1. College of Earth Sciences, Jilin University, Changchun 130061, China;
2. Heilongjiang Mining Group CO., LTD, Harbin 150036, China

In this study, the authors present new zircon U-Pb age and whole-rock major and trace element data for the Niubiziliang granodiorite in the northern margin of Qaidam Basin. LA-ICP-MS zircon U-Pb dating demonstrates that the concordant age and the corresponding weighted mean age of the granodiorite are 393.2~395.6 Ma and (394.4±2.4)Ma, respectively, indicating that the intrusion occurred in the Middle Devonian. The granodiorites are characterized by high SiO₂ (65.70%~69.22%) and Al₂O₃ (14.96%~16.03%), but low MgO (1.37%~1.89%), the rocks fall into the calc-alkaline and metaluminous series with the A/CNK values of 0.95~0.98, being of the characteristics of I-type granite, suggesting that the primary magmas of granodiorites were derived from partial melting of the lower crust. They have high rare elements contents, without obvious Eu anomalies(δEu=0.95~1.30). They are enriched in LREEs and large ion lithophile elements (e.g. K, Rb, Ba and U), depleted in HREEs and high field strength elements (e.g. Nb, Ta, Ti, Th and Zr).Meanwhile, the granodiorites are similar to the post-collision granite geochemically. Integrating the continental volcanic rocks of Maoniushan Formation in the Late Devonian and regional tectonic evolution, we conclude that the granodiorite intrusion was formed in the extensional setting after the collision between the Qaidam block and Southern Qilian block.