Geologic Party No. 243, China National Nuclear Corporation, Chifeng 024000, Inner Mongolia, China

The metallogenic potential of niobium and rubidium mineral occurrence of south Jiyuan, Inner Mongolia is evaluated by geological, geophysical, geochemical and trench exploration methods. The results show that the host rocks of the occurrence are mainly Mesozoic rhyolitic volcanic rocks. Cluster analysis and R factor analysis show that the soil elements in the study area can be divided into three groups obviously:Rb, Y, Nb, Ta, Sn, U; Pb, Zn, La and Cu, W, Mo, Ag, Au. Spatially, the anomalies of Pb, Zn, La, Y, Ta, Sn, Mo and U in the soil present annulus around the sub-rhyolite porphyry, of which the anomalies of Pb, Zn and La are located in the outer annulus. Soil annulus geochemical anomaly area has the geophysical characteristics of medium-high resistivity and high polarization, which are obviously controlled by volcanic edifice. Trench tests show that the Nb₂O₅ and Rb₂O contents of mineralized rocks are all above the cut-off grade. It is speculated that there may be orebodies of rare and rare earth elements such as Nb and Rb related to subvolcanic rocks in the deep part.