Precipitation of Ag-Pb-Zn ores of the Poshan vein deposit in the Qinling orogen (central China) by dilution of magmatic hydrothermal fluids
文献类型：期刊论文
| 作者 | Chai, Ming-Chun2,3,4; Li, Jian-Wei2,3; Xia, Xiao-Ping1; Fan, Gao-Hua2,3; Fu, Wei4 |
| 刊名 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN
 |
| 出版日期 | 2024-09-01 |
| 卷号 | 136期号:9-10页码:4072-4090 |
| ISSN号 | 0016-7606 |
| DOI | 10.1130/B37126.1 |
| 英文摘要 | Constraints on the source, nature, and evolution of ore-forming fluids are crucial for better understanding the ore genesis and mechanisms that lead to metal precipitation. Here, we present results of in situ analysis for quartz oxygen isotopes and sulfide sulfur isotopes, combined with apatite U-Pb age and fluid inclusion data, to provide insights into the source and evolution of ore fluids of the Poshan AgPb-Zn vein deposit in the Qinling orogen, central China. Quartz-carbonate-sulfide veins at Poshan are hosted in lower Paleozoic metavolcanic-sedimentary rocks and structurally controlled by fracture zones associated with the Heqianzhuang anticline. The Ag-Pb-Zn mineralization consists of three stages, which are represented by quartz-pyrite-arsenopyrite (stage I), quartz-carbonate-sulfide-silver minerals (stage II), and quartz-calcite +/- native silver (stage III). Apatite texturally associated with galena from stage II has a U-Pb age of 125 +/- 14 Ma (2 sigma; sigma ; mean square of weighted deviates [MSWD] = 0.9), which suggests that the Poshan deposit formed in the Early Cretaceous and thus significantly postdated the Paleozoic and early Mesozoic orogenic deformation of the Qinling orogen. Aqueous-carbonic fluid inclusions from stages I and II have similar total homogenization temperatures of 263-347 degrees C and calculated salinities of 1.2- 5.1 wt% NaCl equivalent, whereas the values for liquid-dominated aqueous inclusions from stage III are 211-245 degrees C and 0.5-3.0 wt% NaCl equivalent. Five quartz generations are recognized from the three paragenetic stages, including Qz-1 and Qz-2 from stage I, Qz-3 and Qz-4 from stage II, and Qz-5 from stage III. Based on in situ secondary ion mass spectrometry oxygen isotopic analysis of the five quartz generations (Qz-1 to Qz-5), the calculated delta O-18(fluid) values for the ore fluids are 7.8 parts per thousand to 9.2 parts per thousand (mean 8.3 parts per thousand), -3.2 parts per thousand to 8.7 parts per thousand (mean 5.6 parts per thousand), -3.5 parts per thousand to 7.4 parts per thousand (mean 4.6 parts per thousand), -4.5 parts per thousand to 7.6 parts per thousand (mean -0.2 parts per thousand), and -6.4 parts per thousand to 1.4 parts per thousand (mean -3.8 parts per thousand). The oxygen isotopic data and trend among the five quartz generations are best interpreted to represent magmatically derived ore fluid being diluted by modified meteoric water to cause mineralization. Fluid mixing is considered to be the principal mechanism that led to Ag-Pb-Zn precipitation at Poshan. Sulfides coexisting with the quartz generations have delta S-34(V-CDT) values of -1.7 parts per thousand to 4.4 parts per thousand, with no systematic variations among different paragenetic stages. These data, combined with apatite U-Pb age and geologic relations, provide additional evidence for a magmatic origin of the Poshan Ag-Pb-Zn deposit, as inferred from the oxygen isotopes. This study highlights the role of fluid dilution in triggering Ag-Pb-Zn deposition, and sheds light on the origin of silver-polymetallic deposits in orogenic belts. |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:001334344900005 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/81971]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Li, Jian-Wei |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou 510640, Peoples R China 2.China Univ Geosci, Sch Earth Resources, Wuhan 430074, Peoples R China 3.China Univ Geosci, State Key Lab Geol Proc & Mineral Resources, Wuhan 430074, Peoples R China 4.Guilin Univ Technol, Coll Earth Sci, Collaborat Innovat Ctr Explorat Nonferrous Met De, Guilin 541004, Peoples R China |
| 推荐引用方式 GB/T 7714 | Chai, Ming-Chun,Li, Jian-Wei,Xia, Xiao-Ping,et al. Precipitation of Ag-Pb-Zn ores of the Poshan vein deposit in the Qinling orogen (central China) by dilution of magmatic hydrothermal fluids[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2024,136(9-10):4072-4090. |
| APA | Chai, Ming-Chun,Li, Jian-Wei,Xia, Xiao-Ping,Fan, Gao-Hua,&Fu, Wei.(2024).Precipitation of Ag-Pb-Zn ores of the Poshan vein deposit in the Qinling orogen (central China) by dilution of magmatic hydrothermal fluids.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,136(9-10),4072-4090. |
| MLA | Chai, Ming-Chun,et al."Precipitation of Ag-Pb-Zn ores of the Poshan vein deposit in the Qinling orogen (central China) by dilution of magmatic hydrothermal fluids".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 136.9-10(2024):4072-4090. |
入库方式： OAI收割
来源：广州地球化学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。