Dynamic anoxic ferruginous conditions during the end-Permian mass extinction and recovery.
Dynamic anoxic ferruginous conditions during the end-Permian mass extinction and recovery.
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DOI：
10.1038/ncomms12236
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发表时间：
2016-07-19
影响因子：
16.6
通讯作者：
Krystyn L
中科院分区：
文献类型：
--
作者：
Clarkson MO;Wood RA;Poulton SW;Richoz S;Newton RJ;Kasemann SA;Bowyer F;Krystyn L
二叠纪末的大规模灭绝发生在2.52亿年前，值得注意的是一个复杂的恢复期为2.55亿年。广泛的缺氧（缺氧和硫化物）的海洋条件已被提出的灭绝机制和解释的长期恢复期，但缺氧的垂直分布在水柱和它的时间动态，通过这段时间内的约束不足。在这里，我们利用Fe-S-C系统学与古生物学观察相结合，重建一个完整的海洋氧化还原历史的晚二叠世至早三叠世，使用多个部分横跨货架盆地断面的阿拉伯边缘（新特提斯洋）。与其他地方相比，我们表明，缺氧非硫化物（含铁），而不是euxinic，条件普遍存在于新特提斯。阿拉伯边缘的记录表明，铁质条件的反复扩张，远坡是这些时候缺氧的焦点，以及支持不同生物群的短暂缺氧事件。 海洋缺氧被认为是推动二叠纪-三叠纪大灭绝的原因，但对时间、分布和化学状态知之甚少。在这里，作者表明，缺氧，非硫化物（含铁）条件的波动是重要的延迟生物恢复在新特提斯。
The end-Permian mass extinction, ∼252 million years ago, is notable for a complex recovery period of ∼5 Myr. Widespread euxinic (anoxic and sulfidic) oceanic conditions have been proposed as both extinction mechanism and explanation for the protracted recovery period, yet the vertical distribution of anoxia in the water column and its temporal dynamics through this time period are poorly constrained. Here we utilize Fe–S–C systematics integrated with palaeontological observations to reconstruct a complete ocean redox history for the Late Permian to Early Triassic, using multiple sections across a shelf-to-basin transect on the Arabian Margin (Neo-Tethyan Ocean). In contrast to elsewhere, we show that anoxic non-sulfidic (ferruginous), rather than euxinic, conditions were prevalent in the Neo-Tethys. The Arabian Margin record demonstrates the repeated expansion of ferruginous conditions with the distal slope being the focus of anoxia at these times, as well as short-lived episodes of oxia that supported diverse biota. Oceanic anoxia is invoked for driving the Permo-Triassic Mass Extinction, but the timing, distribution and chemical state are poorly understood. Here, the authors show that fluctuations of anoxic, non-sulfidic (ferruginous) conditions were important for the delayed biotic recovery in the Neo-Tethys.