桂东北都庞岭花岗岩中体和东体的成因联系

The Genetic Relationship between the Middle and East Bodies Granite in Du Pangling,Northeast Guangxi

桂东北地区都庞岭岩体是一个复式岩体,分为西体、中体和东体,其中西体为加里东期,中体和东体则存在争议。本文对都庞岭岩体的中体和东体进行年代学、岩相学和全岩地球化学研究,为都庞岭岩体的期次划分提供新的依据。中体和东体在野外未见明显的分界现象,其岩相学特征和全岩地球化学非常相似,锆石U-Pb测年分别获得220Ma和218Ma的平均年龄值,很可能是同一期岩浆脉动侵入结晶的产物。

Dupangling rock is a complex rock in the northeast Guangxi.It is divided into western,middle and eastern bodies.The western part is Caledonian,the middle and east are controversial.New evidence for determining their intrusive sequences is provided by carrying out geochronology,petrography,and bulk rock geochemistry analyses on the mid-body and east-body of the Dupangling granite.Zircon U-Pb dating results show that the mid-body was formed at about 220 Ma,while,the east-body was formed at about 218 Ma,which are consistent in age.Meanwhile,the two bodies are similar in petrography and bulk rock geochemistry.Additionally,there is no geological boundary between the two rocks.These features all indicate that the mid-body and east-body of the Dupangling granite were formed from the same pulse of magma.