Onset of coupled atmosphere-ocean oxygenation 2.3 billion years ago

• 成果类型: Article
• 署名作者: Ostrander, Chadlin M.; Heard, Andy W.; Shu, Yunchao; Bekker, Andrey; Poulton, Simon W.; Olesen, Kasper P.; Nielsen, Sune G.
• 署名单位: Utah System of Higher Education; University of Utah; Woods Hole Oceanographic Institution; Woods Hole Oceanographic Institution; Woods Hole Oceanographic Institution; University of California System; University of California Riverside; University of Johannesburg; University of Leeds; University of Southern Denmark; Centre National de la Recherche Scientifique (CNRS); Universite de Lorraine
• 刊物名称: Nature
• ISSN/ISSBN: 0028-5906
• DOI: 10.1038/s41586-024-07551-5
• 发表日期: 2024-07-11
• 页码: 335-+
• 关键词: timeball hill formation; great oxidation event; isotopic compositions; transvaal supergroup; snowball earth; thallium; rise; sediments; uranium; fractionation

摘要

The initial rise of molecular oxygen (O-2) shortly after the Archaean-Proterozoic transition 2.5 billion years ago was more complex than the single step-change once envisioned. Sulfur mass-independent fractionation records suggest that the rise of atmospheric O-2 was oscillatory, with multiple returns to an anoxic state until perhaps 2.2 billion years ago(1-3). Yet few constraints exist for contemporaneous marine oxygenation dynamics, precluding a holistic understanding of planetary oxygenation. Here we report thallium (Tl) isotope ratio and redox-sensitive element data for marine shales from the Transvaal Supergroup, South Africa. Synchronous with sulfur isotope evidence of atmospheric oxygenation in the same shales(3), we found lower authigenic Tl-205/Tl-203 ratios indicative of widespread manganese oxide burial on an oxygenated seafloor and higher redox-sensitive element abundances consistent with expanded oxygenated waters. Both signatures disappear when the sulfur isotope data indicate a brief return to an anoxic atmospheric state. Our data connect recently identified atmospheric O-2 dynamics on early Earth with the marine realm, marking an important turning point in Earth's redox history away from heterogeneous and highly localized 'oasis'-style oxygenation.