Terrestrial Gamma Ray Dose Rates in the Region from Fuji-Hakone District to the Izu Islands

抄録

In order to understand the distribution of dose rate in the Fuji volcanic belt, theories of partial melting of rock and crystallization‐differentiation of magma have been applied to data of uranium, thorium and potassium contents of bedrocks collected through a literature survey.Dose rates due to mantle material(mantle dose rate) were estimated by using the partial melting theory. Applying the magmatic differentiation theory as well, dose rates due to bedrocks(rock dose rate) were calculated based on the mantle dose rate, which were compared favorably with observed data.Analysis of data of dose rates due to surface soils(soil dose rate) collected by other researchers along with a number of data measured newly in a considerable part of this belt revealed an across‐arc lateral variation in soil dose rate.