选择盐边群底部荒田组玄武质岩石(原划为蛇绿岩),通过岩石化学和微量元素地球化学研究,认为盐边群玄武质岩石可能形成于弧后盆地环境;通过SHRIMP锆石U-Pb年代学研究,获得玄武质岩石岩浆结晶年龄为782±53Ma,其形成时代为新元古代。同时获得其中继承性变质锆石年龄为1837±14Ma。变质锆石年龄可能代表扬子地台西缘变质基底年龄,证明扬子地台西缘可能存在古元古代变质基底。 Based on the petrochemical and trace element geochemical studies, it is considered that the Yanbian Group basaltic rocks may be formed in the backarc basin environment. Through the SHRIMP zircon U- Pb dating, the crystallization age of the basaltic rocks was 782 ± 53Ma, and the formation age was Neoproterozoic. At the same time, the inherited metamorphic zircon ages were 1837 ± 14Ma. Metamorphic zircon ages may represent the age of the metamorphic basalts in the western margin of the Yangtze platform, indicating that there may be Paleoproterozoic metamorphic basement in the western margin of the Yangtze platform.