Isotope geochemical characteristics in uranium deposits in China

Most of the uranium deposits in China occurs in geological setting of the geosynclinal folded zone and the mobile region, and hydrothermal uranium deposits are dominant position. The late Mesozoic and the early Cenozoic (Cretaceous-Tertiary) are the major metallogenetic epochs for uranium deposits, which are characterized by relative concentration in time and space. On the basis of principle of uranium-lead isotope system evolution, the viewpoint of uranium mobilized mineralization has been proved; the sources of uranium is distinguished and metallogenetic prospect is evaluated on the basis of uranium loss and anomalous initial lead from geological bodies. Scientific research on light stable isotope geochemistry indicates that the isotopic composition of sulphur and carbon in ore-forming solution relate to nature of ore-bearing rocks, and the character of 'draw on local resources' displays very clearly; hydrogen and oxygen isotope geochemistry indicates that the source of ore-forming solution for hydrothermal vein-type uranium deposits in China may be divided into three cases, namely mix of magmatic hydrothermal solution and atmospheric water, main origin from atmospheric water, and mix of metamorphic water and atmospheric water. (10 tabs., 4 figs.)