满洲里地区甲乌拉铅锌(银)矿床成矿流体特征及成矿时代  

Ore-forming fluid characteristics and mineralization age of the Jiawula Pb-Zn(Ag) Deposit in Manzhouli area

作　　者：曹鹏[1] 任云生[1] 侯召硕[2] 王晰[1] Cao Peng;Ren Yunsheng;Hou Zhaoshuo;Wang Xi(College of Earth Sciences,Jilin University;Jilin Institute of Geology Survey)

机构地区：[1]吉林大学地球科学学院 [2]吉林省地质调查院

出　　处：《黄金》2018年第9期5-12,共8页Gold

基　　金：国家重点研发项目(2017YFC0601304)

摘　　要：为确定甲乌拉铅锌(银)矿床的成矿流体特征和形成时代,采取主成矿阶段含矿石英脉样品,对其中的流体包裹体开展岩相学和显微测温分析,并采用闪锌矿Rb-Sr等时线法测定铅锌矿石的同位素年龄。研究表明:石英中包裹体类型单一,均为富液相包裹体;所测包裹体的均一温度为141. 6℃～304. 1℃,集中于200℃～240℃,盐度范围为0. 87%～10. 67%Na Cleqv,流体密度为0. 76～0. 95 g/cm3,流体压力为10. 1～32. 1 MPa,估算的成矿深度为0. 34～1. 07 km,成矿流体属于中低温、低盐度、中等密度H2O-Na Cl体系;根据矿石中闪锌矿的Rb-Sr等时线年龄153 Ma±2 Ma,限定甲乌拉铅锌(银)矿床的成矿作用发生于晚侏罗世。根据成矿地质条件、矿化蚀变特征、成矿流体特征及同类矿床对比研究认为,甲乌拉铅锌(银)矿床的成因类型为浅成低温热液型矿床。In order to determine ore-forming fluid characteristics and mineralization age of Jiawula Pb-Zn(Ag)Deposit,the petrography and microthermometry of fluid inclusions within the quartz vein formed in the major mineralization stage have been carried out,and the isotopic age of lead and zinc ores was determined by the sphalerite Rb-Sr isochron method.The results show that the type of inclusions in quartz is single liquid-rich inclusions;the homogenization temperature of the liquid-rich inclusions ranges from 141.6℃to 304.1℃,focused on 200℃to 240℃,the salinity from 0.87%to 10.67%NaCl eqv,the density from 0.76 to 0.95 g/cm 3,the pressure from 10.1 to 32.1 MPa,and the calculated mineralization depth from 0.34 to 1.07 km,indicating the ore-forming fluid is of medium-low-temperature,medium-density,low-salinity H 2O-NaCl hydrothermal system;Rb-Sr isochron age of the sphalerite is 153 Ma±2 Ma,which indicates that the mineralization of the Jiawula Pb-Zn(Ag)Deposit took place in Late Jurassic.According to the metallogenic conditions,the mineral alteration features,the characteristics of ore-forming fluids and the comparative study of similar deposits,it can be concluded that the Jiawula deposit is an epithermal deposit.

关 键 词：流体包裹体 闪锌矿Rb-Sr定年 成矿时代 浅成低温热液型矿床 甲乌拉铅锌(银)矿床 满洲里地区 

分 类 号：TD11[矿业工程—矿山地质测量] P597[天文地球—地球化学]