## 2 Geological Overview and Geophysical Model  
### Geological Overview of the Deposit  
The Jinding lead-zinc deposit is prominently situated within the densely compressed middle segment of the Sanjiang fold system, which is positioned precisely at the northern terminus of the Lamping-Simao Meso-Cenozoic depression. It is strategically positioned between the north-south-oriented faults tightly hemmed in by the Mishahe Fault Zone and the Lancang River Fault Zone and is found to the western flank of the Bihe River Fault Zone, within the ancient Lamping-Yunlong Paleocene graben basin. The deposit is divided into seven distinct mining sections, including Beichang, Jiayashan, Fengzishan, Paomaping, Xipo, Nanchang, and Baicaoping. The mining area exposes a succession of strata ranging from older to younger deposits, comprising the Upper Triassic Sanhedong Formation (T3s) of marine limestones (including breciated limestones, dolomitic limestones, argillaceous limestones, and limestone mudstones), the Maichuqing Formation (T3m, the core strata of the syncline, with alternating layers of quartz sandstones and carbonaceous mudstones), the Middle Jurassic Huakaizuo Formation (J2h, interbedded layers of argillaceous silststones, siltstones, and mudstones), the Upper Jurassic Bazhulu Formation (J2b, consisting of mudstones, argillaceous siltstones, and calcareous conglomerates), the Lower Cretaceous Jingxin Formation (K1j, with alternating layers of quartz sandstones, silty mudstones, and intercalated limestone conglomerates), the Upper Cretaceous Nanxin Formation (K2n, composed of argillaceous conglomerates, fine sandstones, siltstones, and mudstones), the Upper Cretaceous Hutousi Formation (K2h, characterized by long quartz sandstones), the Lower Tertiary Paleocene Yunlong Formation (E1y, interbedded layers of muddy gravelly rocks and argillaceous siltstones), the Guolang Formation (E2g, with alternating layers of argillaceous siltstones, silty mudstones, and intercalated fine sandstones), the Eocene Baoxiangsi Formation (Eb, featuring long quartz sandstones, conglomerates, sandstones, mudstones, and quartzites), the Upper Tertiary Pliocene Sanying Formation (N2s, with interbedded layers of conglomerates, sandy conglomerates, sandstones, and mudstones), and the Quaternary Pleistocene (Qp, with sand and gravel layers) and Holocene (Qh, comprising gravels, sand grains, and sandy clays).  
The primary geological structure of the mining area is a thrust nappe tectonic assemblage, which constitutes a significant component of the large-scale thrust nappe structure that formed during the Paleocene Yunlong period in the Lamping Basin. Klippe structures, or flysch formations, exist in numerous segments throughout the mining area. Furthermore, thrust-sliding planes have also been incorporated into the tectonic domes, resulting in the formation of dome structures that are characterized by the co-deformation of both thrust tectonics and in situ systems. In accordance with these findings, it can be concluded that the thrust tectonics predate the formation of the dome structures, with their inception likely commencing as early as the late Yunlong period. In summary, the geological structures of the Jinding mining area are complex, characterized by well-developed folds and faults that exhibit multiple stages of activity. This underscores the dynamic and protracted geological history of the region. The geological structures of the mining area are primarily characterized by the Gaoping-Laomujing syncline, the Bihe River Fault, horizontal thrust faults, transverse faults, oblique faults, and secondary fault structures.