文献类型：期刊文献

英文题名：Gold and antimony metallogenic relations and ore-forming process of Qinglong Sb(Au) deposit in Youjiang basin, SW China: Sulfide trace elements and sulfur isotopes

作者：Chen, Jun Huang, Zhi-Long Yang, Rui-Dong Du, Li-Juan Liao, Ming-Yang

第一作者：Chen, Jun

通信作者：Huang, ZL[1]

机构：[1]Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550002, Peoples R China;[2]Guizhou Univ, Coll Resources & Environm Engn, Guiyang 550025, Peoples R China;[3]Guizhou Inst Technol, Sch Min Engn, Guiyang 550003, Peoples R China;[4]Guizhou Univ, Key Lab Karst Georesources & Environm, Minist Educ, Guiyang 550025, Peoples R China

第一机构：Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550002, Peoples R China

通信机构：corresponding author), Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550002, Peoples R China.

年份：2021

卷号：12

期号：2

起止页码：1-19

外文期刊名：GEOSCIENCE FRONTIERS

收录：;Scopus(收录号：2-s2.0-85097415476);WOS:【SCI-EXPANDED(收录号:WOS:000611950300008)】；

基金：This study was financially supported by the National Natural Science Foundation of China (Grant No. 41802107), Guizhou Scientific and Technology Fund (Grant No. QKHJC[2019]1315; QKHJC[2019]1149H), China Postdoctoral Science Foundation (Grant No. 2019M653495), and the Talent Introduction Project of Guizhou University (Grant No. 201772). Shaohua Dong, Ningchao Zhou, Yubo Yang and Jianchao Zhang are thanked for helping with the SEM, EPMA, LA-ICP-MS and NanoSIMS analysis, respectively. We thank Jian Zhang for helping with the sampling. We acknowledge Dr. Jeff Steadman (CODES, University of Tasmania) and Dr. Zhaoshan Chang (Colorado School of Mines) for their constructive reviews and suggestions. Special thanks are due to the staffs of the Qinglong mining district for their field support. Cenozoic Geoscience Editing & Consultancy (Australia) is acknowledged for its scientific and language editing service.

语种：英文

外文关键词：Pyrite; Stibnite; LA-ICP-MS and NanoSIMS; Sulfur isotopes; Au and Sb deposits; Youjiang basin

摘要：In the northwestern margin of the Youjiang basin (NWYB) in SW China, many Carlin-like gold deposits are highly antimony (Sb)-rich, and many vein-type Sb deposits contain much Au. These deposits have similar ages, host rocks, ore-forming temperatures, ore-related alterations and ore mineral assemblages, but the Au and Sb metallogenic relations and their ore-forming process remain enigmatic. Here we investigate the large Qinglong Sb deposit in the NWYB, which has extensive sub-economic Au mineralization, and present a new metallogenic model based on in-situ trace elements (EPMA and LA-ICP-MS) and sulfur isotopes (NanoSIMS and fs-LA-MC-ICP-MS) of the ore sulfides. At Qinglong, economic Sb ores contain coarse-grained stibnite, jasperoid quartz and fluorite, whilst the sub-economic Au-Sb ores comprise dominantly veined quartz, arsenian pyrite and fine-grained stibnite. Three generations of ore-related pyrite (Py1, Py2 and Py3) and two generations of stibnite (Stb1 and Stb2) are identified based on their texture, chemistry, and sulfur isotopes. The pre-ore Py1 is characterized by the lower ore element (Au, As, Sb, Cu and Ag) contents (mostly below the LA-ICP-MS detection limit) and Co/Ni ratios (average 0.31) than the ore-stage pyrites (Py2 and Py3), implying a sedimentary/diagenetic origin. The Py2 and Py3 have elevated ore element abundance (maximum As = 6500 ppm, Au = 22 ppm, Sb = 6300 ppm, Cu = 951 ppm, Ag = 77 ppm) and Co/Ni ratios (average 1.84), and have positive As vs. Au-Sb-Cu-Ag correlations. Early-ore Stb1 has lower As (0.12-0.30 wt.%) than late-ore Stb2 (0.91-1.20 wt.%). These features show that the progressive As enrichment in ore sulfides is accompanied by increasing Au, Sb, Cu and Ag with the hydrothermal evolution, thereby making As a good proxy for Au. As-rich, As-poor and As-free zones are identified via NanoSIMS mapping of the Au-bearing pyrite. The As-rich zones in the Qinglong Au-bearing pyrites (Py2 and Py3) and ore stibnites (Stb1 and Stb2) have narrow delta S-H2S ranges (-8.9 parts per thousand to +4.1 parts per thousand, average -3.1 parts per thousand) and -2.9 parts per thousand to +6.9 parts per thousand, average + 1.3 parts per thousand), respectively, indicating that the Au-rich and Sb-rich fluids may have had the same sulfur source. Published in-situ sulfur isotopic data of pyrite As-rich zones from other Carlin-like Au deposits (Shuiyindong, Taipingdong, Nayang, Getang and Lianhuashan) in the NWYB have similar ore-fluid delta S(H2S )values (-4.5 parts per thousand to +6.7 parts per thousand, average -0.6 parts per thousand) to those of Qinglong. Therefore, we infer that the sulfur of both Au and Sb mineralization was derived from the same magmatic-related source (0 + 5 parts per thousand) in the NWYB. Moreover, the core of pyrites (Py1) has variable S isotope fractionation (-18.9 parts per thousand to +18.1 parts per thousand, mostly +3 parts per thousand to +12 parts per thousand), suggesting that the higher-S-34 H2S was produced by bacterial sulfate reduction (BSR). The hydrothermal pyrite (Py2 and Py3) delta S-34 values gradually decrease with increasing As concentrations, and ultimately, within the restricted range (-5 parts per thousand to +5 parts per thousand) in As-rich zones. This variation implies that the As-rich pyrite was formed through ongoing interactions of the magmatic-hydrothermal fluid with pre-existing sedimentary pyrites, causing the progressive decreasing delta S-34 values with As content increase, Hence, the fluid/mineral interaction may have generated the observed variation in delta S-34 and As contents. Overall, comparing the Au and Sb deposits in the NWYB, we favor a magmatic-related source for the Au-Sb-As-rich fluids, but the Au- and Sb-ore fluids were likely evolved at separate stages in the ore-forming system.