Transient surface ocean oxygenation recorded in the ∼2.66-Ga Jeerinah Formation, Australia

• DOI: 10.1073/pnas.1720820115
• Publication Date: 2018-07-09T19:16:35Z
• Authors: Matthew C. Koehler; Roger Buick; Michael A. Kipp; Eva E. Stüeken; Jonathan Zaloumis
• Keywords: Biogeochemical Cycle

Significance Understanding how and when Earth’s surface became oxygenated is essential for understanding its biogeochemical evolution. Incipient oxygenation of environments before the Great Oxidation Event (GOE; ∼2.4 Ga) has been well-documented, but nature these redox changes, whether protracted or transient, poorly understood. We present nitrogen isotope ratios, selenium abundances, ratios from Jeerinah Formation (∼2.66 Ga; Fortescue Group, Western Australia) that represent ( i ) high-resolution evidence transient ocean ∼260 My GOE, ii a possible muted pulse oxidative continental weathering, iii oldest firm nitrification denitrification metabolisms. These results, in concert with previous studies, highlight variability mechanisms magnitudes Neoarchean oxygen fluctuations.