Geology and mapping of laterites, South Eastern Desert, Egypt: Based on field and ASTER data approach

The area between wadi Dungash–wadi Shait in the South Eastern Desert of Egypt comprises ophiolitic nappes structurally overthrust on island arc‐related metasedimentary–metavolcanic rocks, which are traversed by several granitoids, gabbroic and basaltic rocks. This paper focuses on uncovering laterite zones utilizing field geological, mineralogical and geochemical attributes of the investigation region. Laterites are distributed at the border between Neoproterozoic and Phanerozoic rocks. The laterite deposits are developed after the emplacement of Natash flows as a result of lateritization process in tropical regions, during the Late Cretaceous. The laterite sections comprise a sequence from the top to the base, oxide laterite, plasmic laterite, saprolith and bedrock. The laterite sections consist of hematite and goethite together with small quantity of gibbsite. Geochemically, the laterite profiles are marked by an increase in Fe content and decrease in Si from the top to the bottom. Fe 2 O 3 is the most abundant with 30.09–54.67 wt.%, Al 2 O 3 vary from 18.01 to 32.78 wt.%, and SiO 2 vary from 15.05 to 19.43 wt.%. Advanced Spaceborne Thermal Emission and Reflection Radiometer images are utilised to characterize a primer laterite zone. The band ratio 4/5 is found to be efficient in defining the laterite soil in the studied area.