Submarine volcanic-exhalative copper-polymetallic deposit (Cu-Pb-Zn-As-Ag) with significant amounts of associated gold.

The Tieshajie deposit is a sulfide deposit with an estimated ore resource of approximately 5.2 million tons (average grades of Cu 1.07% and Au 0.52 g/t). The exposed formations within the mining area mainly consist of the Mesoproterozoic–Neoproterozoic Tieshajie Group, that mainly comprises marine volcanic-sedimentary sequences of the spilite-keratophyre, rhyolite, slate, shale, sandstone and marble, and the Lower to Middle Jurassic Linshan Group. The orebodies are primarily hosted in the Tieshajie spilite-keratophyre association, which is unconformably overlain by the Jurassic Linshan Group. In addition, Jurassic quartz porphyry dikes are also exposed in the mining area, and intruded into the Tieshajie Group. A total of 26 lens- or layer-shaped copper ore bodies have been identified in the mining area, generally spaced 15–30 m apart. The ore bodies strike approximately EW, dip northward at ∼80–85°, and are arranged nearly parallel to each other, with elevations ranging from 226 m above the surface to –220 m, an average thickness of 3.5–5 m, and a typical strike length of ∼400 m. The ore bodies are strictly stratabound, occurring as lens- or layer-shaped bodies within the spilite–keratophyre association of the Tieshajie Group. Based on structural characteristics, the ore in the Tieshajie deposit can be classified into three main types: massive, disseminated, and vein-type.
The synthesis of ore texture, alterations and geochronology and geochemistry of apatite and titanite suggest the post-VMS modification by magmatic-derived hydrothermal fluids during ∼160 Ma. The coexisting ilmenite and magnetite with apatite provide direct mineralogical evidence that the hydrothermal fluids were relatively oxidized, indicating that at some stage of the mineralization process, the fluid was in a relatively oxidized state. This is further evidenced by the presence of negative Eu anomaly in titanite. The quartz porphyry with age of ∼158 Ma in the ore district may have contributed to the mineralized fluids.

Other Regions, Features and Areas containing this locality

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