Long-Term Reproducibility of SIMS Zircon U-Pb Geochronology

• 作者: Wenhao Zhao Qiuli Li Yu Liu Guoqiang Tang Xiaoxiao Ling Jiao Li Xianhua Li
• 来源期刊: 地球科学学刊（英文版）
• 年，卷（期）: 2022,（1）
• 所属期刊栏目: Special Issue on Isotope Geochronology and Isotope Geochemistry
• 页码范围: 17-24
• 页数: 8页
• 语种: 英文

摘要

Secondary ion mass spectrometry (SIMS) zircon U-Pb dating has been widely used to confine the absolute ages of the magmatic or metamorphic events and to distinguish multiple events. Here, a data set consisting of the zircon standards dating data (～15000 Ple?ovice and～8000 Qinghu items) accumulated for more than 8 years using the CAMECA IMS 1280HR of the Institute of Geology and Geophysics, Chinese Academy of Sciences (IGGCAS) is compiled to evaluate the long-term exter- nal reproducibility. With Ple?ovice zircon as the calibration standard and Qinghu zircon as an un- known sample, the analytical uncertainties for single-spot (n = 7723) and session analyses (n = 691, with more than 7 single spot analyses in one session) are 2.6％and 0.9％(2RSD, relative standard devi- ation), respectively. It means that single-spot U-Pb dating for a standard-level zircon sample could vary 5.2％at 95％confidence level, while the average value (n>7) for each session may vary 1.8％. Thus, these values should be considered as the minimum uncertainty when comparing single spot and individ- ual session analysis results for multiple dating works on a certain geological event.