期刊文献+

辉钼矿的铼—锇同位素地质年龄测定方法研究 预览 被引量:379

A STUDY ON THE RHENIUM-OSMIUM GEOCHRO- NOMETRY OF MOLYBDENITES
在线阅读 下载PDF
收藏 分享 导出
摘要 本研究在国内首次将同位素稀释等离子体质谱法应用于铼-锇同位素系统地质年龄测定。建立的化学分离方法包括碱熔分解样品、丙酮萃取分离铼、蒸馏法分离锇。全流程化学回收率在90%以上。铼和187Os的空白值分别为0.07ng和0.01ng。用本法测定了我国4个钼矿床的钼矿矿化年龄,其年龄测定精度(2σ)在3%以内。测定结果与地质背景的符合情况令人满意。直接测定金属矿床年龄的铼-锇法较之间接测定围岩时代来推断 Rhenium-osmium geochronometry based on the radioactive decay of 187Re to 187Os with a half-life of 4.23 × 1010 years is well suited for dating some sulfide minerals whose formation ages can not easily be determined by other conventional geochronom-eters. An ID-ICPMS technique determining rhenium and osmium concentrations and osmium isotopic composition for the purpose of direcly dating molybdenite is described. Samples were dissolved and equilibrated with 185Re-and 190Os-enriched spikes by alkaline fusion. Separation of rhenium from matrix elements was effected by solvent extraction and cation exchange chromatography while osmium was distilled as OsO4 from H2SO4-Ce(SO4)2 solution. All isotopic measurements were made on a VG Plasma Quad facility. Total chemical recoveries for both elements were greater than 90% and total procedural blanks were 0.07 ng for rhenium and 0.01 ng for 187Os. The Re-Os model ages of molybdenites from Shanxi, Henan and Tibet as well as the Re-Os isochronic age of molybdenite from Liaoning were determined with a precision (2σ) of about ±3%. These results conform satisfactorily with their geological backgrounds and agree reasonably with the previous results obtained by using other conventional geochronometers. Analytical data show that osmium of molybdenites examined is primarilly radiogenic 187Os formed by in-situ decay of 187Re, which is in full agreement with previous observations of other workers.
作者 杜安道 何红蓼 Du Andao, He Hongliao, Yin Ningwan, Zou Xiaoqiu, Sun Yiali Sun Dezhong, Chen Shaozhen and Qu Wenjun(Institute of Rock and Mineral Analysis, Chinese Academy of Geological Sciences, Beijing)
出处 《地质学报》 CAS CSCD 北大核心 1994年第4期 339-347,共9页 Acta Geologica Sinica
基金 国家自然科学基金和地质行业科学技术发展基金联合资助项目(编号49173164)
关键词 辉钼矿床 同位素 地质年龄 rhenium-osmium method, molybdenite, dating of ore-forming age, isotope dilution, inductively couppled plasmasource mass spectrometry
  • 相关文献

参考文献5

  • 1马鸿文,西藏玉龙斑岩钼矿带花岗岩与成矿,1990年 被引量:1
  • 2尚瑞钧,秦巴花岗岩,1988年 被引量:1
  • 3黄典豪,矿床地质,1987年,6卷,3期,22页 被引量:1
  • 4林文蔚,矿床地质,1987年,6卷,1期,23页 被引量:1
  • 5芮宗瑶,中国斑岩铜(钼)矿床,1984年 被引量:1

同被引文献9276

引证文献379

二级引证文献4128

投稿分析
职称考试

相关作者

内容加载中请稍等...

相关机构

内容加载中请稍等...

相关主题

内容加载中请稍等...

浏览历史

内容加载中请稍等...
;
使用帮助 返回顶部 意见反馈