Development of Porphyry Copper-Molybdenum-Lead-Zinc Ore-forming System in East Gangdese Belt, Tibet: Evidence from Re-Os Age of Molybdenite in Bangpu Copper Polymetallic Deposit;

Discussion on sectional mining,technical feasibility and economic rationality of steep side expansion of Guangou quarry is made and some issues to be noted are proposed due to the problems existing in the design and mining of the quarry,such as large stripping volume in the initial mining stage and voriation in stripping ratio during mining.