Spatiotemporal framework of Deposit-Structure-Magma and fluid migration path in the Zhaxikang Pb-Zn-Sb polymetallic Deposit: Construction of a metallogenic model

Since the India-Eurasia continental collision, the Tethyan Himalaya has undergone distinctive tectono-magmatic events, including the emplacement of leucogranites and the development of the South Tibetan Detachment System (STDS). These processes have generated a series of Pb-Zn-Sb-Au deposits that are closely tied to tectono-magmatic activity. However, the spatiotemporal relationships between structures, magmatism, and mineralization, as well as the pathways for fluid migration, remain poorly constrained. This gap in understanding has impeded both the development of a robust metallogenic theory and the deployment of effective exploration strategies. This study focuses on the Zhaxikang Pb-Zn-Sb polymetallic deposit, the largest and most extensively studied deposit in the belt. We integrate multi-scale geophysical surveys, carbonaceous Raman spectroscopy thermometry, and 40 Ar- 39 Ar geochronology to achieve the following objectives: (1) construct a comprehensive spatiotemporal framework linking the deposit to regional structures and magmatism; (2) delineate the ore-forming fluid migration pathways; and (3) propose a new metallogenic model and exploration approach. Our results demonstrate that:(1) A low-resistivity, low-density, partially molten layer exists at a depth of 10–15 km beneath Zhaxikang. The east–west trending regional fault F 1-1 directly connects this deep molten layer to the shallow orebody, forming a vertical fluid transport system. (2) A multi-scale fault network (F 1-2 throw ≈ 1.67 km, F 2-2 throw ≈ 1.44 km, F 3-1 throw ≈ 328 m, V ore vein throw ≈ 172–326 m) controls long-distance, multi-stage fluid migration. (3) The 40 Ar- 39 Ar age of muscovite from the F 1-1 fault (18.9 Ma) is highly consistent with the main Sb mineralization stage in the ore cluster (17.9–12.2 Ma), confirming this fault’s key role in ore formation. Based on these results, we propose a “Zhaxikang-type” tectono-magmatic coupling metallogenic model. In this model, persistent partial melting, coupled with multi-stage fault activity, generates a “seismic pump” suction effect. This mechanism drives ore-forming fluids to migrate over long distances through an interconnected, multi-level fault network, resulting in the multi-stage mineralization observed at Zhaxikang from 43.1 Ma to the present. Following this theoretical framework, we traced the fluid migration path and detected a concealed ore vein (VIe) anomaly 750 m east of the Ve ore vein, successfully completing a loop from theoretical construction to exploration verification. This study not only establishes a new metallogenic paradigm for the Tethyan Himalayan Pb-Zn-Sb-Au belt in a collisional orogenic setting but also provides a transferable methodological framework for exploring deposits formed by long-distance fluid migration.