Nitrogen isotope ratios and selenium abundances from a 2.66 billion-year-old formation of primarily black shale in Western Australia indicate transient surface ocean oxygenation around 260 million years before the Great Oxidation Event, suggest oxidative weathering of sulfide minerals from land, and provide evidence of ancient nitrification and denitrification metabolism, findings highlighting the variability of oxygen concentration in the early atmosphere.
Article #17-20820: "Transient surface ocean oxygenation recorded in the ?2.66-Ga Jeerinah Formation, Australia," by Matthew C. Koehler, Roger Buick, Michael A. Kipp, Eva E. Stueken, and Jonathan Zaloumis.
MEDIA CONTACT: Matthew C. Koehler, University of Washington, Seattle, WA; tel: 207-468-0038; e-mail: <koehlerm@uw.edu>
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