吉林安图刘生店钼矿床辉钼矿Re-Os同位素定年及其地质意义  

Re-Os Dating of Molybdenite from the Liushengdian Molybdenum Deposit in Antu Area of Jilin Province and Its Geological Significance

作　　者：王辉[1] 任云生[1] 赵华雷[1] 鞠楠[1] 屈文俊[2] 

机构地区：[1]吉林大学地球科学学院,吉林长春130061 [2]国家地质实验测试中心,北京100037

出　　处：《地球学报》2011年第6期707-715,共9页Acta Geoscientica Sinica

基　　金：中国地质调查局项目(编号:1212011085485);吉林大学基本科研业务费项目(编号:200903025)联合资助

摘　　要：刘生店钼矿是吉林中东部新发现的一个重要斑岩型钼矿床。6件辉钼矿样品Re-Os同位素分析表明:辉钼矿中Re含量为9.88～11.37μg/g,Os含量为27.68～32.40ng/g,获得的模式年龄为(168.0±2.3)～(170.8±2.5)Ma,加权平均年龄为(169.36±0.97)Ma,MSWD=0.73,等时线年龄(185±12)Ma,MSWD=0.72。以加权平均年龄作为该矿床的形成年龄,即钼的成矿作用发生于中侏罗世,与同属小兴安岭-张广才岭钼矿带的大黑山和福安堡矿床成矿时代基本一致,是燕山早期太平洋板块俯冲构造背景下,吉黑东部大规模钼成矿作用的集中表现。据辉钼矿中Re、Os含量,初步认为刘生店钼矿成矿物质以壳源为主,但混有少量幔源组分。The Liushengdian ore deposit is one of the porphyry molybdenum deposits recently discovered in eastern Jilin Province.Re-Os dating of six molybdenite samples collected from typical ores shows that the Re and Os values of samples vary between 9.88 and 11.37μg.g-1 and between 27.68 and 32.40ng.g-1 respectively;the model age ranges from（168.0±2.3）to（170.8±2.5）Ma,with the weighted mean age being （169.36±0.97）Ma（MSWD=0.73）,and the isochron age being（185±12）Ma（MSWD=0.72）.The results indicate that molybdenum mineralization took place in middle Jurassic,roughly contemporaneous with that of Daheishan and Fuanpu molybdenum deposits,which belong to the Xiao Hinggan Mountains-Zhangguangcai Mountain metallogenic belt.These ore deposits were formed by the large-scale Yanshanian metallogenic activity in the eastern part of northeastern China,influenced by the subduction of the Pacific plate.In addition,the Re content of the molybdenite suggests that the ore-forming materials might have been derived mainly from the crust with the participation of small amounts of mantle materials.

关 键 词：RE-OS同位素定年 辉钼矿 斑岩型钼矿 刘生店钼矿 吉林安图 

分 类 号：P618.65[天文地球—矿床学] P597.3[天文地球—地质学]