同位素稀释热电离质谱法测定锡石U-Pb年龄探索  

An Investigation of U-Pb Isotope Dating of Cassiterite with Isotope Dilution-thermal Ionization Mass Spectrometry

作　　者：涂家润[1] 崔玉荣[1] 郝爽[1] 李惠民[1] 周红英[1] 耿建珍[1] 

机构地区：[1]中国地质调查局天津地质矿产研究所,天津300170

出　　处：《地球学报》2016年第6期779-783,共5页Acta Geoscientica Sinica

基　　金：国家自然科学基金面上项目(编号:41373053);国家重点基础研究发展计划(973计划)(编号:2015CB453000);中国地质调查局地质调查项目(编号:12120115013501);北京离子探针中心开放基金(编号:DDK14-39);国家自然科学基金青年基金(编号:41403045;41503052)联合资助~~

摘　　要：针对我国锡多金属矿床的定年问题,建立一种采用同位素稀释热电离质谱(ID-TIMS)法进行锡石U-Pb同位素定年的方法,并与激光烧蚀电感耦合等离子体质谱(LA-ICP-MS)法进行对比验证。由于采用化学处理技术分别纯化了U和Pb,减少了普通铅的影响,大大提高了分析测定精度。将该方法应用于某地区石英-锡石-黑钨矿脉的锡石样品分析,获得了精确的U-Pb年龄值。Focusing on the problem of the dating of tin polymetallic deposits in China, the authors established a new method for U-Pb isotope dating of cassiterite with isotope dilution-thermal ionization mass spectrometry （ID-TIMS）, and made comparison with laser ablation inductively coupled plasma mass spectrometry. Because U and Pb are purified separately by the new experimental pretreatment technology, the influence of the common lead is reduced, and the analytical precision is greatly improved. This method was applied to the cassiterite samples from a quartz-cassiterite-wolframite vein in a certain area, with a precise U-Pb isotopic age obtained.

关 键 词：锡石 U-PB同位素 锡多金属矿床 等时线 ID-TIMS LA-ICP-MS 

分 类 号：P578.47[天文地球—矿物学] P597[天文地球—地质学]