Survival of presolar p -nuclide carriers in the nebula revealed by stepwise leaching of Allende refractory inclusions.
| Autor: | Charlier BLA; School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington 6140, New Zealand. bruce.charlier@vuw.ac.nz., Tissot FLH; The Isotoparium, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.; Department of the Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA., Vollstaedt H; Thermo Fisher Scientific, Hanna-Kunath-Str. 11, 28199 Bremen, Germany., Dauphas N; Origins Laboratory, Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA., Wilson CJN; School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington 6140, New Zealand., Marquez RT; The Isotoparium, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. |
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| Jazyk: | angličtina |
| Zdroj: | Science advances [Sci Adv] 2021 Jul 09; Vol. 7 (28). Date of Electronic Publication: 2021 Jul 09 (Print Publication: 2021). |
| DOI: | 10.1126/sciadv.abf6222 |
| Abstrakt: | The 87 Rb- 87 Sr radiochronometer provides key insights into the timing of volatile element depletion in planetary bodies, yet the unknown nucleosynthetic origin of Sr anomalies in Ca-Al-rich inclusions (CAIs, the oldest dated solar system solids) challenges the reliability of resulting chronological interpretations. To identify the nature of these Sr anomalies, we performed step-leaching experiments on nine unmelted CAIs from Allende. In six CAIs, the chemically resistant residues (0.06 to 9.7% total CAI Sr) show extreme positive μ 84 Sr (up to +80,655) and 87 Sr variations that cannot be explained by decay of 87 Rb. The extreme 84 Sr but more subdued 87 Sr anomalies are best explained by the presence of a presolar carrier enriched in the p -nuclide 84 Sr. We argue that this unidentified carrier controls the isotopic anomalies in bulk CAIs and outer solar system materials, which reinstates the chronological significance of differences in initial 87 Sr/ 86 Sr between CAIs and volatile-depleted inner solar system materials. (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).) |
| Databáze: | MEDLINE |
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