Paleoproterozoic metamorphism of high-grade granulite facies rocks in the North China Craton: Study advances, questions and new issues

This paper summarizes nearly all new data about the metamorphisms and geochronologist of Paleoproterozoic granulite-facies rocks in the NCC, and also full references other informations in the world. Three main kinds of granulites are pelitic, mafic and ultramafic granulites. They are closely associated in the space and record HP-HT granulite facies metamorphisms with similar metamorphic P-T paths and ages, implying they experienced the same geological history since their peak metamorphic stage. It is worth noting that all three granulites have high T/P gradients and abnormally slow uplifting rates. The concept of incipient plate tectonics has been established in the light of Paleoproterozoic HP-HT granulite facies metamorphism in the NCC. This tectonics presents lateral compressional structure and kinematic interaction between blocks, more or less similar to Phanerozoic collisional orogeny in tectonic style, but it is much smaller in scale. The crucial controlling factor could be Earth’s heat regime with considerable differences between Present and Ancient.