ABSTRACT
About 120 samples representing the Carboniferous and the Cretaceous kaolin deposits collected from Sinai, Eastern Desert, Aswan and W. Kalabsha were petrographically, mineralogically and chemically investigated by means of XRD, XRF SEM, DTA, IR and the Geoscan Electron probe x-ray microanalyzer. These studies reveal the presence of traces of illite, montmorillonite and montmorillonite-illite, biotite-vermiculite and kaolinite-montmorillonite mixed layer, in addition to kaolinite which is the major clay mineral. The main non-clay minerals identified are quartz, feldspars, gypsum, anhydrite, rutile, anatase, brookite, nepheline, natrolite, zircon, tourmaline, apatite, iron oxides and carbonaceous material. The Carboniferous kaolin deposits are characterized by the presence of traces of rhodochrosite (MnCO3), which is mainly associated with iron oxides, gypsum, anhydrite, gibbsite, diaspore and carbonaceous material. Sandy kaolin deposits of the Cretaceous age contain traces of anatase, magnetite, zircon, rutile and apatite. Traces of gypsum anhydrite and goethite characterize the Senonian (Upper Cretaceous) pisolitic kaolin from W. Kalabsha area. The depositional environment of the different kaolin deposits is discussed in the light of the above mentioned data.
