Geological and geochemical characteristics and prospecting model of the Waitongkeng gold deposit in southern Anhui Province

The Waitongkeng gold deposit is located in the Taiping fault fold belt on the northeast margin of the Jiangnan Orogenic Belt, belonging to a hydrothermal altered gold deposit controlled by fault. On the basis of field investigation, the authors carried out soil geochemical survey, rock geochemical profile measurement and other technical means to analyze the metallogenic regularity of the mining area, clarified the ore-prospecting direction and improved the prospecting effect. Soil geochemical survey results show significant gold and arsenic anomaly in the soil distributing along the NE-trending secondary faults. The rock profile measurement results reveal that gold, arsenic, silver and antimony are enriched in the NE-trending extensional secondary fault, which effectively indicate the the occurrence and mineralization of gold. The gold ore body is hosted in Silurian Xiaxiang Formation, and the ore-forming material and heat source mainly came from the magmatic hydrothermal fluid of Yanshanian granite. The metallogenic structure of the mining area is the NE-trending Langqiao-Lidongkeng tensional fault, and the main ore-bearing structure is the NE-trending fracture zone with silicification, arsenopyrite, pyrite and sericitization on the hanging wall of the fault. This paper proposed a geological-geochemical prospecting prediction model of "tectonic-magmatic rock" metallogenic system of the Waitongkeng gold deposit according to the metallogenic law. It is considered that the secondary fault fracture zone, gold and arsenic geochemical anomaly as well as silicification-sericitization alteration can be used as prospecting indicators for the surrounding areas of the Waitongkeng gold deposit. The fractured alteration zone, the deep mining area and Au anomalies of stream sediments distributing along the Langqiao-Lidongkeng fault have good prospecting prospects.