الفهرس 
Clay and Iron ores in Aswan area:
etrographic Examination:Only 14 pages are availabe for public view
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Abstract
The economic Ball clays deposits are relatively scarce in Egypt. This is due to the combination of geological factors needed for their formation and preservation. The economic Ball clays are mined in wadi Abu Subeira and Wadi Abu Aggag to the north east of Aswan City as the main raw materials for ceramic and tile industries. The present study aims to use remote sensing, fieldwork and laboratory examination to make the lithostratigraphic classification and mapping of the area around Aswan city. In addition, it provides an attempt to evaluate the clay minerals in this area. The petrographical examination of the studied sections enabled to identify four microfacies types: Quartz arenite microfacies, Quartz greywacke microfacies, Conglomerate facies, Mudstone and claystone microfacies. Mineralogical analysis carried out by X- Ray Diffraction (XRD) indicated that the most dominant clay minerals in the study samples are kaolinite and traces of illite and illite/smectite (I/S) mixed layers. Scan Electron microscope (SEM) observations show distorted crystals, swirl texture with face to face arrangement, lack the famous booklet shape of kaolinite suggesting a detrital origin of kaolinite. The kaolinite was formed as a chemical weathering product of feldspars in the nearby acidic igneous rocks under humid and warm climatic conditions. A total of nineteen stratigraphic sections of the exposed sedimentary sequence were measured and described (13 sections from Wadi Abu Subeira and 6 sections from Wadi Abu Aggag, north east Aswan). Lithostratigraphically, the economic Ball Clay bearing sequence at Wadi Abu Subiera and Wadi Abu Aggag is differentiated into three rock units from older to younger: The Araba Formation of Cambrian-Ordovician age, The Gilf Formation of Carboniferous age and the Abu Ballas Formation of Late Jurassic-Early Cretaceous age. In Wadi Abu Subeira, The base of the Gilf Formation is defined by the first appearance of iron ore bed in the area of the former iron mines of Aswan. The Gilf Formation includes three clay beds. The clay beds are a character of the so-called Ball clay shale, currently of economic use in ceramics industry. The optical and radar remotely sensed data are used to make geologic and mineralogic mapping. Three types of satellites images of Landsat-8, ASTER, and Sentinel-2 processed and interpreted. Different image processing techniques such as band combinations, band ratio, PCA, MNF, DS were applied to discriminate the lithologic units. The processed images are successfully enhanced the lithologic contacts between the three main stratigraphic formations in the study area. A new and update geologic map is introduced. ASTER data are used to detect the mineralogical contents of iron and clay minerals in the area by using the mineralogical indices. Moreover, structural framework of the area is analyzed and its relation to the mineralization is discussed.