Stepwise oxygenation of early Cambrian ocean controls early metazoan diversification
Stepwise oxygenation of early Cambrian ocean controls early metazoan diversification
复制标题
早寒武世海洋的逐步氧化控制了早期后生动物的多样化
DOI：
10.1016/j.palaeo.2018.05.009
复制
发表时间：
2018-09
期刊：
影响因子：
--
通讯作者：
Shi Qing
中科院分区：
文献类型：
--
作者：
Zhao Xiangkuan;Wang Xinqiang;Shi Xiaoying;Tang Dongjie;Shi Qing
埃迪卡拉-寒武纪过渡期是地球历史上的一个关键时期，在此期间，海洋环境和生物都经历了剧烈的变化。有人认为，海洋中普遍存在的氧化作用和相关的化学变化可能引发了早期寒武纪后生动物的快速多样化。然而，海洋氧化的时间和过程并没有得到很好的限制。本文对湘西四都坪地区下寒武统牛蹄塘组进行了综合研究。利用ICP-MS、元素分析仪、FESEM、EDS和XRD等技术，系统研究了黄铁矿中氧化还原敏感元素的丰度、分布规律、黄铁矿形貌、总有机碳（TOC）、总硫（TS）、黄铁矿硫（SPY）以及N、P含量。结果表明，在NTT沉积过程中，研究区底层海水经历了复杂的演化过程，经历了3个富铁和3个富氧的动态交替，仅在寒武纪第3期晚期出现了缺氧-好氧状态。与扬子地台其他相带相关剖面的对比表明，海水充氧是一个由浅水区向深水区扩展的渐进过程。浅水台地区在晚寒武世第2阶段开始氧化，陆棚边缘区在晚寒武世第3阶段开始氧化，深水盆地直到晚寒武世第3阶段才开始富铁。沉积物Mo/TOC，U/TOC的比例增加，从底部到顶部的部分，再加上升高的Mn，N和P的长期趋势，可能表明海水充氧的整体增强。随着时间的推移，长江地台主要化石群的时空分布和古生态复杂性的增加与海水充氧过程相吻合，这可能意味着海洋充氧增加和富氧海水减少推动了早寒武世后生动物的快速多样化。
The Ediacaran–Cambrian transition is a critical period in Earth history, during which both marine environment and life experienced drastic changes. It was suggested that pervasive oxygenation and associated chemical changes in the ocean have potentially triggered the rapid diversification of early Cambrian metazoans. The timing and process of ocean oxygenation, however, have not been well constrained. In this paper, an integrated study was conducted on the lower Cambrian Niutitang (NTT) Formation in Siduping area, western Hunan, which was paleogeographically located at shelf margin–upper slope setting of the Yangtze Platform. Using ICP-MS, Element Analyzer, FESEM, EDS and XRD techniques, the abundance of RSEs (redox sensitive elements), patterns of RSEs distribution, pyrite morphology, TOC (total organic carbon), TS (total sulfur), SPY(pyrite sulfur) as well as N and P contents were investigated systematically. The results show that during the NTT deposition, bottom seawater in the study area experienced a complicated evolution, with a dynamic alternation of three ferruginous and three euxinic intervals, and suboxic–oxic conditions occurring only in the latest Cambrian Stage 3. Comparison with relevant sections reported previously from other facies belts within the Yangtze Platform shows that the seawater oxygenation was a progressive process expanding from shallow to deep-water areas in time. Shallow-water platform area became oxygenated in the late Cambrian Stage 2, shelf margin area in the late Cambrian Stage 3, and the deep-water basin remained ferruginous until the latest Cambrian Stage 3, when it became euxinic. Sediment Mo/TOC, U/TOC ratios increased from bottom to top in the section, coupled with elevated Mn, N and P secular trends, likely indicating an overall enhancement of seawater oxygenation. The spatial-temporal distribution and increased paleoecologic complexity of major fossil groups on the Yangtze Platform over time coincide with the seawater oxygenation process, likely implying that increased ocean oxygenation and declining euxinic seawaters have driven the rapid diversification of early Cambrian metazoans.
登录
查看更多内容
影响因子：
1.8
作者：
Lina Zhai;Chaodong Wu;Y. Ye;Shuichang Zhang;Zhengze An
通讯作者：
Lina Zhai;Chaodong Wu;Y. Ye;Shuichang Zhang;Zhengze An
动态弱生中深水背景下的海洋钼生物地球化学：以华南下寒武统牛蹄塘页岩为例
DOI：
10.1016/j.gca.2016.03.035
发表时间：
2016-06
期刊：
Geochemica et Cosmochimica Acta
影响因子：
--
作者：
Meng Cheng;Chao Li;Lian Zhou;Thomas Algeo;Feifei Zhang;Stephen Romaniello;Cheng-Sheng Jin;Li-Dan Lei;Lian-Jun Feng;Shao-Yong Jiang
通讯作者：
Shao-Yong Jiang
追踪元古代海洋的逐步氧化过程
影响因子：
64.8
作者：
Scott, C.;Lyons, T. W.;Anbar, A. D.
通讯作者：
Anbar, A. D.
影响因子：
5
作者：
H. Wen;H. Fan;Yuxu Zhang;C. Cloquet;J. Carignan
通讯作者：
H. Wen;H. Fan;Yuxu Zhang;C. Cloquet;J. Carignan
DOI：
10.1016/j.palaeo.2004.10.009
发表时间：
2005-02
期刊：
Palaeogeography, Palaeoclimatology, Palaeoecology
影响因子：
--
作者：
P. Wignall;R. Newton;M. Brookfield
通讯作者：
P. Wignall;R. Newton;M. Brookfield