Characterisation of Apatites as Potential Uranium Reference Materials for Fission‐track Dating by LA‐ICP‐MS |
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| Authors: | Cleber J. Soares Regina Mertz‐Kraus Sandro Guedes Daniel F. Stockli Thomas Zack |
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| Affiliation: | 1. Institut für Geowissenschaften, Johannes Gutenberg‐Universit?t Mainz, Mainz, Germany;2. ChronusCamp Research Thermochronology Laboratory, Campinas, Brazil;3. Departamento de Raios Cósmicos e Cronologia, Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas, Campinas, Brazil;4. Department of Geological Sciences, The University of Texas at Austin, Austin, TX, USA;5. Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden |
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| Abstract: | We report homogeneity tests on large natural apatite crystals to evaluate their potential as U reference materials for apatite fission‐track (AFT) thermochronology by laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS). The homogeneity tests include the measurements of major element concentrations by electron probe microanalysis (EPMA), whereas for U concentration, isotope dilution (ID) ICP‐MS and laser ablation (LA) ICP‐MS were employed. Two apatite crystals are potential reference materials for LA‐ICP‐MS analysis: a 1 cm3 fraction of a Durango crystal (7.5 μg g?1 U) and a 1 cm3 Mud Tank crystal (6.9 μg g?1 U). The relative standard deviation (1 RSD) of the U concentration determined by ID‐ICP‐MS of both apatite crystals was ≤ 1.5%, whereas 1 RSD for the LA‐ICP‐MS results was better than 4%, providing sufficient homogeneity for fission‐track dating. The results on the U homogeneity for two different apatite samples are an important step towards establishing in situ dating routines for AFT analysis by LA‐ICP‐MS. |
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| Keywords: | apatite reference material uranium homogeneity test ID‐ICP‐MS LA‐ICP‐MS fission‐track thermochronology apatite maté riel de ré fé rence uranium tests d'homogé né ité ID‐ICP‐MS LA‐ICP‐MS thermochronologie traces de fission |
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