Uranium Isotope Variations (234U/238U and 238U/235U) and Behavior of U-Pb Isotope System in the Vershinnoe Sandstone-Type Uranium Deposit, Vitim Uranium Ore District, Russia

• 作者: V.N.Golubev I.V.Chernyshev B.T.Kochkin N.N.Tarasov G.V.Ochirova A.V.Chugaev
• 来源期刊: 地球科学学刊（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: Special Issue on Sandstone-Type Uranium Mineralization and Its Metallogenic Background
• 页码范围: 317-324
• 页数: 8页
• 语种: 英文

摘要

The U-Pb isotope system and uranium isotope composition (235U/238U and 234U/238U) were studied in a number of samples from the vertical section of the uranium ore body at the Vershinnoe sandstone-type deposit, Vitim uranium ore district, Russia. These parameters were determined to broadly vary. Deviations of the 234U/238U ratio from the equilibrium value indicate that the uranium ore was not completely conserved during the postore stage, and uranium was determined to continue mi- grating at the deposit. Comparison of the U-Pb isotope age value and 234U/238U isotope ratio provides an insight into the migrate direction of uranium in the ore body. The broad variations (137.377–137.772) in the 238U/235U ratio over the vertical section of the ore body can be explained by the different settings of the samples relative to the ore deposition front and changes in the redox conditions when this front shifted. The fact that theδ238U and K234/238 values are correlated indicates that the transfer of the 234U iso- tope into the aqueous phase may have been coupled with isotope fractionation in the 238U-235U system during the postformation uranium migration within the orebody.