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dc.contributor.authorMeixnerová, Jana
dc.contributor.authorBlum, Joel D.
dc.contributor.authorJohnson, Marcus W.
dc.contributor.authorStüeken, Eva E.
dc.contributor.authorKipp, Michael A.
dc.contributor.authorAnbar, Ariel D.
dc.contributor.authorBuick, Roger
dc.identifier.citationMeixnerová , J , Blum , J D , Johnson , M W , Stüeken , E E , Kipp , M A , Anbar , A D & Buick , R 2021 , ' Mercury abundance and isotopic composition indicate subaerial volcanism prior to the end-Archean “whiff” of oxygen ' , Proceedings of the National Academy of Sciences of the United States of America , vol. 118 , no. 33 , e2107511118 .
dc.identifier.otherRIS: urn:7632DDBE662D279FA933D45842366B6E
dc.identifier.otherORCID: /0000-0001-6861-2490/work/99116216
dc.descriptionFunding: This study was supported by National Aeronautics and Space Administration Exobiology Grant NNX16AI37G (R.B.) and by the MacArthur Professorship (J.D.B.) at the University of Michigan. M.A.K. acknowledges support from an Agouron Institute postdoctoral fellowship.en
dc.description.abstractEarth’s early atmosphere witnessed multiple transient episodes of oxygenation before the Great Oxidation Event 2.4 billion years ago (Ga) [e.g., A. D. Anbar et al., Science 317, 1903–1906 (2007); M. C. Koehler, R. Buick, M. E. Barley, Precambrian Res. 320, 281–290 (2019)], but the triggers for these short-lived events are so far unknown. Here, we use mercury (Hg) abundance and stable isotope composition to investigate atmospheric evolution and its driving mechanisms across the well-studied “whiff” of O2 recorded in the ∼2.5-Ga Mt. McRae Shale from the Pilbara Craton in Western Australia [A. D. Anbar et al., Science 317, 1903–1906 (2007)]. Our data from the oxygenated interval show strong Hg enrichment paired with slightly negative Δ199Hg and near-zero Δ200Hg, suggestive of increased oxidative weathering. In contrast, slightly older beds, which were evidently deposited under an anoxic atmosphere in ferruginous waters [C. T. Reinhard, R. Raiswell, C. Scott, A. D. Anbar, T. W. Lyons, Science 326, 713–716 (2009)], show Hg enrichment coupled with positive Δ199Hg and slightly negative Δ200Hg values. This pattern is consistent with photochemical reactions associated with subaerial volcanism under intense UV radiation. Our results therefore suggest that the whiff of O2 was preceded by subaerial volcanism. The transient interval of O2 accumulation may thus have been triggered by diminished volcanic O2 sinks, followed by enhanced nutrient supply to the ocean from weathering of volcanic rocks causing increased biological productivity.
dc.relation.ispartofProceedings of the National Academy of Sciences of the United States of Americaen
dc.subjectAtmospheric oxygenationen
dc.subjectMercury isotopesen
dc.subjectGE Environmental Sciencesen
dc.titleMercury abundance and isotopic composition indicate subaerial volcanism prior to the end-Archean “whiff” of oxygenen
dc.typeJournal articleen
dc.contributor.institutionUniversity of St Andrews. School of Earth & Environmental Sciencesen
dc.contributor.institutionUniversity of St Andrews. St Andrews Centre for Exoplanet Scienceen
dc.description.statusPeer revieweden

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