Evidence for photic‐zone euxinia in the Early Albian Santana Formation (Araripe Basin, NE Brazil)
Evidence for photic‐zone euxinia in the Early Albian Santana Formation (Araripe Basin, NE Brazil)
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早期阿尔布阶桑塔纳组（巴西东北部阿里佩盆地）中存在光带的证据
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
J. Guzzo
中科院分区：
文献类型：
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作者：
U. Heimhofer;S. Hesselbo;R. Pancost;D. Martill;P. Hochuli;J. Guzzo
对巴西东北部阿拉里普盆地桑塔纳组两个黑色页岩单元的有机质进行了研究，以探讨这一著名化石形成期间的古环境条件。光学和有机地球化学分析表明，主要是一个土生土长的来源与非常有限的陆地输入。绿色硫细菌的分子化石表明，水柱是分层的，其缺氧条件一直延伸到透光层。因此，鱼类大量死亡事件可以用含硫化物的沃茨侵入来解释。低量的材料来自陆地植物在这个内部海洋环境被解释为反映海洋生产力提高的后果，导致大陆信号的稀释。提出了不同的沉积情景来解释我们的研究结果，包括（1）海侵事件期间的海岸侵蚀和营养盐淋溶，（2）在早期Albian OAE期间的富氧沃茨入侵或（3）与温盐分层相关的河口环流模式。
Organic matter from two black shale units in the Santana Formation, Araripe Basin, NE Brazil, has been studied to investigate the palaeoenvironmental conditions prevailing during formation of this famous fossil lagerstätte. Optical and organic geochemical analyses indicate a predominantly autochthonous source with very limited terrestrial input. Molecular fossils of green sulphur bacteria show that the water column was stratified with euxinic conditions reaching up into the photic zone. Thus, mass‐mortality events of fish may be explained by intrusion of sulphide‐containing waters. The low quantity of material derived from land plants in this interior marine setting is interpreted to reflect a consequence of enhanced marine productivity, resulting in dilution of the continental signal. Different depositional scenarios are proposed to explain our findings including (1) coastal erosion and nutrient leaching during a transgressive event, (2) intrusion of euxinic waters during an early Albian OAE or (3) an estuarine circulation pattern associated with thermohaline stratification.
影响因子：
3.5
作者：
Jochum, Klaus Peter;Stoll, Brigitte;Woodhead, Jon D.
通讯作者：
Woodhead, Jon D.