Porphyry copper prospectivity mapping using fuzzy and fractal modeling in Sonajeel area, NW Iran

Main purpose of this research is to present a local scale GIS-based mineral prospectivity model for prospecting Cu porphyry mineralization, and to validate the produced model by field observation, surface sampling and drilling data. Sonajeel area which is the subject of this study is a part of Arasbaran mineralization belt, NW of Iran. Constructing a mathematical exploratory algorithm based on a mineralization type is a complicated and interdisciplinary task. For this purpose, results from processing and interpreting different data sets including geology, geochemistry and remote sensing were considered. A comprehensive exploratory integration model was built up considering the exploration stage and the descriptive porphyry mineralization model suggested by Sillitoe (2010). In order to prepare inputs for GIS-based exploration model, value assigned grids or evidence layers were produced using fuzzy membership curves and then integrated via gamma fuzzy function. In addition, for defuzzification and prioritizing the mineral prospectivity map, a Concentration- Area (C-A) fractal model was applied on the pixel values of the prospectivity map. Finally, the results were confirmed via field observation, surface sampling and drilling. Borehole logs at the first priority displayed a Cu mineralization zone with an average grade of 0.5%