar to 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.