A Predictive GIS Model for Mapping Gold and Copper-bearing Alteration zones at South Gabal Um Monqul and Gabal Al Kharaza Prospects, North Eastern Desert, Egypt

This study reports the application of remote sensing data and knowledge-driven GIS modeling to provide favorability maps for gold and copper mineralized areas. The South Gabal Um Monqul (SGUM) and the Gabal Al Kharaza (GKZ) prospects located in the northern Eastern Desert of Egypt are the targets for the present study. Four thematic layers (lithology maps, old trenches buffer analysis, lineament density maps, and alteration zone maps) were prepared and used as inputs for a weighted overlay GIS model. Combined results from false color composite images, particularly the RGB parameters (PC۲, PC۱, and PC۳) and the RGB parameters (MNF۱, MNF۲, and MNF۳) classified the host rocks in both prospects. PCA-based extraction of lineaments was considered using line algorithm of PCI Geomatica. QuickBird band math (G+B), (R+G), and (G-B) for RGB was successful in delineating ancient workings within the mineralized zones. Old trenches layers were buffered to ۲۰ m wide bands extending in all directions. Landsat-۸ band ratios imagery (۶/۵ * ۴/۵, ۶/۷, and ۶/۲) in red, green, and blue (RGB) is potent in defining alteration zones that host gold and copper mineralizations. Acceptable scores of ۳۰%, ۳۰%, ۲۰%, and ۲۰% were assigned for the alteration zone maps, ancient workings buffer analysis, lithology maps and lineament density maps, respectively. Two favorability maps for mineralizations were generated for the SGUM and GKZ prospects. Validation of these maps and their potential application to detect new mineralization sites in the northern Eastern Desert were discussed.

کلیدواژه ها:

remote sensing ، GIS analysis ، gold and copper mineralization ، Favorability maps ، knowledge-driven method