An expansive global oxygenation of Earth's surface environments 1.4 billion years ago.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41298364.
- Also identified by DOI 10.1038/s41467-025-65551-z and PMC identifier 12658094.
- Licence recorded as CC BY-NC-ND.
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Abstract
The notion of biogeochemical stasis during the Mesoproterozoic era (1.6 to 1.0 billion years ago, Ga) has been increasingly challenged by evidence of transient episodes of increased oxygen (O<sub>2</sub>) levels in localized basins. However, the extent of oxygenation during this period - whether local or global - remains a topic of debate. Here, we present evidence of elevated global seawater molybdenum (Mo) isotope values, surpassing the typical Mesoproterozoic baseline, based on manganese (Mn)- and iron (Fe)-rich chemical sedimentary rocks in the ~1.45 Ga Tieling Formation, North China. Mass balance modeling indicates that as much as 80% of the global seafloor was oxygenated. Combined with prior evidence for elevated O<sub>2</sub> levels, our findings suggest a more expanded and prolonged global oxygenation event centered around ~1.4 Ga than previously recognized.