To elucidate the evolution of hydrothermal activities, we conducted an interdisciplinary study including geochemistry and biology to develop a method of obtaining reliable age information.As geochemical dating techniques, two methods applicable for hydrothermal ore minerals were developed and improved: electron spin resonance method and uranium–thorium disequilibrium method.For a much longer time range, To conduct these studies, the following difficulties to be solved were recognized at the beginning of our project.
Here, Ba serves as a proximal stable isotope for Ra that has no stable isotopes of its own. Within sulfate minerals, barite was chosen as the target mineral because the obtained signals are clear.All three types of decays are discussed, and the user will have a better understanding of the age equations used in radio dating.The user will also learn about Fission Track Dating, a tool that is used to determine both age and temperature of downhole conditions.Consequently, coupling of methodological challenges to produce reliable age information was conducted for the TAIGA project (Urabe et al. Here, the expected life cycle of hydrothermal system ranges from approximately a few years to a few tens of thousands of years.Such a range demands some composite dating protocol for ore minerals.Therefore, flux intensities affect the biogeochemical reactions and the biological diversities in vent areas.The geochemical diversity observed in vent fluids can be elucidated as a result from scavenging process of the infiltrated seawater, frequently forming impressive chimney structures on the seafloor (e.g. The circulation of hydrothermal systems between seawater and the subseafloor environment has played an important role in the geochemical evolution of the earth.A few studies have been conducted to constrain the lifetime of activity at hydrothermal sites (e.g. Some efforts to generalize these results for ordinary hydrothermal systems have been undertaken for the following reasons: (1) unusually large size of mounds within present-day hydrothermal mounds and (2) the slow spreading environment in which TAG is formed.The former point implies that the duration of the hydrothermalism beneath TAG is unusually long-lived or vigorous or both.Cruzan and Templeton ), fossil evidence of hydrothermal vent communities is rare because of the destruction of vent fauna by hydrothermal activity itself.Other methods of calibrating the molecular clock in gene sequences of hydrothermal vent fauna might be geochronological dating techniques of hydrothermal ore minerals and geological events. Such a small amount of constraint is partly attributable to the limited availabilities of numerical dating methods applied to the hydrothermal deposits at inactive sites directly: a gap of 10U disequilibrium method to sulfide deposits collected on and near the ridge axis. Another trial is on TAG-site, which develops slightly off the MAR-axis in 26°45′N (Rona ) reported precipitated age variation within the hydrothermally formed “mound” at the TAG-site, which exceeds 10 ka for core samples obtained in ODP Leg158.