单颗粒锆石CA-ID-TIMS U-Pb法是目前最重要的高精度同位素地质年代学方法。我国CA-ID-TIMS U-Pb方法目前仍存在Pb流程本底相对较高(2-3 pg)以及缺乏高精度U-Pb同位素稀释剂等主要技术瓶颈。本项目拟借鉴国外先进实验室经验，进一步探索降低实验室流程本底的措施，力争将我们CA-ID-TIMS U-Pb实验室Pb流程本底降低至0.5 pg以下，并且精确配制U-Pb同位素稀释剂。通过上述工作，在我国建立达到国际先进实验室水平的CA-ID-TIMS U-Pb高精度年代学方法。配制的稀释剂将供国内ID-TIMS U-Pb年代学实验室共享使用。在此基础上，拟开展华南寒武纪底界地层剖面高精度CA-ID-TIMS U-Pb年代学示范性应用研究工作。本项目对推动我国高精度地质年代学实验技术及应用研究的深入发展，提高我国在同位素地质年代学研究领域的国际地位具有重要意义。

Sing grain zircon CA-ID-TIMS U-Pb radiometric method is very important in high-precision geochronology. The method has been widely used in research fields such as high-precision chronostratigraphy, high-precision dating of important geological events, and calibration of the age of standard zircons used for SIMS and LA-ICP-MS. At current, the main technical bottlenecks for CA-ID-TIMS U-Pb method in China are the relatively high Pb laboratory blank (2-3 pg), and the lack of well-calibrated U-Pb spikes. In this project, we plan to cooperate with famous international ID-TIMS U-Pb geochronological laboratory, to further reduce the U-Pb blank level of the laboratory at the Institute of Geology and Geophysics, Chinese Academy of Sciences (IGGCAS) (to less than 0.5 pg), and produce well-calibrated U-Pb spikes. We will share the spikes with other ID-TIMS U-Pb labs in China. Through these important works, we will establish the high-precision CA-ID-TIMS U-Pb dating method at IGGCAS thoroughly. Then, we will try to further calibrate the age of E-C boundary in south China with the method. The implementation of this project will greatly improve the high-precision geochronology research in China, and contribute to the Earthtime-CN project.