Titelangaben
Rustioni, Greta ; Wiedenbeck, M. ; Miyajima, Nobuyoshi ; Chanyshev, Artem ; Keppler, Hans:
Magnesiowüstite as a major nitrogen reservoir in Earth's lowermost mantle.
In: Geochemical Perspectives Letters.
Bd. 28
(2024)
.
- S. 43-47.
ISSN 2410-3403
DOI: https://doi.org/10.7185/geochemlet.2401
Abstract
Ferropericlase (Mg,Fe)O is after bridgmanite the most abundant phase in the lower mantle. The ultralow velocity zones above the core-mantle boundary may contain very Fe-rich magnesiowüstite (Fe,Mg)O, possibly as result of the fractional crystallisation of a basal magma ocean. We have experimentally studied the solubility of nitrogen in the ferropericlase-magnesiowüstite solid solution series as function of iron content. Multi-anvil experiments were performed at 20–33 GPa and 1600–1800 °C in equilibrium with Fe metal. Nitrogen solubility increases from a few tens ppm (μg/g) for Mg-rich ferropericlase to more than 10 wt. % for nearly pure wüstite. Such high solubilities appear to be due to solid solution with NiAs-type FeN. Our data suggest that during fractional crystallisation of a magma ocean, the core-mantle boundary would have become extremely enriched with nitrogen, such that the deep mantle today could be the largest nitrogen reservoir on Earth. The often discussed “subchondritic N/C” ratio of the bulk silicate Earth may be an artefact of insufficient sampling of this deep reservoir.
Weitere Angaben
Publikationsform: | Artikel in einer Zeitschrift |
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Begutachteter Beitrag: | Ja |
Institutionen der Universität: | Forschungseinrichtungen > Zentrale wissenschaftliche Einrichtungen > Bayerisches Forschungsinstitut für Experimentelle Geochemie und Geophysik - BGI |
Titel an der UBT entstanden: | Ja |
Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie |
Eingestellt am: | 12 Nov 2024 06:23 |
Letzte Änderung: | 12 Nov 2024 06:23 |
URI: | https://eref.uni-bayreuth.de/id/eprint/91010 |