Abstract:Yihegaole area is an important source of coal,oil and other mineral resources in Erlian Basin. It is rich in uranium mineralization information and has good potential for uranium exploration. The evaluation of the hydrogeological conditions of uranium mineralization in this area is one of the important contents of uranium exploration. Based on the 1:250000 uranium hydrochemistry regional survey,this paper analyzed the hydrogeological and hydrogeochemical conditions in Yihegaole area,and puts forward the favorable hydrogeological conditions and prospective areas for uranium mineralization. The analysis showed that the Cretaceous fracture pore aquifer is the main target layer for uranium exploration,and its hydrogeological conditions are mainly controlled by lithofacies and paleogeography. The groundwater in the area flows from northwest to southeast,and the changes of groundwater quality parameters and hydrochemical types are closely related to groundwater recharge runoff discharge system. The information of groundwater radioactive anomaly is rich,three uranium water anomaly halos and four radon water anomaly halos are delineated in total,and the zonation and concentration center of uranium and radon gas in the water are basically the same. The NWW trending tensional and torsional faults in the area are of great significance to the evolution of hydrogeological conditions and uranium mineralization,and play an important role in controlling the distribution of sand bodies and the dynamic conditions of groundwater. The comprehensive analysis shows that Yihegaole area has favorable hydrogeological conditions for the formation of oxidation zone type or paleochannel type sandstone uranium deposits,and preliminarily delineates four areas(pieces)for uranium hydrochemistry prospect prediction.