Estimation of the depth of origin of fluids using noble gases in the surface sediments of submarine mud volcanoes off Tanegashima Island.

ABSTRACT: The helium isotope ratio (³He/⁴He), concentration ratio of neon-20 to helium-4 (²⁰Ne/⁴He), argon (Ar), krypton (Kr), and xenon (Xe) concentrations were measured in the porewater of surface sediments of several submarine mud volcanoes. From the ³He/⁴He values (0.18-0.93R_A), the estimated He origin is almost 90% crustal He, with little contribution from mantle-derived He. The determined Ar, Kr, and Xe concentrations lie within the solubility equilibrium range expected for temperatures from 83 °C up to 230 °C and are consistent with the temperature range of the dehydration origin of clay minerals. Considering the geothermal gradient in the investigated region (25 °C/km), these gases are considered to have reached dis

SUBMITTER: Mitsutome Y 

PROVIDER: S-EPMC10079976 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature