Integration of geophysical and remote sensing data for structural analysis and delineation of gold, fluorite, and barite mineralization in the Dawi shear belt, Egypt

Abstract

This study integrates multispectral satellite imagery, aperture radar (SAR) data, aeromagnetic data, and field observations to identify and delineate hydrothermal alteration zones associated with gold, fluorite, and barite deposits. This integration complements lithologic and structural mapping of the Dawi shear belt within the East African Orogenic Belt. The Enhanced Horizontal Gradient Amplitude (EHGA) filter was applied to RTP aeromagnetic and upward-continued (UWC) data at altitudes of 0.5, 1, and 2 km. The data delineated shallow and deep structural trends that may control mineralized zones of gold, fluorite, and barite. Euler deconvolution and source-parameter imaging were used together to reveal changes in the basement surface. The Dawi shear belt has experienced multiple deformation phases, beginning with NNW-SW shortening, followed by ENE-WSW compressional and sinistral transpression. This deformation is driven by NW-SE-oriented Najd shearing, which creates N-S-trending folds and dextral shearing, culminating in NE-trending folds. Sentinel-1 A backscatter images were used to enhance structural mapping and lineament detection, which are important for hydrothermal ore deposits and gold mineralization. PCA-based lineament density mapping from S1-A data revealed medium to moderately high concentrations in gneissic, ophiolitic, sedimentary, and volcanic units. The area is divided into three prospective zones for ore exploration, where minerals such as gold and fluorite are likely to be found. Fluorite deposits, classified as vein-type mineralization resulting from hydrothermal fluids, are located within pegmatitic veins aligned NE-SW and NW-SE, crossing schists and metavolcanics. Several zones of gold mineralization occur in the Dawi shear belt, with quartz and quartz-carbonate veins aligned with the Najd Fault System, and gold grades ranging from 0.003 to 0.6 g/t.