Abstract:This paper studies the whole-rock element geochemistry and Sr-Nd-Pb isotopic compositions of basalitic andesite for the Lower Qingshan formation in Zouping volcanic basin. With reference to previous research, we discuss petrochemistry property and material sources. The study shows that the basalitic andesite is characterized by sodium-rich and magnesium-rich, as well as rich in Light Rare Earth Element(LREE) and Large Ion Lithophile Element(LILEs, Rb、Sr、Ba), while depletions in High Field-Strength Element(HFSEs, Nb , Ta, Ti). The initial ratios of Sr isotope (87Sr/86Sr)ivaries from 0.705674 to 0.705876, and the initial ratios of Nd isotope 〖QX(Y12#〗ε〖QX)〗Nd(t) ranges from -10.00 to -10.20. The initial ratios of Pb isotope (206Pb/204Pb)i has a range of 16.917 to 17.095 , while (207Pb/204Pb)i ranges from 15.306 to 15.396, and (208Pb/204Pb)i values 36.750 to 37.208. Lower initial Sr-Nd ratios and relatively uniform low-level radioactive Pb isotopic composition suggests that the basalitic andesite may be derived from the partial melting EMI-type enriched mantle. During Late Mesozoic, the thickening North China lithospheric delamination formed silica-rich melt in the lower continental crust, while the interaction between silica-rich melt and Paleozoic lithospheric mantle formed enriched mantle. With the action of lithospheric extension and regional thermal abnormity, enriched mantle decompressed and partially melted, forming basaltic andesitic magma. The magma invaded along the deep structure, emplaced in the upper crust or erupted to the surface, and then formed the basaltic andesite, while the crustal contamination is not obvious during the magma intrusion process.