Destabilization of deep oxidized mantle drove the Great Oxidation Event.

ABSTRACT: The rise of Earth's atmospheric O₂ levels at ~2.4 Ga was driven by a shift between increasing sources and declining sinks of oxygen. Here, we compile recent evidence that the mantle shows a significant increase in oxidation state leading to the Great Oxidation Event (GOE), linked to sluggish upward mixing of a deep primordial oxidized layer. We simulate this scenario by implementing a new rheological model for this oxidized, bridgmanite-enriched viscous material and demonstrate slow mantle mixing in simulations of early Earth's mantle. The eventual homogenization of this layer may take ~2 Ga, in line with the timing of the observed mantle redox shift, and would result in the increase in upper mantle oxidation of >1 log(fO₂) unit. Such a shift would alter the re

SUBMITTER: O'Neill C 

PROVIDER: S-EPMC8856610 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature