Mercury evidence of Emeishan volcanism driving the mid-Capitanian (Middle Permian) extinction

作者：Hu Huang, Changzhou Deng, Stephen E. Grasby, Peter A. Cawood, Mingcai Hou, Chenchen Yang, Mingshi Feng, Fuhao Xiong, Hanting Zhong, Runsheng Yin · 发表于：Geological Society of America Bulletin · 年份：2024 · DOI：10.1130/b37796.1 · 被引用次数：9 · 研究领域：Paleontology and Stratigraphy of Fossils、Astro and Planetary Science、Geology and Paleoclimatology Research

Abstract The mid-Capitanian (Middle Permian) extinction has been widely attributed to the eruption of the Emeishan large igneous province. Here, we investigate the nature and timing of this link by determining Hg concentrations and isotopic compositions of limestones from the Xiongjiachang section of southwestern China, where Emeishan basalts directly overlie sediments recording the mid-Capitanian extinction horizon. Results show an initial Hg-enrichment interval ~2.2 m below the mid-Capitanian extinction horizon. Positive Δ199Hg values in the Hg-enrichment interval suggest enhanced volcanic Hg influx into the ocean via atmospheric Hg(II) deposition. The late stage of the mid-Capitanian extinction interval has lower Δ199Hg values, which indicates enhanced input of terrestrial Hg due to ecosystem collapse and soil erosion. The results of this study provide evidence that the Emeishan large igneous province eruption occurred earlier than the mid-Capitanian extinction, and establish a more reasonable temporal link between Emeishan large igneous province volcanism and the mid-Capitanian extinction.