Pulsed volcanism in the Emeishan Large Igneous Province drove deglaciation during the Guadalupian-Lopingian transition

The Guadalupian-Lopingian transition (late Permian, ∼260 Ma) was a critical turning point in Earth's climate evolution, marking the end of the Late Paleozoic Ice Age (LPIA) and concurrent perturbations in the global carbon cycle. Although the Emeishan Large Igneous Province (ELIP) has been proposed as a potential trigger of this episode, the mechanistic linkages between volcanic pulses, climate fluctuations, and deglaciation remain poorly constrained. Here, we present an integrated high-resolution analysis of the carbonate-dominated Xikou section (South Qinling, China), which spans the Guadalupian-Lopingian interval, and report new data for mercury geochemistry (Hg/TOC anomalies as volcanic proxies), paired carbonate and organic carbon isotopes (δ¹³C_carb, δ¹³C_org), redox-sensitive trace elements (e.g., Mo_EF), and chemical weathering indices (e.g., chemical index of alteration, CIA). Results reveal five distinct volcanic pulses (e.g., Hg/TOC peaks of up to 150 ppb/wt%) during the Capitanian to Wuchiapingian, each roughly coinciding with negative δ¹³C excursions (up to −2.5 ‰), elevated CIA values (up to 88), and synchronous enrichments in redox-sensitive elements (e.g., Mo_EF up to 100). This triple coupling demonstrates that ELIP eruptions released massive amounts of ¹³C-depleted CO₂, driving recurrent episodes of warming that progressively destabilised the P4 glaciation and led to ice-sheet collapse. This mechanism can be extended to the global deglaciation of the LPIA because eruptions from the Tarim II (ca. 290 Ma), Tarim III (ca. 280 Ma), and Emeishan LIPS (ca. 260 Ma) are each associated with interglacial phases. Furthermore, a prominent +1.4 ‰ shift in Δ¹³C (δ¹³C_carb - δ¹³C_org) during the early Wuchiapingian suggests enhanced organic carbon burial under waning volcanism, promoting atmospheric oxygenation and ecosystem recovery. Our study establishes pulsed volcanism as the primary driver of icehouse-greenhouse transitions through carbon cycle disruption, with implications for understanding climate-biosphere feedbacks during the late Permian crises.