[S-GC37] Volatiles in the Earth - from Surface to Deep Mantle

[SGC37-10] Impact of volcanic volatile fluxes on Mesozoic terrestrial biotas in northern China

*Lu Wang^1,2、Jia Liu²、Yan Xiao Gu²、Ke Qun Xia² (1.Shanghai University、2.Zhejiang University)

キーワード：volatile flux, terrestrial biota, Mesozoic, northern China

Volcanic eruptions significantly modify surface environments and climate, with profound effects on biota across various spatial and temporal scales. The spatiotemporal evolution of the Mesozoic Yanliao and Jehol biotas in northern China—two world-renowned terrestrial lagerstätten—correlates with Jurassic to early Cretaceous volcanic activity during the destruction of the North China craton. However, the coupling mechanisms between terrestrial volcanism and biological evolution remain poorly understood. In this study, we measured chlorine, fluorine, and sulfur concentrations in clinopyroxene phenocrysts and apatite inclusions from Jurassic volcanic rocks in northern China. Using experimentally calibrated clinopyroxene/apatite-melt partition coefficients, we quantitatively estimate the volatile degassing during the origin (0.1-3 Gt Cl, 0.06-1 Gt F, and 0.03-1 Gt S), development and flourishing (3-57 Gt Cl, 2-21 Gt F, and 1-10 Gt S), and decay (34-1002 Gt Cl, 10-216 Gt F, and 4-136 Gt S) phases of the Yanliao Biota. Our results, integrated with previous studies, suggest that environmental degradation and climate cooling induced by substantial toxic gas emissions likely contributed to the decline of the Yanliao Biota and impeded the development of the Jehol Biota. In contrast, the relatively limited volatile fluxes, reduced harmful element delivery, and sufficient nutrient element supply from volcanic products may have fostered favorable conditions for the development and flourishing of both the Yanliao and Jehol biotas.