Risk-Based Analysis in Mineral Potential Mapping: Application of Quantifier-Guided Ordered Weighted Averaging Method

Abstract

In this work, a quantifier-guided ordered weighted averaging (OWA) method was employed for mineral potential mapping (MPM) in Nowchun Cu–Mo prospect, SE Iran. The proposed knowledge-driven method has the capability of incorporating the geologists’ preference (weight) and attitude toward risk analysis during MPM. Since quantitative determination of OWA parameters is a tough task, employing linguistic quantifiers aid geologists to simply define their desired strategy for MPM. To implement the method, eight weighted criteria spatially associated with mineralization were derived from geological, geochemical and geophysical datasets. The evidential layer integration was implemented using various OWA operators, which is generated by employing seven linguistic quantifiers. As a result, seven mineral potential maps, which report favorability index from 0 to 1, were produced in a spectrum range of risk from extremely optimistic to extremely pessimistic. According to results, the western and southeastern part of the study area were detected as regions with the lowest and highest mineral favorability. For validation, the results of subsequent geological field works and 106 drilled boreholes were taken into account. The evaluation indicated that the mineral potential map based on the “Some” quantifier has the highest correspondence with underground 3D mineralization zones of Cu and Mo. The mineral potential map based on the “Some” quantifier delineated two main prospective zones in the eastern and central-north parts of the study area. The former zone was recently investigated by drilling, but the latter zone was proposed for new drilling operation. Applying the proposed method in each scale of target delineation (a) generates various continuum favorability maps; (b) reveals mineralization patterns in the study area; and (c) provides an opportunity in exploration to select the optimal mineral potential map for detailed exploration tasks regarding the geologists’ attitudes toward risk and project budget.