Shields, GA, Mills, BJW orcid.org/0000-0002-9141-0931, Zhu, M et al. (3 more authors) (2019) Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial. Nature Geoscience, 12 (10). pp. 823-827. ISSN 1752-0894
Abstract
The Neoproterozoic era witnessed a succession of biological innovations that culminated in diverse animal body plans and behaviours during the Ediacaran–Cambrian radiations. Intriguingly, this interval is also marked by perturbations to the global carbon cycle, as evidenced by extreme fluctuations in climate and carbon isotopes. The Neoproterozoic isotope record has defied parsimonious explanation because sustained 12C-enrichment (low δ13C) in seawater seems to imply that substantially more oxygen was consumed by organic carbon oxidation than could possibly have been available. We propose a solution to this problem, in which carbon and oxygen cycles can maintain dynamic equilibrium during negative δ13C excursions when surplus oxidant is generated through bacterial reduction of sulfate that originates from evaporite weathering. Coupling of evaporite dissolution with pyrite burial drives a positive feedback loop whereby net oxidation of marine organic carbon can sustain greenhouse forcing of chemical weathering, nutrient input and ocean margin euxinia. Our proposed framework is particularly applicable to the late Ediacaran ‘Shuram’ isotope excursion that directly preceded the emergence of energetic metazoan metabolisms during the Ediacaran–Cambrian transition. Here we show that non-steady-state sulfate dynamics contributed to climate change, episodic ocean oxygenation and opportunistic radiations of aerobic life during the Neoproterozoic era.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019, The Author(s), under exclusive licence to Springer Nature Limited. This is an author produced version of an article published in Nature Geoscience. Uploaded in accordance with the publisher's self-archiving policy. |
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) |
Funding Information: | Funder Grant number NERC Not Known |
Depositing User: | Symplectic Publications |
Date Deposited: | 26 Jul 2019 14:15 |
Last Modified: | 02 Mar 2020 01:39 |
Status: | Published |
Publisher: | Nature Publishing Group |
Identification Number: | 10.1038/s41561-019-0434-3 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:149033 |