3D geological modeling based on joint interpretation of gravity, magnetism, electricity and seismicity: A case study of Nanling-Xuancheng ore district

Nanling-Xuancheng ore district has recently emerged as the eighth significant metallogenic district within the Middle-Lower Yangtze River metallogenic belt. Due to the thick surface cover and relatively insufficient research on the deep geological structure, the complex fault systems and concealed intrusions have not yet been systematically modeled and analyzed in 3D model, which significantly restricts the understanding of metallogenic regularities and the progress of deep mineral exploration. To address this issue, the authors in this paper integrated multi-source geophysical data, including gravity, magnetism, electricity, and seismicity, along with the apriori information of borehole data and rock physical properties. And the implicit 3D geological-geophysical modeling approach was optimized to reveal the deep geological structure and provide effective technical support for deep prospecting. Through joint inversion and comprehensive modeling of multi-source data, this study established a 3D geological model of Nanling-Xuancheng ore district, which delineated the spatial distribution characteristics of fault networks, concealed intrusions, and ore-controlling strata in detail. The incorporation of multiple apriori information constraints and borehole information further improved the model's precision and reliability, significantly enhancing the interpretation ability of deep geological structures and metallogenic systems. The results revealed the spatial distribution regularities of ore-controlling factors and identified potential favorable mineralization zones. The findings suggest that there is a close metallogenic coupling relationship between deep magmatic activity and the primary fault systems in Nanling-Xuancheng ore district, and that several contact zones between the identified concealed intrusions and ore-controlling strata have promising mineralization potential.