Tongshanling Mine, Tongshanling ore field, Jiangyong Co., Yongzhou, Hunan, Chinai

Regional Level Types
Tongshanling Mine	Mine
Tongshanling ore field	Ore Field
Jiangyong Co.	County
Yongzhou	Prefecture-level City
Hunan	Province
China	Country

Skarn-type polymetallic deposit.
The Tongshanling Cu–W polymetallic deposit is a medium-scale Cu–Pb–Zn polymetallic deposit located in the southwestern part of the Tongshanling ore field. The total ore reserves of Cu, Pb, and Zn reserves are 2.5 × 103 Mt, including metal reserves of 2.5 Mt Cu, 3.0 Mt Pb, 2.1 Mt Zn, and 175 t Ag. The exposed sedimentary rocks of the ore district are composed of Devonian, Carboniferous, Permian, Jurassic, and Cenozoic strata. The orebodies are primarily found in Devonian and Carboniferous limestones, particularly thick limestones from the middle Devonian Qiziqiao formation and the lower Carboniferous Shidengzi formation.
Hydrothermal alteration of the Tongshanling deposit includes skarnization, siliconization, epidotization, chloritization, sericitization, and carbonatization from the fresh granodiorite to carbonate wall rock. Skarnization, which developed in the contact zone between granodiorite and limestone (Fig. 3b – d), is associated with massive sulfide ores near the limestone (Fig. 3e and f). Epidotization and chloritization replacing garnets and diopside resulted in formation of epidote and chlorite aggregations or veinlets crosscutting earlier skarns. Siliconization is the most widespread alteration process, forming quartz veins and stockworks containing massive sulfides (Fig. 3g – i). Carbonatization developed at the distal margins of the granodiorite, precipitating massive calcite and minor sulfides.

Two mineralization types (skarn and quartz–vein) were revealed in the Tongshanling deposit based on field investigations, microscopic identification, mineral assemblages, ore structures/textures, and superposition relationships of the mineralization. The skarn-type orebodies are hosted in interlayers of carbonate rocks and contact zones between granodiorite stocks and country rock, accompanied by irregular, layered, and lenticular shapes. Their dimensions are 20–230 m and 30–530 m in the strike and dip directions, respectively, with a thickness of 0.1–5 m. Skarn evolutionary stages are well developed, including anhydrous silicate, hydrous silicate, Cu–Fe sulfide, and Pb–Zn sulfide stages, although the oxide stage is poorly developed. The anhydrous silicate stage is characterized by garnet, diopside, and wollastonite, which the hydrous silicate stage shows by the replacement of the majority of garnet and diopside by actinolite, epidote, and chlorite. The Cu–Fe sulfide stage mainly consists of quartz, pyrrhotite, pyrite, arsenopyrite, and chalcopyrite, while the Pb–Zn sulfide stage includes sphalerite and galena that coexist with quartz and minor amounts of fluorite.
The late-stage quartz–vein mineralization is commonly 10–50 cm wide, strikes NNE, dips to the NNW at angles of 60–80° and shows distinct crosscutting relationships with both granodiorite and skarn. The quartz veins are widely developed in various rocks, including a quartz–sericite assemblage in the granodiorite, lump sulfide–quartz assemblages in skarn, and minor stellate sulfides–quartz in limestone. Its ore mineral assemblages vary from Cu–Fe sulfides (pyrrhotite, pyrite, arsenopyrite, and chalcopyrite) in the proximal regions to Pb–Zn sulfides (sphalerite and galena) in the distal regions of the granodiorite.

Other Regions, Features and Areas containing this locality

References