²²⁶ra-²¹⁰pb and²²⁸ra-²²⁸th dating of barite in submarine hydrothermal sulfide deposits collected at the okinawa trough and the Southern Mariana trough

The²²⁶Ra-²¹⁰Pb and²²⁸Ra-²²⁸Th ages were obtained for barite crystals in hydrothermal sulfide deposits taken at the Okinawa Trough and the Southern Mariana Trough. After calibrating the measurement systems with standard samples with pitchblende, it was confirmed that the U and Th concentrations obtained for GSJ samples are consistent with literature values. It was shown that radon does not escape from barite crystals extracted from hydrothermal sulfide deposits, which indicates that²²⁶Ra-²¹⁰Pb dating method works for these barite crystals. Most of the²²⁶Ra-²¹⁰Pb and²²⁸Ra-²²⁸Th ages are younger than ESR and U-Th ages, where this inconsistency would be explained by the mixture of the barite crystals with younger and older ages, formed by several hydrothermal events.