Abstract: The geochemical analysis indicates that the Early Carboniferous basalts in the Santanghu basin are characterized by higher Al203, lower FeO, Fe: 03 and TiO2, and by high concentrations of large-ion lithophile element (LIL) and LREE, showing the characteristics of the calc-alkaline series. In addition, results of discriminant analysis show that the Santanghu area was in an island arc setting during Early Carboniferous. The petrochemical characteristics and REE and trace element abundance show that the andesites of Early Permian belong to high potassium orogenic andesites of calc-alkaline series, comparable with that of the Andes-type active continental margin, indicating that the Santanghu area was in the active continental margin of Siberia plate during Early Permian time.