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Zhang F, Xiao S, Kendall B, Romaniello SJ, Cui H, Meyer M, Gilleaudeau GJ, Kaufman AJ, Anbar AD. Extensive marine anoxia during the terminal Ediacaran Period. Sci Adv 2018; 4:eaan8983. [PMID: 29938217 PMCID: PMC6010336 DOI: 10.1126/sciadv.aan8983] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 05/07/2018] [Indexed: 05/29/2023]
Abstract
The terminal Ediacaran Period witnessed the decline of the Ediacara biota (which may have included many stem-group animals). To test whether oceanic anoxia might have played a role in this evolutionary event, we measured U isotope compositions (δ238U) in sedimentary carbonates from the Dengying Formation of South China to obtain new constraints on the extent of global redox change during the terminal Ediacaran. We found the most negative carbonate δ238U values yet reported (-0.95 per mil), which were reproduced in two widely spaced coeval sections spanning the terminal Ediacaran Period (551 to 541 million years ago). Mass balance modeling indicates an episode of extensive oceanic anoxia, during which anoxia covered >21% of the seafloor and most U entering the oceans was removed into sediments below anoxic waters. The results suggest that an expansion of oceanic anoxia and temporal-spatial redox heterogeneity, independent of other environmental and ecological factors, may have contributed to the decline of the Ediacara biota and may have also stimulated animal motility.
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Affiliation(s)
- Feifei Zhang
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
| | - Shuhai Xiao
- Department of Geosciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Brian Kendall
- Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Stephen J. Romaniello
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
| | - Huan Cui
- Department of Geoscience and NASA Astrobiology Institute, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mike Meyer
- Carnegie Institution for Science, Washington, DC 20005, USA
| | | | - Alan J. Kaufman
- Geology Department and Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20742, USA
| | - Ariel D. Anbar
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
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