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Hu JY, Dauphas N, Tissot FLH, Yokochi R, Ireland TJ, Zhang Z, Davis AM, Ciesla FJ, Grossman L, Charlier BLA, Roskosz M, Alp EE, Hu MY, Zhao J. Heating events in the nascent solar system recorded by rare earth element isotopic fractionation in refractory inclusions. Sci Adv 2021; 7:7/2/eabc2962. [PMID: 33523962 PMCID: PMC7787488 DOI: 10.1126/sciadv.abc2962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 11/16/2020] [Indexed: 05/31/2023]
Abstract
Equilibrium condensation of solar gas is often invoked to explain the abundance of refractory elements in planets and meteorites. This is partly motivated, by the observation that the depletions in both the least and most refractory rare earth elements (REEs) in meteoritic group II calcium-aluminum-rich inclusions (CAIs) can be reproduced by thermodynamic models of solar nebula condensation. We measured the isotopic compositions of Ce, Nd, Sm, Eu, Gd, Dy, Er, and Yb in eight CAIs to test this scenario. Contrary to expectation for equilibrium condensation, we find light isotope enrichment for the most refractory REEs and more subdued isotopic variations for the least refractory REEs. This suggests that group II CAIs formed by a two-stage process involving fast evaporation of preexisting materials, followed by near-equilibrium recondensation. The calculated time scales are consistent with heating in events akin to FU Orionis- or EX Lupi-type outbursts of eruptive pre-main-sequence stars.
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Affiliation(s)
- J Y Hu
- Origins Laboratory, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA.
- Department of the Geophysical Sciences, Enrico Fermi Institute, Chicago Center for Cosmochemistry, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
| | - N Dauphas
- Origins Laboratory, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
- Department of the Geophysical Sciences, Enrico Fermi Institute, Chicago Center for Cosmochemistry, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
| | - F L H Tissot
- Origins Laboratory, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
- The Isotoparium, Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - R Yokochi
- Department of the Geophysical Sciences, Enrico Fermi Institute, Chicago Center for Cosmochemistry, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
| | - T J Ireland
- Origins Laboratory, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
- Department of the Geophysical Sciences, Enrico Fermi Institute, Chicago Center for Cosmochemistry, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
- Department of Earth and Environment, Boston University, 685 Commonwealth Avenue, Boston, MA 02215, USA
| | - Z Zhang
- Origins Laboratory, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
- Department of the Geophysical Sciences, Enrico Fermi Institute, Chicago Center for Cosmochemistry, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
| | - A M Davis
- Department of the Geophysical Sciences, Enrico Fermi Institute, Chicago Center for Cosmochemistry, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
| | - F J Ciesla
- Department of the Geophysical Sciences, Enrico Fermi Institute, Chicago Center for Cosmochemistry, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
| | - L Grossman
- Department of the Geophysical Sciences, Enrico Fermi Institute, Chicago Center for Cosmochemistry, The University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA
| | - B L A Charlier
- School of Geography, Earth and Environmental Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | - M Roskosz
- IMPMC, CNRS, UMR 7590, Sorbonne Universités, Université Pierre et Marie Curie, Muséum National d'Histoire Naturelle, CP 52, 57 rue Cuvier, Paris F-75231, France
| | - E E Alp
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - M Y Hu
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - J Zhao
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
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Pravdivtseva O, Tissot FLH, Dauphas N, Amari S. Evidence of presolar SiC in the Allende Curious Marie calcium aluminum rich inclusion. Nat Astron 2020; 2020:10.1038/s41550-019-1000-z. [PMID: 32021908 PMCID: PMC6999789 DOI: 10.1038/s41550-019-1000-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 12/06/2019] [Indexed: 06/10/2023]
Abstract
Calcium aluminum rich inclusions (CAIs) are one of the first solids to have condensed in the solar nebula, while presolar grains formed in various evolved stellar environments. It is generally accepted that CAIs formed close to the Sun at temperatures above 1500 K, where presolar grains could not survive, and were then transported to other regions of the nebula where the accretion of planetesimals took place. In this context, a commonly held view is that presolar grains are found solely in the fine-grained rims surrounding chondrules and in the low-temperature fine-grained matrix that binds the various meteoritic components together. Here we demonstrate, based on noble gas isotopic signatures, that presolar SiC have been incorporated into fine-grained CAIs in the Allende carbonaceous chondrite at the time of their formation, and have survived parent body processing. This finding provides new clues on the conditions in the nascent solar system at the condensation of first solids.
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Affiliation(s)
- O Pravdivtseva
- Physics Department and McDonnell Center for the Space Sciences, Washington University, Saint Louis, MO 63130, USA
| | - F L H Tissot
- The Isotoparium, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - N Dauphas
- Origins Laboratory, Department of the Geophysical Sciences and Enrico Fermi Institute, The University of Chicago, Chicago, Il 60637, USA
| | - S Amari
- Physics Department and McDonnell Center for the Space Sciences, Washington University, Saint Louis, MO 63130, USA
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Rauscher T, Dauphas N, Dillmann I, Fröhlich C, Fülöp Z, Gyürky G. Constraining the astrophysical origin of the p-nuclei through nuclear physics and meteoritic data. Rep Prog Phys 2013; 76:066201. [PMID: 23660558 DOI: 10.1088/0034-4885/76/6/066201] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A small number of naturally occurring, proton-rich nuclides (the p-nuclei) cannot be made in the s- and r-processes. Their origin is not well understood. Massive stars can produce p-nuclei through photodisintegration of pre-existing intermediate and heavy nuclei. This so-called γ-process requires high stellar plasma temperatures and occurs mainly in explosive O/Ne burning during a core-collapse supernova. Although the γ-process in massive stars has been successful in producing a large range of p-nuclei, significant deficiencies remain. An increasing number of processes and sites has been studied in recent years in search of viable alternatives replacing or supplementing the massive star models. A large number of unstable nuclei, however, with only theoretically predicted reaction rates are included in the reaction network and thus the nuclear input may also bear considerable uncertainties. The current status of astrophysical models, nuclear input and observational constraints is reviewed. After an overview of currently discussed models, the focus is on the possibility to better constrain those models through different means. Meteoritic data not only provide the actual isotopic abundances of the p-nuclei but can also put constraints on the possible contribution of proton-rich nucleosynthesis. The main part of the review focuses on the nuclear uncertainties involved in the determination of the astrophysical reaction rates required for the extended reaction networks used in nucleosynthesis studies. Experimental approaches are discussed together with their necessary connection to theory, which is especially pronounced for reactions with intermediate and heavy nuclei in explosive nuclear burning, even close to stability.
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Affiliation(s)
- T Rauscher
- Department of Physics, University of Basel, 4056 Basel, Switzerland.
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Abstract
A procedure was developed that allows precise determination of molybdenum isotope abundances in natural samples. Purification of molybdenum was first achieved by solvent extraction using di(2-ethylhexyl) phosphate. Further separation of molybdenum from isobar nuclides was obtained by ion chromatography using AG1-X8 strongly basic anion exchanger. Finally, molybdenum isotopic composition was measured using a multiple collector inductively coupled plasma hexapole mass spectrometer. The abundances of molybdenum isotopes 92, 94, 95, 96, 97, 98, and 100 are 14.8428(510), 9.2498(157), 15.9303(133), 16.6787(37), 9.5534(83), 24.1346(394), and 9.6104(312) respectively, resulting in an atomic mass of 95.9304(45). After internal normalization for mass fractionation, no variation of the molybdenum isotopic composition is observed among terrestrial samples within a relative precision on the order of 0.00001-0.0001. This demonstrates the reliability of the method, which can be applied to searching for possible isotopic anomalies and mass fractionation.
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Affiliation(s)
- N Dauphas
- Centre de Recherches Pétrographiques et Géochimiques, CNRS UPR 2300, Vandoeuvre-lès-Nancy, France.
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Abstract
Nitrogen and argon isotopes were measured in carbonatites and associated rocks from the Kola Peninsula in Russia. The Kola mantle source, which is thought to be located in the deep mantle, is enriched in heavy nitrogen (+3 per mil relative to air) as compared to Earth's surface (atmosphere and crust, +2 per mil) and the shallow mantle (-4 per mil). Recycling of oceanic crust (+6 per mil) or metal-silicate partitioning may account for the nitrogen isotopic composition of the deep mantle.
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Affiliation(s)
- N Dauphas
- Centre de Recherches Petrographiques et Geochimiques, CNRS UPR 9046, 15 rue Notre-Dame des Pauvres, Boite Postale 20, 54501 Vandoeuvre-les-Nancy Cedex, France. Ecole Nationale Superieure de Geologie, rue du doyen Marcel Roubault, Boit
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