title: Sulphur geodynamic cycle.
abstract: Evaluation of volcanic and hydrothermal fluxes to the surface environments is important to elucidate the geochemical cycle of sulphur and the evolution of ocean chemistry. This paper presents S/(3)He ratios of vesicles in mid-ocean ridge (MOR) basalt glass together with the ratios of high-temperature hydrothermal fluids to calculate the sulphur flux of 100 Gmol/y at MOR. The S/(3)He ratios of high-temperature volcanic gases show sulphur flux of 720 Gmol/y at arc volcanoes (ARC) with a contribution from the mantle of 2.9%, which is calculated as 21 Gmol/y. The C/S flux ratio of 12 from the mantle at MOR and ARC is comparable to the C/S ratio in the surface inventory, which suggests that these elements in the surface environments originated from the upper mantle.
authors: Division of Ocean-Earth System Science, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba 277-8564, Japan.
authors: Takanori
authors: T
authors: Kagoshima
authors: Division of Ocean-Earth System Science, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba 277-8564, Japan.
authors: Yuji
authors: Y
authors: Sano
authors: Division of Ocean-Earth System Science, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba 277-8564, Japan.
authors: Naoto
authors: N
authors: Takahata
authors: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
authors: Teruyuki
authors: T
authors: Maruoka
authors: Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors: Tobias P
authors: TP
authors: Fischer
authors: Department of Earth Sciences, Advanced Research Complex, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
authors: Keiko
authors: K
authors: Hattori