Comparison of geological characteristics between the Guidong pluton and its peripheral granite in northern Guangdong Province and its significance

Previous studies on the Guidong complex pluton have mostly focused on a single rock mass, and the geological characteristics and mineralization factors of the entire rock mass have not been comprehensively compared and analyzed. This paper aims to further investigate the reasons for the differences in uranium mineralization between the Guidong pluton and its peripheral granite bodies in northern Guangdong. It systematically analyzes the geological characteristics, magmatic evolution stages, mineralogical characteristics, and geochemical characteristics of the Guidong pluton and its surrounding granite bodies. The results indicate that during the evolution of magma, the changes in crystal size of magma are reflected in the content of mineral components, mainly manifested as a gradual increase in quartz content, a gradual decrease in plagioclase content, and the gradual replacement of feldspar by albite, and a decrease in biotite content replaced by muscovite. Compared with the eastern granite in the central and western parts of the Guidong pluton, the content of hornblende and plagioclase is relatively high, and self metamorphism and metasomatic alteration are weaker. The mineral composition of the eastern granite basically does not contain hornblende, and the content of plagioclase is generally low, with strong self metamorphism and metasomatic alteration. The geochemical characteristics indicate that the western central rock mass belongs to subalkaline weakly peraluminous granite bodies, while the eastern and peripheral parts belong to subalkaline weakly peraluminous peraluminous granite bodies. This indicates that there may be a small amount of mantle derived components added during the formation process of the western central rock mass, and it is believed that they are not products of partial melting of homologous materials to varying degrees, but rather formed by partial melting of materials from different homologous regions.