Calcic iron skarn prospectivity mapping based on fuzzy AHP method, a case Study in Varan area, Markazi province, Iran

摘要

Fuzzy analytical hierarchy (AHP) approach is a method for mineral prospectivity mapping (MPM) that is generally used for mineral exploration. This method is feasible for multi-criteria decision-making (MCDM) issues. Geographical information system (GIS) and fuzzy AHP have been applied in this paper to obtain prospectivity model for Calcic Iron Skarn (CIS) mineralization. Several thematic (such as geological, geophysical, and geochemical) geo-datasets have been collected, analysed and integrated based on fuzzy AHP method, in Varan area, central of Iran. Three professional economic geologists with the experience on exploration of CIS mineralization have been used to allocate appropriate weights to layers. Then fuzzy operator was used to integrate weighted evidence layers and mineral prospectivity map of CIS mineralization in Varan area was generated. Eventually for confirming the accuracy of the applied manner, locations of recognized mineral deposits in the Varan area were compared with the generated mineral prospectivity map. The results presented acceptable responses. For detailed assessment of the CIS mineralization model and due to the fact that geological features have fractal dimensions, we used C-A model for classification of prospectivity model to determine thresholds for the final prospectivity map. C-A fractal model, determine thresholds for classifying values in evidential maps. The final prospectivity map was confirmed by checking field of three target areas.