Evidence from fracture filling minerals for the interpretation of uranium isotopes in investigating ancient redox in granitic rock in KURT site

It is necessary to develop an understanding of how the groundwater system has changed over time in response to changing driving forces for groundwater flow and hydrogeochemical evolution. The generation of fracture filling minerals contains geochemical record of the compositions of the groundwaters from which they precipitated. The combination of isotopic characteristics of fracture filling minerals provides very important information of paleo-hydrology of a geological site. In this study, to advance the understanding of uranium isotopes in fracture filling minerals and its response to groundwater flow and chemical evolution, we measured U isotopes such as ²³⁸U, ²³⁵U, ²³⁴U in fracture filling minerals in KURT site. This study evaluated the location of redox front based on the patterns of concentrations of Mn, Fe and U in fracture filling minerals.