NEW ADVANCES IN THE STUDY OF THE DENGFENG COMPLEX IN THE SONGSHAN REGION, HENAN PROVINCE

Through a further study, the original Dengfeng Group is divided into three parts: （1） a Neoarchaeozoic tectonostratigraphic unit named the Dengfeng Group Complex, a meta surpracrustal rock series, representing the greenstone formation; （2） a Neoarchaeozoic tectono lithostratigraphic unit, a metamorphic intrusive rock series; （3） the Early Palaeoproterozoic intrusive rock series. All of the three parts combine to form the Songshan granite greenstone terrane. The Neoarchaeozoic rocks underwent three major stages of deformation and metamorphism: （1） the first episode of the Songyang orogeny （about 2.5 Ga）; （2） the second episode of the Songyang orogeny （about 2.2 Ga）; （3） the Zhongyue orogeny （about 1.9 Ga）. The p T t D path shows that the deformation and metamorphism of the granite greenstone terrane were closely related to the process of the continental crustal collision and uplift.