Application of Integrated Geophysical Exploration Technologies in the Southern Covered Area of the Yixingzhai Gold Deposit, Shanxi Province

ObjectiveThe Yixingzhai Gold Deposit is a significant gold-polymetallic deposit in northeastern Shanxi Province. The deep mineral exploration in its southern Sunzhuang area, which is covered by thick loess, poses a great challenge for conventional geological methods. To achieve a breakthrough in deep prospecting, this study implemented an integrated geophysical exploration technology suite based on regional geology and physical properties of rocks and ores. MethodsBy employing a Time-Domain Induced Polarization (TDIP) survey with a large electrode spacing (AB=2000m), a long charging time (8s), and a high current intensity (>10A), the response of deep polarizable bodies was significantly enhanced. Combined with Controlled-Source Audio-Frequency Magnetotellurics (CSAMT) and high-precision magnetic surveys, the subsurface geological structures, spatial distribution of concealed intrusions, and mineralized alteration zones beneath the cover were interpreted. ResultsThe results indicate that: (1) Integrated geophysical anomalies clearly reveal the NW- and SN-trending fault systems and their control on mineralization; (2) Three concealed intermediate-acid intrusive bodies (diorite, granite porphyry, quartz porphyry) closely related to mineralization were delineated; (3) The coupling method of “IP anomaly - metal factor - geochemical anomaly” effectively distinguished ore-induced anomalies from non-ore interferences, leading to the optimization of prospecting targets. Drill testing in the prioritized targets intersected cumulative gold-copper mineralized zones exceeding 22 meters in thickness, with a maximum gold grade of 1.22 g/t, confirming the effectiveness of this integrated approach. ConclusionsThis study successfully established a comprehensive information prospecting model applicable to the covered areas south of the Yixingzhai orefield, providing crucial technical guidance and a demonstration for deep prospecting in this area.