Investigation of hot spring gas components and soil gas fluxes in Arxan Holocene volcanic field, Inner Mongolia, NE China

The latest research results show that there is a unified magma system and heating channel beneath the Arxan volcanic field, indicating potential risk of eruption. field features multiple gas emission sites (e.g., Jinjianggou hot springs Yinjianggou springs) exhibits strong hydrothermal activity. In this study, measurements spring composition soil CO 2 flux in Holocene were conducted, combined with previous to analyze degassing characteristics region. gases are composed 0.07%–1.09% , 0.33–12 ppm CH 4 1.57–53 H 800–30,241 He, 1.14%–1.86% Ar. He content area notably higher than other dormant volcanoes China. This difference possibly caused by U–Th decay Mesozoic granodiorite acidic rocks study area, which can produce substantial radiogenic He. concentrations near those two volcanoes. peak concentration reach 35,161 ppm. single-site microseepage 4.66–107.18 g m −2 d −1 estimated annual from atmosphere 0.63 × 10 5 t, also demonstrates volcano comparable level Iwojima volcano.