Application of Induced Polarization Sounding in Exploration for Bedrock Gold Deposits in the Periphery of the Bilihe Mining Area, Inner Mongolia
摘要
The northern margin of the North China Craton hosts a significant gold metallogenic belt, resulting from complex tectonic-magmatic evolution during the Paleozoic. The Huobor study area, located in Sonid Right Banner, Inner Mongolia, within this cratonic margin, exhibits high potential for gold exploration. To support the “New Strategic Action for Prospecting Breakthrough,” this study focuses on delineating gold targets in the Huobor area. The southern part of the study area hosts Ore Belt 26 of the Bilihe peripheral bedrock gold deposit, whose geological characteristics are closely related to those of the Huobor area. This study takes Ore Belt 26 of the Bilihe peripheral gold deposit as a typical deposit and summarizes its key characteristics. Induced Polarization (IP) sounding surveys were conducted in the Huobor study area. Integrated interpretation of the IP inversion results, together with regional geology, trenching data, and the typical deposit model, was used to infer the mineralization characteristics and identify prospective zones for gold mineralization. Results indicate that the ore-bearing and ore-controlling structures are developed within volcanic and subvolcanic rock units, interpreted as medium-to-high resistivity and high chargeability bodies. These structures generally dip northward and exhibit a steepening trend with depth, characterized by shallower-dipping upper segments and steeper-dipping lower segments. The gold mineralization in the study area is interpreted as a low-to-intermediate sulfidation epithermal type associated with volcanic-subvolcanic activities. The IP sounding method effectively delineated the electrical properties of subsurface rock (ore) layers, providing critical guidance for mineral exploration. The integration of IP inversion results with trenching results and the typical deposit model enabled precise delineation of prospective gold targets within the study area.