@article{dddb096aaab64e758f77d96bd47a6dac,
title = "Community-Derived Standards for LA-ICP-MS U-(Th-)Pb Geochronology – Uncertainty Propagation, Age Interpretation and Data Reporting",
abstract = "The LA-ICP-MS U-(Th-)Pb geochronology international community has defined new standards for the determination of U-(Th-)Pb ages. A new workflow defines the appropriate propagation of uncertainties for these data, identifying random and systematic components. Only data with uncertainties relating to random error should be used in weighted mean calculations of population ages; uncertainty components for systematic errors are propagated after this stage, preventing their erroneous reduction. Following this improved uncertainty propagation protocol, data can be compared at different uncertainty levels to better resolve age differences. New reference values for commonly used zircon, monazite and titanite reference materials are defined (based on ID-TIMS) after removing corrections for common lead and the effects of excess 230Th. These values more accurately reflect the material sampled during the determination of calibration factors by LA-ICP-MS analysis. Recommendations are made to graphically represent data only with uncertainty ellipses at 2s and to submit or cite validation data with sample data when submitting data for publication. New data-reporting standards are defined to help improve the peer-review process. With these improvements, LA-ICP-MS U-(Th-)Pb data can be considered more robust, accurate, better documented and quantified, directly contributing to their improved scientific interpretation.",
keywords = "ICP-MS, U-(Th-)Pb geochronology, data reporting, laser ablation, uncertainty propagation",
author = "Horstwood, {Matthew S.A.} and Jan Ko{\v s}ler and George Gehrels and Jackson, {Simon E.} and McLean, {Noah M.} and Chad Paton and Pearson, {Norman J.} and Keith Sircombe and Paul Sylvester and Pieter Vermeesch and Bowring, {James F.} and Condon, {Daniel J.} and Blair Schoene",
note = "Funding Information: Sadly, our friend and colleague Prof. Jan Ko{\v s}ler passed away before the completion of this manuscript. Jan was a key driving force of this effort and his input and comradeship are dearly missed by us all. We dedicate this paper to him for his many years of effort on this initiative. The authors and co-ordinators of the LA-ICP-MS U-(Th-)Pb Network would like to thank the sponsors of the workshops we have held to date that have enabled discussions on these points and resulted in this manuscript. These include instrumentation manufacturers, academic and government institutions. NSF is particularly thanked for supporting Grant number EAR-0930223 (awarded to J.F. Bowring) that has been instrumental in the outcomes and for supporting Grant number EAR-1338583 (awarded to G. Gehrels). The International Association of Geoanalysts and members of the EARTHTIME initiative are thanked greatly for their ongoing support. All participants of the workshops (100 different attendees/online contributors across the four workshops) are thanked for contributing to the process and inputting their views and comments during the workshops and subsequent discussions. Thanks also to our collaborators in the SIMS and ID-TIMS communities who have been instrumental in helping us find a way forward whilst learning from their experiences and to Jiri Sl{\'a}ma for the design and maintenance of the PlasmAge.org website. MH thanks Elena Belousova for providing the GJ1 zircon material, Richard Stern and Nicole Rayner for the {\textquoteleft}Stern{\textquoteright} monazite, Anne-Magali Seydoux-Guillaume for the Moacyr monazite and Craig Storey for the Ontario 2 titanite. The authors thank Thomas Meisel for editorial handling and two anonymous reviewers for providing constructive criticism that helped clarify the manuscript. Publisher Copyright: {\textcopyright} 2016 Natural Environment Research Council Geostandards and Geoanalytical Research published by John Wiley & Sons Ltd on behalf of the International Association of Geoanalysts.",
year = "2016",
month = sep,
day = "1",
doi = "10.1111/j.1751-908X.2016.00379.x",
language = "English (US)",
volume = "40",
pages = "311--332",
journal = "Geostandards and Geoanalytical Research",
issn = "1639-4488",
publisher = "Wiley-Blackwell",
number = "3",
}