摘要
建立了一种利用激光探针等离子体质谱测定单颗粒锆石U-Pb同位素年龄的新方法.以线扫描进样法代替传统的剥深进样法,克服U/Pb之间的熔蚀分异.对前寒武纪(>1.0Ga)锆石的定年表明,^(207)Pb/^(206)Pb、^(206)Pb/^(238)U定年精密度和准确度均为优于2%.对两颗中生代锆石进行了测试,获得了与SHRIMP,定年一致的^(206)Pb/^(238)U年龄.研究结果表明,该定年方法可与SHRIMP定年方法相比拟.
A new method for the determination of U-Pb isotopic dating on zircon grains has been developed by using a laser ablation microprobe (LAM) which coupled to an inductively coupled plasma-mass spectrometry(ICPMS). During the sampling process by the LAM, the conventional depth profile method was substituted by a line-scan method, by which the ablation fractionation between Pb and U could be attenuated. The 207Pb/206Pb and 206Pb/238U ages can be determined simultaneously for zircon grains of Precambrian, both the precision and relative error of the 207Pb/206Pb and 206Pb/238U ages for the determination are less than 2%. Our 206Pb/238U ages for the two Mesozoic zircons (Siberian-1 andSiberian-2) are 150±4Ma, and 148±3Ma, which agree with their SHRIMP ages. It demonstrates thatthe presented method may be comparable with the SHRIMP for homogenous zircons.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1999年第10期1121-1125,共5页
Chinese Journal of Analytical Chemistry
基金
国家杰出青年科学基金(49725309)
中国科学院广州分院测试基金资助项目
关键词
LAM
ICPMS
锆石
铀
铅
同位素年龄
定年
Laser ablation microprobe, inductively coupled plasma-mass spectnometry, single zircon grain, Uranium-Lead isotopic age
