Titelangaben
Lin, Yanhao ; Ishii, Takayuki ; van Westrenen, Wim ; Katsura, Tomoo ; Mao, Ho-Kwang:
Melting at the base of a terrestrial magma ocean controlled by oxygen fugacity.
In: Nature Geoscience.
Bd. 17
(2024)
Heft 8
.
- S. 803-808.
ISSN 1752-0908
DOI: https://doi.org/10.1038/s41561-024-01495-1
Abstract
Heat delivered from accretionary impacts is thought to have led to extensive melting of early Earth’s silicate mantle, resulting in a deep magma ocean covering the surface. The mantle’s oxygen fugacity is thought to have increased over accretion and core formation due to increasingly oxidated impactors and lower mantle self-oxidation, but the influence of this on the solidus of deep primitive mantle materials has not been well constrained. Here we assess the effect of oxygen fugacity on conditions at the bottom of a magma ocean by experimentally determining the solidus of mantle pyrolite at pressures of 16–26 GPa at high oxygen fugacities. We find that over this pressure range, the solidus in experiments conducted under oxidizing conditions is at least 230–450 °C lower than in experiments conducted under more reducing conditions. Assuming constant magma ocean temperature, this would imply a magma ocean floor that deepens by about 60 km for each log unit increase in mantle oxygen fugacity. The strong influence of oxygen fugacity on mantle melting suggests that models of early Earth thermal evolution and geochemical models of core formation should be reassessed.
Weitere Angaben
Publikationsform: | Artikel in einer Zeitschrift |
---|---|
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: | 30 Mai 2025 07:56 |
Letzte Änderung: | 30 Mai 2025 07:56 |
URI: | https://eref.uni-bayreuth.de/id/eprint/93802 |