Mapping uncovered a multi-phase arc-back-arc system in the southern Beishan during the Permian.

The Central Asian orogenic belt(CAOB),surrounded by the Baltica and Siberia cratons to the north,and the Tarim and North China cra-tons to the south,records successive evolution cycles of subduction and ac-cretion/collision from Neoproterozoic to the Paleozoic that consumed and eventually closed the Paleo-Asian Ocean[1].