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  • 1
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    Tracing the stepwise oxygenation of the Proterozoic ocean (2008)
    Nature Publishing Group (NPG)
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    Publication Date: 2008-03-28
    Description: Biogeochemical signatures preserved in ancient sedimentary rocks provide clues to the nature and timing of the oxygenation of the Earth's atmosphere. Geochemical data 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 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. 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. 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Scott, C -- Lyons, T W -- Bekker, A -- Shen, Y -- Poulton, S W -- Chu, X -- Anbar, A D -- England -- Nature. 2008 Mar 27;452(7186):456-9. doi: 10.1038/nature06811.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth Sciences, University of California, Riverside, California 92521, USA. cscot002@ucr.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18368114" target="_blank"〉PubMed〈/a〉
    Keywords: Atmosphere/chemistry ; Geologic Sediments/chemistry ; History, Ancient ; Molybdenum/analysis ; Oceans and Seas ; Oxygen/*analysis/chemistry ; Seawater/*chemistry ; Sulfides/chemistry ; Time Factors
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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  • 2
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    Ocean science. Ironing out ocean chemistry at the dawn of animal life (2008)
    American Association for the Advancement of Science (AAAS)
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    Publication Date: 2008-08-16
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lyons, Timothy W -- New York, N.Y. -- Science. 2008 Aug 15;321(5891):923-4. doi: 10.1126/science.1162870.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth Sciences, University of California, Riverside, CA 92521, USA. timothy.lyons@ucr.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18703731" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Atmosphere ; Biological Evolution ; Geologic Sediments/chemistry ; Hydrogen Sulfide/analysis ; Ice Cover ; Iron/*analysis ; Oceans and Seas ; Oxygen/*analysis ; Seawater/*chemistry ; Sulfates/analysis ; Sulfides/analysis ; Time
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 3
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    A stratified redox model for the Ediacaran ocean (2010)
    American Association for the Advancement of Science (AAAS)
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    Publication Date: 2010-02-13
    Description: The Ediacaran Period (635 to 542 million years ago) was a time of fundamental environmental and evolutionary change, culminating in the first appearance of macroscopic animals. Here, we present a detailed spatial and temporal record of Ediacaran ocean chemistry for the Doushantuo Formation in the Nanhua Basin, South China. We find evidence for a metastable zone of euxinic (anoxic and sulfidic) waters impinging on the continental shelf and sandwiched within ferruginous [Fe(II)-enriched] deep waters. A stratified ocean with coeval oxic, sulfidic, and ferruginous zones, favored by overall low oceanic sulfate concentrations, was maintained dynamically throughout the Ediacaran Period. Our model reconciles seemingly conflicting geochemical redox conditions proposed previously for Ediacaran deep oceans and helps to explain the patchy temporal record of early metazoan fossils.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Li, Chao -- Love, Gordon D -- Lyons, Timothy W -- Fike, David A -- Sessions, Alex L -- Chu, Xuelei -- New York, N.Y. -- Science. 2010 Apr 2;328(5974):80-3. doi: 10.1126/science.1182369. Epub 2010 Feb 11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth Sciences, University of California, Riverside, CA 92521, USA. chaoli@ucr.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20150442" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Biological Evolution ; Carbonates/analysis ; China ; Ferrous Compounds/analysis ; *Fossils ; Geologic Sediments/*chemistry ; Hydrogen Sulfide ; Iron ; Oceans and Seas ; Oxidation-Reduction ; Oxygen/*analysis ; Seawater/*chemistry ; Sulfates/analysis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 4
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    Geochemical evidence for widespread euxinia in the later Cambrian ocean (2011)
    Nature Publishing Group (NPG)
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    Publication Date: 2011-01-07
    Description: Widespread anoxia in the ocean is frequently invoked as a primary driver of mass extinction as well as a long-term inhibitor of evolutionary radiation on early Earth. In recent biogeochemical studies it has been hypothesized that oxygen deficiency was widespread in subsurface water masses of later Cambrian oceans, possibly influencing evolutionary events during this time. Physical evidence of widespread anoxia in Cambrian oceans has remained elusive and thus its potential relationship to the palaeontological record remains largely unexplored. Here we present sulphur isotope records from six globally distributed stratigraphic sections of later Cambrian marine rocks (about 499 million years old). We find a positive sulphur isotope excursion in phase with the Steptoean Positive Carbon Isotope Excursion (SPICE), a large and rapid excursion in the marine carbon isotope record, which is thought to be indicative of a global carbon cycle perturbation. Numerical box modelling of the paired carbon sulphur isotope data indicates that these isotope shifts reflect transient increases in the burial of organic carbon and pyrite sulphur in sediments deposited under large-scale anoxic and sulphidic (euxinic) conditions. Independently, molybdenum abundances in a coeval black shale point convincingly to the transient spread of anoxia. These results identify the SPICE interval as the best characterized ocean anoxic event in the pre-Mesozoic ocean and an extreme example of oxygen deficiency in the later Cambrian ocean. Thus, a redox structure similar to those in Proterozoic oceans may have persisted or returned in the oceans of the early Phanerozoic eon. Indeed, the environmental challenges presented by widespread anoxia may have been a prevalent if not dominant influence on animal evolution in Cambrian oceans.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gill, Benjamin C -- Lyons, Timothy W -- Young, Seth A -- Kump, Lee R -- Knoll, Andrew H -- Saltzman, Matthew R -- England -- Nature. 2011 Jan 6;469(7328):80-3. doi: 10.1038/nature09700.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth Sciences, University of California, 900 University Avenue, Riverside, California 92521, USA. bgill@fas.harvard.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21209662" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biological Evolution ; Carbon Cycle ; Carbon Isotopes/analysis ; Carbonates/analysis ; Extinction, Biological ; Fossils ; Geologic Sediments/*chemistry ; History, Ancient ; Iron/analysis/chemistry ; Molybdenum/analysis/chemistry ; Oceans and Seas ; Oxidation-Reduction ; Oxygen/*analysis ; Seawater/*chemistry ; Sulfides/*analysis/chemistry ; Sulfur Isotopes/analysis ; Sweden
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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  • 5
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    The rise of oxygen in Earth's early ocean and atmosphere (2014)
    Nature Publishing Group (NPG)
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    Publication Date: 2014-02-21
    Description: The rapid increase of carbon dioxide concentration in Earth's modern atmosphere is a matter of major concern. But for the atmosphere of roughly two-and-half billion years ago, interest centres on a different gas: free oxygen (O2) spawned by early biological production. The initial increase of O2 in the atmosphere, its delayed build-up in the ocean, its increase to near-modern levels in the sea and air two billion years later, and its cause-and-effect relationship with life are among the most compelling stories in Earth's history.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lyons, Timothy W -- Reinhard, Christopher T -- Planavsky, Noah J -- England -- Nature. 2014 Feb 20;506(7488):307-15. doi: 10.1038/nature13068.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth Sciences, University of California, Riverside, California 92521, USA. ; 1] Department of Earth Sciences, University of California, Riverside, California 92521, USA [2] Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA [3] School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA. ; 1] Department of Earth Sciences, University of California, Riverside, California 92521, USA [2] Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06511, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24553238" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Atmosphere/*chemistry ; *Earth (Planet) ; *Evolution, Chemical ; History, Ancient ; Life ; Oxygen/analysis/history/*metabolism ; Photosynthesis ; Seawater/*chemistry
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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  • 6
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    Widespread iron-rich conditions in the mid-Proterozoic ocean (2011)
    Nature Publishing Group (NPG)
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    Publication Date: 2011-09-09
    Description: The chemical composition of the ocean changed markedly with the oxidation of the Earth's surface, and this process has profoundly influenced the evolutionary and ecological history of life. The early Earth was characterized by a reducing ocean-atmosphere system, whereas the Phanerozoic eon (less than 542 million years ago) is known for a stable and oxygenated biosphere conducive to the radiation of animals. The redox characteristics of surface environments during Earth's middle age (1.8-1 billion years ago) are less well known, but it is generally assumed that the mid-Proterozoic was home to a globally sulphidic (euxinic) deep ocean. Here we present iron data from a suite of mid-Proterozoic marine mudstones. Contrary to the popular model, our results indicate that ferruginous (anoxic and Fe(2+)-rich) conditions were both spatially and temporally extensive across diverse palaeogeographic settings in the mid-Proterozoic ocean, inviting new models for the temporal distribution of iron formations and the availability of bioessential trace elements during a critical window for eukaryotic evolution.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Planavsky, Noah J -- McGoldrick, Peter -- Scott, Clinton T -- Li, Chao -- Reinhard, Christopher T -- Kelly, Amy E -- Chu, Xuelei -- Bekker, Andrey -- Love, Gordon D -- Lyons, Timothy W -- England -- Nature. 2011 Sep 7;477(7365):448-51. doi: 10.1038/nature10327.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth Sciences, University of California, Riverside, California 92521, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21900895" target="_blank"〉PubMed〈/a〉
    Keywords: Biological Evolution ; Geologic Sediments/chemistry ; History, Ancient ; Iron/*analysis/chemistry ; Oceans and Seas ; Seawater/*chemistry ; Sulfur/analysis/chemistry ; Sulfur Isotopes ; Time Factors
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 7
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    Ocean oxygenation in the wake of the Marinoan glaciation (2012)
    Nature Publishing Group (NPG)
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    Publication Date: 2012-09-29
    Description: Metazoans are likely to have their roots in the Cryogenian period, but there is a marked increase in the appearance of novel animal and algae fossils shortly after the termination of the late Cryogenian (Marinoan) glaciation about 635 million years ago. It has been suggested that an oxygenation event in the wake of the severe Marinoan glaciation was the driving factor behind this early diversification of metazoans and the shift in ecosystem complexity. But there is little evidence for an increase in oceanic or atmospheric oxygen following the Marinoan glaciation, or for a direct link between early animal evolution and redox conditions in general. Models linking trends in early biological evolution to shifts in Earth system processes thus remain controversial. Here we report geochemical data from early Ediacaran organic-rich black shales ( approximately 635-630 million years old) of the basal Doushantuo Formation in South China. High enrichments of molybdenum and vanadium and low pyrite sulphur isotope values (Delta(34)S values 〉/=65 per mil) in these shales record expansion of the oceanic inventory of redox-sensitive metals and the growth of the marine sulphate reservoir in response to a widely oxygenated ocean. The data provide evidence for an early Ediacaran oxygenation event, which pre-dates the previous estimates for post-Marinoan oxygenation by more than 50 million years. Our findings seem to support a link between the most severe glaciations in Earth's history, the oxygenation of the Earth's surface environments, and the earliest diversification of animals.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sahoo, Swapan K -- Planavsky, Noah J -- Kendall, Brian -- Wang, Xinqiang -- Shi, Xiaoying -- Scott, Clint -- Anbar, Ariel D -- Lyons, Timothy W -- Jiang, Ganqing -- England -- Nature. 2012 Sep 27;489(7417):546-9. doi: 10.1038/nature11445.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geoscience, University of Nevada, Las Vegas, Nevada 89154, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23018964" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Atmosphere/chemistry ; Biodiversity ; *Biological Evolution ; China ; Fossils ; Geologic Sediments/chemistry ; History, Ancient ; *Ice Cover ; Iron/analysis/chemistry ; Molybdenum/analysis ; Oceans and Seas ; Oxidation-Reduction ; Oxygen/*analysis/metabolism ; Seawater/*chemistry ; Sulfides/analysis/chemistry ; Sulfur Isotopes ; Trace Elements/analysis/chemistry ; Vanadium/analysis
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Published by Nature Publishing Group (NPG)
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