Plume-induced emissions of deep methane linked to the end-Guadalupian mass extinction.

Methane (CH) is a potent greenhouse gas, and massive CH emissions have the capacity to cause rapid and catastrophic climate effects. Here we report findings of large amounts of CH occurring as an important vapor phase in melt inclusions trapped by magmas in the plume-related Permian Emeishan large igneous province (LIP). Lines of evidence indicate that the CH is dominantly abiogenic and primarily had a mantle origin. Undegassed magmas are estimated to contain ~ 0.03% (by weight) CH, which coincides with the relatively low oxygen fugacities of primary Emeishan LIP magmas. Our findings demonstrate that abiogenic CH can be generated in the mantle sources of a plume-related LIP, and that such CH could be brought into the surface by LIP magmatism and lead to strong warming. Quantitative models suggest that release of magmatic CH in the Emeishan LIP (7.4 × 10 Gt) had a significant contribution to the end-Guadalupian mass extinction.