LA-ICPMS与EPMA结合测定铀矿物微区原位U-Pb年龄

U-Pb Isotopic Dating in Situ Microanalysis of Uranium Minerals by EPMA and LA-ICPMS

晶质铀矿、沥青铀矿、铀石等铀矿物的微区原位U-Pb定年对研究铀矿床有着十分重要的意义。使用激光烧蚀电感耦合等离子体质谱(LA-ICPMS)与电子探针(EPMA)相结合的方法更加准确地测定铀矿物微区原位U-Pb年龄,既解决了EPMA不能测定同位素比值,无法准确扣除普通铅等不足,又解决了目前LA-ICPMS测定的铀矿物标样极少,标样难寻的困扰,从而有利于铀矿物微区原位U-Pb定年技术的推广使用,为铀矿床研究提供更准确的定年数据。这一定年方法不但在铀矿床的年代学研究中有重要的应用,在各种地质体的铀矿物U-Pb同位素年代学研究中也有广阔的应用前景。

The U-Pb isotopic dating in situ microanalysis of high uranium minerals has a very important significance in research work.This project combines EPMA and LA-ICPMS.Researchers will obtain accurate U-Pb isotopic age in situ microanalysis of high uranium minerals.Researchers will strive to establish a feasible new method in situ microanalysis on high uranium minerals,and thus greatly improve the precision.It is hard to find the standard sample of uranium in LA-ICPMS,but the ratio of 206Pb,207Pb and 208Pb can be obtained directly.U and Pb content can be obtained by EPMA method.Then the isotope age can be yielded precisely.Researchers will solve the problem of LA-ICPMS standard sample and the EPMA defect of failing to deduce ordinary lead.Therefore the mineralization ages of some uranium deposits can be obtained by directly analyzing the high uranium minerals.The important applications and broad prospects of this new approach can be used not only in the study of uranium deposits dating but also in other geological bodies with high uranium.