New evidence suggests pyroclastic flows are responsible for the remarkable preservation of the Jehol biota
New evidence suggests pyroclastic flows are responsible for the remarkable preservation of the Jehol biota
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新证据表明火山碎屑流是热河生物群得以显着保存的原因
DOI：
10.1038/ncomms4151
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发表时间：
2014-02-01
影响因子：
16.6
通讯作者：
Meng, Jin
中科院分区：
文献类型：
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作者：
Jiang, Baoyu;Harlow, George E.;Meng, Jin
下白垩纪义县组和九佛堂组含有大量保存完好的无脊椎动物、脊椎动物和植物化石，构成了热河生物群。生物群的淡水化石和陆生化石通常在某些层位内同时出现，并被解释为大规模死亡事件的沉积。然而，人们对这些事件的性质和化石保存完好背后的机制知之甚少。在这里，在检查和分析了几个关键层的沉积物和残余化石之后，我们假设因果事件主要是呼吸岩浆喷发。火山碎屑密度流可能是造成主要伤亡的原因，也是将大量来自不同栖息地的陆生脊椎动物，如蜥蜴、鸟类、非鸟类恐龙和哺乳动物，运送到湖泊环境中埋葬的原因。在这一过程中，被火山碎屑流运输和封闭的陆生脊椎动物尸体作为特殊的化石被清楚地保存了下来。
The lower Cretaceous Yixian and Jiufotang formations contain numerous exceptionally well-preserved invertebrate, vertebrate and plant fossils that comprise the Jehol Biota. Freshwater and terrestrial fossils of the biota usually occur together within some horizons and have been interpreted as deposits of mass mortality events. The nature of the events and the mechanisms behind the exceptional preservation of the fossils, however, are poorly understood. Here, after examining and analysing sediments and residual fossils from several key horizons, we postulate that the causal events were mainly phreatomagmatic eruptions. Pyroclastic density currents were probably responsible for the major causalities and for transporting the bulk of the terrestrial vertebrates from different habitats, such as lizards, birds, non-avian dinosaurs and mammals, into lacustrine environments for burial. Terrestrial vertebrate carcasses transported by and sealed within the pyroclastic flows were clearly preserved as exceptional fossils through this process.