Carboniferous volcanic rocks from Ludong-Wucaiwan area of Junggar basin mainly composed of basalts, basaltic andesites and andesites occur within Upper Carboniferous Batamayineishan Formation, and are mainly Calc-alkaline series. These rocks have moderate Mg-#(38 similar to 57) values, relatively high alkali K2O + Na2O)=4.75%similar to 6.16%), TiO2 (0. 96%similar to 2.04%) contents and Na2O/K2O ratios(>2). They are enriched in LREE ((La/Yb)(N)=2.4 similar to 4.7), and with slight fractionation of HREE ((Gd/Yb)(N)= 1.5 similar to 1.8), and possess weak Eu anornalies(delta Eu=0.89 similar to 1.05), without significant Ce anomalies. These samples are enriched in LILE but relatively depleted in HFSE, with strong negative Nb-Ta anomalies. They have high La/Nb (2.0 similar to 2.8), Zr/Y (3.95 similar to 03), but low Th/La(approximate to 0. 1) ratios. Furthermore, They have relatively low I-M (0.70278 similar to 0.70365, iota(DM) (0.47 similar to 0.67Ga), and high (iota) (+5.69 similar to+8.24). These characteristics, along with the discrimination diagrams, indicate that these, volcanic rocks are from extensional setting of post-collisional period, rather than typical intraplate or island are environments, and they were produced by the ascending and melting of asthenospheric material, and the magmas were. contaminated by the are component formed before I,by Carboniferous in the processes of uplift and emplacement. The are charUCteristics carried by the volcanic rocks were inherited from the pre-collisional are component which had contaminated the source region.
