Behavior of Isotope (O-18/O-16, U-234/U-238) Systems during the Formation of Uranium Deposits of the 'Sandstone' Type

摘要

The uneven character of the distribution of O-18/O-16 and U-234/U-238 values was established in the vertical cross section of the productive sequence of the Dybryn uranium deposit (Vitim uranium-ore region, Buryatia). Both a deficiency and an excess of U-234 in relation to the equilibrium U-234/U-238 ratio in the vertical sequence may provide evidence for the extremely low rate of the infiltration water flow. The behavior of oxygen isotope characteristics for different size fractions of terrigenous rocks provides evidence for active uranium redistribution and openness of the isotope system of this element during interaction of terrigenous-sedimentary rocks with infiltration waters.