Integrated gravity and magnetic data for epithermal deposit target area identification: A case study from the Shuangjianzishan Region, Inner Mongolia

In deep-seated and concealed mineral exploration, variations in ore-forming systems lead to significant differences in geophysical responses, driven by contrasting structural and petrophysical characteristics. For instance, epithermal deposits typically occur as veins or disseminated bodies, and their scale, geometry, and spatial distribution strongly influence gravity and magnetic anomalies. Consequently, single-method geophysical approaches often fail to accurately delineate prospecting targets. This study investigates the Shuangjianzishan ore district in southeastern Inner Mongolia, China, using a combination of multi-scale edge detection and 3D gravity and magnetic inversion to analyze ore-forming processes and assess mineral prospectivity. Laboratory measurements of rock physical properties were used to establish quantitative relationships between density and magnetic susceptibility, providing a foundation for lithological discrimination. Multi-scale edge detection revealed structural boundaries and ore-controlling faults at various depths. The three-dimensional density and susceptibility models derived from the inversion of gravity and magnetic data, when integrated with petrophysical statistical analysis, enabled the identification of key lithological units such as ore-hosting strata and intrusive rocks. A 3D lithological model was constructed, from which a conceptual epithermal mineralization model was derived to guide exploration targeting. The results show that major structural boundaries align with known faults, and the inversion models correlate well with confirmed ore bodies. Several delineated prospective zones coincide with known mineralization, confirming the reliability of the proposed method. Additionally, five previously unidentified high-potential zones were recognized. This study enhances the understanding of the genesis of the Shuangjianzishan deposit and offers an effective technical framework for exploring similar concealed epithermal systems in the southeastern Greater Khingan Range. • Gravity–magnetic data integration identifies mineralization targets. • A workflow delineates ore-controlling structures and lithological boundaries. • The integrated method improves epithermal deposit targeting.