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Dodd MS, Shi W, Li C, Zhang Z, Cheng M, Gu H, Hardisty DS, Loyd SJ, Wallace MW, vS Hood A, Lamothe K, Mills BJW, Poulton SW, Lyons TW. Uncovering the Ediacaran phosphorus cycle. Nature 2023:10.1038/s41586-023-06077-6. [PMID: 37258677 DOI: 10.1038/s41586-023-06077-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 04/12/2023] [Indexed: 06/02/2023]
Abstract
Phosphorus is a limiting nutrient that is thought to control oceanic oxygen levels to a large extent1-3. A possible increase in marine phosphorus concentrations during the Ediacaran Period (about 635-539 million years ago) has been proposed as a driver for increasing oxygen levels4-6. However, little is known about the nature and evolution of phosphorus cycling during this time4. Here we use carbonate-associated phosphate (CAP) from six globally distributed sections to reconstruct oceanic phosphorus concentrations during a large negative carbon-isotope excursion-the Shuram excursion (SE)-which co-occurred with global oceanic oxygenation7-9. Our data suggest pulsed increases in oceanic phosphorus concentrations during the falling and rising limbs of the SE. Using a quantitative biogeochemical model, we propose that this observation could be explained by carbon dioxide and phosphorus release from marine organic-matter oxidation primarily by sulfate, with further phosphorus release from carbon-dioxide-driven weathering on land. Collectively, this may have resulted in elevated organic-pyrite burial and ocean oxygenation. Our CAP data also seem to suggest equivalent oceanic phosphorus concentrations under maximum and minimum extents of ocean anoxia across the SE. This observation may reflect decoupled phosphorus and ocean anoxia cycles, as opposed to their coupled nature in the modern ocean. Our findings point to external stimuli such as sulfate weathering rather than internal oceanic phosphorus-oxygen cycling alone as a possible control on oceanic oxygenation in the Ediacaran. In turn, this may help explain the prolonged rise of atmospheric oxygen levels.
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Affiliation(s)
- Matthew S Dodd
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu, China
- School of Earth Sciences, University of Western Australia, Perth, Western Australia, Australia
- Forrest Research Foundation, Perth, Western Australia, Australia
| | - Wei Shi
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu, China
| | - Chao Li
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China.
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China.
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu, China.
| | - Zihu Zhang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu, China
| | - Meng Cheng
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu, China
| | - Haodong Gu
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Dalton S Hardisty
- Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI, USA
| | - Sean J Loyd
- Department of Geological Sciences, California State University, Fullerton, CA, USA
| | - Malcolm W Wallace
- School of Geography, Earth and Atmospheric Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Ashleigh vS Hood
- School of Geography, Earth and Atmospheric Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Kelsey Lamothe
- School of Geography, Earth and Atmospheric Sciences, University of Melbourne, Parkville, Victoria, Australia
| | | | - Simon W Poulton
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Timothy W Lyons
- Department of Earth and Planetary Sciences, University of California, Riverside, Riverside, CA, USA
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