Geochronology and Genesis of the Xitian W-Sn Polymetallic Deposit in Eastern Hunan Province, South China: Evidence from Zircon U-Pb and Muscovite Ar-Ar Dating, Petrochemistry, and Wolframite Sr-Nd-Pb Isotopes

Abstract

Abstract:The recently explored Xitian tungsten-tin (W-Sn) polymetallic ore field, located in Hunan province, South China, is one of the largest ore fields in the Nanling Range (NLR). Two major metallogenic types appeared in this ore field, skarn-and quartz vein-type. They are distributed within Longshang, Heshuxia, Shaiheling, Hejiangkou, Goudalan, and so on. Hydrothermal zircons from two altered granites yielded U-Pb ages of 152.8 ± 1.1 Ma, and 226.0 ± 2.8 Ma, respectively. Two muscovite samples from ore-bearing quartz vein yielded 40 Ar/ 39 Ar plateau ages of 156.6 ± 0.7 Ma, 149.5 ± 0.8 Ma, respectively. Combined with the geological evidence, two metallogenic events are proposed in the Xitian ore field, with skarn-type W-Sn mineralization in Late Triassic (Indosinian) and quartz vein/greisen type W-Sn mineralization in Late Jurassic (Yanshanian). The relatively low Ce/Ce* ratios and high Y/Ho ratios in zircons from two altered granites indicate that the hydrothermal fluids of two metallogenic events are characterized by low oxygen fugacities and enrichment in F. The similar chondrite-normalized patterns between the skarn and Xitian Indosinian granites and Sr-Nd-Pb isotopic compositions of wolframite suggest that the metal sources for both types W-Sn mineralization are derived from a crustal source.

Petrogenesis of the Microgranular Enclaves and Their Host Granites from the Xitian Intrusion in South China: Implications for Geodynamic Setting and Mineralization

“…The Xitian intrusion is located in the central part of the Nanling Range, accompanied by tinpolymetallic deposits [24]. Nanling Range is one of the world's most important magmatichydrothermal W-Sn provinces (Figure 1) [25][26][27]. It contains widely distributed granites and numerous W-Sn deposits, including Shizuyuan, Furong, Taoxikeng, Da'ao, Xihuashan, and Guposhan (Figure 1) [1][2][3]22].…”

Episodic Precipitation of Wolframite during An Orogen: The Echassières District, Variscan Belt of France

“…Current genetic models for economic W deposition proposed in the literature invoke an early pre-enrichment during differentiation of a granitic magma followed by metal redistribution by related orthomagmatic fluids, resulting in wolframite and/or scheelite mineralization more or less proximal to the intrusive body (e.g., [4,5]). Recently, polyphased W-Sn deposits in the Nanling range (southern China) have been shown to grow during two clearly distinct magmatic/hydrothermal events, occurring at ~220 and ~150 Ma [6,7],…”

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

“…South China is characterized by widely exposed granites and intensely developed mineral resources of Mesozoic age (Figure ; Cao, Wu, et al, ; Hua et al, ; Jiang & Zhu, ; Li, Li, & Li, ; Li, Myint, et al, ; Li, Watanabe, & Yonezu, ; Mao, Cheng, Chen, & Pirajno, ; Wang et al, ). The Nanling Range in the central part of South China hosts an economically important W–Sn polymetallic ore belt (Figure ; Shu, Wang, Sun, Xu, & Dai, ; Zhu et al, ) that contains more than 60% of the world's total W reserves and about 20% of the Sn reserves (Li et al, ; Mao et al, ; Sheng et al, ).…”