Egyptian Desert Research Articles

Basement rocks around the eastern sector of Baranis-Aswan Road, Egypt: Remote sensing data analysis and petrology

The basement rocks around Baranis-Aswan Road, South Eastern Desert of Egypt encompasses a variety of the oldest Pan-African rock units including medium-grade hornblende schist, a variety of gneisses and migmatite as well as medium- to low-grade metavolcanics. These were intruded by syn- to late-tectonic tonalite, granodiorite, quartz diorite as well as gabbros. The exposed basement rock units in the area were discriminated with the detailed lithological mapping using the processed data of ASTER, Landsat-8 and Sentinel-2. Spectral signatures of these rocks were achieved by ASD TerraSpec Halo mineral identifier device. Petrography and geochemistry data enabled to put constraints on their petrogenesis. Geochemically, the schist and gneisses imply K-poor mafic igneous precursors that were developed in a primitive juvenile oceanic environment. The migmatite pertains to stromatic type, whereas granitic magma (neosome) was injected in hornblende schist (paleosome) through cleavage planes. The syn-tectonic tonalite to quartz diorite are also low-K, non-mature calc-alkaline rocks and pertain to oceanic plagiogranite. They display a continuous fractionation evolution trend from quartz-diorite to tonalite and granodiorite.

Characterization of Possible α-Glucosidase Inhibitors from Trigonella stellata Extract Using LC-MS and In Silico Molecular Docking.

The current study accentuates the significance of performing the multiplex approach of LC-HRESIMS, biological activity, and docking studies in drug discovery, taking into consideration a review of the literature. In this regard, the investigation of antioxidant and cytotoxic activities of Trigonella stellata collected from the Egyptian desert revealed a significant antioxidant capacity using DPPH with IC50 = 656.9 µg/mL and a moderate cytotoxicity against HepG2, MCF7, and CACO2, with IC50 values of 53.3, 48.3, and 55.8 µg/mL, respectively. The evaluation of total phenolic and flavonoid contents resulted in 32.8 mg GAE/g calculated as gallic acid equivalent and 5.6 mg RE/g calculated as rutin equivalent, respectively. Chemical profiling of T. stellata extract, using LC-HRESIMS analysis, revealed the presence of 15 metabolites, among which eleven compounds were detected for the first time in this species. Interestingly, in vitro testing of the antidiabetic activity of the alcoholic extract noted an α-glucosidase enzyme inhibitory activity (IC50 = 559.4 µg/mL) better than that of the standard Acarbose (IC50 = 799.9 µg/mL), in addition to a moderate inhibition of the α-amylase enzyme (IC50 = 0.77 µg/mL) compared to Acarbose (IC50 = 0.21 µg/mL). α-Glucosidase inhibition was also virtualized by binding interactions through the molecular docking study, presenting a high binding activity of six flavonoid glycosides, as well as the diterpenoid compound graecumoside A and the alkaloid fenugreekine. Taken together, the conglomeration of LC-HRESIMS, antidiabetic activity, and molecular docking studies shed light on T. stellata as a promising antidiabetic herb.

Utilization of Landsat-8 (OLI) Image Data for Geological Mapping of the Neo-Proterozoic Basement Rocks in the Central Eastern Desert of Egypt

Utilization of Landsat-8 (OLI) Image Data for Geological Mapping of the Neo-Proterozoic Basement Rocks in the Central Eastern Desert of Egypt

Evidence for Upper Cretaceous seismites in the Abu Tartur area, Western Desert, Egypt

Upper Cretaceous tidal-flat sediments of the Abu Tartur region, Western Desert of Egypt, contain a variety of soft-sediment deformation structures (SSDSs) in the Mut Member of the Quseir Formation and the overlying Duwi Formation. Here, we document recognition of a set of SSDSs characterized by complex morphology and large size. The SSDS include: 1) water-escape structures, 2) minor recumbent, chevron, and slump folds, 3) syn-sedimentary minor faults, 4) neptunian dykes, 5) regular ball-and-pillow structures, flattened pseudo-nodules, and load casts, 6) syn-sedimentary undulations, 7) fractures and joints, 8) sand injectites, and 9) autoclastic breccia and brecciated siderite clasts. The dimensions of the SSDSs range from a few centimeters to several decimeters. Both extensional and contractional forces appear to have been involved in development of these structures. A detailed analysis of facies relationships, combined with consistent orientations of SSDSs and the regional tectonics of the target area suggests earthquakes as the triggering mechanism for sediment deformation and large-scale mass failure. The deformed strata are consistent with most of the well-known criteria of typical seismites. Thus, syn-sedimentary liquefaction was identified as the primary driving force in most of the observed deformation horizons for these Upper Cretaceous SSDSs in the Abu Tartur area.

Design methodology for sewage water treatment system comprised of Imhoff ‘s tank and a subsurface horizontal flow constructed wetland: a case study Dakhla Oasis, Egypt

In this study, in order to reuse the treated wastewater in irrigation in rural areas, a new sewage water treatment system comprised of primary treatment Imhoff’s tank, Hama drying basins, inlet well, a subsurface horizontal flow constructed wetland (HSFW), water control device, and a groundwater tank is proposed and designed in Dakhla Oasis western desert of Egypt. The proposed system serves a population of 5000 capita with a designed discharge of 750 m3 d−1. The kinetic parameters involved macrophyte organisms, media forms, water level, hydraulic retention time (HRT), and hydraulic loading rate (hl) for the system were selected to achieve an efficient wastewater treatment system design. Imhoff’s tank is sized as the primary sedimentation efficiency is 30%, and HSFW is sized based on the first-order kinetics (k-C∗) model, and total hydraulic design theory. The air temperatures were 29.7 °C and 13.8 °C in summer and winter respectively, influent pollutant concentrations after primary sedimentation for BOD, fecal coliforms (FC), total nitrogen (TN), and total phosphorus (TP) were 210 mg L−1, 108 CFU100 mL−1, 30 and 7 mg L−1, respectively. The expected designed effluent BOD and FC were 30 mg L−1 and 1000 CFU100 mL−1 respectively. The results show that FC removal controls the area of the HSFW (2.87 ha), 6 units of reed (Phragmites Australis and Papyrus) plants each one is 66 m with hl of 2.6 cm d−1 and HRT of 6.91 d. The expected overall removal efficiencies for BOD and FC were 85.7%, and 99.9% respectively.

Interpretation of the subsurface tectonic setting of the Natrun Basin, north Western Desert, Egypt using Satellite Bouguer gravity and magnetic data

The Natrun Basin, north Western Desert of Egypt, represents a significant oil and gas province as it contains numerous oil and gas production fields. The basin has huge hydrocarbons recovery, mainly from the Jurassic rocks and minor amounts from Cretaceous rocks. The satellite Bouguer gravity, magnetic data, geologic, and available deep-drilled wells represent the primary data for the current research. The study's main goals are to interpret the subsurface tectonic setting, investigate the tectonic evolution of the Natrun Basin, and estimate the depth to the basement surface. Several geophysical techniques were applied to the satellite Bouguer gravity and magnetic data using Geosoft Oasis Montaj (Version. 8.3.3, 2015) to achieve the study's goals. The total magnetic intensity data was transformed into the reduced to pole map to prepare the magnetic data for further separations. The power spectrum was applied to detect the cut-off wavenumbers used in high and low-pass filters to separate the regional and residual anomalies. The first vertical derivative was applied to enhance the residual anomalies. The total horizontal and tilt derivatives were calculated to delineate the edges of the subsurface causative bodies. The 2D modeling was applied to estimate the depth to the basement surface and reveal the configuration of the subsurface rock units. A basement structure map was constructed to reveal the subsurface tectonic setting and evaluation of the Natrun Basin. The depth to the basement surface ranges between 1880 m and 6200 m. The subsurface tectonic setting of the basin was controlled by the N–S East Africa, NE-SW Hercynian, E-W Mediterranean, ENE-WSW Syrian Arc, NW-SE Gulf of Suez, and NNE-SSW Aqaba tectonics from the oldest to the youngest, respectively.

Flare Gas Recovery from an Existing Oil Plant using Gas Compressors

Global warming is nowadays one of the main and important issues. As the increase in the concentration of carbon dioxide and other greenhouse gases in the atmosphere as a result of the combustion of these gases causes such phenomena. Therefore, oil and gas plants need to be constantly reviewed over time to maintain high performance and operability, especially while changing feed composition and rate to meet standard product specifications. The aim of this study is to study the effect of flare gases recovery using gas compressors on the economic and environmental performance of an existing oilfield plant. A commercial simulation program aspen HYSYS Version 11 was used. The Kalabsha Central Processing Facility (KCPF) in the Western Desert of Egypt is the studied plant. This plant handles 30 million standard cubic feet per day (MMSCFD) from free water knock out drum and 1.6 MMSCFD of gases from heaters. 20 MMSCFD from gas is charged to the gas pipeline and 10 MMSCFD is sent to the flare with the 1.6 MMSCFD. It is proposed to install gas compressors to capture the gases from the free water knock out drum and heaters before sending them to the flare. Such technology can be used as a guide in upgrading existing and new oil and gas plants to reduce gas flaring. In addition, environmental protection also adds more economic profits from burning the recovered gas besides increasing the life of the flare equipment.

Studies of plant impressions preserved on daub excavated at the archaeological sites of the Western Desert in the area of Nabta Playa and Bargat El-Shab

The archaeological and archaeobotanical research conducted in southern part in the Western Desert in Egypt included efforts at identifying the plant material preserved in daub. The samples selected for this type of analysis were taken from site E-05-1 in Bargat El-Shab. This site were occupied seasonally by nomadic people from the beginning of the Holocene. The study provide very little data on plant remains preserved in daub and confirms application of grass, as a temper added to clay before firing or drying.

Assessing the Radiological Risks Associated with High Natural Radioactivity of Microgranitic Rocks: A Case Study in a Northeastern Desert of Egypt

This study aimed to evaluate the radiological hazards of uranium (238U), thorium (232Th), and potassium (40K) in microgranitic rocks from the southeastern part of Wadi Baroud, a northeastern desert of Egypt. The activity concentrations of the measured radionuclides were determined by using a gamma-ray spectrometer (NaI-Tl-activated detector). The mean (238U), (232Th), and (40K) concentrations in the studied rocks were found to be 3680.3, 3635.2, and 822.76 Bq/kg, respectively. The contents in these rocks were elevated, reaching up to 6.3 wt%. This indicated the alkaline nature of these rocks. The high ratios of Th/U in the mineralized rocks could be related to late magmatic mineralization, suggesting the ascent of late magmatic fluids through weak planes such as faults and the contact of these rocks with older granites. The present data were higher than those of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) guideline limits. All the radiological hazard results indicated high human health risks. This confirmed that this area is not radiologically safe, and care must be taken when working in this area. This study showed that the area under investigation had high U content suitable for uranium extraction that could be used in the nuclear fuel cycle.

Petrogenesis of Gabbroic Intrusions in the Central Eastern Desert of Egypt: Implications for Neoproterozoic Post-Collisional Magmatism Associated with Najd Fault System

Petrogenesis of Gabbroic Intrusions in the Central Eastern Desert of Egypt: Implications for Neoproterozoic Post-Collisional Magmatism Associated with Najd Fault System

Recovery of Cassiterite and Topaz Minerals from an Old Metallurgical Dump, Eastern Desert of Egypt

Huge amounts of tailing dumps as a result of mines’ blasting operations were impacting economic and environmental problems. Evaluation of one of these tailing dumps of the Eastern Desert of Egypt showed the presence of reasonable amount of cassiterite mineral reaching 0.199% SnO2. The mineral cassiterite was found as finely disseminated particulates, reached to 5 microns, within varieties of quartz-feldspar-hornblende-biotite granitic formations. In the present study, the processing regime considered from the beginning the alignment between reaching cassiterite mineral liberation size, and its extreme brittleness character. Stirring ball milling technique was applied to produce −0.51 mm product with minimum fines as possible, which was left aside for a separate study. The ground product −0.51 + 0.074 mm was subjected to joint shaking table/dry high intensity magnetic separation techniques after splitting it into two fractions, −0.51 + 0.21 mm and −0.21 + 0.074 mm. Each fraction was separately subjected to “Wilfley” shaking table. At optimum conditions, a shaking table concentrate was obtained with 0.29% SnO2 and an operational recovery reached 96.94% from a feeding contained 0.19% SnO2. The heavies and the two middling products after shaking table were directed separately after dryness to dry high intensity magnetic separation using “Eriez” rare earth roll separator, meanwhile the light fractions were rejected. Mathematically designed experiments were applied to optimize the separation process. At optimum conditions, a final cassiterite concentrate was obtained with 11.25% SnO2, and an operational recovery 94.08%. In addition, a topaz mineral concentrate was separated at splitter angle 65˚.

Detection of Uranium Anomalies and Alteration Zones Using Airborne Gamma-Ray Spectrometry at Gabal Attala and Its Surrounding Area, Eastern Desert, Egypt

Gamma-ray spectrometry method is widely used in various fields. The study area is located in the Central Eastern Desert of Egypt and covers about 1200 square kilometers. The rock units in the study area can be organized in ages from the Precambrian (mainly granite) to Quaternary. Airborne gamma-ray spectrometry data were collected by Aero-Service, 1984. The main objectives of this study are to detect hydrothermal alteration zones and the uranium anomalies in the study area. The processing of the data was conducted to generate radioactive element concentration maps (K, eU and eTh). Hydrothermal alteration zones such as potassic and phyllic altered areas were detected using the Potassium Ternary Composite Image map and the eTh/K map. The F-parameter technique and K ideal method were used to determine the locations of the potassium-enrichment. These locations are characteristically associated with the orogenic gold mineralization in the study area. Fourteen radioactivity zones were classified based on the Interpreted Radio-Spectrometric Zonation (IRSZ) Map. These zones were divided into high, medium and low radioactive response where zones of high radioactive response were revealed as zones 1, 6, 9 and 13. Uranium anomalies have been identified as these anomalies are abundant in eU values and also associated with higher values of eU/eTh and eU/K, where the maximum value of eU is associated with the Younger Granite with a value of 18.831 ppm. These uranium anomalies are associated with Taref Formation, Post-Hammamat felsite, Quaternary deposits and Younger Granite. The locations of uranium anomalies are considered important exploration targets, as these locations are promising and have priority for ground geophysical and geological follow-up.

Saint John Kolobos or the little in the medieval Eastern Christian world

The paper presents extant writings about St. John Kolobos or the Little (c. 339 - c. 409), a monk who lived in a lavra in Scetis in the Nitrian Desert in Egypt. Attention is paid to his relics, which were transferred from Clysma near Suez to his monastery in the Nitrian Desert at the end of the eighth century. Basic data about the Monastery of St. John the Little, abandoned at the end of the fifteenth century, are presented. Preserved medieval representations of the saint are listed. Conclusions about his cult and depiction in art follow in the final part.

Extracts of wild Egyptian plants from the desert inhibit the growth of Toxoplasma gondii and Neospora caninum in vitro.

Wild medicinal plants have been traditionally used as antimicrobial agents. Here, we evaluated the in vitro activity of extracts from wild Egyptian desert plants against Toxoplasma gondii and Neospora caninum. From 12 plant extracts tested, the methanolic extracts from Artemisia judaica, Cleome droserifolia, Trichodesma africanum, and Vachellia tortilis demonstrated potent activity against the growth of T. gondii, with half-maximal inhibitory concentrations (IC50s) of 2.1, 12.5, 21.8, and 24.5 µg/ml, respectively. C. droserifolia, an ethanolic extract of P. undulata, T. africanum, A. judaica, and V. tortilis demonstrated potent efficacy against N. caninum, with mean IC50s of 1.0, 3.0, 3.1, 8.6, and 17.2 µg/ml, respectively. Our data suggest these extracts could provide an alternative treatment for T. gondii and N. caninum infections.

Evaluating the application of thermal comfort passive strategies in buildings' design within the Egyptian desert climatic design region

The deficiency of the thermal performance of contemporary buildings in Egypt, with its different climatic design regions, lead to poor thermal comfort for buildings' users. This is probably caused by designs that neglect adopting the Environmental techniques and strategies in. The problem is that there are no clear reasons for this deficiency. This research aims to evaluate the application of passive thermal comfort strategies in buildings' design within the largest Egyptian climatic design region, namely (the desert region). In addition, it tries to identify the causes behind the deterioration in the thermal performance of contemporary Egyptian buildings across this region. The research employs a mixed methodology that includes analytical and investigative approaches. In the analytical part, the climatic data for (Minya) city (the representative city of the desert region) are analyzed and the most effective strategies in achieving thermal comfort within the region are identified. These effective strategies are the basis upon which the investigative part of the research is based. As for the investigative part of the methodology, questionnaire technique is adopted to collect data from local architects and experts with various qualifications and professional experiences. They are asked to assess their knowledge with effective passive strategies and their usage in design, as well as, define the constrains behind non-implementation.

Trash from a temple: a deposit next to the Isis Temple at Berenike (Egypt)

The article discusses the stratigraphy and chronological phasing of a late antique trash deposit discovered just outside the north wall of the Isis Temple courtyard. It appears to be consumption waste collected from a large-scale event taking place in the immediate vicinity over a short period of time. Several elements of architectural decoration were found among the rubble, including three fragments of ‘Ionic’ cornice blocks that are an indication of the presence of at least one building with a classical-style architecture in the urban landscape. The fragments are quite unusual in the southern part of the Eastern Desert of Egypt and the first and somewhat unexpected attestation of this style recorded from Berenike.

Comprehensive 3D reservoir modelling and basin analysis: An insight into petroleum geology to re‐evaluate the hydrocarbon possibilities in the Siwa Basin, North‐Western Desert, Egypt

Three‐dimensional (3D) reservoir modelling and basin analysis were performed for the Siwa Basin in the North‐Western Desert of Egypt. An integrative study from the available data were done, including geochemical data to construct a 1D basin model, petrophysical data to realize the characteristics of the reservoir, and geological data to understand the subsurface geologic setting, has been undertaken. Basin modelling was done for the Siwa A1‐X well to determine the burial and thermal history, sedimentation rate, level of maturity, and finally the event chart for the petroleum system. Siwa Basin comprises one petroleum system. The source rock is represented by the Palaeozoic Dhiffah, Desouky, and Zeitoun formations, with fair to good organic richness, producing oil and gas, which entered the oil window in 143.91, 162.87, and 167.31 Ma, and entered the wet gas in 138.75, 141.82, and 143.63 Ma, with sedimentation rate varying from low to high 543.96, 22.79, and 1,404.46 m/Ma, respectively. The Safa Member (Khatatba Formation) is the main reservoir, with hydrocarbon saturation reaching up to 80%, and with a low subsidence rate of 76.43 m/Ma. The Original Oil In Place for the new prospects is 197.177 Stock Tank Barrel (STB), while for the oil reserve is 50.618 Stock Tank Barrel (STB).

Evaluation of Desertification Severity in El-Farafra Oasis, Western Desert of Egypt: Application of Modified MEDALUS Approach Using Wind Erosion Index and Factor Analysis

Desertification is a serious threat to human survival and to ecosystems, especially to inland desert oases. An assessment of desertification severity is essential to ensure national sustainable development for agricultural and land expansion processes in this region. In this study, Index of Land Susceptibility to Wind Erosion (ILSWE) was integrated with a Modified Mediterranean Desertification and Land Use (MEDALUS) method and factor analysis (FA) to develop a GIS-based model for mapping desertification severity. The model was then applied to 987.77 km2 in the El-Farafra Oasis, located in the Western Desert of Egypt, as a case study. Climate and field survey data together with remote sensing images were used to generate five quality indices (soil, climate, vegetation, land management and wind erosion). Based on the FA, a weighted value was assigned to each index. Five thematic layers representing the indices were created within the GIS environment and overlaid using the weighted sum model. The developed model showed that 59% of the total area was identified as high-critical and 38% as medium-critical. The results of an environmentally sensitive area index suggested by the original MEDALUS model indicated similar results: 18.37% of the total area was classified as high-critical and 78.73% as medium-critical. However, the sensitivity analysis indicated that weights derived from FA resulted in better performance of the developed spatial model than that derived from the original MEDALUS method. The proposed model would be a suitable tool for monitoring vulnerable zones, and could be a starting point for sustainable agricultural development in inland oases.

Radioactive mineralization detection using remote sensing and airborne gamma-ray spectrometry at Wadi Al-Miyah area, Central Eastern Desert, Egypt

Band rationing, principal component analysis (PCA) and decorrelation stretch (DS) techniques of Landsat-8 with Sentinel-2 data successfully used in the discrimination of the lithological units and the surface structure features of Wadi Al-Miyah area in the Central Eastern Desert of Egypt. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were processed to identify the hydrothermal mineralized alteration zones related to the radioactive minerals. Airborne gamma-ray spectrometry (AGRS) has been used to determine the naturally occurring radioactive anomalous zones such as potassium (K), equivalent uranium (eU) and equivalent thorium (eTh) and to follow their spatial distribution in Wadi Al-Miyah area. The analysis of AGRS data revealed that, the study area owns a wide range of radioelement concentrations ranging from 15.5 to 98.4 μR/h, 5.9–37.1 ppm, 17.2–95.4 ppm, and 0.53%-10.29% of total count (TC), (eU), (eTh), and (K), respectively. The interpretation of the Radioelements Composite Image (RCI) successfully delineated the enrichment zones with radioelement concentrations within the alkali feldspar granite, biotite-muscovite schist, granodiorite and the hydrothermal alteration areas within the diorite of Gabal Al- Bakriyah. The results concluded that the integrated remote sensing and airborne AGRS data are promising in detecting the potential areas enriched with K, eU and eTh.

An integrated high-resolution image log, sequence stratigraphy and palynofacies analysis to reconstruct the Albian – Cenomanian basin depositional setting and cyclicity: Insights from the southern Tethys

Borehole image logs are used to overcome the lack of core samples and other conventional open-hole logs in many subsurface reservoirs around the world, significantly reducing the likelihood of petroleum resource exploration. These image logs can provide high-resolution data to visualize sedimentary structures, facies types, lithofacies, geomechanical characteristics, and depositional trends. Sedimentologists recognize the Bahariya Formation of the North-Western Desert of Egypt as the typical coastal -shallow marine depositional model that emphasizes a typical heterogeneous sandstone reservoir with many obstacles in production profile. One of the most significant issues related to the heterogeneous Bahariya reservoir that confronts hydrocarbon producers is the loss of productive target zones due to spatial facies changes. This research aims to overcome the exploration and development challenges of the complex and heterogeneous sandstone reservoir of the Albian – Cenomanian Bahariya Formation that lies in the Abu Gharadig Basin, Southern Tyths, Egypt. In this work, we used integrated image logging in conjunction with palynofacies, core samples, and sequence stratigraphy to provide high resolution information that can aid in better resource exploitation. Furthermore, we utilized the integrated work in the definition of the high-resolution para-sequences, sequences boundaries, lithofacies characteristics and paleocurrent analysis of each facies association. The interpretation of coastal shallow marine facies from four BHI-logs was established and calibrated with two core sets in order to define the best hydrocarbon reservoir intervals and focus on improving the development plan of the study area. Our findings show that the Bahariya Formation is characterized by eleven facies associations which have been interpreted based on the integrating of the twenty-seven electrofacies extracted from the FMI images, wireline logs, and core photographs. The identified facies associations were classified into five depositional sequences and their boundaries were determined using dipmeter patterns and extracted lithofacies from BHI. The LST and MFS deposits in both the fourth and fifth depositional cycles, respectively, whereas the HST deposits are found only in the third depositional cycle. According to our findings, the development of the shoreface sandy facies of cycles three and five represents the maximum rate of sea-level rise, as well as the development of the offshore sand bar system, which represents high-quality sandstone reservoirs. This case study demonstrates how image logs can be used to better understand the spatial distribution and geometries of sandstone bodies in the Bahariya Formation. Furthermore, it provides a reference imaging fingerprint of high-resolution coastal shallow marine, high-frequency sequences analysis, sedimentary structures, and extracted electrofacies analogues that can be used in the basin and elsewhere.