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Community‐Derived Standards for LA ‐ ICP ‐ MS U‐(Th‐)Pb Geochronology – Uncertainty Propagation, Age Interpretation and Data Reporting
Author(s) -
Horstwood Matthew S. A.,
Košler Jan,
Gehrels George,
Jackson Simon E.,
McLean Noah M.,
Paton Chad,
Pearson Norman J.,
Sircombe Keith,
Sylvester Paul,
Vermeesch Pieter,
Bowring James F.,
Condon Daniel J.,
Schoene Blair
Publication year - 2016
Publication title -
geostandards and geoanalytical research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.037
H-Index - 73
eISSN - 1751-908X
pISSN - 1639-4488
DOI - 10.1111/j.1751-908x.2016.00379.x
Subject(s) - geochronology , population , overprinting , monazite , calibration , computer science , geology , statistics , workflow , mineralogy , zircon , environmental science , geochemistry , mathematics , database , demography , metamorphic rock , sociology
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 230 Th. 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 2 s 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.