Dating the evolution of oxygenic photosynthesis using La-Ce geochronology

• 成果类型: Article
• 署名作者: Patry, Laureline A.; Bonnand, Pierre; Boyet, Maud; Afroz, Munira; Wilmeth, Dylan T.; Ramsay, Brittany; Nonnotte, Philippe; Homann, Martin; Sansjofre, Pierre; Fralick, Philip W.; Lalonde, Stefan V.
• 署名单位: Centre National de la Recherche Scientifique (CNRS); Ifremer; Universite de Bretagne Occidentale; Institut Universitaire Europeen de la Mer (IUEM); Universite Clermont Auvergne (UCA); Centre National de la Recherche Scientifique (CNRS); Lakehead University; University of London; University College London; Museum National d'Histoire Naturelle (MNHN); Universite Paris Cite; Sorbonne Universite; Grand Valley State University; Queens University - Canada
• 刊物名称: Nature
• ISSN/ISSBN: 0028-1333
• DOI: 10.1038/s41586-025-09009-8
• 发表日期: 2025-06-05
• 关键词: rare-earth-elements; isotope measurements; carbonate platform; iron-formation; oxidation; geochemistry; sedimentology; yttrium; fractionation; supergroup

摘要

There is ongoing debate as to when oxygenic photosynthesis evolved on Earth1,2. Geochemical data from ancient sediments indicate localized or ephemeral photosynthetic O2 production before the Great Oxidation Event (GOE) approximately 2.5-2.3 billion years ago (Ga), and currently suggest Archaean origins, approximately 3 Ga or earlier3, 4, 5, 6, 7, 8-9. However, sedimentary records of the early Earth often suffer from preservation issues, and poor control on the timing of oxidation leaves geochemical proxy data for the ancient presence of O2 open to critique10, 11, 12-13. Here, we report rare Earth element data from three different Archaean carbonate platforms preserved in greenstone belts of the northwest Superior Craton (Canada), which were deposited by the activity of marine photosynthetic bacteria 2.87 Ga, 2.85 Ga and 2.78 Ga. All three indicate O2 production before the GOE in the form of significant depletions in cerium (Ce), reflecting oxidative Ce removal from ancient seawater, as occurs today14. Using 138La-138Ce geochronology, we show that La/Ce fractionation, and thus Ce oxidation, occurred at the time of deposition, making these the oldest directly dated Ce anomalies. These results place the origin of oxygenic photosynthesis in the Mesoarchaean or earlier and bring an important new perspective on a long-standing debate regarding Earth's biological and geochemical evolution.