Geochemical prospecting for lead and zine in Gebel el Rousas,Eastern Desert,Egypt

Gebel El Rousas is an isolated hillock in the Eastern Desert of Egypt. It consists of the Basement Complex (subsurface) which is non-conformably overlain by the Middle Miocene and successively by Pleistocene-Recent terraces. The Miocene strata are mineralized by oxidized hypogene lead-zinc deposits.Geochemical prospecting was attempted for the first time in Gebel El Rousas and for the second time in Egypt. The old terraces of gravels and sands covering the hillock were sampled on a grid pattern of a 30 m spacing. The samples were taken at a depth of 30 cm from the surface. They were sieved to –150 mesh and analyzed for Pb, Zn, Cu, Fe, Mn, and CO₂.Significant contrasts and anomalies resulted for Pb, Zn, and Fe. The main anomalies are parallel and generally coincide with the subsurface mineralized zone which is inferred to cross the area on the same trend. The mineralized zone extends as shown by the geochemical pattern southward, from the known northern part, to a southern district which has not been checked by drilling or any other testing.

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Zusammenfassung Djebel El Rousas ist ein isolierter Hügel in der Ägyptischen Ostwüste. Er besteht aus dem Basementkomplex, der diskordant von MittelmiozÄn und aufeinanderfolgend von PleistozÄn-HolozÄn-Terrassen überlagert wird. Die MiozÄn-Schichten sind mit oxydischen hypogenen Blei-Zink-Ablagerungen vererzt.Im Djebel El Rousas wurde zum erstenmal der Versuch einer geochemischen Prospektion durchgeführt, für ganz Ägypten ist es das zweite Mal. Gitterförmig wurden im Abstand von 30 m den alten Kies- und Sandterrassen, die den Hügel bedecken, Proben aus einer Tiefe von 30 cm unter der OberflÄche entnommen. Die Proben wurden mit 150 Maschenweite gesiebt und auf Pb, Zn, Cu, Fe, Mn und CO₂ analysiert.Eindeutige Kontraste und Anomalien wurden für Pb, Zn und Fe festgestellt. Die Hauptanomalien sind parallel und fallen normalerweise mit der mineralisierten Zone unter Tage zusammen, die das Gebiet in derselben Richtung durchquert. Wie aus der geochemischen Karte hervorgeht, setzt sich die vererzte Zone nach Süden in ein Gebiet fort, das bisher noch nicht durch Bohrungen untersucht wurde.

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Résumé Gebel El Rousas est un monticule isolé dans le Désert Oriental de l'égypte. Il se compose de roches du Basement Complex (sous-sol) surmontées en discordance par des terrasses du Miocène Moyen et succéssivement par des terrasses du Pleistocène-Récent. Les couches du Miocène sont mineralisées par des dépÔts hypogènes de plomb et de zinc oxidés.Les prospections géochimiques furent essayées pour la première fois au Gebel El Rousas et pour la seconde fois en égypte. Des échantillons des anciennes terrasses de galets et de sables recouvrant ce monticule furent prises en une carte quadrillé de 30 m. Les échantillons furent prélevés à une profondeur de 30 cm de la surface. Ils furent criblés jusqu'aux mailles de 150 analysées pour la détermination de Pb, Zn, Cu, Fe, Mn, et CO₂.Des contrastes et des anomalies significatifs furent obtenus pour le Pb, Zn, et Fe. Les anomalies essentielles sont parallèles et généralement coincident avec la zone minéralisée du sous-sol qui est supposée traverser la région suivant la mÊme direction. La zone minéralisée s'étend comme l'indique la carte géochimique du Nord au Sud vers un district qui n'a pas été vérifié par forage ou par toute autre méthode éxpérimentale.

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The transboundary non-renewable Nubian Aquifer System of Chad,Egypt, Libya and Sudan: classical groundwater questions and parsimonious hydrogeologic analysis and modeling

Parsimonious groundwater modeling provides insight into hydrogeologic functioning of the Nubian Aquifer System (NAS), the world’s largest non-renewable groundwater system (belonging to Chad, Egypt, Libya, and Sudan). Classical groundwater-resource issues exist (magnitude and lateral extent of drawdown near pumping centers) with joint international management questions regarding transboundary drawdown. Much of NAS is thick, containing a large volume of high-quality groundwater, but receives insignificant recharge, so water-resource availability is time-limited. Informative aquifer data are lacking regarding large-scale response, providing only local-scale information near pumps. Proxy data provide primary underpinning for understanding regional response: Holocene water-table decline from the previous pluvial period, after thousands of years, results in current oasis/sabkha locations where the water table still intersects the ground. Depletion is found to be controlled by two regional parameters, hydraulic diffusivity and vertical anisotropy of permeability. Secondary data that provide insight are drawdowns near pumps and isotope-groundwater ages (million-year-old groundwaters in Egypt). The resultant strong simply structured three-dimensional model representation captures the essence of NAS regional groundwater-flow behavior. Model forecasts inform resource management that transboundary drawdown will likely be minimal—a nonissue—whereas drawdown within pumping centers may become excessive, requiring alternative extraction schemes; correspondingly, significant water-table drawdown may occur in pumping centers co-located with oases, causing oasis loss and environmental impacts.     

Characterization of some bacterial strains isolated from the Egyptian eastern and northern coastlines with antimicrobial activity of Bacillus zhangzhouensis OMER4

Marine microorganisms were considered to be important sources of marine bioactive compounds. The major objective of the study was to isolate and characterize bacteria with antimicrobial activities from the various marine environment of Egypt. In this respect, thirty-five bacterial isolates were recovered from sediment samples collected from different spots along the Egyptian Red Sea coastline and Alexandria coastline during the summer season of 2017 and 2018. According to the morphological, phys...