PDF(Pubmed)
Abstract：
The latest Triassic was characterised by protracted biotic extinctions concluding in the End-Triassic Extinction (~ 200 Ma) and a global carbon cycle perturbation. The onset of declining diversity is closely related to reducing conditions that spread globally from upper Sevatian (uppermost Norian) to across the Norian-Rhaetian boundary, likely triggered by unusually high volcanic activity. We correlate significant organic carbon cycle perturbations to an increase of CO2 in the ocean-atmosphere system, likely outgassed by the Angayucham igneous province, the onset of which is indicated by the initiation of a rapid decline in 87Sr/86Sr and 188Os/187Os seawater values. A possible causal mechanism involves elevated CO2 levels causing global warming and accelerating chemical weathering, which increased nutrient discharge to the oceans and greatly increased biological productivity. Higher export production and oxidation of organic matter led to a global O2 decrease in marine water across the Norian/Rhaetian boundary (NRB). Biotic consequences of dysoxia/anoxia include worldwide extinctions in some fossil groups, such as bivalves, ammonoids, conodonts, radiolarians.
摘要：
最新的三叠纪的特征是在三叠纪末灭绝（〜200Ma）和全球碳循环扰动中结束的长期生物灭绝。多样性下降的开始与减少从上塞瓦蒂安（最高诺里安）到横跨诺里安-拉赫蒂安边界的全球范围内的条件密切相关，可能是由异常高的火山活动引发的。我们将显着的有机碳循环扰动与海洋大气系统中CO2的增加相关联，很可能被Angayucham火成岩省释放，87Sr/86Sr和188Os/187Os海水值的快速下降表明了其开始。一个可能的因果机制涉及二氧化碳水平升高导致全球变暖和加速化学风化，这增加了向海洋的养分排放，大大提高了生物生产力。较高的出口产量和有机物的氧化导致整个Norian/Rhaetian边界（NRB）的海水中O2的全球减少。失氧/缺氧的生物后果包括一些化石群的全球灭绝，比如双壳类动物，氨酰胺类,牙形牙,放射虫。
