Geochemistry and Petrogenesis of the Proterozoic Granitoids in the East Shandong Peninsula,China
胶东东部地区元古宙花岗岩类的地球化学及岩石成因

The granite gneiss complex in eastern Jiaodong peninsula can be divided into three kinds of lithologies, i.e.(1) quartz dioritic tonalitic granodioritic gneiss,(2)adamellitic granitic gneiss; and (3)leucocratic granite.The intrusion sequences among them can be identified and the tabular zoned plagioclase crystals,belonging to plutonic mineral fabrics are widely preserved in the intrusions.The geochemistry of the different lithologies shows the features of independent evolution and the characteristics of anatectic granites. Combined with isotopic ages,it has been determined that they are the granites formed during different stages of Proterozoic orageny.These rocks are commonly intensively depleted in Ti, Y, Sr, Ni, Mg, etc.,which proves that the magma was not directly derived from upper mantle or lower crust and they were the products of the anatexis of rocks that were formed in different stages of Proterozoic. This conclusion is very helpful to understand the Proterozoic crustal formation and evolution mechanism of the east sector of the south margin of North China platform.