Collision belt between the Khanka block and the North China block in the Yanbian Region, Northeast China

摘要

The pre-Jurassic geotectonics in Northeast China and its adjacent regions are characterized by collision of microcontinental blocks. The Yanbian region lies between the North China block (NCB) and the Khanka block (KB). Along the Dashanzui-Antu-Kaishantun collision belt, the Yanbian pre-Jurassic fold belt can be divided into two parts. One part represents the western margin of the KB, which consists of Late Proterozoic metamorphic basement and a Permian active continental margin. The other one is located at the eastern margin of the NCB and is composed of Proterozoic passive margin deposits, where the Seluohe and Qinglongcun groups are developed, and rocks of the Permian passive margin. Collision of these two parts took place along the Dashanzui-Antu-Kaishantun collision zone during the Late Permian to Early Triassic, as evidenced by the emplacement of syncollision granites and A-type granites. In northeast China and adjacent regions, a series of microcontinental blocks collided with one other from the end of Early Paleozoic to the Early Triassic. The collision event that took place in the Yanbian region may represent the latest collision event in the Paleo-Asian oceanic domain.