Abstract:Skarn and hydrothermal vein deposits constitute the main resources of lead and zinc in the Gangdise metallogenic belt. In recent years, especially since the beginning of the Geological Survey Project in 1999, great progress in geological survey and resource exploration has been made, several large-size lead and zinc ore deposits have been discovered, and many important regional geological data have been accumulated in Gangdise region. Based on detailed collection of geological, ore deposits, minerals, geophysical and geochemical data and remote-sensing information in this region, the authors established a mineral resources evaluation system based on GIS technology. The basic data of the mineral resources evaluation system cover a wide range of information, which includes geology (stratigraphy, tectonics, magmatic rocks and metamorphic rocks), minerals (ore deposits and mineralized spots), geophysical data (magnetic and gravitational method), geochemical data (individual and composite Cu, Pb, Zn, Ag, Cd and Au geochemical anomalies) and geography. Using characteristic analysis model and mathematical statistics, the authors determined the metallogenic model and quantitative geological variables for prognosis of skarn and hydrothermal veinlike lead and zinc deposits respectively, which constitute the dominant lead and zinc ore types in the Gangdise metallogenic belt. The result has shown that the most important geological factors for the prognosis of lead and zinc deposits include intermediate-acid granitic intrusive bodies, known ore deposits and mineralized spots, individual Cu, Pb, Zn, Ag, Cd, Au, Bi geochemical anomalies, composite Cu-Pb-Zn-Ag, Pb-Zn, Pb-Zn-Ag-Cd geochemical anomalies, positive-negative change of magnetic anomalies, and middle-low negative gravity anomalies. According to the calculation of the MRAS system (developed by Institute of Mineral Resources, CAGS), 57 target areas for skarn and hydrothermal vein lead and zinc deposits were delineated in the Gangdise metallogenic belt. The results obtained by statistics are in well accord with the geological deduction. The lead and zinc reserves were estimated by the areal productivity method, which shows that there still exists great potential for lead and zinc deposits in Gangdise region, and that the predicated lead and zinc reserves within the depth of 1000 m are over 290 million tons. The most potential lead and zinc target areas mainly include Yaguirang-Sharang-Dongzhongsongduo, Bangpu-Songduoxiong-Xiamari-Nongruri, Zexue lead and zinc deposits, Bengbunong gold deposit, Mengyaa-Longmala etc., in which the potential lead and zinc reserves are over 20 million tons.