新疆火烧云超大型铅锌矿床闪锌矿微量(稀散)元素组成特征与指示意义  

Trace(Dispersed)Elements in Sphalerite from the Giant Huoshaoyun Lead-Zinc Deposit,Xinjiang and Their Geological Implications

作　　者：袁鑫 吴越[1,2] 段登飞 朱江 欧阳荷根[3] 曹亮 周豹[5] YUAN Xin;WU Yue;DUAN Dengfei;ZHU Jiang;OUYANG Hegen;CAO Liang;ZHOU Bao(Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University),Ministry of Education,Wuhan,Hubei 430100;Hubei Key Laboratory of Petroleum Geochemistry and Environment(Yangtze University),Wuhan,Hubei 430100;Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037;Wuhan Center of Geology Survey,China Geological Survey,Wuhan,Hubei 430205;Hubei Geological Survey,Wuhan,Hubei 430034)

机构地区：[1]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [2]油气地球化学与环境湖北省重点实验室(长江大学资源与环境学院),湖北武汉430100 [3]中国地质科学院矿产资源研究所,北京100037 [4]中国地质调查武汉地质调查中心,湖北武汉430205 [5]湖北省地质调查院,湖北武汉430034

出　　处：《地质与勘探》2022年第3期545-560,共16页Geology and Exploration

基　　金：国家重点研发计划项目(编号:2017YFC0602502);国家自然科学基金项目(编号:42172088);湖北省自然科学基金(编号:2019CFB586);油气资源与勘探技术教育部重点实验室(长江大学)开放基金项目(编号:KY-2018-05)联合资助。

摘　　要：位于青藏高原西北部的新疆和田火烧云超大型铅锌矿床是近年来我国乃至全球最重要的铅锌找矿发现之一。该矿床矿石矿物以铅锌碳酸盐为主(菱锌矿和白铅矿),同时还发育有少量的铅锌硫化物矿体,目前对于火烧云矿床的成因仍存在较大分歧。本文以矿床硫化物矿体中的闪锌矿为研究对象,通过LAICP-MS微量元素测试和Mapping分析,揭示闪锌矿中微量元素(稀散元素)的富集规律和赋存状态,为矿床成因的厘定提供依据。结果表明,火烧云铅锌矿床闪锌矿中微量元素分布不均一,含量变化较大,以富集Cd、Tl、Ge等稀散元素为特征;Cd、Tl、Ge、Mn、As、Hg等微量元素以类质同象的形式赋存在闪锌矿中,其中,Cu与Ge的含量呈现较好的线性关系,推测在闪锌矿结晶过程中存在3Zn^(2+)Ge^(4+)+2Cu^(+)的替代机制,而Cd进入闪锌矿的方式可能为Zn^(2+)Cd^(2+),且Cd的异常富集可能与闪锌矿中低Fe含量有关;闪锌矿中微量元素Ga、Ge、Fe、Mn、In的组成特征指示了硫化物矿体形成于低温环境(65~140℃),与MVT型矿床的成矿温度一致。总体上,该矿床中的闪锌矿以富集Cd、Tl、Ge,贫Fe、Mn、In为特征,这与典型的MVT型矿床基本一致,明显区别于SEDEX、VMS与矽卡岩型铅锌矿床。结合矿床地质特征,笔者认为火烧云铅锌矿床中硫化物矿体成因与金顶铅锌矿床类似,属于MVT型矿床。The giant Huoshaoyun lead-zinc deposit in Hetian County,Xinjiang,located in the northwest of Qinghai-Tibet Plateau,is one of the most important lead-zinc prospecting discoveries in China and even in the world in recent years.The ore minerals of the deposit are mainly lead-zinc carbonate(smithsonite and cerussite),and few lead-zinc sulfide ore bodies are also developed.Considerable debate exists about the genesis of this deposit.In this paper,sphalerite in sulfide ore body of the deposit is taken as the research object.Through LA-ICP-MS trace element tests and Mapping analysis,the enrichment law and occurrence state of trace elements(dispersed elements)in sphalerite are revealed,which provides basis for determining the genesis of the deposit.The test results show that the distribution of trace elements in sphalerite of the Huoshaoyun Pb-Zn deposit is inhomogeneous and content changes greatly,which is characterized by enrichment of rare elements such as Cd,Tl and Ge.The trace elements such as Cd,Tl,Ge,Mn,As and Hg occur in sphalerite in the form of isomorphism,and the content of Cu and Ge shows a good linear relationship.It is speculated that there is a substitution mechanism of 3Zn^(2+)Ge^(4+)+2Cu+in the crystallization process of sphalerite.The way of Cd entering sphalerite may be Zn^(2+)Cd^(2+),and the abnormal enrichment of Cd may be related to the low Fe content in sphalerite.The composition characteristics of trace elements Ga,Ge,Fe,Mn and In in sphalerite indicate that sulfide ore bodies were formed in low temperature environment(65~140℃),which is consistent with the mineralizing temperature of MVT type deposit.In general,the sphalerite in the deposit is characterized by enrichment of Cd,Tl,Ge and depletion of Fe,Mn,In,which is basically consistent with the typical MVT deposit,and is obviously different from SEDEX,VMS and skarn type lead-zinc deposits.Combined with the geological characteristics of the deposit,it is suggested that the Huoshaoyun lead-zinc deposit is inferred to be similar to the Jinding le

关 键 词：闪锌矿 微量元素 稀散元素 LA-ICP-MS Mapping MVT型矿床 火烧云铅锌矿床 新疆 

分 类 号：P587.23[天文地球—岩石学] P595[天文地球—地质学]