干旱区生态环境知识资源中心

Eastern desert of Egypt is well-endowed with noble mineral resources that provide challenges for the future economy and development in Egypt. Such mineral resources are not yet well-mapped and fully understood; however, various geological maps are available. The newly advanced sensors of earth observations such as advanced space thermal emission and reflection radiometer (ASTER) images were functioned to map the lithology, the structural patterns and the alteration zones related to gold mineralization at the Fawakhir area, Central Eastern Desert of Egypt. Integration of band rationing and principal component analysis (PCA) clearly determined the lithological units of the study area. The alteration zones of the study area were efficiently mapped from the ASTER radiance data using reference spectra based on two supervised classification techniques including the spectral angle mapper (SAM) and spectral information divergence (SID). Field visits and laboratory microscopic examination of thin and polished sections were used for validating the process. The final resulted map of the alteration mineral zones consists of sericite, clay minerals, quartz, carbonate, and pyrite. Auto-detection of the structural lineaments, which are zones of deformation and fracturing that implies secondary porosity, was mapped from the satellite image. These structures represent significant pathways for migration of hydrothermal solutions, which influence the creation of the alteration zones and become potential zones for mineral resources. The spatial analysis showed the high correlation between the density of lineaments and the occurrence of the alteration zones, which represent high probability of the presence of gold deposits that validated against the old gold mines.