Egyptian Desert Research Articles

Regional overview potential zones for groundwater recharge in Wadi Hodein, south Eastern Desert of Egypt

ABSTRACT Wadi Hodein (WH) is one of the largest arid wadies in the eastern desert, where the groundwater (GW) is the main water resource, to meet the water demand of its residents. Therefore, GW recharge (GWR) potential zones map is to be constructed as an effective tool for GW management in WH. Analytical hierarchy process (AHP) with geospatial analysis using ArcMap was used to delineate the GWR. Six thematic layers (soil map, slope, geology, geomorphology, lineament density, and drainage density) were used to produce the recharge map. The results classified the potential of WH recharging into five categories very low, low, moderate, high, and very high with their corresponding percentage areas of 2.60%, 9.30%, 42.9%, 31.30%, and 14.00%, respectively. Verification analysis using water quality data of the drilled wells inside the study area was conducted to confirm the resulted GWR potential map.

The Mississippi valley type Zn-Pb-celestite deposits at Wadi Essel, the Eastern Desert of Egypt: fluid inclusions and microthermometry evidences

The Mississippi valley type Zn-Pb-celestite deposits at Wadi Essel, the Eastern Desert of Egypt: fluid inclusions and microthermometry evidences

Coupling of purity assessment and quantitative analysis of heavy metals in Central Eastern Desert of Egypt

Coupling of purity assessment and quantitative analysis of heavy metals in Central Eastern Desert of Egypt

Magmatic Evolution and Rare Metal Mineralization in Mount El-Sibai Peralkaline Granites, Central Eastern Desert, Egypt: Insights from Whole-Rock Geochemistry and Mineral Chemistry Data

The Ediacaran peralkaline granites, which were emplaced during the post-collisional tectonic extensional stage, have a limited occurrence in the northern tip of the Nubian Shield. In this contribution, we present new mineralogical and geochemical data of Mount El-Sibai granites from the Central Eastern Desert of Egypt. The aim is to discuss their crystallization condition, tectonic setting, and petrogenesis as well as the magmatic evolution of their associated mineralization. Mount El-Sibai consists of alkali-feldspar granites (AFGs) as a main rock unit with scattered and small occurrences of alkali-amphibole granites (AAGs) at the periphery. The AAG contain columbite, nioboaeschynite, zircon and thorite as important rare metal-bearing minerals. Geochemically, both of AFG and AAG exhibit a highly evolved nature with a typical peralkaline composition (A/CNK = 0.82–0.97) and formed in within-plate anorogenic setting associated with crustal extension and/or rifting. They are enriched in some LILEs (Rb, K, and Th) and HFSEs (Ta, Pb, Zr, and Y), but strongly depleted in Ba, Sr, P and Ti with pronounced negative Eu anomalies (Eu/Eu* = 0.07–0.34), consistent with an A-type granite geochemical signature. The calculated TZrn (774–878 °C) temperatures indicate that the magma was significantly hot, promoting the saturation of zircon. The texture and chemistry of minerals suggest that they were crystallized directly from a granitic magma and were later subject to late- to post-magmatic fluids. Both granitic types were most likely generated through partial melting of a juvenile crustal source followed by magmatic fractionation. The lithospheric delamination is the main mechanism which causes uplifting of the asthenospheric melts and hence provides enough heat for crustal melting. The produced parent magma was subjected to prolonged fractional crystallization to produce the different types of Mount El-Sibai granites at different shallow crustal levels. During magma fractionation, the post-magmatic fluids (especially fluorine) contribute significantly to the formation of rare metal mineralization within Mount El-Sibai granites.

Geospatial model for allocating favorable plots for groundwater-dependent cultivation activities in Egypt

Moving towards horizontal expansion in the vast barren lands to alleviate overpopulation along the Nile River is imperative to Egypt’s 2030 sustainable development strategy. Accordingly, a mega reclamation project was advocated with a key goal of achieving food self-sufficiency. Solar-powered groundwater pumping system was adopted as the main water supply. Planning efforts are therefore inevitable to help locate the most favourable sites for such extensive cultivation activities. Herein, a multicriteria decision analysis was conducted to facilitate the zoning of potential rural communities across the northern portions of the Western Desert of Egypt. For this purpose, data of groundwater exploration, soil characterization, terrestrial accessibility, insolation intensity, and terrain information were fused to produce a high-resolution suitability map. The analytical hierarchy process approach was adopted to set the weighted importance of adopted criteria. The study area was categorized into Best, Good, Moderate, Fair, Poor, and Restricted classes at 1.7%, 13%, 42.6%, 26%, 10%, and 3%, respectively, of the entire region, while the constrained plots were masked out. The implemented and proposed wells fields within the underway national rural development project extend over agriculturally suitable pixels affirming the validity of the developed geospatial model. About 1.5 million ha, representing 7.2% of the undeveloped area, were found to be highly suitable for future expansion of agribusiness activities. The generated priority map will assist the decision-makers in the planning procedures for ongoing reclamation activities throughout Egypt.

Geochemistry and petrogenesis of late Neoproterozoic Nuweibi and Atawi rare metals bearing granites, central Eastern Desert, Egypt

Nuweibi albite granite (NAG) and Atawi two feldspar granites (AG) are silica rich, highly evolved intrusions and rare metals-bearing in the Central Eastern Desert of Egypt exhibiting different stages of magmatic-late magmatic evolution. Both are evolved from low-P2O5 metaluminous to peraluminous granitic magma resulting from partial melting of crustal source. The chemical features of both of NAG and AG as Na2O + K2O, FeOt/MgO, Ga, Nb and Ta high concentrations are compatible with an anorogenic within plate tectonic setting. However, NAG have higher concentration of Al2O3, Na2O, MnO, Ga, Rb, Hf and Ta and lower concentrations of SiO2, TiO2, Fe2O3t, MgO, CaO, K2O, P2O5, Ba, Zr, Y, Sn, W, F and REEs. NAG shows obvious enrichment of heavy rare earth elements (HREEs) relative to light rare earth elements (LREEs), negative Eu anomaly and tetrad effect. On the other hand, AG has higher concentration of REEs and its pattern is slightly enriched in LREEs relative to HREEs with negative Eu anomaly. For NAG, the fluid-mobilization of REEs and other trace elements is supported by very low ratios of Eu/Eu* (0.17–0.3), (La/Yb)n (0.06–0.4), Nb/Ta (0.44–1.09), Zr/Hf (1.84–2.61), K/Rb (66.8–109.9) and Y/Ho ratios (2.9–6.3) together with high Sr/Eu (160–440). On the other hand, AG represents moderately fractionated granitic melt in regard to chondrites still showing chondritic or almost chondritic Nb/Ta (5.5–15.9), Zr/Hf (14.8–28.6), Y/Ho (26.2–45), K/Rb (99.24–346.28) and Sr/Eu (56.6–520) ratios indicating the lower effect of late magmatic fluid-rock interaction compared to NAG. Fluid phase enriched in alkalis from a nearly solidified granite causes local albitization in Atawi and Nuweibi areas where Nuweibi granite is more albitized. Moreover, greisenization (decomposition of feldspar and Fe-mica) is also more common in NAG.

Characterization of bacterial-associated with Egyptian Tirmania nivea and Terfezia canariensis

Recently, various studies investigate the cultivable microbial diversity of different truffles species. However, this study is still very limited for Egyptian desert truffles. Two morphologically different kinds of wild desert truffles collected from Western Egyptian Desert were characterized using general description in combination with ITS-rDNA data. The phylogeographic analysis of the obtained sequences in comparison to Mediterranean genera from GeneBank revealed the identification of white truffle as Tirmania nivea with 100% identity of isolate from Libya. While the red truffles were Terfezia canariensis which was grouped in one clade with isolates from Canary Island Spain and Portugal. A scanning electron microscope (SEM) analysis indicated bacterial cells inhabiting the healthy gleba of the truffles. The cultivable bacterial isolates were Gram-positive related to the Firmicutes phyla identified as Bacillus boroniphilusMZ361726 (B2), Lactococcus lactisMZ361727 (B4), Bacillus licheniformisMZ361728 (B7), Bacillus haynesiiMZ361729 (B8), and Bacillus velezensisMZ361730 (B11) based on partial sequencing of 16S rRNA. The liquid chromatography-mass spectrometry (LC-MS) of the most potent identified strains (B4, B7, and B11), revealed bioactive compounds showing antimicrobial activity as docosahexaenoic acid, fucosterol, and kolaflavanone which exist in truffle literatures. In conclusion, our findings reveal new insight into the microbiota associated with T. nivea and T. canerienasis and supported that these organisms represent a rich source for the development of novel antimicrobial bioactive compounds.

Geothermal Gradients Inside Water Wells of East Oweinat Area, South Western Desert of Egypt

The regional geothermal pattern of Egypt has been previously defined from bottom hole temperature data inside oil wells in Northern Egypt and Gulf of Suez. For the same objective, geothermal gradient/heat flow determinations have also been conducted inside existing mineral exploration and water wells in Eastern Egypt and in Kharga Oasis in Western Desert as well as inside specially drilled regional gradient shallow boreholes in Eastern Egypt. To complement the regional geothermal picture in the southern part of Egypt, temperatures were measured inside seven water wells in a remote area in the south Western Desert at East Oweinat. The average calculated temperature gradient was found to amount to 12 mK/m, a value similar to that obtained from bottom hole temperature/depth relationship of deep artesian wells at Dakhla Oasis 300 km to the north, but much less than the normal gradient amounting to 20 mK/m in Northern Egypt. The data obtained emphasize the extension of the low heat flow province of the Mediterranean north of Egypt to its southern border with Sudan. A distribuição regional de fluxo geotérmico no Egito foi previamente definida a partir de temperaturas de fundo de poço medidas em poços de petróleo no norte do Egito e no golfo de Suez. Com o mesmo objetivo, determinações de gradientes térmicos e de fluxo de calor foram realizadas em poços para exploração mineral e de água no leste do Egito e no oásis de Kharga no deserto ocidental, assim como em poços rasos especialmente perfurados no leste do Egito. Para complementar a representação do fluxo térmico regional na parte sul do Egito, foram medidas temperaturas em sete poços de água em uma área remota no deserto do sudoeste em East Oweinat. O gradiente térmico médio encontrado é de 12 mk/m, valor similar ao obtido a partir de relações de temperatura de fundo de poço/profundidade de poços profundos no oásis de Dakhla 300 quilômetros mais ao norte, mas muito inferior ao gradiente geotérmico normal de 20 mk/m encontrado no norte do Egito. Os dados obtidos enfatizam a extensão da província de baixo fluxo térmico do norte mediterrâneo do Egito para a sua fronteira sul com o Sudão.

Multiple Functions of Compatible Solute Ectoine and Strategies for Constructing Overproducers for Biobased Production.

Ectoine and its derivative 5-hydroxyectoine are compatible solutes initially found in the hyperhalophilic bacterium Ectothiorhodospira halochloris, which inhabits the desert in Egypt. The habitat of ectoine producers implies the primary function of ectoine as a cytoprotectant against harsh conditions such as high salinity, drought, and high radiation. More extensive and in-depth studies have revealed the multiple functions of ectoine in its native producer bacterial cells and other types of cells and its biomolecular components (such as proteins and DNA) as a general protective agent. Its chemical properties as a bio-based amino acid derivative make it attractive for basic scientific research and related industries, such as the food/agricultural industry, cosmetic manufacturing, biologics, and therapeutic agent preparation. This article first discusses the functions and applications of ectoine and 5-hydroxyectoine. Subsequently, more emphasis was placed on advances in bio-based ectoine and/or 5-hydroxyectoine production. Strategies for developing more robust cell factories for highly efficient ectoine and/or 5-hydroxyectoine production are further discussed. We hope this review will provide a valuable reference for studies on the bio-based production of ectoine and 5-hydroxyectoine.

Assessing environmental and radiological impacts and lithological mapping of beryl-bearing rocks in Egypt using high-resolution sentinel-2 remote sensing images

Emerald and other beryls represent a family of the most valuable gemstone around the world and particularly in Egypt. Beryllium (Be) contents in beryl-bearing bedrocks in south Sinai (Wadi Ghazala and Wadi Sedri), and in central and south Eastern Desert of Egypt (Igla area, Zabara-Um Addebaa belt, Homret Akarem, and Homret Mukpid) were investigated in this study. The environmental risk levels of Be, associated major ions, and heavy metals in groundwater nearby to beryl-bearing mineralization were also evaluated. Results showed that Be contents ranged from 1 to 374 ppm in beryl-bearing bedrocks, while in nearby groundwater, Be content has a range of 0.0001–0.00044 mg/L with an average of 0.00032 mg/L, which is within the permissible levels and below (0.004) the U.S. EPA maximum contaminant level (MCL). Most levels of heavy metals (e.g., Be, B, Ni, V, Fe, and Al) in the investigated groundwater of central and south Eastern Desert and south Sinai are within the permissible levels and below their corresponding U.S. EPA MCLs. This study also investigated the radiological risk of natural radionuclides distributed in beryl-bearing bedrocks in the study area using gamma spectrometry; Sodium Iodide [NaI(Tl)] scintillation detector. Among the estimated mean 238U, 232Th, and 226Ra activity concentrations of the studied beryl-bearing rocks, Homret Mukpid (79, 87.15, 60.26 Bq kg−1) and Homret Akarem (111.6, 51.17, 85.1 Bq kg−1) contain the highest values. This may be attributed to their highly fractionated granitic rocks that host uranium and thorium reservoir minerals such as zircon, allanite, and monazite. The estimated data of multi-radiological parameters such as absorbed gamma dose, outdoor and indoor annual effective dose, radium equivalent activity, internal and external indices, index of excess cancer, and effective dose to human organs reflecting no significant impacts from the emitted natural gamma radiation.

Origin and evolution of Neoproterozoic metaophiolitic mantle rocks from the eastern Desert of Egypt: Implications for tectonic and metamorphic events in the Arabian-Nubian Shield

The mantle rocks from Kadaboura and Madara areas represent sections of dismembered ophiolitic complexes developed during the Neoproterozoic in the Eastern Desert of Egypt, which is located in the northwestern corner of the Arabian–Nubian Shield. The Kadaboura mantle rocks comprise serpentinites and serpentinized dunites, whereas those of the Madara consist of serpentinites and serpentinized pyroxenites.Despite the serpentinization of the studied mantle rocks, few relicts of primary chromite, olivine and pyroxene are preserved. Chromite is partly altered having unaltered Al-rich chromite cores surrounded by Fe-rich chromite and Cr-rich magnetite rims. The unaltered Al-rich chromite cores show compositions equilibrated at temperatures mostly below ~500-600°C, which is a temperature comparable to that estimated for primary chromite in greenschist up to lower amphibolite facies rocks. The high Cr# [100×Cr/(Cr+Al)= 47-76] of the unaltered chromite cores and the Mg-rich nature of the olivine relicts (Fo91–94) indicate that the studied mantle rocks were produced from a highly depleted mantle that experienced high degrees of melt extraction (mostly ~30-40%). This range of melt extraction resembles that estimated for supra-subduction zone peridotites, but higher than that in abyssal and passive margin peridotites. Furthermore, the clinopyroxene relicts show compositions comparable to those from the Mariana forearc peridotites. Bulk-rock geochemistry also reflects derivation from an extremely depleted and a highly refractory mantle source. Modelling of rare-earth elements suggests that the studied mantle rocks were possibly formed by the interaction of their highly depleted harzburgitic mantle precursors with subduction-related melts/fluids during their evolution in a fore-arc basin of the supra-subduction zone.The proposed geodynamic model suggests that the oceanic lithosphere generated during the seafloor spreading of the Mozambique Ocean was emplaced in the upper plate of the intra-oceanic subduction zone, in which the formely depleted Neoproterozoic mantle of the Arabian-Nubian Shield experienced mature phases of hydrous melting, extreme depletion and enrichment.

Optimization of wind off-grid system for remote area: Egyptian application

Due unexpected nature of renewable energy systems, the (Wind/Diesel/Battery) (W/D/B) off-grid system has initially been investigated at a South Sinai location in Egypt for home-scale consumption. Eight different systems, each of which consists of a small wind turbine, storage batteries, and diesel generator, are investigated in accordance with the varying needs of the power loads and seasonal weather data. The major goal is to investigate how adding wind power as an energy source will affect the price of electricity generated while taking into account the cost of reducing CO2 emissions as an external benefit of the wind turbine, which emits no pollutants during operation. In order to compare a Taguchi OA design to a two-level full factorial design to evaluate the systems at two separate sites (South Sinai and the Western Desert in Egypt), a design evaluation tool in DOE++ will be used. To pinpoint the crucial variables and analyze the impact of six different factors on eight different sets, Taguchi OA is used. The proportion of power shortfall is a production indicator, while the net present cost (NPC) and cost of energy (COE) are used as economic indicators. The simulation results demonstrate that W/D/B systems are economically viable for the hypothetical community site when using HOMER software, with electricity generated at a cost of about 0.285$/kWh without accounting for external benefits and 0.221$/kWh if CO2 emissions are competitive with diesel-only systems, where COE is 0.432$/kWh. As a new evaluation approach, the Box-Cox transformation calculated the best λ is about −2 at the two locations, indicating similar technique behaviors, and the fitted probability shows, meaning that the significant impact of system components are wind turbines. Regression model of CO2 emission is demonstrated to be successful for estimates at the Western Desert location than the South Sinai region

Microstructural and strain studies of neoproterozoic rocks encapsulating hammamat molasse deposits in theWadi El-Qash area, Central Eastern Desert, Egypt

Understanding deformational processes and related structures at various scales, necessitates an estimate of microstructural and finite strain characterization of deformed rocks. In the current research, 23 collected samples of metaconglomerates, metsediments, and metavolcanics from the Wadi El-Qash region, placed in the Central Eastern Desert of Egypt, were used to quantify the finite strain of quartz, feldspar porphyroclasts, and mafic grains. Finite strain techniques were utilized to produce and analyze 46 thin sections. The metaconglomerate rocks have undergone high to moderate grades of deformation, according to the strain results. Using the Rf/φ and the Fry techniques, the axial ratios in the XZ section vary from 2.20 to 5.40 and from 2.00 to 5.30, respectively. The strain results point out high to moderate rates of deformation of the metaconglomerates, metsediments, and metavolcanic rocks. The direction of finite strain in X axis exhibits shallow WNW dipping and grouping following an N-to-WNW trend in most of the measured samples. The subvertical and subhorizontal foliation related to the short axes in Z axis. The results show that contacts developed in semi-brittle to ductile deformation and the magnitude of strain is the same for all lithologic units that are exposed in the studied area. Also, these results contradict the generally accepted belief that simple-shear deformation is responsible for nappe development in orogens.

Phytosociological Studies on the Associated Species of Balanites aegyptiaca In The Eastern and Western Egyptian Deserts

Phytosociological Studies on the Associated Species of Balanites aegyptiaca In The Eastern and Western Egyptian Deserts

Tectonic evolution of the Gabal Loman area, North Eastern Desert, Egypt: implications from low-temperature multithermochronometry on the Arabian-Nubian shield

The Neoproterozoic Arabian-Nubian Shield (ANS) in the Eastern Desert of Egypt encloses the regional thermal-tectonic history from its development till the Oligo-Miocene when the Red Sea rift system was initiated. The application of multi-thermochronometry techniques has proven to be a successful approach to revealing the influence and extent of each regional tectonic event and the recreation of the tectono-thermal development of the studied region through time. Therefore, characteristic samples from the ANS different rock suits of the Gabal Loman area at the western flank of the northern Red Sea were collected. The Zircon fission-track data reveals the Carboniferous cooling ages, while the apatite fission-track cooling ages present two differential time spans of Cretaceous and Eocene-Oligocene. The time-temperature history modeling is integrated with fission-track data to reveal three differentiated cooling events developed in response to regional tectonic events: 1) the Hercynian (Variscan) tectonic event that influenced the ANS vicinity with rock uplifts of ca. 4 km through the Devonian-Carboniferous time, 2) the Gondwana disintegration event which influenced the region with differential rock exhumations, and 3) the northern Red Sea rifting through the Oligo-Miocene which caused a regional ca. 1 km of rift flanks exhumation. This modest rift flank uplift suggests a passive rift of the northern Red Sea rifting in the region of study.

Effect of mineralogical variations on physico-mechanical and thermal properties of granitic rocks

The present study aims to explain the geochemical and mineralogical details of the granitic rock types in Gabal EL-Faliq area, South Eastern Desert of Egypt, in relation to geotechnical engineering and their suitability as dimension stones. The objective of the current research was achieved through two steps; the first step involved geological studies such as the petrographic, geochemical, and mineralogical investigations. The second and applicable step involved the geotechnical assessment of the studied rocks by measuring their engineering properties such as physical, mechanical, and thermal expansion properties. The petrographic investigation revealed that the studied granitic rocks are divided into two main classes: (1) gneissose granites (Biotite–Perthite) of medium to fine-grained size and (2) alkali-feldspar granites of coarse to medium-grained size. Mineralogically, the studied rocks are composed mainly of albite, orthoclase and quartz in varying proportions, along with some accessory minerals such as apatite and rutile in addition to some minor quantities of iron-group minerals such as hematite and ilmenite. The engineering properties showed that the maximum water absorption and apparent porosity values are 0.34% and 0.77%, respectively, while the minimum bulk density is 2604.03 kg/m3. The compressive strength ranges from 999.68 to 2469.10 kg/cm2, while the abrasion resistance varies from 29.67 to 54.64 Ha. The increase in albite content led to an increase in water absorption while a decrease in bulk density and compressive strength. The increase in the grain size led to an increase in apparent porosity and a decrease in mechanical properties. A Great variation in the expansion coefficient as well as the length change, occurs under changes in temperature, mineral composition, and physical properties. The increase in heating temperatures caused an insignificant increase in linear thermal expansion with a maximum value of 0.0385% at 100 °C. These results indicated the suitability of the studied granites as dimension stones for use in indoor and outdoor decorative purposes (cladding/paving) under variable temperature conditions.

Impact of DEMs for Improvement Sentinel 2 Lithological Mapping Utilizing Support Vector Machine: A Case Study of Mineralized Fe-Ti-Rich Gabbroic Rocks from the South Eastern Desert of Egypt

Fused remote sensing datasets have greatly contributed to enhancing lithological targets and providing significant information for mineral exploration. For instance, multispectral datasets can discriminate rock units through their unique spectral signatures. Digital Elevation Models (DEMs) could be an effective tool boosting lithological discrimination based mainly on their topographic variations. Consequently, the current study applied the power of the support vector machine (SVM) algorithm and the integrated Phased Array L-type band Synthetic Aperture Radar (PALSAR) DEM and multispectral Sentinel 2 data to: 1—Create an updated lithological map of a poorly mapped arid terrain (Khashir-Ras El-Kharit district, Eastern Desert of Egypt), and 2—Compare and assess the distribution of ferrogabbros with the aim of improving the localization of these rock bodies and investigating their mineral content. Our results enhanced the lithological mapping and revealed a better generalization of mineralized ferrogabbros when the input was a fused DEM with Sentinel 2 compared to the salt and pepper effect observed when adopting the Sentinel 2 solely as the input data. Additionally, the current research strongly recommends detailed exploration programs for Fe-Ti oxide ores within the gabbroic rocks delineated through the resultant thematic map. The ferrogabbros were subjected to a comprehensive analysis involving whole rock geochemistry, XRD, EDX, and light-reflecting investigations, which revealed the existence of magnetite, titanomagnetite, and hematite. The titanomagnetite crystals display subhedral morphology and exhibit fine- to medium-grained surfaces with irregular shapes. X-ray diffraction (XRD) analysis revealed the presence of magnetite and hematite in the concentrated Fe-Ti oxides. Additionally, the whole rock geochemistry highlighted the origin of the ferrogabbros and their proposed tectonic setting as an alkaline to calc-alkaline magma type that developed in a continental arc setting.

Review of The Archaeological Survey of the Desert Road between Berenike and the Nile Valley: Expeditions by the University of Michigan and the University of Delaware to the Eastern Desert of Egypt, 1987–2015


 
 
 The Archaeological Survey of the Desert Road between Berenike and the Nile Valley: Expeditions by the University of Michigan and the University of Delaware to the Eastern Desert of Egypt, 1987–2015. Edited by Steven E. Sidebotham and Jennifer E. Gates-Foster. American Schools of Oriental Research, Archaeological Reports, vol. 26. Boston: American SchooLs of Oriental Research, 2019. Pp. xxiii + 480, illus. $84.95. [Distributed by ISD, Bristol, CT]
 
 

Multiscale (microscopic to remote sensing) preliminary exploration of auriferous-uraniferous marbles: A case study from the Egyptian Nubian Shield

Since their recent first record within the Egyptian Nubian Shield, auriferous and uraniferous marbles (Au = 0.98–2.76 g/t; U = 133–640 g/t) have rarely been addressed, despite not only their probable economic importance but also the fact that it is a new genetic style of gold and uranium mineralization in the Nubian Shield rocks. This is mainly attributed to the inadequate localization of these marbles within harsh terrains, as well as the cost and time spent with conventional fieldwork for their identification compared to the main lithological components of the Nubian Shield. On the contrary, remote sensing and machine learning techniques save time and effort while introducing reliable feature identification with reasonable accuracy. Consequently, the current research is an attempt to apply the well-known machine learning algorithm (Support vector Machine—SVM) over Sentinel 2 remote sensing data (with a spatial resolution of up to 10 m) to delineate the distribution of auriferous-uraniferous marbles in the Barramiya-Daghbagh district (Eastern Desert of Egypt), as a case study from the Nubian Shield. Towards better results, marbles were accurately distinguished utilizing ALOS PRISM (2.5 m) pan-sharpened Sentinel 2 data and well-known exposures during fieldwork. With an overall accuracy of more than 90%, a thematic map for auriferous-uraniferous marbles and the major rock units in the Barramiya-Daghbagh district was produced. Marbles are spatially related to ophiolitic serpentinite rocks, as consistent with their genesis within the Neoproterozoic oceanic lithosphere. Field and petrographic investigations have confirmed the newly detected Au and U-bearing zones (impure calcitic to impure dolomitic marbles in Wadi Al Barramiya and Wadi Daghbagh areas and impure calcitic marble in Gebel El-Rukham area). Additionally, X-ray diffraction (XRD), back-scattered electron images (BSEIs), and Energy Dispersive X-ray spectroscopy (EDX) results were integrated to verify our remote sensing results and petrographic investigations. Different times of mineralization are indicated, ranging from syn-metamorphism (gold in Wadi Al Barramiya and Gebel El-Rukham) to post-metamorphism (gold in Wadi Daghbagh and uranium in all locations). Based on the application of geological, mineralogical, machine learning and remote sensing results for the construction of a preliminary exploration model of the auriferous-uraniferous marble in the Egyptian Nubian Shield, we recommend a detailed exploration of Au and U-bearing zones in Barramiya-Dghbagh district and applying the adopted approach to other districts of similar geological environments.

Noise Reduction of Aeromagnetic Data Using Artificial Neural Network

The high-frequency content of high-resolution aeromagnetic data is of particular interest to geophysic ists to identify mineral deposits, shallow faults, and dikes. However, high-resolution aeromagnetic data is contaminated by cultural noise generated from aircraft and man-made features. The culture noise must be removed before starting the interpretation process. Manual techniques are more selective of the noise; however slower and more expensive because they require considerable hands-on interaction. The present study develops a novel method for detecting and removing the culture noise from aeromagnetic data based on an artificial neural network (ANN) in an automatic way and comparing the results with a conventional algorithm using the nonlinear filter. The proposed method is tested using a theoretical example that combine a magnetic anomaly due to a dyke with three sources of cultural noise, besides using a practical example to increase the number of training pattern. The network is trained based on the backpropagation training function, where the algorithm updates the weight and bias states as per the Levenberg–Marquardt optimization. The optimization is reached during the training and validation process after 3,000 iterations. The correlation coefficient ( R) is utilized along with the mean squared error (MSE) as performance indices of the ANN. The ANN demonstrates the capability to detect the spiky data based on the optimal weights, thus allowing for removing and replacing them with clean data using the piecewise cubic Hermite interpolating polynomial (PCHIP) function. The practical utility of the two-method is discussed using high-resolution aeromagnetic data from the Tushka area located in the southwestern desert of Egypt. Comparing the denoising results using the two methods shows that the current approach is more effective in processing and more closely recovering the original magnetic data.