豫西沙沟Ag-Pb-Zn矿床矿物沉淀机制和矿床成因研究  

Mechanism of mineral precipitation and genesis of the Shagou Ag- Pb- Zn deposit in the western Henan, China

作　　者：徐进鸿 吴承泉[2] 张正伟[2] 唐燕文[2] 姜玉平 胡书礼 郑超飞 李溪遥 靳子茹 XU Jinhong;WU Chengquan;ZHANG Zhengwei;TANG Yanwen;JIANG Yuping;HU Shuli;ZHENG Chaofei;LI Xiyao;JIN Ziru(Institute of Resources and Environment,Tongren University,Tongren,Guizhou 554300,China;State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang,Guizhou 550081,China;Institute of Fanjingshan National Park,Tongren University,Tongren,Guizhou 554300,China;Henan Province Non-ferrous Metals Geological Mineral Resources Bureau,Zhengzhou,Henan 450053,China;Enterprise Alliance Service Center,Wuyi University,Jiangmen,Guangdong 529000,China)

机构地区：[1]铜仁学院,资源与环境研究所,贵州铜仁554300 [2]中国科学院地球化学研究所,矿床地球化学国家重点实验室,贵州贵阳550081 [3]铜仁学院,梵净山国家公园研究院,贵州铜仁554300 [4]河南省有色金属地质矿产局,河南郑州450053 [5]五邑大学,企业(行业)联盟联络服务中心,广东江门529000

出　　处：《地质学报》2025年第2期502-519,共18页Acta Geologica Sinica

基　　金：铜仁学院博士科研启动基金项目(编号trxy DH2016);铜仁市博士人才科技计划项目(编号铜市科研(2024)3);贵州省教育厅高等学校科学研究项目青年项目(编号黔教技[2022]349、黔教技[2022]350、黔教技[2024]219);贵州省基础研究计划项目(编号黔科合基础-ZK[2024]一般684、黔科合基础-ZK[2023]一般463);国家自然科学基金项目(编号U1603245、41703051)联合资助的成果。

摘　　要：豫西洛宁县发育多个脉状银多金属矿床,其中沙沟大型Ag-Pb-Zn矿床普遍发育与硫化物共生的自形石英颗粒,记录不同成矿阶段的物理-化学条件,为揭示矿物沉淀机制和矿床成因提供良好契机。本文在矿床地质特征研究的基础上,通过阴极发光、流体包裹体显微测温和单个流体包裹体成分分析,对沙沟矿床中的石英开展精细的矿物学研究和单个流体包裹体成分分析。沙沟矿床成矿过程由石英-菱铁矿-黄铁矿阶段、石英-白云石-多金属硫化物阶段和石英-方解石阶段构成。在石英-白云石-多金属硫化物阶段识别出三个世代的石英:Q1位于石英颗粒核部,CL图像发光强度均一,生长环带不发育,无共生硫化物;Q2位于石英颗粒幔部,与硫化物共生,CL图像发光较暗,生长环带不规则;Q3位于石英颗粒边部,CL图像发光强度均一,生长环带发育。通过对各世代石英的成分分析显示,Al与Li具有明显的正相关关系(R^(2)=0.97),并且和阴极发光亮度密切相关,指示Al^(3+)与Li^(+)替代Si^(4+)进入石英中。Q1和Q2的Ti含量分别为0.722×10^(-6)~3.62×10^(-6)和0.387×10^(-6)~1.12×10^(-6),Al含量分别为81.9×10^(-6)~2436×10^(-6)和3.67×10^(-6)~132×10^(-6),表明成矿体系为中-低温热液环境,温度下降和pH升高是引发矿物沉淀的主要因素。单个流体包裹体LA-ICP-MS分析显示,成矿流体富集碱金属,具有较高的Rb/Na和Cs/Na比值,表明沙沟矿床与岩浆作用有关,属于岩浆-热液成矿。Several vein-like silver polymetallic deposits are developed in Luoning County, western Henan Province, China. Among these, the Shagou deposit, characterized by significant Ag-Pb-Zn mineralization, commonly contains authigenic quartz grains coeval with sulfides.These quartz grains provide valuable insights into the physicochemical conditions prevailing during different mineralization stages and the precipitation mechanisms of metal minerals from ore-forming fluids. This study presents a detailed mineralogical investigation of quartz in the Shagou deposit, utilizing cathodoluminescence(CL) imaging, fluid inclusion microcalorimetry, and individual fluid inclusion composition analysis. These techniques were applied in conjunction with detailed field geological investigations. The mineralization process of the Shagou deposit comprises three stages: a quartz-siderite-pyrite stage, a quartz-dolomite-polymetallic sulfide stage, and a quartz-calcite stage. In the quartz-dolomite-polymetallic sulfide stage, three generations of quartz were identified:(1) Q1, located in the core of quartz grains, exhibits uniform bright CL intensity with undeveloped growth zonings;(2) Q2, found in the mantle of quartz grains and coeval with sulfides, is characterized by dark CL intensity and chaotic growth zonings;(3) Q3, situated at the edge of quartz grains, displays bright CL intensity with well-defined growth rings. Compositional analysis of quartz from various generations revealed a strong positive correlation between Al and Li content(R^(2) =0.97) across all stages. This correlation is closely linked to CL brightness, indicating that Al^(3+) and Li^(+) substitute for Si^(4+) within the quartz structure. Ti content in Q1 and Q2 ranges from 0.722×10^(-6) to 3.62×10^(-6) and 0.387×10^(-6) to 1.12×10^(-6), respectively, while Al content ranges from 81.9×10^(-6) to 2436×10^(-6) and 3.67×10^(-6) to 132×10^(-6), indicating a medium-low temperature hydrothermal environment for mineralization, with decreasing temperature and increasin

关 键 词：沉淀机制 阴极发光 单个流体包裹体 石英原位微量元素 脉状Ag-Pb-Zn矿床 沙沟 

分 类 号：P61[天文地球—矿床学]