Abstract The Carnian Pluvial Episode was a phase of global climatic change and biotic turnover that occurred during the early Late Triassic. In marine sedimentary basins, the arrival of huge amounts of siliciclastic sediments, the establishment of anoxic conditions, and a sudden change of the carbonate factory on platforms marked the Carnian Pluvial Episode. The sedimentary changes are closely associated with abrupt biological turnover among marine and terrestrial groups as, for example, an extinction among ammonoids and conodonts in the ocean, and a turnover of the vertebrate fauna and the flora on land. Multiple negative carbon-isotope excursions were recorded during the Carnian Pluvial Episode in both organic matter and marine carbonates, suggesting repeated injection of 13C-depleted CO2 into the ocean–atmosphere system, but their temporal and causal links with the sedimentological and palaeontological changes are poorly understood. We here review the existing carbon-isotope records and present new data on the carbon-isotope composition of organic carbon in selected sections of the western Tethys realm that record the entire Carnian Pluvial Episode. New ammonoid, conodont and sporomorph biostratigraphic data were collected and coupled to an extensive review of the existing biostratigraphy to constrain the age of the sampled sections. The results provide biostratigraphically constrained composite organic carbon-isotope curves for the Carnian, which sheds light on the temporal and causal links between the main carbon-isotope perturbations, and the distinct environmental and biotic changes that mark the Carnian Pluvial Episode. The carbon-isotope records suggest that a series of carbon-cycle perturbations, possibly recording multiple phases of volcanic activity during the emplacement of the Wrangellia Large Igneous Province, disrupted Carnian environments and ecosystems repeatedly over a remarkably long time interval of about 1 million years.

中文翻译：

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卡尼阶雨季（晚三叠世）期间的多次负碳同位素偏移

摘要 卡尼期雨季是晚三叠世早期全球气候变化和生物周转的一个阶段。在海相沉积盆地中，大量硅质碎屑沉积物的到来、缺氧条件的建立以及平台上碳酸盐工厂的突然变化标志着卡尼期雨季。沉积变化与海洋和陆地群体之间的突然生物周转密切相关，例如，海洋中菊属植物和牙形动物的灭绝，以及陆地脊椎动物群和植物群的周转。在卡尼阶雨季期间有机质和海洋碳酸盐中记录了多次负碳同位素偏移，这表明将消耗 13C 的 CO2 重复注入海洋-大气系统，但它们与沉积学和古生物变化的时间和因果关系知之甚少。我们在此回顾了现有的碳同位素记录，并提供了关于记录整个卡尼期雨季事件的西特提斯界选定部分中有机碳的碳同位素组成的新数据。收集了新的菊石、牙形石和孢子形生物地层数据，并结合对现有生物地层的广泛审查，以限制采样截面的年龄。结果提供了卡尼阶的生物地层约束复合有机碳同位素曲线，揭示了主要碳同位素扰动与标志着卡尼阶雨季的独特环境和生物变化之间的时间和因果关系。