Egyptian Desert Research Articles

Multiscale Characterization of the Albian-Cenomanian Reservoir System Behavior: A Case Study from the North East Abu Gharadig Basin, North Western Desert, Egypt

Since its discovery in 2010, the NEAG 2 has been one of the most productive oil fields of the Badr El-Din Petroleum Company (BAPETCO) in the northern Western Desert of Egypt. The Albian-Cenomanian reservoir system has a unique performance but suffers from several issues hindering its production. The latest production report in 2023, NEAG-2 Field was producing 1760 bbls of oil with 36500 bbls of water, i.e., 95% water cut. Despite that, the field has reached a 39% recovery factor but the reservoir forecast suggests a much higher recovery factor. Therefore, the NEAG 2 Field requires a comprehensive geological model to depict its reservoir heterogeneities better. We introduce a solid and integrated workflow to investigate the reservoir characters among different scales of geological heterogeneity and offer solutions to overcome some data gaps. After characterizing the reservoir elements by the structural, stratigraphic, petrographic, and petrophysical analyses, a machine learning-based method was applied to overcome the missing whole rock cores in creating a detailed electro-facies log for all field wells. The Neural-Network algorithm required the facies types to be grouped into definitive reservoir qualities to be applied. The resultant electro-facies log had a very good match with the input logs, which validated the facies grouping. This was followed by the porosity-permeability transforms, estimated from mobility data, to create a permeability curve for all field wells, despite the unavailability of core data. The reservoir was categorized into three rock types, each with a specific range of quality, signifying their different flow abilities which were supported by dynamic data. The Lower Bahariya-Kharita in NEAG 2 was ultimately concluded to be a complex heterogeneous reservoir with varying flow abilities and production behaviors. The recovery factor mismatch is due to unrecovered reserves, and a new production strategy should be introduced to reach the ultimate recovery. This integration of geologic and dynamic data is strongly recommended for any reservoir characterization study to avoid oversimplifying the reservoir system and to design the right reservoir development plan.

Cynometroxylon aegyptiacum n. sp. (Fabaceae-Detarioideae) from the Miocene of Egypt with palaeoclimatic and biogeographic insights

A new morphospecies of Cynometroxylon is described from the early Miocene deposits of the Gebel El-Khashab Formation exposed along the Cairo-Bahariya desert road in the north Western Desert of Egypt. It is compared with the 13 currently recognized fossil wood species of Cynometroxylon/Cynometra recorded worldwide. The characteristics of this fossil wood align with those typical of the non-seasonal tropical climate during the Miocene period, indicating its habitat at that time. This habitat is consistent with that of some living species of its analogue Cynometra. Upon reviewing the worldwide biogeography of the genus, its extensive distribution in Africa and Asia was observed. Furthermore, the biogeography of the subfamily Detarioideae was compiled, tracing its evolutionary history back to Africa. This confirms the possibility that family Fabaceae likely originated in Africa during the Late Cretaceous to early Paleogene, with subsequent dispersal into Asia and South America. The present record is indicative of a subtropical to warm tropical climate which prevailed in the Miocene of Egypt.

Development of the Arabian-Nubian Shield along the Marsa Alam-Idfu transect, Central-Eastern Desert, Egypt: geochemical implementation of zircon U-Pb geochronology

The magmatic complex along the Marsa Alam-Idfu transect, Central-Eastern Desert of Egypt, represents the northern segment of the Arabian–Nubian Shield (ANS), which developed within the framework of the East African Orogen. The basement rocks of the Arabian-Nubian Shield have been developed through three distinct phases of magmatic activity: the island-arc, the syn-orogenic, and the post-orogenic phases. Transitioning of the magmatic phases from the syn-orogenic to the post-orogenic, identifies changing the tectonic regime from a compressional to an extensional setting. The scarcity of comprehensive regional geochronological data that rely on precise isochron methods, such as the zircon U-Pb technique, could limit the comprehensive understanding of this region’s geological and tectonic history. That would raise a number of uncertainties ranging from the timing of the different magmatic activities and timing of changes in the tectonic regime to the existence of the pre-Pan-African crust in the CED. Our study provides new insights into the aforementioned uncertainties through zircon U-Pb dating of different rock units along the Marsa Alam-Idfu transect, CED, Egypt. The resulting ages ranged from 729 ± 3 Ma to 570 ± 2 Ma, constraining the temporal evolution of the ANS in the studied region into (1) the island-arc phase, represented by a metamorphic sample with an age of 729 ± 3 Ma. (2) the syn-orogenic phase, represented by calc-alkaline and alkaline granitic samples with ages ranging from 699 ± 4 Ma to 646 ± 2 Ma. These two phases indicate initiation of the compressional subduction regime in the CED since 729 ± 3 Ma and being dominated till 646 ± 2 Ma. (3) the post-orogenic phase, represented by metavolcanics, volcanic rocks, and alkaline plutonic samples with ages ranging from 623 ± 3 Ma to 570 ± 2 Ma. This phase suggests dominance of the compressional-to-extensional tectonic transition setting from 623 ± 3 Ma to 600 ± 1 Ma along with the Dokhan volcanism and activation of post-collision tensional regime activated at 582 ± 3 Ma. Our findings discourage the proposed dominance of the island-arc and syn-orogenic phases in the CED and the classical restriction of older magmatic activity to calc-alkaline granitic rocks and younger magmatic activity to alkaline granitic rocks. Additionally, we identified evidence of local magmatic sources by dating five grains with Mesoproterozoic (pre-Arabian–Nubian Shield) xenocrysts with ages ranging from 1549 ± 4 to 1095 ± 25 Ma.

Rodingitization of Neoproterozoic Al-Barramiya ophiolite metagabbro in the Eastern Desert of Egypt, Arabian-Nubian Shield

ABSTRACT The present work studies the rodingite that is recorded for the first time as being associated to Al-Barramiya Neoproterozoic ophiolite at Eastern Desert of Egypt, Arabian-Nubian Shield (ANS). Al-Barramiya ophiolite is one of the most important ophiolitic sequences exposed in the ANS. It is affected by different styles of alterations included carbonatization, listvenitization, chloritization and rodingitization. The Neoproterozoic ophiolitic rocks of Al-Barramiya district consists of serpentinized peridotite and metagabbros. Serpentinized peridotites are highly altered to assemblages of talc-carbonate rocks, listvenite and magnesite, while metagabbro is partly converted into rodingite. The field studies indicate that serpentinite and rodingite in Al-Barramiya area display high-strain cataclastic deformation. Rodingite consists of garnet, diopside, vesuvianite and chlorite with minor epidote, prehnite, actinolite and opaque minerals. The garnets and vesuvianite are mostly concentrated near the peripheries of the studied rodingite masses, while clinopyroxene, chlorite, epidote and prehnite gradually increase inwards due to progressive decreasing water/rock ratio as fluids originally buffered by serpentinite move towards equilibrium with gabbroic bulk chemistry. Some rodingite samples preserve a few relics of igneous textures of ophiolitic metagabbros. Garnets are distinguished into andradite, hydroandradite and grossular. Pyroxene is represented mainly by secondary clinopyroxene beside primary fresh relics of diopside; the latter has high Mg# (0.92–0.97) similar to ophiolitic clinopyroxene in the ANS. Rodingite is enriched in CaO, Fe2O3 and MgO but depleted in SiO2, Al2O3 and Na2O compared to associated metagabbro. The association of rodingite with serpentinites and metagabbros suggests that Al-Barramiya rodingite is genetically related to serpentinization of ultramafic rocks. The rodingitization occurred during ocean floor alteration contemporaneous with the serpentinization process. The superposition of cataclastic deformation on the altered rocks indicates that alteration preceded obduction and occurred on the seafloor of the suprasubduction zone where Al-Barramiya ophiolite was originally emplaced. During serpentinization the olivine in the peridotite broke down and released Mg2+ in the metasomatic fluids and clinopyroxene broke down producing Ca-rich fluids. These fluids react with the mafic protoliths and enrich them in MgO and CaO. Also, serpentinization fluids react with the plagioclase of the metagabbro, releasing Ca from the mafic source and concentrated it in the rodingitized samples. The positive Eu anomalies beside high Sr contents of the rodingite can be inherited from a plagioclase-rich protolith such as ophiolitic metagabbro. The enrichment of rodingite in Th and U indicates two distinct solutions affected the gabbroic protolith because the alteration of depleted peridotite to serpentinite cannot be an efficient source to enrich these elements. The present study indicates that the rodingitization process underwent lower greenschist facies conditions associating metamorphism that caused serpentinization and released Ca-rich metasomatic fluids.

Geochronological assessment of the Arabian-Nubian Shield plutonic intrusions in the arc assemblages along the Qift-Quseir transect, Central Eastern Desert of Egypt

The ophiolitic mélange and granitic intrusions along the Qift‒Quseir transect in the Central Eastern Desert (CED) of Egypt are parts of the Egyptian Nubian Shield (ENS), which is the northern segment of the East African Orogeny (EAO). The Arabian-Nubian Shield (ANS) is the longest Neoproterozoic belt on Earth, and it was formed during the East and West Gondwanaland collisions within the framework of the EAO. The ANS basement rocks were developed during three distinct phases of magmatic activity: the island arc and syn-collisional phases, identifying a compressional tectonic regime, and a post-collisional phase that identifies changing the tectonic regime into an extensional type. The geochronological assessment of these magmatic activities is essential for understanding the regional geology and tectonic development of the ANS. In our study, we dated different rock units along the Qift‒Quseir transect and revealed ages ranging from the Late Tonian (820 ± 8 Ma) to the Late Ediacaran (563 ± 4 Ma). These ages were associated with three different magmatic pulses: (1) a seafloor spreading and island arc phase (ophiolite and related rocks), represented by sample QQ05, which was dated from 820 ± 8 Ma; (2) a syn-collisional phase, represented by samples QQ08 and QQ10, dated from 733 ± 10 Ma and 729 ± 10 Ma, respectively; and (3) a post-collisional phase, represented by all the other samples, dated from the Ediacaran at 603 ± 9 Ma to 563 ± 5 Ma. These results showed that the post-collisional phase was dominant, especially in terms of the alkali-feldspar granites, relative to ophiolitic rocks, and the syn-collisional granites in the CED. Initiation of the Dokhan Volcanic eruptions at 639 ± 2 Ma gave us the date of the compressional-to-extensional tectonic transition setting, and the post-collisional tensional regime was activated at 603 ± 9 Ma. Additionally, we identified evidence of local magmatic sources by dating 11 grains of Paleo-to Meso-Proterozoic xenocrysts with ages ranging from 1876 ± 18 to 1070 ± 13 Ma (i.e., components of the pre-Arabian-Nubian Shield).

Petrology, mineral chemistry and geochemistry of chloritite associated with Neoproterozoic ophiolitic ultramaficsin the Eastern Desert of Egypt, Arabian-Nubian Shield

This study presents for the first time, the field observations, petrography, mineral chemistry and geochemistry of chloritite hosted in the Al-Barramiya Neoproterozoic ophiolite of the Eastern Desert of Egypt, Arabian-Nubian Shield (ANS). The Al-Barramiya ophiolite is one of the most important ophiolitic sequences exposed in the ANS. It is affected by different types of alterations including carbonatization, listvenitization, chloritization and rodingitization. The Al-Barramiya chloritite occurs as thin layers associated with highly serpentinized peridotite. It is a fine-grained rock entirely composed of chlorite (85–95 vol.%) with minor talc and accessory minerals (epidote, rutile, titanite, corundum and opaque minerals). The chlorite minerals in the chloritite are represented mainly by diabantite, while those in the serpentinites include ripidolite. Depending on the chemical composition of the chlorites, the chlorite in chloritite formed at temperatures ranging between 200 and 250°C, which are lower than those of the disseminated chlorite in the serpentinite (310–345oC), indicating their formation in different hydrothermal stages. The chloritite samples are rich in total REE contents (17.9–27.3 ppm) compared with the associated serpentinites (0.69–0.87 ppm). They are characterized by slightly depleted LREE relative to HREE [(La/Lu)n = 0.8–0.9], with a moderately negative Eu-anomaly [(Eu/Eu*)n = 0.4–0.5]. The negative Eu-anomalies are derived from chloritization fluids or reflect the presence of talc in the chloritite. Based on field work, petrography, mineralogical and geochemical data, the studied chloritite has been interpreted as being derived from the associated serpentinized ultramafics by hydrothermal alterations. This is supported by an enrichment of chloritite in compatible trace elements (Cr = 2031–2534 ppm, Ni = 1264–1988 ppm, Co = 76–101 ppm) similar to that which is observed in the associate serpentinite.

Re-geomorphic Mapping of Unroofed Cave of Crystal Mountain Area, Bahariya – Farafra Depressions, Western Desert of Egypt

Re-geomorphic Mapping of Unroofed Cave of Crystal Mountain Area, Bahariya – Farafra Depressions, Western Desert of Egypt

Petrogenesis and tectonic evolution of mineralized mafic intrusions in the Eastern Desert of Egypt: Implications for gold–sulfide genesis

The whole–rock chemistry, mineral chemistry, and remote sensing data of the Atud–UmKhasila Neoproterozoic mafic intrusions in the Eastern Desert of Egypt show two different mafic plutons: (1) the metagabbro–diorite complex; and (2) the G. Atud gabbros. Both of these contain two types of Cu–Ni–Fe–sulfide mineralizations. Multispectral remotely sensed images of Landsat 8 OLI/TIRS, Sentinel 2–B, and ASTER1T were used to give an overview of hydrothermal alteration signatures and distinguish different lithological units. The G. Atud gabbros are intruded into the metagabbro–diorite complex and consist mainly of olivine gabbros, while the metagabbro–diorite complex comprises metagabbros, diorites, and quartz diorites. They were formed under high fO2 (ΔFMQ= +1.43 to + 0.33) with a higher crystallization temperature (∼ 900–1100 °C) and pressure (∼ 6.0 kbar on average) at 18 km depth relative to associated metagabbros. Like magmatic sulfides in mafic intrusions, the G. Atud gabbros contain disseminated grains of pyrrhotite, pentlandite, chalcopyrite, and pyrite, up to 5 vol%. On the other hand, sulfide deposits (up to 30 vol%) such as pyrite, As–bearing pyrite, arsenopyrite, and gold with minor sphalerite and galena at the Atud gold mine, are related to the metagabbro–diorite intrusion. They are found as disseminations, patches, microveinlets, and bands. The sulfide deposits and economic gold are spatially concentrated in smoky quartz veins (up to 25 g/t) and metasomatic alteration zones, i.e., silicification and hematization of metagabbros (0.32 g/t), phyllic, argillic, and propylitic alteration, and carbonate–silicified zones, along gabbroic intrusive contacts, which all follow the Najd NW–SE shear zone. They are possibly of hydrothermal origin (epigenetic). They are also precipitated by mineralized fluids (rich in Si, K, Fe, Pb, Ag, Au, As, S, Ni, Zn, Cu, CO2, and H2O) that have been derived from a mixed magmatic–metamorphic source. The high Au contents with As–bearing pyrite and arsenopyrite in both Fe–rich and smoky quartz veins are related to the interaction between Fe from metagabbro–diorites and the Au(HS)-2 compound as well as the crystallization of pyrite, which reduced the sulfur contents in the mineralized fluids and hence led to gold precipitation. The late intrusion of G. Atud gabbros into metagabbro–diorite rocks enhanced the circulation of sulfide-gold-bearing hydrothermal fluids towards the contacts of the latter ones. These fluids along the shear zones cause metasomatic alteration in addition to leaching and the collection of sulfides and gold in the metagabbros. The protoliths of metagabbro–diorite rocks have a calc–alkaline nature and were formed in a volcanic arc setting, while the G. Atud gabbros were crystallized from Mg-rich tholeiitic melts in the extensional rift (e.g., rifted arc) setting as a result of asthenospheric upwelling due to the slab detachment and/or lithospheric delamination. The Atud gold–sulfide mineralization was related to the thermal uplifting–extensional tectonism. The enrichment of the G. Atud gabbros in LILE, alongside LREE over HFSE, reflects their derivation from a metasomatized mantle source during a rifted arc following the subduction processes.

Composite Granitic Plutonism in the Southern Part of the Wadi Hodein Shear Zone, South Eastern Desert, Egypt: Implications for Neoproterozoic Dioritic and Highly Evolved Magma Mingling during Volcanic Arc Assembly

The Abu Farayed Granite (AFG), located in the southeastern desert of Egypt, was intruded during the early to late stages of Pan-African orogeny that prevailed within the Arabian–Nubian Shield. The AFG intrudes an association of gneisses, island arc volcano–sedimentary rocks, and serpentinite masses. Field observations, supported by remote sensing and geochemical data, reveal a composite granitic intrusion that is differentiated into two magmatic phases. The early granitic phase comprises weakly deformed subduction-related calc–alkaline rocks ranging from diorite to tonalite, while the later encloses undeformed granodiorite and granite. Landsat-8 (OLI) remote sensing data have shown to be highly effective in discriminating among the different varieties of granites present in the area. Furthermore, the data have provided important insights into the structural characteristics of the AFG region. Specifically, the data indicate the presence of major tectonic trends with ENE–WSW and NW–SE directions transecting the AFG area. Geochemically, the AFG generally has a calc–alkaline metaluminous affinity with relatively high values of Cs, Rb, K, Sr, Nd, and Hf but low contents of Nb, Ta, P, and Y. The early magmatic phase has lower alkalis and REEs, while the later phases have higher alkalis and REEs with distinctly negative Eu anomalies. The AFG is structurally controlled, forming a N–S arch, which may be due to the influence of the wadi Hodein major shear zone. The diorite and tonalite are believed to have been originally derived from subduction-related magmatism during regional compression. This began with the dehydration of the descending oceanic crust with differential melting of the metasomatized mantle wedge. Magma ascent was long enough to react with the thickened crust and therefore suffered fractional crystallization and assimilation (AFC) to produce the calc–alkaline diorite–tonalite association. The granodiorite and granites were produced due to partial melting, assimilation, and fractionation of lower crustal rocks (mainly diorite–tonalite of the early stage) after subduction and arc volcanism during a late orogenic relaxation–rebound event associated with uplift transitioning to extension.

Characterization of recharge sources of the Miocene Fluvial Moghra aquifer in the North Western Desert of Egypt

Study regionThe Miocene Fluvial Moghra Aquifer in the North Western Desert of Egypt Study focusThe study integrates stable isotope analyses with aeromagnetic and hydrogeological datasets to accomplish the following: (1) define the primary source(s) of recharge to the Moghra aquifer, (2) assess aquifer connectivity with the Nile River aquifer, and (3) investigate the vertical connectivity of the Moghra aquifer with the underlying Nubian Aquifer System (NAS) through subvertical faults. New hydrological insights for the regionThe findings reveal (1) significant heterogeneity in groundwater isotopic compositions (Group A: δ18O: 1.1–13.8 ‰; δD: 4.6–73.5 ‰, B: δ18O:−0.99 to 0.85; δD: −7.58 to 4.38 ‰; and C: δ18O:−1.1 to −3.4; δD: − 6.3 to −18.2 ‰) indicative of variability in recharge sources. (2) Groundwater compositions west (up to 30 km) of the Nile River (Group A) resemble enriched modern Nile waters following the Aswan High Dam (AHD) construction that give way further west to relatively depleted groundwater (Group B) resembling historical pre-AHD Nile water compositions. (3) Further west from Group B depleted Group C samples occur along intersections of multiple fault systems (NW and NE-oriented faults) interpreted as mixtures of rising highly-depleted paleo Nubian Aquifer System (NAS) waters and pre-AHD Nile waters. (4) The advocated structural control is reported in similar settings in Egypt, suggesting that intersections of multiple fault systems provide regional connections between deep and shallow aquifers in northeast Africa, recharge overlying shallow aquifers, and should be considered in groundwater management scenarios.

Spatial and temporal variation of Syrian Arc structures in the onshore and offshore Eastern Mediterranean region

Syrian Arc structures form a belt of folds and faults oriented northeast to southwest and north-northeast to south-southwest extending from the Western Desert of Egypt (and farther westward to Tunisia) via northern Sinai to Levant eastward. Detailed studies of surface and subsurface areas in onshore Egypt as well as the offshore Eastern Mediterranean show evidence for continued deformation since the Santonian with local mild start during the Turonian. Santonian deformation was the strongest, whereas the later continued deformation was less. Previous studies of Syrian Arc structures proposed discrete phases of deformation, but the present study shows evidence that deformation was continuous since the Santonian. The lack of a continuous rock record, erosion of the crestal areas of some folds, nondeposition of younger sediments, and the scattered nature of younger rocks at the exposed Syrian Arc folds led some investigators to propose a short period(s) of Syrian Arc deformation. The relatively well-preserved subsurface stratigraphic record of Syrian Arc structures in some onshore and offshore areas led to the conclusion that the Syrian Arc folding continued to present time. However, the intensity of deformation and the associated structural relief have varied through time and space with its climax during Santonian time. We consider the Late Cretaceous–Cenozoic Syrian Arc structures to be the manifestation of the closure history of the Neo-Tethys Ocean and its successor, the Mediterranean Sea.

Adaptive response of Balanites aegyptiaca (L.) Del to severe aridity in the Western desert of Egypt

Adaptive response of Balanites aegyptiaca (L.) Del to severe aridity in the Western desert of Egypt

Pooping in Public: Syrian and Egyptian Desert Fathes as Textual Constructs

Pooping in Public: Syrian and Egyptian Desert Fathes as Textual Constructs

Hydrothermal alteration processes in monzogranite: a case study from the Eastern Desert of Egypt: implications from remote sensing, geochemistry and mineralogy

The South Eastern Desert (SED) of Egypt is one of the most promising areas in Egypt; it is widely explored for exploring the rare earth elements (REEs) and uranium-bearing ores. It is a main part of the Arabian-Nubian Shield (ANS). Therefore, the present study concerns with Sikait-Nugrus area as one of the most prolific sites in this region. The study provides a detailed geological, structural, and mineralogical investigation of the monzogranites to describe and characterize the various alteration types and sequence. For this purpose, remote sensing, geochemical and petrographical techniques were applied. The remote sensing technique helped in constructing a detailed geologic map of the study area to follow up strictly the alteration zone of the Sikait-Nugrus area. Petrographically, the granites predominates in the study area, they are described as slightly and highly altered monzogranites. The slightly altered one is composed mainly of quartz (~ 20–35%), alkali feldspar (~ 25–30%), plagioclase (~ 25–30%), and mica (~ 5–15%), while accessory minerals are represented by zircon and monazite. On the other hand, the portion of this granite close to the shearing zone is intensively altered and characterized by sericitization as the main alteration processes. This sheared portion is characterized by accessory minerals as, uranothorite, allanite, fluorite and Nb-minerals (ishikawaite). Minerlogically, the altered monzogranites are predominated by the following mineral groups: (1) radioactive minerals as uranyl silicates (soddyite, uranophane and kasolite), and thorium minerals (thorite and uranothorite), (2) Nb–Ta minerals (betafite, plumbobetafite, columbite, fergusonite, and aeschynite), (3) REE minerals (monazite, cheralite and xenotime), and (4) zircon and fluorite as accessory minerals. Geochemically, the recorded pattern of the REEs tetrad effect (M-type) for the highly altered samples indicate that these granites are highly evolved and affected by late stage of hydrothermal alteration and the effective water-rich alteration processes that connected to intensive physico-chemical changes. The total REE concentrations equal 241.8 and 249.75 ppm for the highly and slightly altered samples. A significant mass change (MC) was analyzed by the isocon technique (22.95 & 11.11) and volume change (VC) (1.8 &-7.99) for the highly and slightly altered samples, respectively. The mass balance calculations and the isocon diagrams revealed that some major oxides were removed from the slightly altered monzogranites and transformed later into highly altered monzogranites with increasing the alteration intensity due to the impacts of hydrothermal alteration processes. The studied area is virgin, where no detailed studies have been applied to this region. It is extendable to other parts of the Arabian-Nubian Shield in around the Red Sea in Egypt, Sudan, Saudi Arabia and Yemen. The applied technical workflow is also extendible to other surface analogues everywhere.

A multi-disciplinary approach for uranium exploration using remote sensing and airborne gamma-ray spectrometry data in the Gebel Duwi area, Central Eastern Desert, Egypt

Uranium exploration plays a pivotal role in meeting global energy demands and advancing nuclear technology. This study presents a comprehensive approach to uranium exploration in the Gebel Duwi area of the Central Eastern Desert of Egypt, utilizing remote sensing and airborne gamma-ray spectrometric data. Multispectral remote sensing techniques, including Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), and Band Ratioing (BR), are employed to identify lithological units and hydrothermal alteration zones associated with uranium deposition, such as iron oxides, argillic, propylitic, and phyllic alterations. Additionally, airborne gamma-ray spectrometry data provide insights into the spatial distribution of radioelements, including uranium (eU), thorium (eTh), and potassium (K), as well as radioelement ratios (eU/eTh, eU/K, and eTh/K). The uranium migration index map (eU-(eTh/3.5)) and the F-parameter map (K*(eU/eTh)) have been generated to investigate the movement of uranium within various geological zones and characterize anomalous uranium concentrations. Statistical analyses, including mean (X), standard deviation (S), and coefficient of variability (C.V.), are conducted to identify uranium-rich zones. The integration of these datasets enables the generation of a uranium potential map highlighting areas of elevated concentrations indicative of uranium mineralization. Field observations and mineralogical analyses of collected samples validate our findings, confirming the presence of minerals associated with uranium mineralization in mapped high-potential areas. The significance of minerals like Fe-Chlorite, Fe-Mg-Chlorite, ferrihydrite, goethite, calcite, muscovite, dolomite, actinolite, vermiculite, and gypsum in indicating potential uranium mineralization processes underscores the importance of our results.

Processing of mineralized microgranite dike for the recovery of niobium, tantalum, and rare earth elements using 1, 2-propyleneglycol extractant

ABSTRACT A number of strategic and economic rare-metal and Rare Earth Elements (REEs)-bearing minerals were recorded in mineralized microgranite dike (MMGD) from Ras Abdah area located in the Northern Eastern Desert of Egypt. Firstly, by sulphuric acid digestion at 300 °C, 3 h, 1/3 ore/Acid ratio, the RE, Nb, and Ta present in the MMGD can be efficiently extracted into the leach solution while Zr, Fe, and Th remained in the unattacked residue. The experimental digestion proved the dissolution of 98.9, 99.2, and 96 % for Nb, Ta, and REEs, respectively. In this study, a novel method was used to selectively recover Nb and Ta content from REEs in the digested concentrate sulphate solution. Solvent extraction using 1, 2-propyleneglycol was applied for the first time to achieve this secondary recovery process. From infrared and 1H-NMR data, the extraction was achieved, and the extractant bonded to Nb and Ta through glycol and alcoholic oxygen atoms. Niobium and Tantalum ions were stripped with water for Ta and 1M HF for Nb, achieving 98.6 and 98.8 % stripping efficiency, respectively. By employing an oxalic acid precipitation technique, a precipitate of extremely pure REEs was extracted from the raffinate solutions.

Facies controls and tectonic evolution on oil accumulation and entrapment in the Cenomanian Abu Roash G member, northern-central Egypt: Deltaic and channel sandstones as good reservoirs

Along northern-central Egypt, the oil accumulation and entrapment were mainly controlled by variable parameters including the stratigraphic architecture, sedimentary features, and tectonic evolutions. The present paper presents a new model for oil occurrences in the Abu Roash G Member (Cenomanian) along Gindi, Abu Gharadig and to a few extents the Beni Suef basins, in the northern-central part of the Western and Eastern Deserts of Egypt. The studied concessions include the Wadi El Rayan, East Bahariya and El Diyur (Gindi basin and Abu Gharadig basins, Western Desert) and the Ghariboun (Beni Suef Basin, Eastern Desert) fields. Twenty sedimentary facies were recorded from the studied subsurface sections of the Abu Roash G Member and grouped into three facies associations. A new depositional model is achieved where estuarine, open marine, deltaic distributaries, and tidal channel deposits are the main facies associations recorded in the studied Abu Roash “G". These deltaic and channel deposits occurred as an arch like form between open marine and estuarine deposits. These deltaic and tidal channel sandstone deposits act as a good reservoir to accumulate oil from nearby areas. As well, these areas were subjected to the well-known Syrian arch compressional deformation that affected northern Egypt during the Mesozoic, up to late Senonian time. A regional NE-SW oriented fold system took place, forming NE-SW oriented ridges in addition to the dextral strike-slip movement that took place along these ridges because of this compressional deformation.To sum up, oil accumulation in the studied Abu Roash G Member was mainly controlled by facies distribution mainly of channel sandstone enhanced by the tectonic movements (Syrian Arc System) affecting the areas studied.

Alteration and Non-Formula Elements Uptake of Zircon from Um Ara Granite, South Eastern Desert, Egypt

The Um Ara granites are a suite of granitoid rocks located in the southern part of the Eastern Desert of Egypt. The integration of various electron probe micro analyzer (EPMA) techniques, such as backscattered electron (BSE) imaging, X-ray compositional mapping, and wavelength dispersive spectrometry (WDS), has provided valuable insights into the alteration process of zircon in the Um Ara granite. The zircon exhibits high concentrations of non-formula elements such as P, Al, Ca, Fe, Ti, and REEs, suggesting that the alteration involved coupled dissolution-reprecipitation processes influenced by aqueous fluids. The negative correlations between Zr and the non-formula elements indicate that these elements were incorporated into zircon at the expense of Zr and Si, significantly affecting the distribution and fractionation of REEs in the original zircon. Based on the presented data and literature knowledge, the sequence of alteration events is proposed as follows: (1) initial zircon crystallization around 603 Ma accompanied by the formation of other U- and Th-bearing minerals like xenotime, thorite, monazite, and apatite; (2) long-term metamictization leading to fractures and cracks that facilitated fluid circulation and chemical changes; (3) a major hydrothermal event around 20 Ma that released a suite of non-formula elements from the metamicted zircon and associated minerals, with the enriched hydrothermal fluids subsequently incorporating these elements into the modified zircon structure; and (4) further low-temperature alteration during subsequent pluvial periods (around 50,000–159,000 years ago), facilitated by the shear zones in the Um Ara granites, may have allowed further uptake of non-formula elements. The interplay between hydrothermal fluids, meteoric water, and the shear zone environments appears to have been a key driver for the uptake of non-formula elements into the altered zircon.

Re-geomorphic Mapping of Unroofed Cave of Crystal Mountain Area, Bahariya – Farafra Depressions, Western Desert of Egypt

Re-geomorphic Mapping of Unroofed Cave of Crystal Mountain Area, Bahariya – Farafra Depressions, Western Desert of Egypt

Experimental characterization of contact resistance of desert soil with waste-enhancement materials in grounding systems

This study aims to investigate how the electrical-resistivity of different soils and grounding enhancement-materials is influenced by water-content and the dehydration under ambient and high-constant temperatures. The used enhancement-materials were extracted from surrounding wastes in Egyptian desert. First, waste enhancement-materials, their developed-mixture and soil samples were prepared for experimental testing. The contact-resistance between soil and enhancement-material was measured by using a designed soil-box. It was observed that adding a wood-ash as an interface-layer between the soil and enhancement-materials decreased significantly the contact-resistance. The developed-mixture and wood-ash demonstrated highest water-content retention when compared against the other enhancement-materials. This maintains their resistivity values low to serve for grounding purpose. The wood-ash has the smallest grain–size diameter among the enhancement-materials. This is why it ensures effective contact between the soil and enhancement-materials in grounding systems. The effect of varying injected-current through the soil-box on the resistance values of soils and enhancement-materials is also investigated. Finally, the effectiveness of using of these materials in reducing the resistance-to-ground of a practical copper rod buried into desert soil is evaluated.