Application of integrated geophysical prospecting to deep mineral exploration in the Bangpu mining area, eastern Gangdese metallogenic belt

The Bangpu mining area, located in the eastern Gangdese metallogenic belt, represents a typical porphyry-skarn deposit. Since skarn ore bodies occurring in shallow skarns at the periphery of porphyries have been largely exhausted, there is an urgent need to explore deep replacement resources. This study aims to further determine the spatial distribution of deep-seated concealed rock masses and their surrounding ore bodies in the study area. This effort will help achieve breakthroughs in mineral exploration. To this end, this study conducted 1:10000 gravity surveys, high-precision magnetic surveys, and audio-frequency magnetotelluric (AMT) surveys in the eastern part of the Bangpu mining area, followed by an analysis and summary of the causes of geophysical anomalies. The comprehensive geophysical prospecting results indicate that the high- and low-amplitude gravity anomaly zones in the central part of the study area correspond to intermediate-mafic and intermediate-acid concealed rock masses, respectively. Two magnetic anomalies identified in the southwest might be ore-induced anomalies caused by magnetite and pyrrhotite surrounding skarns. In combination with the AMT data, boreholes were drilled in low-resistivity zones at the edge of high-amplitude gravity anomalies, as well as zones with strong magnetism, moderate gravity, and low-amplitude resistivity anomalies, to explore the deep rock masses and their surrounding skarn-type ore bodies. Consequently, two copper belts (ore bodies) and two lead-zinc ore bodies were identified. The exploration results of this study demonstrate that high-precision gravity surveys, magnetic surveys, and AMT surveys perform well in exploring deep concealed ore bodies in the Bangpu mining area, Tibet. These methods constitute an effective technical combination for deep mineral exploration of similar deposits in the Gangdese metallogenic belt.