Tang, D., Zhou, H., Jiang, G. et al. (13 more authors) (2025) Terminal Mesoproterozoic (1.1–1.0 Ga) shallow ocean oxygenation and the rise of crown-group eukaryotes. GSA Bulletin. ISSN 0016-7606
Abstract
At the end of the Mesoproterozoic Era (1.1–1.0 Ga), crown-group eukaryotes including rhodophytes and chlorophytes diversified and began to dominate the marine ecosystem. It is commonly thought that the oxygenation of Earth’s surface environment was the driver behind this eukaryotic evolution and ecosystem change, but there is currently little evidence for an increase in biospheric oxygenation across the Meso35 Neoproterozoic transition. Here, we report mineralogical and geochemical data from the ca. 1.1 Ga Nanfen Formation, North China, to explore possible causal relationships between marine redox conditions and terminal Mesoproterozoic biotic innovation. Elevated Ba concentrations and the occurrence of authigenic barite in the Nanfen Formation indicate an increase in seawater sulfate concentrations, likely caused by enhanced oxidative weathering of the continents. In addition, carbonate I/(Ca+Mg) ratios of up to 15 μmol/mol, coupled with a negative shift in carbonate δ¹³C, indicate oxidation of iodide and dissolved organic carbon as a result of enhanced water column oxygenation on the North China Platform. These geochemical trends occur coincident with increased P/Al ratios, suggesting that enhanced P bioavailability ultimately drove more extensive oxygenation. These results, in combination with highly fractionated carbonate Cr isotope data from time-equivalent strata in West Africa and extensive Mn deposits in Western Australia, suggest widespread oxic shallow ocean conditions during the terminal Mesoproterozoic. This suggests that shallow ocean oxygenation likely created favorable conditions for the diversification of crown-group eukaryotes at ca. 1.1 Ga.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This is an author produced version of an article published in GSA Bulletin, made available under the terms of the Creative Commons Attribution License (CC-BY), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | North China; Nanfen Formation; eukaryotic evolution; I/(Ca+Mg); redox conditions |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Earth Surface Science Institute (ESSI) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 05 Feb 2025 11:25 |
Last Modified: | 26 Mar 2025 16:09 |
Published Version: | https://pubs.geoscienceworld.org/gsa/gsabulletin/a... |
Status: | Published online |
Publisher: | Geological Society of America |
Identification Number: | 10.1130/B37943.1 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:222891 |