Knowledge-Driven Fuzzy AHP Model for Orogenic Gold Prospecting in a Typical Schist Belt Environment: A Mineral System Approach

In this paper, the knowledge-driven fuzzy AHP (FAHP) model was applied in the predictive prospectivity mapping of orogenic gold deposits using the mineral system approach. The main criteria of the mineral system of orogenic gold mineralization considered were heat source, gold/ligand source, structural control, and hydrothermal alteration. The proxies and alternatives of the main criteria of the mineral system of orogenic gold mineralization were derived from geological, geophysical, and remote sensing datasets. Assignment of weights using the FAHP model indicates that heat source with weight of 0.4318 has the highest contribution to orogenic gold mineralization in the study area. This was closely followed by gold/ligand source (0.3669), structural control (0.1659) and hydrothermal alteration (0.0355). The integration of these criteria using the multi-index overlay method produced the predictive mineral potential map (MPM) which was further classified into six classes (background, very low, low, moderate, high, and very high potentials) using the concentration area (C–A) fractal model. New major prospects of orogenic gold mineralization were delineated in the western and eastern flanks of the study area. The validation of the produced MPM using 10 geochemical sampling points via the prediction area (P–A) plot yielded 77% success rate indicating the model is suitable for predictive prospecting of orogenic gold mineralization. The study concluded that the mineral system approach should be adopted in further research in similar geologic environments for reliable potential mapping of any mineral deposits because it considers every “player” involved in mineralization.