Deep geological architecture and prospecting potential of the giant Jinding lead-zinc ore field, Lanping: Constraints from integrated geophysical data

Objective The giant Jinding lead–zinc ore field in northwestern Yunnan is situated in the central part of Meso–Cenozoic Lanping Basin, SE Qinghai−Xizang Plateau. Influenced by tectonic transitions associated with the oblique Indo–Eurasian collision and orogeny, deep and shallow crustal materials have undergone multi−phase structural deformation and mutual superposition. This study aims to analyze the deep geological structure of the ore field, clarify its mineral exploration potential, and identify directions for deep prospecting.

Methods Based on two audio−frequency magnetotellurics (AMT) and gravity survey profiles simultaneously traversing the Beichang and Paomaping ore deposits within the Jinding ore field, and supported by surface structural mapping data and lithological interfaces constrained by existing exploration drillholes, we conducted an intergrated interpretation of the ore field’s stratigraphic framework and its structural relationships with faults, thereby delineating the deep geological architecture.

Results Due to E–W directed crustal shortening and deformation since the Cenozoic, extensive basement rock series and basin−fill strata in the region have undergone deformation and mutual superposition along the approximately N–S−trending thrust faults and/or E–W oriented strike–slip tilting faults. This resulted in the thrusting of the Upper Triassic Sanhedong (T₃s) and Maichuqing (T₃m) formations, the Cretaceous Jingxing (K₁j) and Nanxin (K₂n) formations, and the Paleogene−Eocene Yunlong–Guolang Formation (E₁y+g) over the Neogene Miocene Jinding Group(N₁J), thereby forming the ore−controlling geological structure.

Conclusions Eleven deep prospecting targets have been delineated, indicating substantial ore−forming potential in the deep regions of the Jinding orefield.