Mesozoic multi‐stage W–Sn polymetallic mineralization in the Nanling Range, South China: An example from the Dengfuxian–Xitian ore field

Abstract

The Dengfuxian and Xitian ore fields, located in the central Nanling Range of South China, are characterized by multi‐stage W–Sn polymetallic mineralization. In this study, whole‐rock and zircon compositions in altered granites from four typical deposits in these ore fields (i.e., Dalong Pb–Zn, Xiangdong W, Gaolong fluorite, and Shaiheling Sn–Pb–Zn) were studied to constrain their fluid chemistry and mineralization history. Compared to unaltered granites at Dengfuxian and Xitian, these fluid‐altered granites are characterized by more variable SiO2 (64.2–78.4%) and lower TiO2 (0.02–0.12%), CaO (0.25–1.2%), and Na2O (0.31–2.6%) concentrations, lower ΣREE (87–156 ppm), and higher Zr/Hf (11.1–31.6) and Y/Ho (31.1–53.4) ratios, suggesting intense F‐rich fluid metasomatism. Zircon cathodoluminescence (CL), transmitted light and back‐scattered electron (BSE) imaging, laser ablation multi‐collector inductively coupled plasma mass spectrometry (LA‐MC‐ICP‐MS) trace‐element analysis, U–Pb dating, and Hf isotopes revealed a sequence of three W–Sn polymetallic mineralization stages: a Triassic stage (~220 Ma), a Jurassic stage (~150 Ma), and a Cretaceous stage (~80 Ma). The Triassic episode was associated with a highly fractionated granitic magma derived from the lower crust and contaminated by basement rocks; the magmatic fluid was affected by a high 176Hf/177Hf component from the ~770‐Ma basement and probably precipitated under high F and high fO2 conditions. The Jurassic episode was related to mantle–crust interaction and resulted in large‐scale W–Sn mineralization at decreased fO2. The Cretaceous episode was marked by Sn mineralization in a lithospheric extensional setting. We infer that basement rocks were the major source of metals for the world‐class W–Sn ore deposits in the Nanling Range of South China. This study also demonstrates that whole‐rock geochemistry of hydrothermally altered granites in combination with Lu–Hf isotopic, U–Pb dating, and trace element analyses of magmatic and hydrothermal zircons can be a useful approach to recognition of multi‐stage magmatic and mineralization processes.

Source Enrichment Control on the Scale of Magmatic‐Hydrothermal W‐Sn Mineralization: Insights from Triassic and Jurassic Magma Reservoirs in the Continental Crust, Xitian, South China

“…2016; Wu et al, 2016;Cao et al, 2018Cao et al, , 2020He et al, 2018;Li et al, 2018). The total exposed outcrop of ~240 km 2 can be separated into three distinct rock-types: ~210 km 2 of porphyritic granitoids with ~50 vol% phenocrysts (pale red in Fig.…”

Hydrothermal Systems Characterized by Crustal Thermally‐dominated Structures of Southeastern China

“…Magmatic activity reached a peak in the Late Jurassic-Early Cretaceous, tectonic transformation occurring in the Late Cretaceous, with the continental lithosphere undergoing regional extension (Li J H et al, 2017;Li H et al, 2019;Suo et al, 2019;Hu et al, 2023;Wan et al, 2023). The subduction of the Paleo-Pacific Plate below the Eurasian Plate since the Mesozoic and the collision of the Philippine Sea Plate were both critical in determining the magmatic-volcanic activity throughout eastern Asia (Fig.…”

Genesis of the Huangshaping W–Mo–Cu–Pb–Zn deposit, South China: Role of magmatic water, metasomatized fluids, and basinal brines during intra‐continental extension

“…The Huangshaping polymetallic deposit is located close to Chenzhou City in the southern Hunan Province (Figure ). The South Hunan W–Mo–Cu–Pb–Zn ore belt is the most important part of the Nanling tectono‐magmatic belt in South China, which hosts complex geologic structures, experienced multiple magmatic events (Kong et al, ; Mao, Cheng, Chen, & Pirajno, ), and has a rich base‐metal and nonferrous metal mineral resources (Jiang, Li, Evans, Wu, & Cao, ; Li, Sun, et al, ; Li, Palinkaš, Watanabe, & Xi, ; Li, Wu, Evans, Jiang, & Zhou, ; Liu et al, ; Wu, Li, Algeo, Jiang, & Zhou, ). Caledonian movement resulted in metamorphism of Cambrian–Sinian sedimentary rocks and folding and uplift of the basement in South Hunan.…”