Plesovice zircon: A new natural reference material for U-Pb and Hf isotopic microanalysis
2008 (English)In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 249, no 02-jan, 1-35 p.Article in journal (Refereed) Published
Matrix-matched calibration by natural zircon standards and analysis of natural materials as a reference are the principle methods for achieving accurate results in inicrobeam U-Pb dating and Hf isotopic analysis. We describe a new potential zircon reference material for laser ablation ICP-MS that was extracted from a potassic granulite facies rock collected in the southern part of the Bohemian Massif (Plesovice, Czech Republic). Data from different techniques (ID-TIMS, SIMS and LA ICP-MS) and several laboratories suggest that this zircon has a concordant U-Pb age with a weighted mean Pb-206/U-238 date of 337.13 +/- 0.37 Ma (ID-TIMS, 95% confidence limits, including tracer calibration uncertainty) and U-Pb age homogeneity on the scale used in LA ICP-MS dating. Inhomogeneities in trace element composition due to primary growth zoning prevent its use as a calibration standard for trace element analysis. The content of U varies from 465 ppm in pristine parts of the grains to similar to 3000 ppm in actinide-rich sectors that correspond to pyramidal faces with a high degree of metamictization (present in ca. 30% of the grains). These domains are easily recognized from high intensities on BSE images and should be avoided during the analysis. Hf isotopic composition of the Plesovice zircon (>0.9 wt.% Hf) is homogenous within and between the grains with a mean Hf-176/Hf-177 value of 0.282492 +/- 0.000013 (2SD). The age and Hf isotopic homogeneity of the Plesovice zircon together with its relatively high U and Pb contents make it an ideal calibration and reference material for laser ablation ICP-MS measurements, especially when using low laser energies and/or small diameters of laser beam required for improved spatial resolution.
Place, publisher, year, edition, pages
2008. Vol. 249, no 02-jan, 1-35 p.
zircon reference material, laser ablation ICP-MS, Plesovice, U-Pb dating, Hf isotopes, Bohemian Massif
IdentifiersURN: urn:nbn:se:su:diva-58577DOI: 10.1016/j.chemgeo.2007.11.005ISI: 000255097800001OAI: oai:DiVA.org:su-58577DiVA: diva2:424984
authorCount :142011-06-202011-06-032011-06-20Bibliographically approved