Mineral Resource Prediction and Assessment of Copper Multi-mineral Deposit Based on GIS Technology in the North of Sanjiang Region, China

On the basis of the multi-information on geology, geophysics, geochemistry, and remote sensing, mineral resource prediction and assessment is one of the keystones and popular topics in quantificational geosciences both in China and abroad, for it can not only be used to extract metallogenetic information and delineate metallogenetic targets, but provide important data for the quantitative assessment of mineral resources. This article takes the northern part of Sanjiang region in the south of Qinghai Province, China, as a case study area. On the basis of the conventional mineralized factors of mineral resource prediction and assessment, combined with the research on post-ore change and preservation, a new insight into mineral resource prediction and assessment, in terms of regional mineralization, change, and preservation factors, is built on account of the features of deposits at high altitudes, big slopes, emergence in surface, and denudation in the study area. According to the 24 copper complex deposits and geological settings in the study area, 29 variations, including mineralized factors, change factors, and preservation factors have been extracted by Geographic Information System (GIS) technology. To show the effect of the new insight, two mineral resource prediction models have been built with the 29 variations and 20 mineralized variations, respectively. Weight-of-evidence modeling is applied to map copper complex potential areas in this study area. The posterior probability maps of copper complex deposits delineated by weights of evidence method are made by contrasting mineralized factors with mineralization, and also changed factors with preservation factors. The results of the latter is better than that of the former: on one hand, the latter eliminates the nonmineralized area that is produced by glacier, water, or wind denudation; on the other hand, it can delineate mineral prospects that have concealed mineralized stratum or magma.