Was the Ediacaran Shuram Excursion a globally synchronized early diagenetic event? Insights from methane-derived authigenic carbonates in the uppermost Doushantuo Formation, South China
文献类型：期刊论文
| 作者 | Cui, H (Cui, Huan); Kaufman, AJ; Xiao, SH; Zhou, CM (周传明） ; Liu, XM
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| 刊名 | Chemical Geology
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| 出版日期 | 2017 |
| 卷号 | 450页码:59-80 |
| 关键词 | Shuram Excursion Authigenic carbonate Early diagenesis Ediacaran Period Sulfate-Methane Transition Zone (SMTZ) Anaerobic Oxidation of Methane (AOM) Neoproterozoic Oxygenation Event (NOE) delta C-13 and delta O-18 co-variation |
| ISSN号 | 0009-2541 |
| DOI | 10.1016/j.chemgeo.2016.12.010 |
| 英文摘要 | The Ediacaran Period is characterized by the most profound negative carbon isotope (delta C-13) excursion in Earth history, the Shuram Excursion. Various hypotheses - including the massive oxidation of dissolved organic carbon (DOC) in the oceans, the weathering of terrestrial organic carbon, or the release and oxidation of methane hydrates and/or expelled petroleum from the subsurface - have been proposed as sources of the C-13-depleted carbon. More recently, it has been suggested that global-scale precipitation of early authigenic carbonates, driven by anaerobic microbial metabolism in unconsolidated sediments, may have caused the Shuram Excursion, but empirical evidence is lacking. Here we present a comprehensive analysis of a Shuram-associated interval from the uppermost Doushantuo Formation in South China. Our study reveals petrographic evidence of methane-derived authigenic calcite (formed as early diagenetic cements and nodules) that are remarkably depleted in C-13- suggesting a buildup of alkalinity in pore fluids through the anaerobic oxidation of methane (AOM) - and systematically depleted in O-18 relative to co-occurring dolomite. Early authigenesis of these minerals is likely to be driven by increased microbial sulfate reduction, triggered by enhanced continental weathering in the context of a marked rise in atmospheric oxygen levels. In light of the finding of methane-derived authigenic carbonates at Zhongling, and based on our basin-scale stratigraphic correlation, we hypothesize that the marked C-13 and O-18 depletion (including their co-variation noted worldwide) in the Shuram Excursion may reflect an episode of authigenesis occurring within a sulfate-methane transition zone (SMTZ). If true, the Shuram Excursion was then a global biogeochemical response to enhanced seawater sulfate concentration in the Ediacaran ocean driven by the Neoproterozoic oxidation of surface environments. This paleo-oceanographic transition may have therefore paved the way for subsequent evolution and diversification of animals. Our study highlights the significance of an integrated approach that combines petrography, mineralogy, and texture-specific micro-drilling geochemistry in chemostratigraphic studies. (C) 2016 Elsevier B.V. All rights reserved. |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000394473600005 |
| 出版者 | ELSEVIER SCIENCE BV |
| 源URL | [http://ir.nigpas.ac.cn/handle/332004/13712]  |
| 专题 | 中国科学院南京地质古生物研究所 南京地质古生物研究所_其他 |
| 通讯作者 | Cui, H (Cui, Huan) |
| 推荐引用方式 GB/T 7714 | Cui, H ,Kaufman, AJ,Xiao, SH,et al. Was the Ediacaran Shuram Excursion a globally synchronized early diagenetic event? Insights from methane-derived authigenic carbonates in the uppermost Doushantuo Formation, South China[J]. Chemical Geology,2017,450:59-80. |
| APA | Cui, H ,Kaufman, AJ,Xiao, SH,Zhou, CM ,&Liu, XM.(2017).Was the Ediacaran Shuram Excursion a globally synchronized early diagenetic event? Insights from methane-derived authigenic carbonates in the uppermost Doushantuo Formation, South China.Chemical Geology,450,59-80. |
| MLA | Cui, H ,et al."Was the Ediacaran Shuram Excursion a globally synchronized early diagenetic event? Insights from methane-derived authigenic carbonates in the uppermost Doushantuo Formation, South China".Chemical Geology 450(2017):59-80. |
入库方式： OAI收割
来源：南京地质古生物研究所
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