The Permian-Triassic mass extinction (PTME), the most severe biocrisis of the Phanerozoic, has been widely attributed to intense volcanism. Although the Siberian Traps Large Igneous Province is regarded as the main trigger of this bioevent, volcanic-arc activity around the margins of the Tethys Ocean may have played a significant role also. Here, we report results of a high-resolution study of zirconium (Zr) isotopes in bulk limestone and volcanic ash beds of the Permian-Triassic transition at Meishan, South China. Mass-dependent fractionation of Zr isotopes, which is controlled by magmatic crystallization, has the potential to differentiate between primitive and evolved igneous sources. The Zr isotopic composition (δ^94/90Zr) of volcanic ash in Permian-Triassic transition beds at Meishan is more positive than mantle values, indicating that inputs were probably dominated by regional arc volcanism. The sedimentary beds having the heaviest Zr isotopes during the pre-PTME interval may also record inputs from a felsic volcanic source. A mixing model indicates that the observed negative shift of δ^94/90Zr at the PTME horizon was likely due to detrital Zr inputs linked to intensified continental weathering. This study demonstrates that volcanism in South China during the Permian-Triassic transition was linked to regional arc magmatism.

二叠纪-三叠纪大灭绝（PTME）是显生宙最严重的生物危机，被广泛归因于强烈的火山活动。尽管西伯利亚陷阱大火成岩省被认为是这一生物事件的主要触发因素，但特提斯洋边缘的火山弧活动也可能发挥了重要作用。在这里，我们报告了对华南眉山二叠纪-三叠纪过渡的大块石灰岩和火山灰床中锆 (Zr) 同位素的高分辨率研究结果。受岩浆结晶控制的 Zr 同位素的质量依赖分馏具有区分原始火成岩源和演化火成岩源的潜力。Zr 同位素组成 (δ ^94/90眉山二叠系-三叠系过渡层火山灰 Zr) 值比地幔值更正，表明输入可能以区域弧形火山作用为主。在 PTME 前间隔期间具有最重 Zr 同位素的沉积床也可能记录来自长英质火山源的输入。混合模型表明，在 PTME 层位观察到的 δ ^94/90 Zr 负位移可能是由于与强化的大陆风化有关的碎屑 Zr 输入。本研究表明，二叠纪-三叠纪过渡时期的华南火山活动与区域弧形岩浆作用有关。