THE DUAL-EVOLUTIONARY SERIES OF ARCHAEAN GRANITOIDS AND THEIR, FORMATION IN NORTHERN LIAONING PROVINCE
辽北太古宙花岗质岩石的双重演化系列及成因机制

In northern Liaoning Province, there exists a great area of Archaean granitoid, which is dual-evolutionary, and represents a tonalitic-trondhjemitic(TT) trend and a calc-alkali(CA) trend. The study shows that the TT trend, as a fractional-crystallized differentiated magma series of a tonalitic magma, represents the evolutionary feature of paleo-plutonic intrusion before late Archaean metamorphism, and the CA trend, as a result of anatexism of Paleo-intrusion during the Late Archaean metamorphism, represents a magmatic system with variable amount of melts and residual materials. It can be concluded that the Archaean granitoid in this area is a composite product of TT and CA trends, and the CA trend is not primarily characteristic of Archaean granitic magmatism.