Abstract: The Jundong granitic pluton is located in the southwest of the Qin-Hang belt, with the rock combination of dioritetonalite-granodiorite. In this study, we present LA-ICP-MS zircon U-Pb ages of granitic rocks from the Jundong pluton, the crystallization age of the Jundong rock body is 423-430 Ma, belonging to the Caledonian period. The rocks have lower SiO₂ contents of 55.47-62.95 wt%. One of the samples belongs to the shoshonite series and the others are high-K calc-alkaline series. The A/CNK values are 0.70-1.18, showing as quasi-aluminous or peraluminous rocks. The rocks are enriched in large ion lithophile elements (LILE, e.g., Rb, Ba, Th and U) and relatively depleted in high field strength elements (HFSE, e.g., Nb, Ta, Sr, P and Ti) relative to primitive mantle. The Jundong granitic pluton are mixing products of different original rock sources and formed in the intracontinental collisional orogenic tectonic environment.

Key words: Jundong granitic pluton, Caledonian period, geochemistry, zircon U-Pb dating, tectonic environment, Northeastern Guangxi