Technical note: RA138 calcite U–Pb LA-ICP-MS primary reference material
| Autor: | M. Guillong, E. Samankassou, I. A. Müller, D. Szymanowski, N. Looser, L. Tavazzani, Ó. Merino-Tomé, J. R. Bahamonde, Y. Buret, M. Ovtcharova |
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| Jazyk: | angličtina |
| Rok vydání: | 2024 |
| Předmět: | |
| Zdroj: | Geochronology, Vol 6, Pp 465-474 (2024) |
| Druh dokumentu: | article |
| ISSN: | 2628-3697 2628-3719 |
| DOI: | 10.5194/gchron-6-465-2024 |
| Popis: | A promising primary reference material for U–Pb laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) carbonate dating is analysed and reported here. The new reference material (RM) is a botryoidal cement (C1) from sample RA138. The sample was collected in outcrop strata of mid-Carboniferous age in northern Spain near La Robla, and multiple aliquots have been meticulously prepared for distribution. RA138 is characterized by variable U/Pb ratios (from ∼ 1 to ∼ 19) and a relatively high and homogeneous U content (∼ 4 ppm). This material exhibits a low age uncertainty (0.2 %, 2 s; unanchored; ID-TIMS), allowing for the establishment of a well-defined isochron, particularly when anchored to the initial Pb ratio using LA-ICP-MS. Isotope dilution thermal ionization mass spectrometry (ID-TIMS) analyses of micro-drilled C1 cement (17 sub-samples) produce a lower-intercept age of 321.99 ± 0.65 Ma, an initial 207Pb/206Pb ratio of 0.8495 ± 0.0065, and a mean square weighted deviation (MSWD) of 5.1. The systematic uncertainty of 1.5 % observed in repeated LA-ICP-MS analyses challenges previous estimations of 2 %–2.5 % based on repeated analyses of ASH-15D and JT using WC-1 as primary reference material, underscoring the precision and reliability of RA138 for U–Pb dating applications. |
| Databáze: | Directory of Open Access Journals |
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