State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing 100083, PR China.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China.
Proc Natl Acad Sci U S A. 2021 Oct 5;118(40). doi: 10.1073/pnas.2109895118.
The Late Triassic Carnian Pluvial Episode (CPE) saw a dramatic increase in global humidity and temperature that has been linked to the large-scale volcanism of the Wrangellia large igneous province. The climatic changes coincide with a major biological turnover on land that included the ascent of the dinosaurs and the origin of modern conifers. However, linking the disparate cause and effects of the CPE has yet to be achieved because of the lack of a detailed terrestrial record of these events. Here, we present a multidisciplinary record of volcanism and environmental change from an expanded Carnian lake succession of the Jiyuan Basin, North China. New U-Pb zircon dating, high-resolution chemostratigraphy, and palynological and sedimentological data reveal that terrestrial conditions in the region were in remarkable lockstep with the large-scale volcanism. Using the sedimentary mercury record as a proxy for eruptions reveals four discrete episodes during the CPE interval (ca. 234.0 to 232.4 Ma). Each eruptive phase correlated with large, negative C isotope excursions and major climatic changes to more humid conditions (marked by increased importance of hygrophytic plants), lake expansion, and eutrophication. Our results show that large igneous province eruptions can occur in multiple, discrete pulses, rather than showing a simple acme-and-decline history, and demonstrate their powerful ability to alter the global C cycle, cause climate change, and drive macroevolution, at least in the Triassic.
晚三叠世卡尼期洪积事件（CPE）见证了全球湿度和温度的急剧上升，这与 wrangellia 大火成岩省的大规模火山活动有关。气候变化与陆地生物大更替相吻合，包括恐龙的崛起和现代针叶树的起源。然而，由于缺乏对这些事件的详细陆地记录，因此尚未能够将 CPE 的不同原因和影响联系起来。在这里，我们提出了华北济源盆地卡尼期湖相序列的多学科火山作用和环境变化记录。新的 U-Pb 锆石定年、高分辨率地球化学、孢粉学和沉积学数据表明，该地区的陆地条件与大规模火山作用惊人地同步。利用沉积汞记录作为喷发的示踪剂，揭示了 CPE 期间（约 234.0 至 232.4 百万年前）有四个离散的喷发阶段。每个喷发阶段都与大的、负的 C 同位素偏移和主要气候变化有关，导致更潮湿的条件（以喜湿植物的重要性增加为标志）、湖泊扩张和富营养化。我们的结果表明，大火成岩省的喷发可以多次发生，而不是表现出简单的顶峰和衰退历史，并证明了它们强大的能力，可以改变全球碳循环、引起气候变化并推动宏观进化，至少在三叠纪是如此。
