CHARACTERISTICS AND GEOLOGICAL IMPLICATION OF THE CRYPTOEXPLOSIVE BRECCIA IN THE DALETINGCHAGAN Pb-Zn-Ag DEPOSIT IN INNER MONGOLIA

The Daletingchagan Pb-Zn-Ag ore deposit is located in the northeastern part of the Qagan Obo Fe-Pb-Zn metallogenic belt in the middle section of Daxinganlin Mountains. The wallrocks of ore are the Upper Jurassic Manketouebo Formation and the acid crypto-explosive breccia within the Yanshanian granite porphyry. The breccia body has a significant lithologic zonation, from rubble-bearing tuff at the center, with increasing of rubble size, gradually to shattered breccias in outside. The breccia is strongly altered with an obvious alteration zoning, mainly including kaolinization, chloritization, epidotization, sericitization, carbonatization and locally strong silicification. The orebodies occur as veins in the breccia body. The study of the crypto-explosive breccia will provide a significant reference for the ore prospecting in the depth and adjacent areas.