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This study focuses on the geochemistry of redox-sensitive elements of marine black shales at the Qusseir area of the Duwi Formation to infer their depositional environment. The black shales from the uppermost member of the Duwi Formation in the Qusseir area is conformably overlain by the Qusseir variegated shale and underlain by the Dakhla shale. Detailed mineralogical and geochemical characteristics were examined using several techniques, including X-ray diffractometry, scanning electron microscopy and X-ray fluorescence. Mineralogically, black shales in the Duwi Formation are composed mainly of montmorillonite, kaolinite, calcite, gypsum, quartz and pyrite. They are detrital and authigenic in origin. They are most probably derived from basic volcanic rocks by intensive chemical weathering under the prevalence of semiarid conditions. The redox-sensitive trace metals suggest anoxic sulfidic conditions that favoured the accumulation of these metals in the Qusseir area of the Duwi Formation.

T HE Duwi Formation in Qusseir-Safaga region is conformably overlain by the Qusseir variegated shales and underlain by the Dakhla shales. The studied phosphatic rocks in the Duwi Formation, is an attractive rock unit for it's enrichment in heavy metals and U content.Mineralogically, phosphatic rocks in the Duwi Formation are mainly composed mainly of fluorapatite, in addition to minor occurrence of calcite, dolomite, gypsum, quartz, and pyrite. Geochemical data reveal that the rocks of the Duwi Formation were deposited under anoxic environments. The present study used the statistical result of the interrelation between P 2 O 5 , F and U concentrations on Egyptian phosphate samples and compared to the measured data. Uranium mostly occurs in an oxidized U 6+ state. It could be fixed with the phosphatic ion, forming secondary uranium phosphate minerals such as phosphuranylite and belovite in Qusseir region. In addition to Uranyl phosphates, uranium minerals in Safaga region contain also Uranyl carbonates and Uranyl sulfates, which had been attributed to the post-depositional U enrichment. The chemical data and index show that the phosphatic rocks in Safaga region are more enriched in the majority trace and rare earth elements, and are subjected to high chemical weathering than those in Qusseir region.

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A SSIUT District represents an important part of central Nile Valley. It is a complex district containing many big industries, urbanization and agricultural activities. These activities can lead to the pollution of agricultural soil with toxic heavy metals. The aim of this work is the assessment of potential risks of these metals in soils using pollution indices; Enrichment Factor (EF), Index of Geoaccumulation (I geo ), Contamination Factor (CF), Ecological Risk Factor (E r ), Degree of Contamination (C d ), Pollution Load Index (PLI) and Potential Ecological Risk Index (PERI). The present study calculated the mentioned indices for eight heavy metals; As, Cd, Co, Cr, Cu, Ni, Pb, and Zn.Pollution indices calculations revealed that the investigated area can considered generally moderately polluted with the studied heavy metals. The emission of heavy metals from the factories as well as agricultural practices, urban runoff and sewage stations in the zone may be the source of that pollution. Consequently, control methods must be functional to the area adjacent to the factories to diminish the pollution. Finally, the studied cultivated soils showed low pollution than other cultivated soils in Australia,