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The constant oxidation state of Earth's mantle since the Hadean.
- Source :
-
Nature communications [Nat Commun] 2024 Aug 10; Vol. 15 (1), pp. 6521. Date of Electronic Publication: 2024 Aug 10. - Publication Year :
- 2024
-
Abstract
- Determining the evolutionary history of mantle oxygen fugacity (fo <subscript>2</subscript> ) is crucial, as it controls the fo <subscript>2</subscript> of mantle-derived melts and regulates atmospheric composition through volcanic outgassing. However, the evolution of mantle fo <subscript>2</subscript> remains controversial. Here, we present a comprehensive dataset of plume-derived komatiites, picrites, and ambient mantle-derived (meta)basalts, spanning from ~3.8 Ga to the present, to investigate mantle thermal and redox states evolution. Our results indicate that fo <subscript>2</subscript> of both mantle plume-derived and ambient mantle-derived melts was lower during the Archean compared to the post-Archean period. This increase in the fo <subscript>2</subscript> of mantle-derived melts over time correlates with decreases in mantle potential temperature and melting depth. By normalizing fo <subscript>2</subscript> to a constant reference pressure (potential oxygen fugacity), we show that the fo <subscript>2</subscript> of both the mantle plume and ambient upper mantle has remained constant since the Hadean. These findings suggest that secular mantle cooling reduced melting depth, increasing the fo <subscript>2</subscript> of mantle-derived melts and contributing to atmospheric oxygenation.<br /> (© 2024. The Author(s).)
Details
- Language :
- English
- ISSN :
- 2041-1723
- Volume :
- 15
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Nature communications
- Publication Type :
- Academic Journal
- Accession number :
- 39127717
- Full Text :
- https://doi.org/10.1038/s41467-024-50778-z