胶东牟平-乳山成矿带载金黄铁矿元素组成特征及其地质意义  

Element composition characteristics and geological significance of gold-bearing pyrite in Muping-Rushan metallogenic belt,Jiaodong

作　　者：程南南 马毓民 亢怡萱 侯泉林 石梦岩 潘结南[1] 李剑斌 CHENG NanNan;MAYuMin;KANG YiXuan;HOU QuanLin;SHI MengYan;PAN JieNan;LI JianBin(School of Resources and Environment,Henan Polytechnic University,Jiaozuo 454003,Henan,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454003 [2]中国科学院大学地球与行星科学学院,北京100049

出　　处：《矿床地质》2025年第1期159-182,共24页Mineral Deposits

基　　金：河南省博士后科研项目(编号:202102055);河南省高等学校重点科研项目(编号:23A170009、23A170015);河南省自然科学基金项目(编号:232300420437、232300420439);河南省科技攻关项目(编号:242102320359)联合资助。

摘　　要：牟平-乳山成矿带是胶东地区重要的石英脉型金矿成矿带,矿体主要赋存于晚侏罗世昆嵛山花岗岩体内,严格受次级剪切带的控制。黄铁矿作为牟平-乳山成矿带内主要的载金矿物,精细分析其元素组成特征可以查明金的赋存状态,也可为探讨成矿流体性质、成矿环境以及矿床成因提供重要信息。文章选取胶东东部牟平-乳山成矿带内的乳山、邓格庄、英格庄金矿,在野外地质调查基础上,通过显微岩相学观察、SEM、EPMA以及LA-ICP-MS等实验分析方法,揭示了黄铁矿的主量、微量元素含量及Au的赋存特征,探讨了该成矿带上金矿床的成因机制。实验及分析结果表明,乳山、邓格庄、英格庄金矿中载金黄铁矿均呈现亏Fe、亏S的特征。显微观察与Au-As含量图解显示牟平-乳山成矿带中Au主要有2种赋存形式:一类是与黄铁矿密切相关的可见独立金矿物,另一类是赋存于矿物晶格或晶格缺陷中的以固溶体金(Au+)和纳米金(Au^(0))形式存在的不可见金。黄铁矿激光剥蚀曲线以及微量元素相关性图解表明邓格庄、英格庄金矿Cu、Zn、Pb、Bi与Au的富集没有明显的正相关关系,而乳山金矿中Au与Cu、Zn、Pb、Bi呈正相关关系,可能是该金矿中Te含量较高而导致。乳山金矿、邓格庄金矿及英格庄金矿黄铁矿的Co/Ni比值均大于1,表明黄铁矿为热液成因。通过对黄铁矿Co/Ni比值投图、Co-Ni-As投图、S、Fe含量相关性以及δS、δFe特征投图,结果表明,乳山金矿、邓格庄金矿及英格庄金矿均为岩浆热液型金矿床,结合前人流体包裹体以及黄铁矿的δ^(34)S研究,笔者认为牟平-乳山成矿带的金矿床是与浅部脆性变形相关的岩浆热液型金矿床。The Muping-Rushan metallogenic belt is an important quartz vein type gold metallogenic belt in eastern Jiaodong Peninsula.The ore body is mainly hosted within the late Jurassic Kunyushan granite and strictly controlled by the secondary shear zones.Pyrite is the main gold bearing mineral in Jiaodong region and Muping-Rushan metallogenic belt.A detailed analysis of the characteristics of trace elements in pyrite not only indicate the occurrence state of Au,but it also can provide important information for discussing the nature of ore-forming fluid,metallogenic environment and genesis of the deposit.Therefore,in this paper,we take the Rushan,Denggezhuang and Yinggezhuang gold deposits in the Muping-Rushan metallogenic belt in eastern Jiaodong region as the representative.On the basis of detailed field geological survey,through the experimental analysis methods such as microscopic petrographic observation,Scanning Electron Microscope,Electron Probe Micro Analysis,Laser Ablation Inductively Coupled Plasma Mass Spectrometry and other experimental analysis methods,this paper reveals the major and trace element contents of pyrite and the occurrence characteristics of Au,and discusses the metallogenic environment and genesis of the gold deposits in the Muping-Rushan metallogenic belt.The results show that the main elements S and Fe of gold-bearing pyrite in Rushan,Denggezhuang and Yinggezhuang gold deposits all showing a slight depletion characteristics.Microscopic observation and Au-As content diagram show that there are two main occurrence states of Au in the Muping-Rushan metallogenic belt:One is the visible gold minerals closely related to pyrite,which may occur in pyrite particles in the form of Au-Ag minerals,the other is the invisible gold existing in the form of solid solution gold(Au+)and nano-gold(Au^(0))within the mineral lattice or lattice defects.The laser ablation curve of pyrite and the correlation diagrams of trace elements show that there is no evident positive correlation between the enrichments of Au an

关 键 词：黄铁矿 微量元素 EPMA LA-ICP-MS 牟平-乳山成矿带 胶东地区 

分 类 号：P618.51[天文地球—矿床学]