Western Desert Of Egypt Research Articles

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

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

Integrated seismic, petrophysical, and geochemical studies for evaluating the petroleum system of the Upper Bahariya-Abu Roash G sequence in the Karama Field, Abu Gharadig Basin, North Western Desert, Egypt

The main aim of this study is to delineate the hydrocarbon potential and evaluate the petroleum system elements of the Cenomanian Abu Roash G (AR/G) and the Upper Bahariya Members in the Karama Field. It lies at the southeast borders of the Abu Gharadig Basin, a well-known basin in the W.D. to the NE of Africa. We accomplish this study by analyzing a total of thirty 2D seismic profiles, a complete data set of well logs for five wells, and their geochemical data. The workflow starts with illustrating the dominant subsurface structural features, defining the main potential reservoirs and their parameters, and checking the maturity of the probable source rocks. The seismic interpretation indicated that the research area had been influenced by a NE-SW anticlinal structure accompanied by a set of WNW-ESE and NW-SE normal faults that are controlled by the positive compression inversion process that dominated during the Late Cretaceous. Analyzing and processing the well log data sets suggest that the reservoirs of the Abu Roash G (AR/G) and the Upper Bahariya Members are characterized by poor to good reservoir settings with net-pay thickness reaching up to 13–50 feet in the different wells (av. Effective porosity (∅eff) = 17.7 % and 15.6% for the AR/G and the Upper Bahariya Members, av. Shale volume (Vsh) = 17.4 % and 13.6 %, av. Water saturation (Sw) = 38.9 % and 39.8 %, while av. Hydrocarbon saturation values (So) = 60.2 % and 61.1%, respectively). The geochemical and maturity analyses assisted in determining the potential mature source rocks of the Jurassic Khatatba Shale (TOC = 0.70–5.67%; S1+S2 = 0.43–5.97 mg/g, Ro = 0.54–1.06 %) with some contribution from the Cretaceous sources (Alam El-Bueib and Bahariya Formations). Studying elements of the petroleum regime of the Karama Field indicates that the trapped hydrocarbons are structurally controlled by three-way dip closures, horst blocks, sealing faults, and vertical sealing by impervious shale and limestone beds. This case study could be applied to similar analogs in other oil fields in the Egyptian Western Desert to delineate their hydrocarbon potential and structural setting.

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

Origin of the post-orogenic dyke swarms of Saharan Metacraton, at Qaret El-Maiyit-Bir Safsaf area, southwest Egypt: Constraints on the magmatic–tectonic processes at the end of the Precambrian

Deep in the Western Desert of Egypt, in the southernmost part, between Qaret El-Maiyit and Bir Safsaf, swarms of dykes cut through the Neoproterozoic rocks. This area lies halfway between the juvenile crust of the Arabian-Nubian Shield (ANS) and the Gebel Kamil terrains, close to the border with Libya. Acidic dykes include rhyolites and trachy-dacites. Intermediate dykes include trachy-andesite, basalt-trachy-andesite, and basalt-andesite, while basic dykes consist of basalt. Felsic dykes are more numerous and younger compared to the mafic (intermediate and basic) dykes. Felsic dykes trend mostly run to the northeast and northwest, while mafic dykes mainly run to the northwest, less frequently to the eastwest. Acidic and intermediate dykes show elevated REE concentrations (up to 164 and 203 ppm, respectively) with highly fractionated patterns (av. (La/Lu)N = 20.56 and 18) and moderately fractionated HREEs (av. (Gd/Lu)N = 2.5 and 3.2) and LREEs (av. (La/Sm)N = 5.7 and 3.6 respectively). The basic dyke samples exhibit modest REE concentrations (up to 112 ppm), weakly fractionated patterns (av. (La/Lu)N = 8), and mildly to weakly fractionated HREE (av. (Gd/Lu)N = 2.3) and LREEs (av. (La/Sm)N = 2.5) patterns. There are no recognizable Eu anomalies in the dyke samples. The magma ascended in an extensional setting and the geochemical features indicate a subduction mode, possibly originating from the Atmur-Delgo suture zone in northern Sudan or by mantle delamination during the early Neoproterozoic. Both the felsic and mafic dykes are derived from a mafic calc-alkaline melt and show fractionation on a single downward line, indicating a genetic relationship. The mafic dykes were formed by partial melting of an enriched mantle source (about 10%) that started at 2.7–3.0 GPa and a solidus temperature of about 1420 °C. The enrichment of the mantle melt beneath the Saharan metacraton, which is the origin of the studied melts, could be related to mantle delamination.

Tectonic and climate changes influences on distribution and morphology of Quaternary travertine, Kurkur oasis, Egypt

The present study aims to investigate the relationship between tectonic activity, climate changes and Quaternary travertine deposition around Kurkur Oasis in the southern Western Desert of Egypt. Our findings, based on field observations and structural investigations, revealed that extensional tectonics played a significant role in the formation and the distribution of travertine deposits in the study area. Three main travertine morphotypes are documented: fissure ridge, spring mound, and terrace mound along with four lithotypes: crystalline crust, fine-grained lithoclast, paper-thin raft, and reed. The spatial distribution of these travertine occurrences indicates that travertines located closest to the springs exhibit crystalline crust and paper-thin raft lithotypes. While, the reed and the fine-grained lithoclastic types are situated farther from the water sources. Terraces mounds are related to pluvial episodes, which led to travertine deposition in the suitable tectonically created depressions. A two-stage hypothesis for travertine deposition are proposed herein, involving tectonic fissuring and the circulation of carbonated water. These results may enhance our understanding of travertine formation and have broader implications for geological research in similar tectonic environments.

Natural radiological risk assessment around archaeological sites, El-Dakhla Oasis (EDO), Egypt

The natural radionuclides in ancient El-Qasr village located in the El-Dakhla oasis (EDO), Egypt's Western Desert were measured using gamma-ray spectrometry equipped with a NaI (Tl) detector. The findings indicate that the samples' mean activity concentrations were 18.61 ± 1.02, 16.67 ± 0.9, and 137.67 ± 6.9 Bq kg−1 for 226Ra, 232Th, and 40K, respectively. The values of Raeq, D, AED, Hex, Hin, Iγ, and ELCR for the samples ranged anywhere from 34.1 to 83.9 Bq kg−1, 15.7 to 37 nGy h−1, 19.26 to 45.384 Sv y−1, 0.09 to 0.23, 0.12 to 0.23, 0.25 to 0.59, and 6.74E−05 to 1.59E−04, respectively. These values are significantly lower than the international limit of 370 Bq kg−1 for Raeq, 59 nGy h−1 for D, 70 Sv y−1 for AED, 1 for Hex and Hin, 2 for Iγ, and 29E−03 for ELCR. According to the obtained data, none of the samples seemed to be a significant risk when it came to radiation exposure. Using these data, we will determine the baseline level of radionuclides that occur naturally in the area that is the subject of the inquiry.

Abu Roash F reservoir hydrocarbon potential, Western Desert, Egypt

The Western Desert of Egypt is recognized for its significant potential in oil and gas reserves, making it a prominent hydrocarbon-producing area with conventional reservoirs. Recent findings from various wells suggest that unconventional reservoirs in the Western Desert may hold considerable promise. The primary objective of this study was to explore this potential. Accordingly, a comprehensive and multidisciplinary approach has been employed to assess the Abu Roash/F (AR/F) reservoir. The methodology involved meticulously examining formation characteristics and integrating borehole images with existing core data and thin sections. This integration aimed to analyse and interpret the lithofacies of the reservoir, with a specific focus on identifying fractures and decoding potential diagenesis effects. As a result, we successfully identified wells exhibiting optimal reservoir quality, unveiling the presence of fractured dolomite or vuggy dolomite in wells containing promising oil and gas pay intervals. Notably, some wells displayed low porosity (3%), yet seismic attribute maps in their vicinity indicated a high density of fractures. This underscores the importance of combining borehole images with seismic attributes to evaluate carbonate formations effectively. The fractures, predominantly oriented NW–SE, were found to be associated with deformation zones. Our findings emphasize the critical role of this integrated approach in unlocking the full potential of hydrocarbon reservoirs in the Western Desert.

Climate variability in northern Africa during the late Holocene: A multiproxy perspective from El-Beida Lake (Wadi El-Natrun, Egypt)

North Africa is a key region hosting ca. 230 million people that are dependent on climate to maintain their subsistence through agriculture. Because of the current global changes, understanding the mechanisms behind the climate variations that occurred in this region is extremely important. To contribute to a more accurate modelling projection, we reconstructed the paleoclimatic and paleoenvironmental variations from the Meghalayan (∼1,500 ka) to recent using palynological and geochemical data from a sediment core from El-Beida Lake (Wadi El-Natrun area, north Western Desert of Egypt). North Africa underwent significant shifts in climatic conditions forced by different drivers since the Roman Warm Period (RWP) until recent. Our sediment core record indicates that this region experienced a persistent dry and warm climate during the RWP until the first half of the Medieval Climate Anomaly (MCA). The positive North Atlantic Oscillation was the main driver for controlling the precipitation pattern and pushing the precipitation towards central and north Europe and favoring the dry climate in North Africa during the RWP. The dry and slightly cold conditions in the study area during the Dark Age Cold Period (DACP) can be ascribed to the coupling between the more southward position of the Azores Front and the weak Atlantic Meridional Overturning Circulation. Northern Africa showed variable climatic conditions during the Medieval Climate Anomaly (MCA) due to the complicated thermohaline circulation of the Mediterranean Sea. During this time, the Eastern Mediterranean experienced a cold or partially cold MCA that may be extended to the present study area. An abrupt change to humid and cold climatic conditions occurred in northern Africa during the Little Ice Age (LIA) due to large-scale processes like the ENSO and NAO. The SST warming of the North Tropical Atlantic (NTA), significantly influenced by ENSO, causes the position of the Atlantic ITCZ to be shifted northward affecting precipitation in Africa.

Assessment of the hydrocarbon potential in the black shales of the Jurassic Khatatba Formation and generated hydrocarbons, North Western Desert, Egypt: Depositional mechanism of organic rich rocks related to syn-rift differential subsidence

Jurassic rocks comprise the main source rocks in the Western Desert of Egypt. In this study, a rare case of Jurassic oil shale occurrence is recorded and studied as an extension of the Khatatba Formation. The study is based on an integrated model for oil shale deposition using seismic data, organic geochemical analyses, and palynomorph thermal alteration assessment to determine the hydrocarbon generation potential of these rocks. The seismic data were used to construct structure and lithofacies models and to relate the facies distribution with the geochemical parameters of the different rock units in addition to examining the lithofacies changes between the study wells adding value to the understanding of the environment of deposition and the structure of the study area. The Zahra, U. Safa, and L. Safa members are affected by two sets of normal faults, the first of which has a downthrown side to the east while the second set has downthrown westward sides. The 3D facies models show that the Zahra Member is composed mainly of limestone encountered in the central parts of the basin, while shale is mostly found in the north. The U. Safa consists mainly of sandstone and the L. Safa consists of sandstone and siltstone. The geochemical evaluation shows organic richness ranging from poor to good for the Zahra, while the Safa shows poor to excellent richness. Kerogen is Type III and IV in most samples. The Zahra samples are immature in the TUT-21X well and mature in only one sample from the AMOUN NE-2X well. The U. Safa samples are immature to marginally mature while the L. Safa samples are marginally mature to mature in the TUT-21X well and immature in the SHAMS-15X well. Palynomorph thermal alteration data confirm the above maturation levels. The bulk and biomarker composition of two oils samples from U. and L. Safa, AMOUN NE-1X well, are similar and indicate a terrigenous source of the kerogen. The oils are not biodegraded but are normal mature oils generated by kerogen that was deposited under oxic conditions. Data integration from this study can be used to show the variation in organic richness (TOC) and thermal maturity (Tmax) in the area between the four wells, which will help define the exploration risk and provide for a new vision for more exploration activity.

Survey of Bird Species at Petroleum Worker Camps at Marsa Matrouh Governorate, Western Desert of Egypt

Survey of Bird Species at Petroleum Worker Camps at Marsa Matrouh Governorate, Western Desert of Egypt

A Comprehensive Study on the Population Dynamics of Stray Dogs, Wild Foxes, and Rodents in the western desert of Egypt.

A Comprehensive Study on the Population Dynamics of Stray Dogs, Wild Foxes, and Rodents in the western desert of Egypt.

Towards an understanding of hunting equipment used by early Holocene foragers of the Egyptian Southwestern Desert: Triangles of the El-Ghorab Unit

One of the Early Holocene archaeological cultures distinguished in the Egyptian Western Desert is defined as the El Ghorab Unit, and is dated to the 10th millennium cal BP. These hunter-gatherer groups lived on the shores of seasonal lakes (playas) and wetlands typical for the Early and Middle Holocene landscape of that part of the Saharan North Africa. They manufactured characteristic lithic artifact assemblages that have not been studied, so far, from a microwear perspective. The El Ghorab Unit lithic artifact assemblages are dominated by morphologically distinct triangular microliths, ca. 30–40 mm long and made from relatively wide blades, ca. 10 mm in width.This paper presents the results of morphological and functional analyses of El-Ghorab triangles from site E-16-03 located in the Gebel Ramlah/Nabta Playa region. At this locality, remnants of a few activity areas have been recorded on the northwestern margin of the Gebel Ramlah paleo-lake basin. The site consists of lithic artifact concentrations scattered around burned-earth hearth features (fireplaces). The function of the triangles is examined and interpreted here by also taking into account the specific paleoenvironmental and paleozoological record from site E-16-03.The El-Ghorab area of the Gebel Ramlah basin at E-16-03 contains three seasonally-specific, short-term hunting camps where hunting equipment was repaired and hunted game was brought to the site during spring time. Triangles were the main goal of lithic production. In the course of this research it has become evident that triangular microliths were mounted in hafts in different ways. This observation can be used as supporting evidence to conclude that various prehistoric human groups visited the Gebel Ramlah area during several seasonal cycles.

Reservoir characterization of the Abu Roash D Member through petrography and seismic interpretations in Southern Abu Gharadig Basin, Northern Western Desert, Egypt

This research combines petrography and seismic analysis to assess the Upper Cretaceous Abu Roash (AR)/D’s carbonate member composition in the Southwest Abu-Sennan oil field in the Southern Abu Gharadig Basin within the Northern Western Desert of Egypt. Various datasets were used, including petrographic thin sections, and electrical well logs for four stratigraphic wells (01, -02, -03, and, -04), along with a time domain seismic dataset covering the study area. Petrographic analysis across multiple depths and intervals has provided valuable insights. Well-01 demonstrates mud-wackstone with diverse mineral components at 1671–74 m MD, indicating favorable reservoir quality. Well-02 exhibits diverse compositions at intervals 1740–43 m MD and 1746–49 m MD, also showcasing good reservoir quality. Well-03 reveals a packstone rock type at 1662–65 m MD with favorable reservoir characteristics. Well-04 displays peloids Wack-Packstone and Oolitic Packstone at intervals 1764–67 m MD and 1770–73 m MD, respectively, both indicating good reservoir quality. Integrating the petrography and seismic attributes results concerning the structural level of AR/D concerning the used wells, it's evident that Well-03 stands out due to its relatively high structural level, drilled near a major fault, revealing distinct fracture sets that contribute to a notably high reservoir quality as depicted in the RMS amplitude and Ant track attributes maps. AR/D reservoir levels in wells 02, and, 04, are relatively positioned at structurally lower levels, and face challenges with overburden pressure and mechanical compaction, resulting in diminished facies quality for the reservoir. Seismic attributes like the Ant track and RMS amplitude indicated that the presence of fractures within the AR/D Member's carbonate is linked to the prevalence of interpreted normal faults. The implemented procedure in this research can be applied to enhance comprehension of AR/D carbonate reservoirs in adjacent regions, thereby increasing the hydrocarbon exploration possibilities.

Exploring carbonate reservoirs potential, north Egypt

Carbonate reservoirs contain a significant portion of the world's oil reserves. The Middle East is home to many of these reservoirs. Carbonate reservoirs can be found in a few very large oil fields, including Egypt's Zohr field, the largest conventional gas field in Egypt. In this article, we present a couple of successful tertiary carbonate reservoirs that are bearing hydrocarbon in the Egyptian Western Desert and Gulf of Suez provinces, they are distributed across Egypt's subsurface, and they are characterized by heterogeneous porosity and permeability. These heterogeneities are caused by the wide spectrum of tectonostratigraphic environments in which carbonates are deposited and by subsequent diagenetic alteration of the original rock fabric. The structural analysis of the study areas based on the interpretation of both geophysical and geological data, in JD, Abu Sennan, and the North Amer areas in the Western Desert and offshore Gulf of Suez respectively showed that tectonostratigraphic history during tertiary time affected a great extent carbonate reservoir quality. Major fault trends formed secondary fracture porosity possibly allowing hydrothermal solutions to pass through the reservoirs and form secondary vuggy porosity. These characteristics are considered important factors of promising carbonate reservoirs. In this study, several carbonate reservoirs have been outlined. The study workflow helped us better identify carbonate prospects with high fractured density.

Late Mesozoic–Cenozoic geoheritage resources of the Kharga Oasis (Egypt): Novel assessment, exploitation perspectives, and policy implications

Geoheritage resources are valuable to countries and regions, which make urgent their exploration. Particularly, Egyptian geoheritage has been examined only partly, and it has not been reported from many areas. New field investigations in the Kharga Oasis in the southern Western Desert of Egypt permit to report a new portion of geoheritage resources. The collected materials are used to propose six geosites, describe them (particularly, standardized geoheritage types are established), and assess semi-quantitatively. The approach is the same as already used for some other areas of Egypt, and the semi-quantitative assessment is based on scoring of various geosite properties with the different weight. It is established that these geosites exhibit lithologies and depositional environments of Upper Cretaceous–Eocene terrestrial and marine sedimentary rocks, Quaternary terrestrial carbonates (tufa deposits), and residual desert landforms. The geosites are attributed to the sedimentary, palaeogeographical, stratigraphical, palaeontological, and geomorphological geoheritage types. Scoring them by several criteria implies that two geosites (Naqb El-Rufuf and Naqb Bulaq) are national and four geosites (Naqb Assiut, Wadi El-Midawara, Gebel Taref, and Kharga Stadium) are regional in rank. The accessibility of some geosites is limited, and the Kharga Stadium geosite demonstrates significant vulnerability due to its location in the urban area. Generally, the analyses imply the presence of a valuable geoheritage resource in the Kharga Oasis. The outcomes of the present study also indicate the perspectives of scientific, educational, and touristic exploitation of the established geoheritage resources and the need in the development of the optimal policy for their effective management. Geopark creation seems to be a plausible instrument for the implementation of this policy, and its proposal requires further investigations of geological and cultural heritage of the Kharga Oasis.

Irrigation Water Management in a Water-Scarce Environment in the Context of Climate Change

Climate change has a considerable impact on irrigated agriculture, which is vital for food and fiber production. In this study, in the context of climate change, simulation model CROPWAT 8 was employed to compute the reference evapotranspiration, and net irrigation water requirement for wheat, barley, maize, sugar beet, potato, tomato, and date palm. In addition, the WaterGEMS model was utilized to design a new sprinkler irrigation system to run long-term simulations of hydraulic behavior within pressurized pipe networks to irrigate 43 acres for two arid sites (Siwa Oasis and West Elminya fields) inside the 1.5-million-acre groundwater irrigation project in the Egyptian western desert. Five scenarios for climate change were employed in the current (1991–2023), representative concentration path (RCP) 8.5 greenhouse gas emission scenarios for the 2040s, 2060s, 2080s, and 2100s. Mean ETo values for the current scenario show 4.56 and 5.7 mm for the Siwa Oasis and West Elminya fields, respectively. The climate changes cause an increase of the reference evapotranspiration by 4.6, 5.9, 9.4, and 12.7% for RCP: 8.5 greenhouse gas emissions for the 2040s, 2060s, 2080s, and 2100s scenarios, respectively, for the Siwa Oasis field. On the other hand, an increased ratio for the reference evapotranspiration by 4.2, 5.4, 8.6, and 11.6% was observed for the scenarios in the West Elminya field, respectively. The designed sprinkler system indicated a capacity of 111.4 m3 h−1 and 167 m3 h−1 for Siwa and West Elminya fields, respectively. The study suggests using crop patterns for wheat, barley, potato, and sugar beet to save irrigation water.Graphical abstract

Late Neolithic tethering or trapping stones from Bargat el-Shab (Western Desert of Egypt). Function and meaning

Pastoral communities left numerous and varied traces of activity in the Sahara. Among them are so-called tethering/trapping stones, attested mainly in an area stretching from Algeria through Egypt to Sudan. Discovered in a variety of contexts, these originally utilitarian items with multiple functions occasionally gained importance in rituals performed by Middle Holocene pastoral communities. This paper focuses on stones found in the southern zone of the Western Desert of Egypt and discusses their function and significance in the broader context of North Africa.