投稿时间：2023-06-02
修订日期：2023-11-06
网络发布日期：2023-12-29
中文摘要:复兴屯矿床位于大兴安岭南段，是一个以银为主，伴生铅锌的超大型矿床。矿体产于早白垩世火山岩及火山碎屑岩中，发育贫铁闪锌矿+方铅矿+黄铜矿+（银）黝铜矿的矿物组合，围岩蚀变以碳酸盐化、高岭土化和叶腊石化为主。其成矿可以划分为以下3个阶段：铜锌硫化物阶段（阶段Ⅰ）、铅锌硫化物阶段（阶段Ⅱ）和银锌硫化物阶段（阶段Ⅲ）。文章对复兴屯矿床闪锌矿开展了LA-ICP-MS微量元素分析，矿床中闪锌矿以富集Cu、Ag、Pb，贫Fe、Cd、Ga、Ge为特征。矿床闪锌矿均为贫铁闪锌矿，暗示复兴屯矿床形成于中低温环境。由阶段Ⅰ至阶段Ⅲ，闪锌矿中的Fe、Mn、In含量逐渐降低，Ga、Ge、Sb含量略有增加，暗示成矿流体温度逐渐下降。复兴屯闪锌矿中Ag可与Cu联合置换Zn进入闪锌矿晶格，这可能是复兴屯矿床闪锌矿中Ag含量高的重要因素。此外，闪锌矿中常见韵律环带，反映了闪锌矿形成过程中成矿流体有多次压力波动，成矿流体多次压力波动引发的流体相分离是矿质沉淀的主要机制之一。闪锌矿微量元素含量与中低温岩浆热液矿床基本一致，明显区别于MVT型矿床、块状硫化物矿床、矽卡岩型矿床和中高温岩浆热液矿床，结合矿床地质特征，认为复兴屯银铅锌矿床属于浅成低温热液矿床。
Abstract:The Fuxingtun deposit, located in the southern Great Xing'an Range, is a newly discovered giant Ag-Pb-Zn deposit dominated by Ag. The deposit, hosted in the early Cretaceous volcanic rocks and pyroclastic rocks, is characterized by the occurrence of (Fe-poor) sphalerite, chalcopyrite, galena, and tetrahedrite / tennantite associations. Carbonate, kaolinization, and pyrophyllitization are the most common wall rock alteration in this deposit. The ore-forming process of this deposit can be divided into three stages: Cu-Zn sulfide stage (stage Ⅰ), Pb-Zn sulfide stage (stage Ⅱ), and Ag-Zn sulfide stage (stage Ⅲ). The composition and trace elements occurrence of sphalerite in this deposit were analyzed by LA-ICP-MS. The results show that the sphalerite in this deposit is characterized by enrichment of Cu, Ag, Pb and depletion in Fe, Cd, Ga and Ge. The Fe-poor sphalerite in the deposit indicates that the Fuxingtun deposit was formed in a medium to low temperature environment. From the stages Ⅰ to Ⅲ, Fe, Mn, and In in sphalerite gradually decreased, while the contents of Ga, Ge and Sb slightly increased, indicating that the temperature of ore-forming fluid gradually decreased. Ag and Cu can substitute Zn in the lattice of sphalerite, which may be an important possible factor for the enrichment of Ag in the sphalerite of this deposit. The oscillatory zoning of sphalerite reflects that the ore-forming fluid was in an oscillatory environment during sphalerite formation. The phase separation of ore-forming fluids caused by multiple pressure fluctuations is an important mechanism of metallogenic material precipitation. The trace elements of sphalerite in this deposit are similar to that of medium-low temperature magmatic-hydrothermal deposit and different from MVT, Sedex, VMS, Skarn, and medium-high temperature magmatic-hydrothermal deposits. Combined with the geological characteristics, we considered that the Fuxingtun Ag-Pb-Zn deposit belongs to the epithermal deposit.
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基金项目:本文得到内蒙古自治区地质勘查基金项目（编号：18-1-KY02）、国家自然科学青年基金项目（编号：42202080）和内蒙古玉龙矿业股份有限公司科研项目（编号：2020110033002072）联合资助
引用文本：
陆泽芊,陈公正,段海龙,杨艳霞,刘洪岩,李敏,钱军,李海军,梁新强,武广.2023.内蒙古复兴屯超大型银铅锌矿床成因：闪锌矿微量元素组成的制约[J].矿床地质,42(6):1195~1213LU ZeQian,CHEN GongZheng,DUAN HaiLong,YANG YanXia,LIU HongYan,LI Min,QIAN Jun,LI HaiJun,LIANG XinQiang,WU Guang.2023.Genesis of Fuxingtun super large Ag-Pb-Zn deposit, Inner Mongolia: Constraints on the trace elements composition of sphalerite[J].Mineral Deposits42(6):1195~1213
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