Weight of Evidence Allocates Mineral Depositional Zones

Abstract

Problem statement: Yunnan province in general and Pulang area in particular is geological rich area which prevents field study in multi locations due to high risk outcrop. Approach: New technology such as Geographic Information System (GIS) and an ArcView extension module Arcweight of evidence (WofE) became very handy to provide safety for researchers and allow organization to control their budget. Results: In order to guide mineral exploration, to achieve the purpose of rapid evaluation of mineral resources a serial of modeled prediction methods were established. Weight of evidence model is to predict the existent thing by combining the known evidence of the study area, the importance of evidence is determined based on statistical method. Contrary to the fuzzy logic method, it avoids the subjective selection of evidence and the subjective evaluation of evidence. The weight of evidence can determine the weight in the same standard conditions (using known mine sites as guidance data), so that the variables can be compared in the united scale, a higher reliability. Conclusion/Recommendations: Comparing predicted and known distribution patterns of porphyry, most mine sites are located in the areas with high posterior probability, forecast area accounts for 11.5% of the entire study area. Predicted results show clearly that the boundary of potential areas and the non-potential areas is clear. Therefore, fuzzy logic and other methods should be applied to predict the results for further comparison. More accurate prediction would draw a big smile on faces of share holders.