The present work aims at integrating detailed field studies to prospect for uranium ores associated with microgranite dike. The investigated El Sela area is covered by two types of granitic intrusion comprising biotite granite and two-mica granite. They are cut by microgranite, dolerite, and bostonite dikes, and quartz and jasper veins. U mineralization is observed along an ENE-WSW shear zone where quartz and jasper veins bounded the microgranite dike which is affected by successive brecciation and fracturing. Ferrugination, silicification, kaolinization, illitization, and fluoritization affected microgranite dike having visible U mineralization. Different fractures in two-mica granite acted as good channels for the ascending hydrothermal fluids and the percolating meteoric water that leached uranium from its bearing minerals disseminated all over the host two-mica granite and redeposited them in microgranite dike along the main shear zone trending ENE-WSW. Uranium was determined in the collected samples spectrophotometrically using arzenaso III as complexing agent. Uranium concentrations measured by chemical analyses are higher than the "gamma radiometric" determinations of the same microgranite samples, which can be explained by a state of disequilibrium in the uranium decay series. Sulphuric acid was used, in the present work, for leaching uranium from a representative mineralized sample of highly ferruginated microgranite. Conditions were briefly studied to achieve uranium recovery under optimum conditions. The acid-leaching operating conditions allowed us to obtain a uranium recovery of about 90 %. Ion exchange resin was used for the concentration and purification of our pregnant solution. A 75 % dry uranium concentration in final yellow cake product has been achieved.

The present work deals with geology, geochemistry, radioactivity and tectonic environment of the granitic and volcanic rocks at Hadarba area, South Eastern Desert of Egypt. The granitic rocks comprise tonalite-granodiorite and monzogranite, while the volcanic rocks include rhyolite, rhyodacite and dacite. These rocks are characterized by high concentrations of SiO 2 , Na 2 O, Fe 2 O 3 , K2O, Zr, Nb and Y but low in MgO, CaO, Cr, Ni, Sr, Ga and V. Field studies indicate that Dokhan volcanics extrude both tonalite-granodiorite and monzogranite with sharp contact forming a thick successive sequence of laminated acid lava flows, crystal lapilli tuffs and agglomerates. They range in composition from rhyolite, rhyodacite to dacite. Shear zone comprise lines-arranged intrusions trending NE-SW direction were recorded north Gabal Hadarba and extends for about 2.3 km in length with a width reaches up to 10 meter. These lines-arranged intrusions include quartz vein, microgranite and basic dykes. These shear zones cut through monzogranite. Petrochemical studies and tectonic discrimination diagrams for the monzogranite reveal that it is classified as granite developed in the within-plate tectonic environment, while Dokhan volcanics are classified as rhyolite and dacite developed in the immature island arcs and active continental margin environments. Field radiometric measurements of the granitic and volcanic rocks reveal low uranium and thorium contents.

The present work deals with geology, geochemistry, radioactivity and tectonic environment of the granitic and volcanic rocks at Hadarba area, South Eastern Desert of Egypt. The granitic rocks comprise tonalite-granodiorite and monzogranite, while volcanic rocks include rhyolite, rhyodacite anddacite. These rocks are characterized by high concentrations of SiO2, Na2O, Fe2O3, K2O, Zr, Nb and Y but low in MgO, CaO, Cr, Ni, Sr, Ga and V. Field studies indicate that Dokhan volcanics extrude both tonalite-granodiorite and monzogranite with sharp contact forming a thick successive sequence of laminated acid lava flows, crystal lapilli tuffs and agglomerates. They range in composition from rhyolite, rhyodacite to dacite. Shear zone comprise lines-arranged intrusions trending NE-SW direction were recorded north Gabal Hadarba and extends for about 2.3 km in length with a width reaches up to 10 meter. These lines-arranged intrusions include quartz vein, microgranite and basic dykes. These shear zones cut through monzogranite. Petrochemical studies and tectonic discrimination diagrams for the monzogranite reveal that it is classified as granite developed in the within-plate tectonic environment, while Dokhan volcanics are classified as rhyolite and dacite developed in the immature island arcs and active continental margin environments.Field radiometric measurements of these granitic and volcanic rocks reveal low uranium and thorium contents. Uranium contents range from 1.2 to 2.7 ppm in the tonalite-granodiorite, from 1.1 to 8.5 ppm in the monzogranite, from 1.3 to 9.3 ppm in the Dokhan volcanic and from 1.4 ppm to 15.4 ppm in the felsite dyke.

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