内蒙古沙布楞山铜锌矿床成矿机制:来自流体包裹体、O-H与原位S同位素的制约  

The metallogenic mechanism of the Shabulengshan Cu-Zn deposit:Constrain from fluid inclusions,O-H and in situ S isotopes

作　　者：王一存 王承洋 张雪冰 孙珍军 刘广虎 高玲玲 李顺达 WANG YiCun;WANG ChengYang;ZHANG XueBing;SUN ZhenJun;LIU GuangHu;GAO LingLing;LI ShunDa(Hebei Key Laboratory of Strategic Critical Mineral Resources,Shijiazhuang 050031,China;College of Earth Sciences,Hebei Province Collaborative Innovation Center for Strategic Critical Mineral Research,Hebei GEO University,Shijiazhuang 050031,China;MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;College of Earth Sciences,Institute of Disaster Prevention,Sanhe 065201,China;College of Geology and Mining Engineering,Xinjiang University,Urumqi 830047,China)

机构地区：[1]河北省战略性关键矿产资源重点实验室,石家庄050031 [2]河北地质大学,河北省战略性关键矿产研究协同创新中心,地球科学学院,石家庄050031 [3]中国地质科学院矿产资源研究所,自然资源部成矿作用与资源评价重点实验室,北京100037 [4]防灾科技学院地球科学学院,三河065201 [5]新疆大学地质与矿业工程学院,乌鲁木齐830047

出　　处：《岩石学报》2023年第5期1441-1458,共18页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(42002093);河北省自然科学基金(D2021403041)联合资助.

摘　　要：沙布楞山矿床是大兴安岭南段近年来新发现的中型脉状铜锌矿床,其矿体主要赋存于下二叠统大石寨组和上侏罗统满克头鄂博组内,受北西向的断裂构造控制。依据矿物组合和矿脉穿切关系,可将成矿作用分为:辉钼矿-石英阶段(Ⅰ阶段),含铜锌硫化物阶段(Ⅱ阶段),石英-方解石(Ⅲ阶段)三个主要成矿阶段。流体包裹体研究表明,沙布楞山矿床主要发育气液两相包裹体(Ⅰa和Ⅰb型)、富气相包裹体(Ⅱa和Ⅱb型)和含子矿物包裹体(Ⅲ型)。Ⅰ阶段、Ⅱ阶段、Ⅲ阶段的包裹体的均一温度和盐度分别为313~412℃和3.2%~48.5%NaCleqv、310~367℃和1.0%~7.8%NaCleqv、178~283℃和2.7%~5.0%NaCleqv。计算获得压力为15~32MPa,对应估算的成矿深度为3.2~4.4km。激光拉曼光谱成分分析表明,主成矿阶段(Ⅱ阶段)包裹体中普遍含有CH_(4)±CO_(2)成分,表明沙布楞山铜锌矿床主成矿阶段属于含CH_(4)-CO_(2)的中高温-中低盐度体系热液。不同矿化阶段流体包裹体的δD值为-136‰~-146‰,估算的成矿流体δ^(18)O_(H2O)值为-4.38‰~5.42‰,显示初始成矿流体主要来自岩浆水,晚期有大气降水的混入。成矿流体较低的δD值和CH_(4)等烃类组分的存在,表明该矿床的形成可能受到了地层有机质的影响。硫化物原位微区的δ^(34 )S值变化范围为-0.8‰~-9.0‰,说明沙布楞山矿床成矿物质具有深部岩浆来源的特征并有地层的混染作用。综上分析认为,沙布楞山矿床成矿机制为源自深部的含矿热液向浅部运移的过程中发生沸腾作用,并与地层产生交代反应,导致CH_(4)、CO_(2)逃逸,最终诱发矿质富集沉淀成矿。The Shabulengshan deposit,located in the southern Great Xing an Range,Inner Mongolia,is a newly discovered medium-sized copper-zinc deposit.Ore bodies are hosted in the Late Permian Dashizha Formation and the Early Jurassic Manketouebo Formation volcanic rocks and slate.Based on the mineral assemblage and interaction of the hydrothermal veins,the ore-forming stages can be divided into:molybdenite-quartz veins(stage-Ⅰ),Cu-Zn polymetallic sulfide-quartz veins(stage-Ⅱ)and quartz-calcite veins(stage-Ⅲ).Three types of the fluid inclusions can be identified in the deposit:H 2O-NaCl fluid inclusions(Type-Ⅰa,Ⅰb),gas-rich fluid inclusions(Type-Ⅱa,Ⅱb)and daughter mineral-bearing fluid inclusions(Type-Ⅲ).The homogenization temperature and the salinity of fluid inclusions of stage I,stageⅡand stageⅢare 313~412℃and 3.2%~48.5%NaCleqv,310~367℃and 1.0%~7.8%NaCleqv,178~283℃and 2.7%~5.0%NaCleqv,respectively.The calculated pressure is 15~32MPa with the estimated depth of 3.2~4.4km.The fluid inclusions and Raman spectrum analysis shows that the inclusions of main mineralization stage(StageⅡ)widely obtain CH_(4)±CO_(2) components.It indicates that the main ore-forming stage of Shabulangshan Cu-Zn deposit belongs CH_(4)±CO_(2) bearing hydrothermal system with medium to high temperatures and medium to low salinities.TheδD values of different stages vary from 136‰to-146‰,with the calculatedδ^(18)Ovalues between-4.38‰and 5.42‰,indicating the ore-forming initially coming from magmatic water and mixed with a meteoric water.In situδ^(34 )S values of sulfides value ranges from-0.8‰to-9.0‰,suggesting the metallogenic materials of Shabulengshan deposit have the deep magmatic source characteristics.The ore-forming fluid are characterized by lowδD values and CH_(4) components,indicating that organic materials from the strata addition may added in the ore-forming fluids.Therefore,the metallogenic process of Shabulengshan deposit can be summarized as follows:the ore-forming fluid boiling took place whe

关 键 词：沙布楞山铜锌矿床 流体包裹体 矿床成因 H-O同位素 原位S同位素 

分 类 号：P597.2[天文地球—地球化学] P611[天文地球—地质学] P618.41P618.43