文献类型：期刊文献

英文题名：Sphalerite Records Cd Isotopic Signatures of the Parent Rocks in Hydrothermal Systems: A Case Study From the Nayongzhi Zn-Pb Deposit, Southwest China

作者：Song, Wenrui Zhu, Chuanwei Wen, Hanjie Huang, Zhilong Wei, Chen Zhang, Yuxu Zhou, Zhengbing Yang, Zhen Chen, Xiaocui Luais, Beatrice Cloquet, Christophe

第一作者：Song, Wenrui

通信作者：Zhu, CW[1];Zhu, CW[2]

机构：[1]Changan Univ, Sch Earth Sci & Resources, Xian, Peoples R China;[2]Chinese Acad Sci, State Key Lab Ore Deposit Geochem, Inst Geochem, Guiyang, Peoples R China;[3]Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian, Peoples R China;[4]Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing, Peoples R China;[5]Helmholtz Inst Freiberg Resource Technol, Helmholtz Zent Dresden Rossendorf, Freiberg, Germany;[6]East China Univ Technol, State Key Lab Nucl Resources & Environm, Nanchang, Peoples R China;[7]China Univ Geosci, Sch Earth Resources, Wuhan, Peoples R China;[8]Guizhou Inst Technol, Guiyang, Peoples R China;[9]Ctr Rech Petrog & Geochim, CNRS, UMR 7358, Vandoeuvre Les Nancy, France

第一机构：Changan Univ, Sch Earth Sci & Resources, Xian, Peoples R China

通信机构：corresponding author), Changan Univ, Sch Earth Sci & Resources, Xian, Peoples R China;corresponding author), Chinese Acad Sci, State Key Lab Ore Deposit Geochem, Inst Geochem, Guiyang, Peoples R China.

年份：2024

卷号：25

期号：5

外文期刊名：GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS

收录：;EI(收录号：20242116136824);Scopus(收录号：2-s2.0-85193794562);WOS:【SCI-EXPANDED(收录号:WOS:001226526200001)】；

基金：This research was financially supported by the Technology Foundation of Guizhou Province (Grant [2019]1459), National Natural Science Foundation of China (Grants 92162214, 41773015, U1812402, and 92162218), Key Research and Development Program of Yunan Province (Grant 202103AQ100003), and a special fund managed by the State Key Laboratory of Ore Deposit Geochemistry, Chinese Academy of Sciences.

语种：英文

外文关键词：Cd isotopes; S isotopes; low-temperature hydrothermal system; fluid mixing; Nayongzhi Zn-Pb deposit

摘要：Metal stable isotopes (e.g., Zn, Cd, and Cu) have been used to track metal sources in different types of hydrothermal systems. However, metal isotopic variations in sulphides could be triggered by various factors such as mineral precipitation and fluid mixing. Thus, tracking the metal sources of hydrothermal systems is still a big challenge for metal isotopes. In this study, we investigated the Cd isotopic systematics of sphalerite from the Nayongzhi Zn-Pb deposit, which is a Mississippi Valley-type (MVT) deposit in the Sichuan-Yunnan-Guizhou mineralization province (SYGMP). We reinterpreted the published S isotope data for the SYGMP and found that the large S isotopic variations were controlled by Rayleigh fractionation between sulphide and reduced S. As such, a model that involves mixing of a metal-rich fluid with a reduced S pool formed by thermochemical sulfate reduction (TSR) can explain the ore formation in the Nayongzhi deposit. Based on this model, no Cd isotopic fractionation was observed due to its low solubility in fluids during mixing, and thus the Cd isotopic variations of sphalerite were inherited from the source rocks. The large range of Zn/Cd ratios and uniform Cd isotopic compositions of the sulphides are similar to those of igneous rocks but different from those of sedimentary rocks, indicating that Zn and Cd were derived mainly from basement rocks (e.g., migmatite, gneiss, and granulite). Our results reaffirm that metal stable isotopes, particularly Cd isotope compositions of sphalerite, are powerful geochemical tracers for investigating the formation mechanisms of ore deposits. Metal stable isotopes, particularly Cd isotopes, have been widely used in investigating the metal sources, fluid evolution, and formation mechanisms of ore deposits. Here, we studied the Cd isotopic compositions of sphalerite from the Nayongzhi Zn-Pb deposit in the Sichuan-Yunnan-Guizhou mineralization province. The range of delta 114/110CdNIST-3108 value is smaller in the Nayongzhi deposit (-0.16-0.21 parts per thousand), but the published S isotopic composition has significant variation (11.8-33.0 parts per thousand). We found that the large S isotopic variations were controlled by Rayleigh fractionation between sulphide and reduced S. Thus, a mineralization model of the Nayongzhi deposit has been proposed, which involves the mixing of a metal-rich fluid with a reduced S pool formed by thermochemical sulfate reduction. Based on this model, no Cd isotopic fractionation was observed due to its low solubility in fluids during mixing. Therefore, the Cd isotopic variations of sphalerite were inherited from the source rocks. Combining the Zn/Cd ratios and Cd isotopic composition characteristics of the sulphides, igneous rocks, and sedimentary rocks, it is indicated that Zn and Cd were derived mainly from basement rocks (e.g., migmatite, gneiss, and granulite). S isotopic variations caused by Rayleigh fractionation between sulphide and reduced S; Cd isotopic variations inherited from source rocks Zn/Cd ratios and Cd isotopic compositions reveal that Zn and Cd were dominantly derived from basement rocks The Nayongzhi deposit was formed by mixing between metal-rich and reduced sulfur ore-forming fluids