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DOI	10.1073/pnas.2107511118
	Mercury abundance and isotopic composition indicate subaerial volcanism prior to the end-Archean “whiff” of oxygen
	Meixnerová J.; Blum J.D.; Johnson M.W.; Stüeken E.E.; Kipp M.A.; Anbar A.D.; Buick R.
发表日期	2021
ISSN	0027-8424
卷号	118 期号:33
英文摘要	Earth’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. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Archean; Atmospheric oxygenation; Mercury isotopes
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/238438
作者单位	Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195-1310, United States; Astrobiology Program, University of Washington, Seattle, WA 98195-1310, United States; Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, United States; School of Earth and Environmental Sciences, University of St. Andrews, St. Andrews, KY16 9AL, United Kingdom; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; School of Earth and Space Exploration and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, United States
推荐引用方式 GB/T 7714	Meixnerová J.,Blum J.D.,Johnson M.W.,等. Mercury abundance and isotopic composition indicate subaerial volcanism prior to the end-Archean “whiff” of oxygen[J],2021,118(33).
APA	Meixnerová J..,Blum J.D..,Johnson M.W..,Stüeken E.E..,Kipp M.A..,...&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,118(33).
MLA	Meixnerová J.,et al."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 118.33(2021).