Pyrite framboid study of marine Permian-Triassic boundary sections: A complex anoxic event and its relationship to contemporaneous mass extinction
Pyrite framboid study of marine Permian-Triassic boundary sections: A complex anoxic event and its relationship to contemporaneous mass extinction
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DOI：
10.1130/b30042.1
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发表时间：
2010-07-01
影响因子：
4.9
通讯作者：
Wignall, Paul B.
中科院分区：
文献类型：
--
作者：
Bond, David P. G.;Wignall, Paul B.
为了评价缺氧的强度和持续时间，在世界各地的陆表海二叠-三叠系界线剖面上进行了黄铁矿草莓状体的粒度分析。中古纬度部分从北方（斯匹次卑尔根，格陵兰岛）和新特提斯海洋（西澳大利亚）的边缘，揭示了整个二叠纪-三叠纪边界间隔与缺氧条件频繁发展，缺氧，即使在相对浅水设置以上的风暴波基地。在赤道古纬度，弱含氧（dysopolytic）的条件下广泛发展，在广泛的水深范围内，包括那些浅到足以产生鲕粒沉积，虽然euxinia是罕见的。特提斯西部和东部的位置揭示了一个复杂的和不稳定的氧化还原历史：Hindeodus praeparvus带的缺氧被二叠-三叠纪边界间隔（H。changxingensis为H. parvus区）。贫氧沉积在随后的Isarcicella isarcica区返回。在较冷的水中，中古纬度剖面的氧限制发展更加持久和强烈，这表明变暖和溶解氧下降不是二叠-三叠纪界线缺氧的关键原因。在较高的古纬度，底栖无脊椎动物的减少发生在缺氧沉积的长期阶段，而在赤道特提斯地区，底栖动物的损失发生在第一缺氧阶段结束时（在H. praeparvus区）。
Size analysis of pyrite framboids has been undertaken on epicontinental Permian-Triassic boundary sections throughout the world in order to evaluate the intensity and duration of anoxia. Mid-paleolatitude sections from the margins of the Boreal (Spitsbergen, Greenland) and Neotethyan oceans (Western Australia) reveal intense anoxia throughout the Permian-Triassic boundary interval with euxinic conditions frequently developing, and dysoxia encountered even in relatively shallow-water settings above storm wave base. At equatorial paleolatitudes, weakly oxygenated (dysoxic) conditions are widely developed in a broad range of water depths including those shallow enough to produce oolite deposition, although euxinia was rare. Western and eastern Tethyan locations reveal a complex and unstable redox history: anoxia in the Hindeodus praeparvus Zone was replaced by oxygenated facies in the Permian-Triassic boundary interval (H. changxingensis to H. parvus zones). Oxygen-poor deposition returned during the succeeding Isarcicella isarcica Zone. The more persistent and intense development of oxygen restriction in cooler water, mid-paleolatitude sections argues against warming and dissolved oxygen decline as the key cause of Permian-Triassic boundary anoxia. In higher paleolatitudes the benthic invertebrate extinctions occurred during a prolonged phase of oxygen-poor deposition, while in equatorial Tethyan locations benthic losses occurred at the end of the first anoxic phase (in the late H. praeparvus Zone).