氟碳铈矿富含U和Th，是U-Pb同位素定年的理想对象。由于它通常存在碳酸岩、碱性岩等岩石及稀有金属矿床中，氟碳铈矿U-Pb定年具有广阔的应用前景。但氟碳铈矿U-Pb定年极少有报道，国际上还没有激光原位U-Pb定年工作的任何报道，同时，氟碳铈矿富集轻稀土元素，也是激光原位Nd同位素测定的理想对象。本申请旨在利用193 nm准分子激光、Agilent 7500a等离子质谱（ICP-MS）和Neptune多接收等离子质谱（MC-ICP-MS），对氟碳铈矿进行系统的实验方法研究，研发合适的氟碳铈矿U-Pb年龄及Nd同位素标样。在此基础之上，结合详细岩石学与矿物学工作，对我国内蒙古白云鄂博和四川牦牛坪稀土矿床中氟碳铈矿开展其矿床同位素年代学和源区性质研究。本项目的实施对开展含氟碳铈矿的稀土矿床同位素年代学与地球化学研究具有重要意义。

Bastnaesite is an ideal mineral for U-Pb isotopic dating because of its relatively high U and Th contents. Since minerals of the bastnaesite group have a fairly wide distribution of carbonatites, alkaline rocks, and relative rare metal deposits, they can be considered as a promising geochronological tool suitable for U-Pb dating. However, studies of U-Pb dating on bastnaesite are still rare. There is no analytical protocol reported in the litureature of LA-ICP-MS dating bastnaesite. Additionally, bastnaesite is also an ideal objective for in situ Nd isotopic measurement. The goal of this proposal is to establish analytical protocol of U-Pb geological dating bastnaesite as well as its in situ Nd isotopic analysis by LA-(MC)-ICP-MS. Then we will apply our developed protocol to U-Pb dating and Nd isotopic analysis of bastnaesites from Bayan Obo giant REE-Nb-Fe deposit, Inner Mongolia and Maoniuping REE deposit, Sichuan, China. This proposal will play an important and potential role in study of geochemistry and geochronology of REE deposits in the near future.