Uranium isotopes in groundwater of the Mezen syneclise Vend

Higher activities of U isotopes were recorded in hydrocarbonate freshwater on watersheds in the regions of occurrence of red Vend sandstones, Fe concentrations being minimal. The lowest activities of U isotopes and the highest Fe concentrations are typical of highly mineralized water under paleovalleys. The highest activities of U isotopes were recorded in the zones of hydrocarbonate freshwater intrusion into brine water on paleovalleys’ slopes. The mineral and fresh waters confined to the water-bearing complex of Vend sandstones can be used for drinking and balneological purposes.