Abstract:The Late Carboniferous Basike granodiorite located in the Yemaquan island of east Junggar, which have important geological significance for constraining the tectonic evolution of the east Junggar, but no report on isotope and tectonic setting about this granodiorite.Methods: Based on the field work, we finished microscope observation, whole-rock geochemical analysis and LA-ICP-MS zircon U-Pb dating for the granodiorite in this paper.Results:Zircon grains of two samples from the Basike granodiorite are euhedral to subhedral in shape, display fine- scale oscillatory growth zoning with Th/U rations of 0.39~1.12 and 0.37~0.91 respectively, indicating a magmatic origin. U- Pb dating results show that the pluton was emplaced with age of 301.3±2.5 Ma and 310.7±3.6 Ma. The granodiorite have high SiO2 contents of 65.7%~68.6% and Al2O3 contents of 14.78%~15.50%, Na2O concentrations of 4.36%~4.70%, and K2O concentrations of 2.44%~3.40%, with(Na2O+K2O) concentrations of 6.94%~7.98% and Na2O/K2O rations of 1.34~1.88, A/CNK values of 0.93~1.03, Mg#values of 42.41~50.42. The samples are enrichment of light rare earth elements(LREEs) and large ion lithophile elements (LILE), such as K, Rb, Ba, and depletion of heavy rare earth elements (HREEs) and high field-strength elements (HFSE), such as Nb, Ta, Ti, with (La/Yb)N ratios of 5.78~10.14 and weak negative Eu anomalies(δEu=0.69~0.89).Conclusions: These granodiorites chemically belongs to metaluminous—weak peraluminous, calc-alkaline I-type ones, and their magma could be mixed by mantle and crust, formed under the tectonic setting of extension. Combining regional geological characteristics, we propose that the east Junggar was in extensional setting after collision in Late Carboniferous, and with the characteristics of incremental emplacement.