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现代地质 ›› 2020, Vol. 34 ›› Issue (03): 569-578.DOI: 10.19657/j.geoscience.1000-8527.2020.013

• 矿床学 • 上一篇    下一篇

闽中梅仙铅锌多金属矿区S、Pb同位素组成及对成矿物质的示踪:以丁家山和峰岩铅锌多金属矿为例

肖晓牛1,2,3(), 费利东1,3, 秦新龙1, 肖娥1,3, 刘荣芳1   

  1. 1.江苏省有色金属华东地质勘查局,江苏 南京 210007
    2.福建金东矿业股份有限公司,福建 三明 365101
    3.南京大学 地球科学与工程学院,江苏 南京 210093
  • 收稿日期:2018-12-10 修回日期:2019-12-18 出版日期:2020-07-04 发布日期:2020-07-05
  • 作者简介:肖晓牛,男,博士,教授级高级工程师,1980年出生,矿物学、岩石学、矿床学专业,主要从事矿产地质调查研究工作。Email: 978612177@qq.com
  • 基金资助:
    国家自然科学基金项目(41402077);福建省自然科学基金项目(2018J01143)

Sulfur and Lead Isotopic Compositions of Meixian Zinc-lead Polymetallic Deposit, Central of Fujian Province, China and Tracing for the Source of Metals: Examples from the Dingjiashan and Fengyan Zinc-lead Polymetallic Deposits

XIAO Xiaoniu1,2,3(), FEI Lidong1,3, QIN Xinlong1, XIAO E1,3, LIU Rongfang1   

  1. 1. East China Mineral Exploration and Development Bureau for Non-ferrous, Nanjing, Jiangsu 210007, China
    2. Fujian Jindong Mining Company Limited, Sanming, Fujian 365101, China
    3. School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210093, China
  • Received:2018-12-10 Revised:2019-12-18 Online:2020-07-04 Published:2020-07-05

摘要:

闽中梅仙铅锌多金属矿产于中—新元古代“变质基底天窗”绿片岩系中,目前对其成矿物质来源、矿床成因认识不一。对该矿区的丁家山和峰岩铅锌多金属矿床主成矿期的闪锌矿和方铅矿等金属硫化物进行S、Pb同位素分析,结果表明:丁家山和峰岩矿床的硫、铅同位素组成基本一致,其金属硫化物的δ34S值分别为0.4‰~5.0‰和1.8‰~4.2‰,平均值则分别为2.66‰和2.88‰,表明硫为幔源硫。金属硫化物的铅同位素组成206Pb/204Pb、207Pb/204Pb和208Pb/204Pb值则分别为18.326~18.496和18.378~18.646、15.658~15.817和15.619~15.746、38.724~39.257和38.365~39.009,平均值则分别为18.388和18.447、15.705和15.700、38.880和38.823,表明2矿床铅均为壳幔混合源铅。综合硫、铅同位素分析结果,认为丁家山和峰岩铅锌多金属矿床成矿物质主要来自燕山期花岗(斑)岩。结合矿床、矿体地质特征分析,丁家山和峰岩铅锌多金属矿的形成主要与燕山期花岗(斑)岩侵入接触交代作用有关。

关键词: 梅仙铅锌多金属矿田, 硫同位素, 铅同位素, 成矿物质来源, 接触交代作用

Abstract:

The Meixian lead-zinc polymetallic ore field is located in the central Fujian Province, and occurs in the Mid-Late Proterozoic greenschist-facies metamorphic basement window. Workers still dispute about the ore-forming material source and metallogenic origin of the Pb-Zn deposits in the ore field. Here, we analyzed the sulfur and lead isotope compositions of the main-ore-stage sphalerite and galena from the Dingjiashan and Feng-yan lead-zinc polymetallic deposits in the ore field. Our study shows similar sulfur and lead isotope compositions in these sulfides. The ore sulfides from the Dingjiashan and Fengyan deposits have δ 34S=0.4‰-5.0‰ (average 2.66‰) and 1.8‰-4.2‰ (average 2.88‰),respectively, indicating an identical mantle-derived sulfur source. The ore sulfides from the two deposits have, respectively,206Pb/204Pb=18.326-18.496 (average 18.388) and 18.378-18.646 (average 18.447),206Pb/204Pb=15.658-15.817 (average 15.705) and 15.619-15.746 (average 15.700), and 208Pb/204Pb=38.724-39.257 (average 38.880) and 38.365-39.009 (average 38.823), indicating the same crust-mantle mixed source. The sulfur and lead isotopic characteristics of ore sulfides suggest that the ore-forming materials were mainly from the Yanshanian (porphyritic) granites. Integrating the geological characteristics of deposits and orebody, we suggest that the formation of the Dingjiashan and Fengyan lead-zinc polymetallic deposits was related to the intrusion and contact metasomatism of the Yanshanian (porphyritic) granites.

Key words: Meixian lead-zinc polymetallic ore field, sulfur isotope, lead isotope, ore-forming material source, contact metasomatism

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