流体包裹体中Sr同位素的激光剥蚀多接收等离子体质谱原位微区分析  

In Situ Strontium Isotope Analysis of Fluid Inclusion Using LA-MC-ICPMS

作　　者：袁洪林[1] 高山[1,2] 戴梦宁[1] 宗春蕾[1] 李荣西[3] 

机构地区：[1]西北大学地质学系,大陆动力学国家重点实验室,西安710069 [2]中国地质大学(武汉)地质过程与矿产资源国家重点实验室,武汉430074 [3]长安大学地球科学与国土资源学院,西安710064

出　　处：《矿物岩石地球化学通报》2009年第4期313-317,共5页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(40973011,40672029,40821061);教育部专项(B07039,NCET-07-0687);国家重点基础研究发展规划项目(2003CA214600);霍英东教育基金会资助项目(111018);西北大学大陆动力学国家重点实验室资助项目

摘　　要：本文研究了用激光剥蚀多接收等离子体质谱(LA-MC-ICPMS)技术原位微区分析包裹体中Sr同位素的分析方法。5、10、16和30μm剥蚀序列进行包裹体的Sr同位素组成分析结果表明,包裹体中Sr同位素比值和Rb含量明显高于与包裹体接触的方解石矿物,从大个体包裹体(大于2μm)可获得较准确的Sr同位素组成(精密度为0.08%)。由于87Rb的含量只能通过85Rb计算而来,有限包裹体分析信号而导致的Sr同位素分析精度较传统的化学方法略差,因此本方法不能得到包裹体中的Rb-Sr年龄。We have developed a new method for in situ strontium isotope measurement of fluid inclusion using LA MC-ICPMS. The method includes an ablation sequence of 5 10-16-30 μm until the fluid is reached. The results in dicated that the rubidium concentration and relative strontium isotopic compositions are higher than the hosted calcite matrix, especially for the fluids with larger size （〉2 μm）, and the method precision is better than 0.08% when the fluid inclusions are larger than 2 μm. This method cannot measure the Rb-Sr ages of fluid inclusions due to the interference of ^87 Rb which is calculated from ^85 Rb and limited signal which is the obstacle for high precision strontium isotopic analyses.

关 键 词：流体包裹体 激光剥蚀 多接收等离子体质谱 SR同位素 

分 类 号：P597[天文地球—地球化学]