Tracing the stepwise oxygenation of the Proterozoic ocean

doi:10.1038/nature06811

	Tracing the stepwise oxygenation of the Proterozoic ocean
	Scott, C.1; Lyons, T. W.1; Bekker, A.2; Shen, Y.3; Poulton, S. W.4; Chu, X.5; Anbar, A. D.6,7
刊名	NATURE
	2008-03-27
卷号	452 期号:7186 页码:456-U5
ISSN号	0028-0836
DOI	10.1038/nature06811
文献子类	Article
英文摘要	Biogeochemical signatures preserved in ancient sedimentary rocks provide clues to the nature and timing of the oxygenation of the Earth's atmosphere. Geochemical data(1-6) suggest that oxygenation proceeded in two broad steps near the beginning and end of the Proterozoic eon ( 2,500 to 542 million years ago). The oxidation state of the Proterozoic ocean between these two steps and the timing of deep- ocean oxygenation have important implications for the evolutionary course of life on Earth but remain poorly known. Here we present a new perspective on ocean oxygenation based on the authigenic accumulation of the redox- sensitive transition element molybdenum in sulphidic black shales. Accumulation of authigenic molybdenum from sea water is already seen in shales by 2,650 Myr ago; however, the small magnitudes of these enrichments reflect weak or transient(7) sources of dissolved molybdenum before about 2,200 Myr ago, consistent with minimal oxidative weathering of the continents. Enrichments indicative of persistent and vigorous oxidative weathering appear in shales deposited at roughly 2,150 Myr ago, more than 200 million years after the initial rise in atmospheric oxygen(1,2). Subsequent expansion of sulphidic conditions after about 1,800 Myr ago ( refs 8, 9) maintained a mid- Proterozoic molybdenum reservoir below 20 per cent of the modern inventory, which in turn may have acted as a nutrient feedback limiting the spatiotemporal distribution of euxinic ( sulphidic) bottom waters and perhaps the evolutionary and ecological expansion of eukaryotic organisms(10). By 551 Myr ago, molybdenum contents reflect a greatly expanded oceanic reservoir due to oxygenation of the deep ocean and corresponding decrease in sulphidic conditions in the sediments and water column.
WOS关键词	ATMOSPHERIC OXYGEN ; SULFUR ; RISE ; IRON ; MOLYBDENUM ; EVOLUTION ; SEA ; CHEMISTRY ; ANOXIA ; BASIN
WOS研究方向	Science & Technology - Other Topics
语种	英语
出版者	NATURE PUBLISHING GROUP
WOS记录号	WOS:000254341300028
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/69652]
专题	中国科学院地质与地球物理研究所
通讯作者	Scott, C.
作者单位	1.Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA 2.Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA 3.Univ Quebec, Dept Sci Terre & Atmosphere, Montreal, PQ H3C 3P8, Canada 4.Univ Newcastle, Sch Civil Engn & Geosci, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England 5.Chinese Acad Sci, Key Lab Mineral Resources, Inst Geol & Geophys, Beijing 100029, Peoples R China 6.Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA 7.Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA
推荐引用方式 GB/T 7714	Scott, C.,Lyons, T. W.,Bekker, A.,et al. Tracing the stepwise oxygenation of the Proterozoic ocean[J]. NATURE,2008,452(7186):456-U5.
APA	Scott, C..,Lyons, T. W..,Bekker, A..,Shen, Y..,Poulton, S. W..,...&Anbar, A. D..(2008).Tracing the stepwise oxygenation of the Proterozoic ocean.NATURE,452(7186),456-U5.
MLA	Scott, C.,et al."Tracing the stepwise oxygenation of the Proterozoic ocean".NATURE 452.7186(2008):456-U5.