What’s going on with the “Carnian humid period” in southwestern China? Recently, researchers have unveiled the characteristic features of this geological epoch—a typical abrupt shift between dry and wet climates—as well as the biological and environmental responses to this shift and the underlying mechanisms driving it.

　　This study was jointly conducted by researchers from the Wuhan Geological Survey Center of the China Geological Survey, Erlangen-Nürnberg University in Germany, the Geological Survey of Canada, and China University of Geosciences (Wuhan). The findings provide important insights and clues for exploring the formation of modern ecological systems, the co-evolution of organisms and their environments, and the mechanisms underlying the occurrence of extreme modern climates—such as droughts and rainfall events. The related paper, “The Late Triassic ‘Carnian Wet Season’ in Southwest China Was Accompanied by Extreme Marine Hypoxia and Large Fluctuations in Carbon Isotopes,” has been published in the internationally renowned, multidisciplinary geoscience journal Global and Planetary Change.

　　This study indicates that in the southwestern region of China, the event occurred near the boundary between the Zhugangpo Formation and the Wayao Formation (Xiaoa Formation), accompanied by a transition in lithology from carbonate rocks to clastic rocks. The event was marked by multi-stage negative shifts in inorganic carbon isotopes, and these negative carbon isotope excursions were closely associated with the Langgela Volcanic Event and other volcanic eruptions of the same period. Volcanic activity was also the primary driver behind the climatic shift. Geological records from the Nanpanjiang area show that this event was accompanied by anoxic/sulfidic conditions in the ancient ocean, and the anoxic environment likely persisted into the Late Carnian stage. In the southwestern region of China, the selective extinction of marine organisms during this period was closely linked to high temperatures and oceanic anoxia. (Zhang Zaitian)