均洞花岗岩体出露于钦杭结合带西南部，对揭示桂东北构造演化具有重要意义，其岩石组合为石英黑云母闪长岩、黑云母二长花岗岩和黑云母二长岩。文章运用LA-ICP-MS锆石U-Pb测年方法，获得均洞岩体的结晶年龄为423~430 Ma，为加里东期造山作用的产物。均洞岩体的SiO₂含量较低（55.47~62.95 wt%）；其中一个样品属于钾玄岩系列，其余均属高钾钙碱性系列，铝饱和指数A/CNK为0.70~1.18，样品为准铝质或过铝质，富集大离子亲石元素（如Rb、Ba、Th、U），亏损高场强元素（如Nb、Ta、Sr、P、Ti）。结合邻区壳幔混合特征及地球化学数据，认为均洞花岗岩体岩浆源岩具有多样性，可能存在不同来源的岩浆混合作用，为陆内碰撞造山后伴随软流圈的高温上涌，导致部分基性下地壳的部分熔融后，随着幔源物质的加入形成母岩浆，后经历不同程度的分异演化最终成岩。

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.