Interlaboratory comparison of cosmogenic 21 Ne in quartz

• Published in: Quaternary Geochronology
• Main Authors: Vermeesch, Pieter, Balco, Greg, Blard, Pierre-Henri, Dunai, Tibor, Kober, Florian, Niedermann, Samuel, Shuster, David, Strasky, Stefan, Stuart, Finlay, M, Wieler, Rainer, Zimmermann, Laurent
• Other Authors: Institute of Geochemistry and Petrology ETH Zürich, Department of Earth Sciences Swiss Federal Institute of Technology - ETH Zürich (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), London Geochronology Centre, Department of Earth Sciences UCL London, University College of London London (UCL)-University College of London London (UCL), Berkeley Geochronology Center (BGC), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Universität zu Köln = University of Cologne, German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), Department of Earth and Planetary Science UC Berkeley (EPS), University of California Berkeley (UC Berkeley), University of California (UC)-University of California (UC), Scottish Universities Environmental Research Centre (SUERC), University of Glasgow-University of Edinburgh (Edin.)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: 21Ne; Quartz; Cosmogenic nuclides; Calibration Standard; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Antarctic; Cronus; Antarc*
• Online Access: https://hal.univ-lorraine.fr/hal-01770043; https://doi.org/10.1016/j.quageo.2012.11.009

International audience We performed an interlaboratory comparison study with the aim to determine the accuracy of cosmogenic 21Ne measurements in quartz. CREU-1 is a natural quartz standard prepared from amalgamated vein clasts which were crushed, thoroughly mixed, and sieved into 125–250 μm and 250–500 μm size fractions. 50 aliquots of CREU-1 were analyzed by five laboratories employing six different noble gas mass spectrometers. The released gas contained a mixture of 16–30% atmospheric and 70–84% non-atmospheric (predominantly cosmogenic) 21Ne, defining a linear array on the 22Ne/20Ne-21Ne/20Ne three isotope diagram with a slope of 1.108 ± 0.014. The internal reproducibility of the measurements is in good agreement with the formal analytical precision for all participating labs. The external reproducibility of the 21Ne concentrations between labs, however, is significantly overdispersed with respect to the reported analytical precision. We report an average reference concentration for CREU-1 of 348 ± 10 × 106 at [21Ne]/g[SiO2], and suggest that the 7.1% (2σ) overdispersion of our measurements may be representative of the current accuracy of cosmogenic 21Ne in quartz. CREU-1 was tied to CRONUS-A, which is a second reference material prepared from a sample of Antarctic sandstone. We propose a reference value of 320 ± 11 × 106 at/g for CRONUS-A. The CREU-1 and CRONUS-A intercalibration materials may be used to improve the consistency of cosmogenic 21Ne to the level of the analytical precision.