Abstract: Zarijia metamorphic core complex in the northern part of Bayankala Mountain has the typical double-layer structure.The dome anticline of the Zarijia metamorphic core complex consists of tectonic schist,tectonic gneiss and phyllite and the middle of the core is Yanshanian monzonitic granite.The cover layer consists of the low metamorphic sand-slate.There are stripping faults between the core part and the cover layer,showing that there exists Mesoproterozoic basement below the Bayankala sedimentary basin,and providing a new genetic type for the Dachang gold mine.