Hydrothermal Alteration Mapping Using Landsat 8 and ASTER Data and Geochemical Characteristics of Precambrian Rocks in the Egyptian Shield: A Case Study from Abu Ghalaga, Southeastern Desert, Egypt

This study evaluates the geological attributes of rocks within Abu Ghalaga area using spatial, geochemical, and petrographic approaches. ASTER Landsat imagery processed band ratio principal component analysis were used to map hydrothermal alterations, while a regional tectonic evaluation was based on automated extraction lineaments from digital elevation model. Geochemical analyses then employed for discrete scale alteration patterns across location. Based satellite image processing, are widespread, evidence lineament suggests dominant NW–SE trend accompanied by less ENE–WSW direction. The different rock units exposed in studied district arranged chronologically oldest youngest as arc metavolcanic group (basalt rhyolite), metagabbro–diorite, gneissose granite (granodiorite tonalite), dykes (aplite felsite). Various types igneous metamorphic have propylitic, phyllic, argillic zones. data indicate that classified into granite, granodiorite, gabbroic diorite, gabbro. Geochemically, sub-alkaline magma type. granodiorite–tonalite is derived calc–alkaline nature, gabbro diorite samples exhibit tholeiitic affinity. setting trends toward volcanic (VAG). petrographic, remote analyses, sericitization, chloritization, epidotization, kaolinitization, carbonatization, silicification main present area. As result analysis, existing fractures structural planes form valid flow paths mineral-bearing solutions.