No abstract

No abstract

No abstract

The integration of the ASTER image processing and the airborne spectrometric Gamma-Ray interpretation helped in identifying the types and illustrating the distributions of the probable sites for radioactive mineralization at the Gabal Abu Garadi area. Appling various techniques of image processing for Landsat OLI and ASTER satellite to discrimination the differently exposed rock units and extract major and minor structural lineaments. This study resulted that the ASTER VNIR-SWIR bands are effectively used for clarifying the sericite, kaolinite, chlorite, illite and hematite bearing alteration zones, whereas the ASTER TIR bands are most effective in delineation of the silica-rich zones which could be pathfinders for radioactive mineralization within the study area. The resultant alteration maps show good coincidence with the explored uranium sites and suggest further similar unexplored sites. The predominance of low eTh/eU= 1.31 indicates U mobilization and reveals that magmatic differentiation was not the sole process responsible for the concentration of these radioactive elements in the Abu Gradi area. Where the presence of adequate structures such as shear zones and fault planes facilitates the circulation of hydrothermal fluids and meteoric waters leading to mobilization and a redistribution of uranium. This paper could assist the principals of uranium exploration techniques.

The integration of remote sensing, spectral measurements and field verification helped in discriminating new iron occurrences hosted in the metavolcanic rocks at Wadi Karim and Gabal El-Hadid areas in the Central Eastern Desert (CED) of Egypt. The iron host rocks were carefully recognized through different image processing techniques that were applied on Landsat-8 satellite image data with the implementation of the spectral signatures of the various iron minerals and host rocks. The detected iron ore is found in the form of Banded Iron Formation (BIF), veins and lenses of varied thicknesses ranging from a few centimetres to 5 m. They are composed mainly of magnetite and hematite, as well as accessories of aluminium, iron silicates and quartz. Moreover, the structure controls on iron ore occurrences were also illustrated in the investigated areas. The alignment of the iron forms with the primary and secondary structural planes of their host rocks may indicate the origin and mode of occurrence of the explored iron ore, as contemporaneous and syngenetic deposition with the solidification of the host metavolcanics. Several remote sensing techniques including Crosta principal component analysis (CPCA), constrained energy minimization (CEM) supervised classification technique and a newly proposed Landsat-8 band ratio (band6/band2) were applied for discriminating the iron-rich localities within the studied areas. These techniques showed high efficiency and applicability in the accurate delineation of the iron-enriched areas; this was validated through the field study.