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A UV laser ablation microprobe-inductively coupled plasma mass spectrometry (LAMICPMS) is used to determine the Pb/Pb and Pb/U ages of several zircon grains whose ages have been measured by the conventional U-Pb thermal ionization mass spectrometry (TIMS) method. The mass fractionation factor of Pb isotope ratio was typically between 0.010--0.012 and corrected by NIST610 glass standard. Several factors that influence the stability of Pb/U ratio have been investigated and optimized. The precision of ~(207)pb/~(206)Pb and (206)pb/~(238)U from each sampling crater is within 0.6%—2.4% and 1%—10% respectively, while the precision for the average of mean ratios from different craters is 0.7% and 6% correspondingly. The ~207)Pb/~(206)pb and ~(206)pb/~(238)U age differences compared with TIMS results are 《1% and <3% respectively.
A UV laser ablation microprobe-inductively coupled plasma mass spectrometry (LAMICPMS) is used to determine the Pb / Pb and Pb / U ages of several zircon grains whose ages have been measured by the conventional U-Pb thermal ionization mass spectrometry (TIMS) method . The mass fractionation factor of Pb isotope ratio was typically between 0.010--0.012 and corrected by NIST 610 glass standard. Several factors that influence the stability of Pb / U ratio have been investigated and optimized. The precision of ~ (207) pb / ~ (206) Pb and (206) pb / ~ (238) U from each sampling crater are within 0.6% -2.4% and 1% -10% respectively, while the precision for the average for the mean ratios from different craters is 0.7% and (206) pb / ~ (206) pb / ~ (238) U age differences compared with TIMS results are "1% and <3% respectively.