Potassium isotope heterogeneity in the early Solar System controlled by extensive evaporation and partial recondensation.

Autor: Hu Y; Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, UMR 7154, Paris, 75005, France. yanhu@ipgp.fr., Moynier F; Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, UMR 7154, Paris, 75005, France. moynier@ipgp.fr., Bizzarro M; Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, UMR 7154, Paris, 75005, France.; StarPlan - Centre for Star and Planet Formation, GLOBE Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen, DK-1350, Denmark.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2022 Dec 12; Vol. 13 (1), pp. 7669. Date of Electronic Publication: 2022 Dec 12.
DOI: 10.1038/s41467-022-35362-7
Abstrakt: Volatiles are vital ingredients for a habitable planet. Angrite meteorites sample the most volatile-depleted planetesimal in the Solar System, particularly for the alkali elements. They are prime targets for investigating the formation of volatile-poor rocky planets, yet their exceptionally low volatile content presents a major analytical challenge. Here, we leverage improved sensitivity and precision of K isotopic analysis to constrain the mechanism of extreme K depletion (>99.8%) in angrites. In contrast with the isotopically heavy Moon and Vesta, we find that angrites are strikingly depleted in the heavier K isotopes, which is best explained by partial recondensation of vaporized K following extensive evaporation on the angrite parent body (APB) during magma-ocean stage. Therefore, the APB may provide a rare example of isotope fractionation controlled by condensation, rather than evaporation, at a planetary scale. Furthermore, nebula-wide K isotopic variations primarily reflect volatility-driven fractionations instead of presolar nucleosynthetic heterogeneity proposed previously.
(© 2022. The Author(s).)
Databáze: MEDLINE
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