Supervolcano eruptions have played a major role in the evolution of life and environments on Earth. The Emeishan large igneous province (LIP) eruptive activity had been suggested to be the cause of the Guadalupian (Middle Permian) mass extinction event and the transition from icehouse to greenhouse climate in the Permian. However, the causal mechanism of the Emeishan LIP’s impact on the environment and mass extinction is still unresolved. This study presents 300 foraminiferal species, mercury (Hg) and carbon isotopic compositions, zircon U-Pb ages, biomarkers, and elemental data across the Guadalupian-Lopingian (G-L; i.e., middle−upper Permian) boundary of South China to investigate mass extinction and the evolution of the Emeishan LIP. A precise chronological framework across the G-L boundary is reconstructed using five U-Pb age data integrated with carbon isotopic stratigraphic correlations. A U-Pb age of 260.58 ± 0.86 Ma determined using secondary ion mass spectrometry from a section of continuous deposition is suggested as a revised age for the G-L boundary. Organic carbon isotopic composition (δ13Corg) and Hg geochemistry data show three pulses of Emeishan LIP eruptive activity in the earliest Wordian, in the middle Capitanian, and at the G-L boundary, respectively. The second and third pulses of the Emeishan LIP eruptive activity in the middle Capitanian and at the G-L boundary, respectively, coincided with two stages of the Guadalupian mass extinction, demonstrating a causal link. The Emeishan LIP eruptive activity probably caused the Guadalupian mass extinction by triggering marine anoxia and global warming.
Sun et al. (Wed,) studied this question.