Structures of the Zhazixi Sb-W deposit, South China: Implications for ore genesis and mineral exploration

摘要

The Zhazixi Sb-W deposit is located in the Xuefeng uplift belt, South China. It is a structurally controlled hydrothermal vein-type deposit with unique metal associations of Sb and W. Field investigations suggest that structures in the Zhazixi Sb-W deposit are dominated by NW-trending faults and interlayer fractures. The former are critical to Sb mineralization, which is simplified by quartz-stibnite veins. In contrast, the latter are closely associated with W mineralization, which is predominantly composed of quartz-scheelite veins. Kinematic analyses suggest that the NW-trending faults experienced a sinistrally transpressional tectonic movement before Sb mineralization and converted to an extensional kinematic regime during Sb mineralization. Rose diagrams and stereographic projection of W-bearing fractures indicate that the interlayer fractures may form under compressional stress in a NW-SE direction. Ore genesis is discussed based on the geological and geochemical features, which indicate the metal associations of Sb and W are a superosition of two separate ore-forming periods that took place during the early Mesozoic intracontinental orogeny. Finally, integrated with the trend surface of Sb, the ore grade distribution regularities are discussed and favorable mineral exploration areas of Sb and W are proposed in the Zhazixi Sb-W deposit.