Sm-Nd Dating and In-Situ LA-ICP-MS Trace Element Analyses of Scheelite from the Longshan Sb-Au Deposit, Xiangzhong Metallogenic Province, South China

China has the largest W reserves in the world, which are mainly concentrated in south China. Although previous studies have been carried out on whether mantle material is incorporated in granites associated with W deposits, the conclusions have been inconsistent. However, rare gas isotopes can be used to study the contribution of mantle-to-W mineralization. In this paper, we investigated the He and Ar isotope compositions of fluid inclusions in pyrite and wolframite from the Xingluokeng ultra-large W-Mo deposit to evaluate the origin of ore-forming fluids and discuss the contribution of the mantle-to-tungsten mineralization. The He-Ar isotopic compositions showed that the 3He/4He ratios of the ore-forming fluid of the Xingluokeng deposit ranged from 0.14 to 1.01 Ra (Ra is the 3He/4He ratio of air, 1 Ra = 1.39 × 10−6), with an average of 0.58 Ra, which is between the 3He/4He ratios of mantle fluids and crustal fluids, suggesting that the mantle-derived He was added to the mineralizing fluid, with a mean of 8.7%. The 40Ar/36Ar ratios of these samples ranged from 361 to 817, with an average of 578, between the atmospheric 40Ar/36Ar and the crustal and/or mantle 40Ar/36Ar. The results of the He-Ar isotopes from Xingluokeng W-Mo deposit showed that the ore-forming fluid of the deposit was not the product of the evolution of pure crustal melt. The upwelling mantle plays an important role in the formation of tungsten deposits.

Section: Deposit Geologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mantle-Derived Noble Gas Isotopes in the Ore-Forming Fluid of Xingluokeng W-Mo Deposit, Fujian Province

Gao

Chen

et al. 2022

“…The metallogenic age of Longshan Au-Sb deposit is 195 ± 36 Ma [4], and the formation age of granodiorite porphyry dikes in the area range from 217 to 220 Ma [5]. Additionally, the ages of the Chanziping Au deposit, the Daping Au deposit and the scheelite of the Xiejiashan deposit are 205.6 ± 9.4 Ma, 204.8 ± 6.3 Ma [2] and 210 ± 2 Ma [6], respectively, while the zircon crystallization age of the Baimashan-Longshan super-unit granite in the nearby area is 228.2 ± 1.3 Ma [7]. The formation age of molybdenite in the Dayongxi tungsten deposit is 223.3 ± 3.9 Ma [8], and the zircon crystallization age in nearby Dashenshan granite is 224 ± 1.0 Ma [9].…”

Section: Introductionmentioning

confidence: 99%

Tungsten–Gold Metallogenetic Potential of the Ziyunshan Pluton in Central Hunan, South China: Insights from Element Geochemistry of Granites

Leng

YuLong

et al. 2023

In order to reveal the metallogenic potential of the Indosinian Ziyunshan granite in central Hunan, the temporal, spatial and genetic relationship between the mineralization and the granite is discussed, and the concentrations of ore-forming elements for different granites are measured. The geochemistry of the elements, isotope geochemistry and chronology, and the data derived from the analysis on Au-W deposit in the area are compared with the geologic features of the regional metallogenic rock. The results indicate that Ziyunshan granite is an irregular shaped complex of late Indosinian by multi-stage intrusion. Elements such as W, Sn, Cu, Pb, Ag, Sb, Be, Li and Ta are enriched in the granite. The sulfophilic elements including Au, Pb, Zn and Ag are relatively enriched in the main body of the Ziyunshan granite, while the lithophilic elements including W and Sn are relatively enriched in the late phase of the Ziyunshan granite. The zoning of the ore-forming elements could be observed in the granite: Nb and Ta (inside the granite); W, Sn, Mo and Bi (inner contact zone); Pb, Zn and Cu (contact zone); and Au and Sb (outer contact zone). All the deposits in the area are formed after the intrusion of the Ziyunshan granite except the Ni-Ta-Sn ore formed simultaneously with the Ziyunshan granite. The Ziyunshan granite provides necessary heat, active fluid and partial ore-forming materials sources, which may show good metallogenic potential.

“…Scheelite (CaWO 4 ) is one of the dominant tungsten-containing minerals in porphyry-skarn W deposits, quartz vein W and Au-W deposits, and some metamorphic Au deposits [1,2]. Scheelite incorporates relatively high amounts of REE and Sr in substitution for Ca [3,4], and has been used to characterize the ore-forming fluids [5][6][7][8] and the genetic type of deposits [9][10][11]. The REE patterns in scheelite are highly sensitive to the hydrothermal evolution, making scheelite act as a promising tool to understand prevailing hydrothermal conditions [3,4].…”

Section: Introductionmentioning

confidence: 99%

Geochemistry and Origin of Scheelites from the Xiaoyao Tungsten Skarn Deposit in the Jiangnan Tungsten Belt, SE China

Mao

Sun

et al. 2020

Self Cite

The type, association, variations, and valence states of several metal elements of scheelite can trace the source and evolution of the ore-forming fluids. There are four types of scheelite from the Xiaoyao deposit: (1) scheelite intergrown with garnet in the proximal zone (Sch1a) and with pyroxene in the distal zone (Sch1b), (2) scheelite replaced Sch1a (Sch2a) and crystallized as rims around Sch1b (Sch2b), (3) quartz vein scheelite with oscillatory zoning (Sch3), and 4) scheelite (Sch4) within micro-fractures of Sch3. Substitutions involving Mo and Cd are of particular relevance, and both elements are redox-sensitive and oxidized Sch1a, Sch2b, Sch3 are Mo and Cd enriched, relatively reduced Sch1b, Sch2a, Sch4 are depleted Mo and Cd. Sch1a, Sch2a, Sch3, and Sch4 are characterized by a typical right-inclined rare earth element (REE) pattern, inherited from ore-related granodiorite and modified by the precipitation of skarn minerals. Sch1b and Sch2b are characterized by low light rare earth element/heavy rare earth element (LREE/HREE) ratios, influenced by a shift in fO 2 during fluid-rock alteration. Sch1b, Sch2b and Sch3 have higher Sr contents than those of Sch1a and Sch2a, reveal that host-rock alteration and fluid-rock interaction have elevated Sr contents. The Y/Ho ratios of scheelite gradually increase from skarn to quartz vein stages, due to fluid fractionation caused by fluid-rock interaction. Thus, the variation in REE and trace elements in scheelite in time and space reflects a complex magmatic-hydrothermal process involving various fluid-rock interactions and fluid mixing.Minerals 2020, 10, 271 2 of 22 (CL) imaging has been proven to be an effective technique to reveal internal textures, zoning and trace element distributions in scheelite [3]. However, previous studies did not evaluate dissolution and re-precipitation processes in scheelite from tungsten skarn deposits due to the changing hydrothermal fluids [13,14]. The detailed textural characterization and systematic investigations of scheelite from each stage prior to in situ chemical analysis are critical to constraint the evolution of skarn systems and W ore precipitation.The Jiangnan tungsten belt in the southeastern margin of the Yangtze Craton is a new giant tungsten province with WO 3 reserves over 5.0 million tons [19][20][21][22][23], including the Dahutang (reserves of 1.10 Mt and grade of 0.18%) and the Zhuxi (reserves of 3.44 Mt and grade of 0.54%) deposits, as well as other large-scale tungsten deposits, such as Yangchuling, Xiaoyao, Dongyuan, Zhuxiling deposits [24][25][26]. The present study focuses on the Xiaoyao tungsten skarn deposit, characterized by complex scheelite textural features. The Xiaoyao deposit has reserves of 75,000 tons of WO 3 with an average grade of 0.2% [27]. We present both textural and compositional features for scheelite from the Xiaoyao deposit to evaluate the importance of dissolution and re-precipitation processes in the formation of skarn-related scheelite.