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LA-ICPMS zircon U-Pb dating has been greatly advanced and widely applied in the past decade because it is a cheap and fast technique.The internal error of LA-ICPMS zircon U-Pb dating can be better than 1%,but reproducibility(accuracy)is relatively poor.In order to quantitatively assess the accuracy of this technique,zircons from two dioritic rocks,a Mesozoic dioritic microgranular enclave(FS06)and a Neoproterozoic diorite(WC09-32),were dated independently in eight laboratories using SIMS and LA-ICPMS.Results of three SIMS analyses on FS06 and WC09-2 are indistinguishable within error and give a best estimate of the crystallization age of 132.2 and 760.5 Ma(reproducibility is~1%,2RSD),respectively.Zircon U-Pb ages determined by LA-ICPMS in six laboratories vary from 128.3±1.0 to 135.0±0.9 Ma(2SE)for FS06 and from 742.9±3.1 to777.8±4.7 Ma(2SE)for WC09-32,suggesting a reproducibility of~4%(2RSD).Uncertainty produced during LA-ICPMS zircon U-Pb analyses comes from multiple sources,including uncertainty in the isotopic ratio measurements,uncertainty in the fractionation factor calculation using an external standard,uncertainty in the age determination as a result of common lead correction,age uncertainty of the external standards and uncertainty in the data reduction.Result of our study suggests that the uncertainty of LA-ICPMS zircon U-Pb dating is approximately 4%(2RSD).The uncertainty in age determination must be considered in order to interpret LA-ICPMS zircon U-Pb data rationally.
LA-ICPMS zircon U-Pb dating has been greatly advanced and widely applied in the past decade because it is a cheap and fast technique. The internal error of LA-ICPMS zircon U-Pb dating can be better than 1%, but reproducibility ( accuracy) is relatively poor.In order to quantitatively assess the accuracy of this technique, zircons from two dioritic rocks, a Mesozoic dioritic microgranular enclave (FS06) and a Neoproterozoic diorite (WC09-32), were dated independently in eight laboratories using SIMS and Results of three SIMS analyzes on FS06 and WC09-2 are indistinguishable within error and give a best estimate of the crystallization age of 132.2 and 760.5 Ma (reproducibility is ~ 1%, 2RSD), respectively. Zircon U-Pb ages determined by LA-ICPMS in six laboratories vary from 128.3 ± 1.0 to 135.0 ± 0.9 Ma (2SE) for FS06 and from 742.9 ± 3.1 to 777.8 ± 4.7 Ma (2SE) for WC09-32, suggesting a reproducibility of ~ 4% ( 2RSD). Uncertainty produced during LA-ICPMS zircon U-Pb analyzes comes from multiple sources, incl uding uncertainty in the isotopic ratio measurements, uncertainty in the fractionation factor calculation using an external standard, uncertainty in the age determination as a result of common lead correction, age uncertainty of the external standards and uncertainty in the data reduction. that the uncertainty of LA-ICPMS zircon U-Pb dating is approximately 4% (2RSD). The uncertainty in age determination be be considered in order to interpret LA-ICPMS zircon U-Pb data rationally.