Geochemical evidence from bio-apatite for multiple oceanic anoxic events during Permian-Triassic transition and the link with end-Permian extinction and recovery
Geochemical evidence from bio-apatite for multiple oceanic anoxic events during Permian-Triassic transition and the link with end-Permian extinction and recovery
复制标题
二叠纪-三叠纪过渡期间多次海洋缺氧事件的生物磷灰石地球化学证据以及与二叠纪末灭绝和恢复的联系
DOI：
10.1016/j.epsl.2012.07.005
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发表时间：
2012-11-01
影响因子：
5.3
通讯作者：
Chen, Yanlong
中科院分区：
文献类型：
--
作者：
Song, Haijun;Wignall, Paul B.;Chen, Yanlong
利用牙形刺钠长石冠磷灰石的Ce异常(Omega Ce)和Th/U比值，建立了二叠纪至三叠纪(长兴期至卡尼期)20 MYR的详细氧化还原历史。结果表明，在牙形刺Omega Ce和Th/U数据中，忠实地记录了海洋强烈缺氧(与二叠纪末期大灭绝一致)这一公认的现象。延长牙形刺的氧化还原记录表明，二叠纪末期的缺氧可能持续到第二叠纪早期，早三叠世(最早的史密斯期-最早的斯巴斯蒂期和斯巴西期中期)也发生了两次强烈的海洋缺氧事件，随后在艾尼西期出现了较弱的缺氧表现，如Omega ce数据所示。二叠纪末期大灭绝之后的海洋底栖生物辐射，开始于史密斯期-最早的斯巴斯蒂亚缺氧事件之后，表明在此之前由于这些不利条件而导致的进化受到抑制。斯巴达中段的缺氧事件未能延缓演化的反弹，这意味着浅海陆架在这个时候仍然通风良好，即使海洋不是这样。早三叠世记录的其他属性也与氧化还原波动密切相关：缺氧强化阶段微生物碳酸盐的增殖和主要的负碳同位素摆动可归因于化跃层变浅导致碱度脉冲和光、再矿化碳和/或指示与来自西伯利亚火山来源的光C通量增加有关的触发机制。(C)2012爱思唯尔B.V.保留所有权利。
A detailed, 20 myr redox history of Permian to Triassic oceans (Changhsingian to Carnian stages) has been constructed using Ce-anomaly (Omega Ce) and Th/U ratios from conodont albid crown apatite material. The results show that the well-established phenomenon of intense ocean anoxia (coincident with the end-Permian mass extinction) is faithfully recorded in conodont Omega Ce and Th/U data. Extending this conodont redox record shows that end-Permian anoxia persisted possibly into the earliest Dienerian Stage and that two intense oceanic anoxic events also occurred later in the Early Triassic (earliest Smithian-earliest Spathian, and middle Spathian), followed by a weaker manifestation of anoxia in the Anisian Stage, seen in Omega Ce data. Marine benthic radiation, following the end-Permian mass extinction, began after the Smithian-earliest Spathian anoxic event suggesting a suppression of evolution prior to this due to these inimical conditions. The failure of the middle Spathian anoxic event to retard the evolutionary rebound implies shallow shelf seas remained well ventilated at this time even if the oceans did not. Other attributes of the Early Triassic record also closely coincide with redox fluctuations: phases of anoxia intensification saw the proliferation of microbial carbonates and major negative carbon isotope swings that can be attributed to chemocline shallowing causing alkalinity pulses and enrichment in light, remineralised carbon and/or indicate a trigger meachnaims related to increased fluxes of light C from Siberian volcanic sources. (C) 2012 Elsevier B.V. All rights reserved.