地学前缘 ›› 2011, Vol. 18 ›› Issue (1): 179-193.

• 论文 • 上一篇    下一篇

江西冷水坑Ag-Pb-Zn矿田碳、氧、硫、铅同位素特征及成矿物质来源

王长明,徐贻赣,吴淦国,张达,杨磊,刘建光,万浩章,狄永军,余心起,何明跃,张垚垚   

  1. 1中国地质大学 地质过程与矿产资源国家重点实验室, 北京 100083
    2中国地质大学 岩石圈构造、深部过程及探测技术教育部重点实验室, 北京 100083
    3江西省地质矿产勘查开发局912地质队, 江西 鹰潭 334000
  • 收稿日期:2010-09-10 修回日期:2010-11-20 出版日期:2011-01-15 发布日期:2011-01-15
  • 作者简介:王长明(1974—),男,博士研究生,讲师,矿物学、岩石学、矿床学专业。Email: wcm233@163.com
  • 基金资助:

    中国地质调查局地质调查工作项目(1212010981048);中央高校基本科研业务费专项资金资助项目(2010ZY02);国土资源部公益性行业科研专项经费项目(200911007);国家自然科学基金项目(40772134);“111计划”项目(B07011);中国博士后科学基金资助项目(20090460400)

C, O, S and Pb isotopes characteristics and sources of the ore metals of the Lengshuikeng AgPbZn ore field, Jiangxi.

  1. 1State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences, Beijing 100083, China
    2Key Laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education, China University of Geosciences, Beijing 100083, China
    3No 912 Geological Surveying Team, Bureau of Geology and Mineral Exploration and Development, Yingtan 334000, China
  • Received:2010-09-10 Revised:2010-11-20 Online:2011-01-15 Published:2011-01-15

摘要:

江西冷水坑矿田是武夷山地区重要的银铅锌集中区之一。无论是世界上少有的斑岩型银铅锌矿床还是火山沉积热液改造矿床都独具特色,具有很高的研究意义。该矿田的黄铁矿、闪锌矿和方铅矿等硫化物的δ34S值变化为-380‰~694‰,平均为187‰。大约为-411‰的δ13C值与峰值约为2‰的δ34S值的很窄分布表明成矿流体中的碳和硫来源于深部岩浆,并不排除地层提供一部分硫和碳的可能性。硫化物矿石的206Pb/204Pb、207Pb/204Pb和208Pb/204Pb比值分别为17771~17867、15564~15685和38235~38652。地层中火山岩、火山岩沉积岩以及变质岩石的 206Pb/204Pb比值为17899~18220,与矿石铅既有联系又有分离。然而,矿石和花岗斑岩的长石铅中206Pb/204Pb、207Pb/204Pb和208Pb/204Pb比值是相近的,它们在208Pb/204Pb206Pb/204Pb和207Pb/204Pb206Pb/204Pb图上落在同一条直线上。这条铅同位素混合线两个端员分别为上地壳和地幔。这些证据都强烈地支持了成矿物质主要来源于斑岩岩浆系统,地层对于成矿流体和物质的贡献不可或缺。冷水坑是一个典型的与次火山岩有关的岩浆热液成因的AgPbZn矿田,成矿作用均发生于中国东部燕山中期陆内环境。

关键词: 冷水坑Ag-Pb-Zn矿田, 同位素地球化学, 成矿物质, 成矿机制, 武夷山

Abstract:

The Lengshuikeng ore field in Jiangxi Province is one of the most important AgPbZn deposits in northern Wuyi Mountains, China. It is a rare typical porphyry AgPbZn deposit in the world and a volcanic sedimentaryhydrothermal reworked deposit with unique features, so it is worthy of detailed research. The δ34S values of chalcopyrite, pyrite, sphalerite, and galena sulfides collected from the Lengshuikeng ore field range from -380‰ to +694‰ with an average of +187‰. The narrow distribution of δ13C values around -411‰ and the δ34S values with ~+2‰ peak value suggest that the sulfur and carbon of the oreforming fluid were derived from hypomagma, but it did not exclude the possibility that a certain amount of sulfur and carbon were provided by the hosted strata. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of sulfide ores range respectively within 1777117867, 1556415685 and 3823538652. But, the volcanic rock, volcanicsedimentary rock, and metamorphic rock contain higher radiogenic lead with the 206Pb/204Pb ratios of 1789918220, showing both relevance and disparity between rock lead and ore lead. However, the 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of the ore and granite porphyry leads are similar and lie on the same lines in the diagrams of 208Pb/204Pb vs. 207Pb/204Pb and 207Pb/204Pb vs. 207Pb/204Pb. For the mixing lines, the two end members are respectively upper crust and mantle, which means mixing the matters of the upper crust and of the mantle. All the evidences strongly support that the metallogenic elements were carried by the porphyry magmatic system and strata. Therefore, the Lengshuikeng ore field is a typical magmatichydrothermal type of ore deposit associated with subvolcanic rocks, and formed on the intracontinental setting in Eastern China during the midYanshanian period.

Key words: Lengshuikeng Ag-Pb-Zn ore field, isotope geochemistry, metal sources, metallogenic mechanism, Wuyi Mountains

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