Three-dimensional Quantitative Mineralization Prediction Study On Bainiuchang Silver Polymetallic Deposit In Mengzi, Yunna

The Bainiuchang Ag polymetallic deposit in Mengzi,Yunnan is located in the southeastern Yunnan tin polymetallic metallogenic belt.It was confirmed to be a super-large deposit in China in the 1980s.At present,there is an obvious tendency that the mine is in short supply of mineral resources,and thus there is an urgent need to start the exploration of deep hidden deposits in Bainiuchang Ag polymetallic mining area.In this paper,on the basis of reviewing a large amount of literature and data,we conducted a study on the Bainiuchang Ag polymetallic deposit,discussed the controlling effects of stratigraphic lithology,mining area structure and granite body on the formation of ore bodies in the mining area,constructed the geological body model and prediction model of the deposit by using 3D modeling software,and finally delineated the scope of potential concealed ore in the mining area.The main research results and conclusions are as follows:1.The exposed strata of Bainiuchang Ag polymetallic mining area are mainly Middle and Lower Cambrian and Lower Devonian,and the main occurrence horizon of ore body is Middle Cambrian Tianpeng Formation;the structure of the region is dominated by northwest faults,among which fault F₃has the greatest control effect on the ore body.The magmatic rocks in the mining area are mainly concealed granites intruded in Yanshan period,which have a certain influence on mineralization.2.Collected and organized a large amount of exploration engineering information of the mine area,and constructed a geological database model of the mine area based on the3D modeling software platform;on this basis,the geological model of Bainiuchang Ag polymetallic mining area is constructed by using the method of multi-source data interaction,including surface model,ore body model,fault model,stratum model and granite body model.3.Establishment of two mineralization prediction models,the weight of evidence method and the information value method,to delineate potential mineralization areas;the classification of potential metallogenic target areas is divided into three categories:A,B and C according to the decreasing order of metallogenic probability;Using the ROC characteristic curve analysis,it was found that the prediction effect of the information value method was slightly superior,and finally one class A target area and three class B target areas were delineated in the Bainiuchang Ag polymetallic mining area.