Cairo-Suez District Research Articles

An overview on structural geophysics application along Cairo-Suez District: Case studies

An overview on structural geophysics application along Cairo-Suez District: Case studies

Structural architecture of Gebel Hamza, Northwestern sector of Cairo-Suez District, Egypt

Structural architecture of Gebel Hamza, Northwestern sector of Cairo-Suez District, Egypt

Palaeoenvironmental analysis of bivalve-dominated concentrations from the lower‒middle Miocene succession, Gebel Gharra, Cairo-Suez District, Egypt

Palaeoenvironmental analysis of bivalve-dominated concentrations from the lower‒middle Miocene succession, Gebel Gharra, Cairo-Suez District, Egypt

Taphonomy of the middle Miocene regular echinoid spines from Cairo-Suez District, Egypt: Palaeoecological and palaeoenvironmental interpretations

The palaeoecology and palaeoenvironment of a dense cluster of regular echinoid spines that occur in an oyster-rich limestone layer are interpreted based on detailed taphonomic study. The paucispecific macrobenthic assemblage associated with these echinoid spines have been studied in the middle Miocene Geniefa Formation, Gebel Gharra, Cairo-Suez District of Egypt. Both echinoid spines and macrobenthic assemblages are dominated by moderately to well-preserved, moderately packed, highly disarticulated, moderately to poorly sorted, re-oriented, and moderately to highly fragmented specimens, confirming parautochthonous nature of this assemblage. The spines are commonly encrusted and bored. At least four taxonomic groups of encrusters are identified, including juvenile oysters, sheet-like cheilostome bryozoans, serpulids, and balanoid barnacles. The diversity of bioerosional ichnotaxa is moderate and includes Gastrochaenolites, Entobia, Maeandropolydora, Trypanites, and Spirolites. Moreover, some echinoid spines display distinct biting traces of fish, representing the first recorded of fish tooth bite marks on remains of regular echinoid spines from the Miocene deposits of Egypt. The faunal composition and trophic structure of the studied faunal assemblage indicate fully oxygenated and euhaline shallow-marine environment with meso- to eutrophic productivity level. The controlling environmental parameters include substrate consistency, bathymetry, water energy, surface-water productivity, and rate of sedimentation. Furthermore, two scenarios for sclerobionts colonisation and development of fish bite marks have been proposed. In the first syn vivo scenario, predatory fish either focused on the encrusting organisms attached to the spines or attacked the echinoid as a food source, resulting in the separation of spines from their original test during the echinoid’s life. In the second post-mortem scenario, disarticulated spines serve as a hard substrate for the colonisation of sclerobionts. Once again, the spines became subject to attacks by fish that fed on the encrusters, resulting in additional bite marks.

Integration of geological and geophysical data for delineating groundwater potential zones at highly faulted area: a case study Cairo-Suez district, Egypt

Integration of geological and geophysical data for delineating groundwater potential zones at highly faulted area: a case study Cairo-Suez district, Egypt

Delineation of the proper locations for wastewater disposal in arid regions using TEM and ERT techniques: A case study at Rubiki industrial zone, Badr City, Egypt

Proper wastewater disposal is crucial for the sustainable development of rapidly growing megacities worldwide. The emergence of waterlogging near evaporation ponds (EVP) and in desert areas surrounding these cities poses a significant environmental threat. This study employs an integrated approach, combining transient electromagnetic (TEM) and 2D-electrical resistivity tomography (2D-ERT) methods with remote sensing techniques, to understand wastewater flow patterns around EVPs and identify suitable disposal sites. The research focuses on a complex subsurface structure in the Cairo-Suez district, characterized by extensive surface waterlogging. Initial monitoring relies on satellite imagery and land use-land cover maps. TEM provides an overview of subsurface layer distribution, while 2D-ERT offers detailed insights into near-surface flow paths. To address the limitations of geoelectrical methods in locating conductive layers, advanced inversion techniques (AIS) are applied. The findings reveal a four-layer subsurface composition, with waterlogging primarily attributed to the argillaceous limestone layer interbedded with shale. This layer is shallower in the eastern and northwest areas, correlating with higher instances of waterlogging. Moving northward, the argillaceous limestone layer deepens, and the upper clastic layer thickens, resulting in reduced waterlogging. The study underscores the influence of subsurface structure on near-surface layer distribution. Based on these findings, optimal wastewater disposal sites are recommended, with a focus on the northern region where the argillaceous limestone layer is deeper and the upper clastic layer is thicker. To mitigate waterlogging, the installation of disposal wells is highly advised, leveraging the insights derived from this research. This study offers a versatile and reproducible approach suitable for both pre-project planning and post-project phases in desert regions.

Fault-related folds at the central northern part of the Cairo-Suez District, Egypt: example from Gebel Um Raqm area

Fault-related folds at the central northern part of the Cairo-Suez District, Egypt: example from Gebel Um Raqm area

Geotechnical Investigation and Characterization of intact rocks using destructive and Non-destructive techniques: A Case Study at Gebel El Ramliya-Akheider, Cairo-Suez District, Egypt

Geotechnical Investigation and Characterization of intact rocks using destructive and Non-destructive techniques: A Case Study at Gebel El Ramliya-Akheider, Cairo-Suez District, Egypt

Utilizing shallow seismic reflection for mitigating seismic and geo-environmental hazards in the development project of Gabal Ataqa Area, Cairo–Suez District, Egypt

Nowadays, development projects are becoming so rapid in many developing countries worldwide. The study of interest focuses on Cairo–Suez District, which represents the most important location in Egypt for major infrastructure projects and urbanization expansion. Consequently, it is very important to reduce the hazards surrounding this area from natural disasters, so all information that supports geo-environmental hazards assessment is importantly needed. The Gabal Ataqa area has socioeconomic importance as it is considered the industrial zone in the national project for developing the northern part of the Gulf of Suez. The situation of Gabal Ataqa area for being rich with numerous geological structures, and its socioeconomic importance calls the need for the delineation of the subsurface structural features in this area using the appropriate method. The geological framework has recognized all Quaternary faults in the Gabal Ataqa area as they are exposed to the surface, at the same time, no seismic reflection data has been acquired in the Gabal Ataqa area. Accordingly, the shallow seismic reflection method is applied in the Gabal Ataqa area to detect the Quaternary faults that are not exposed to the surface and also to detect any subsurface features that may cause construction problems, such as water-wet sands, sabkhas, and limestone cavities. Three lines of 2D seismic profiles are acquired in the study area. After applying seismic data processing and interpretation, two Quaternary faults have been recognized in the first and third lines. The location of the first seismic line has been chosen to be between two historic earthquake events, increasing the probability that the sources causing these two events will be located on the newly recognized quaternary fault. A dim spot has been recognized in the second seismic line at a depth of 50 m, which may indicate the presence of a groundwater aquifer or wet sandstone layer. Based on these results, changing the industrial zone place to another side to be away from the area of the three seismic lines is highly recommended.

Integrated structural, geophysical and remote sensing data for characterizing extensional linked fault systems and related land deformation hazards at Cairo-Suez District, Egypt

A tiered framework has been developed to map and characterize extensional linked fault systems at Cairo-Suez District, Egypt to better understand seismic and land deformation hazards. As a test site, the present tiered approach is applied on the Cairo-Suez District (CSD), Egypt, which is considered as an active seismogenic zone that encompasses complex deformation settings. Tier 1, which involves outcrop observations and structural mapping, reveals four geometries belonging to soft- and hard-linkage transfer zones (TZs). Considering the mapped TZs, the near-surface heterogeneity is characterized using a 2D-electrical resistivity tomography (2D-ERT) technique at “tier 2” applying an advanced inversion scheme (AIS). Inversion results of the 2D-ERT profiles indicate a subsurface continuity of the mapped surface geological and structural features including shale smears of fault zones and shale layer distributions. At “tier 2”, we particularly identify a highly deformed shale bed of 15-m thick, that accommodate fault slips as indicated by internal gouge zones. We further represent all local hazard factors including slope, drainage density, land use/land cover and displacement maps using the “Fuzzy-Shannon Entropy Model”. Overall, our findings show that most of the delineated deformation hazards in the test site are related to hard-linked TZs. At “tier 3”, we ultimately provide our recommendation for regional and site-specific engineering mitigation and to avoid active faults by defining setback-zone buffer (i.e., no build zone) correlated with the local fault activity and near-surface geometry. For Egypt, an economically developing country, this approach represents a major advancement from conventional geologic and geotechnical investigations through introducing a tiered framework for risk-relevant characterization of the extensional linked fault systems to apply adequate procedures/precautions by engineers for urban planning.

Integrated microfacies, macrobenthos and trace-fossil analysis of the lower‒middle Miocene succession of Gebel Gharra, Cairo-Suez District, Egypt

Integrated microfacies, macrobenthos and trace-fossil analysis of the lower‒middle Miocene succession of Gebel Gharra, Cairo-Suez District, Egypt

Calcareous tube-dwelling encrusting polychaetes from a lower-middle Miocene sedimentary succession, Cairo-Suez District, Egypt

Calcareous tube-dwelling encrusting polychaetes from a lower-middle Miocene sedimentary succession, Cairo-Suez District, Egypt

Spatiotemporal evolution of transfer structures and linked fault systems in an extensional setting: Southwest Gebel Akheider, Cairo-Suez District, Egypt

Detailed geological field mapping of the area located to the southwest of Gebel Akheider, south-central part of the Cairo-Suez District (Egypt), was carried out to identify the geometry, structural style, and evolution of the normal fault systems in the study area. The present structural geometry of the study area is of Miocene age and is the result of the propagation, kinematic interaction, and eventual linkage of extensional fault segments. Eight mapped relay ramps formed between synthetic non-overlapping and overlapping normal faults. Fault displacement profiles showing variation in displacement along strike revealed steep displacement gradients and local displacement minima at the locations of these relay ramps. Conjugate normal faults in the area also showed signs of kinematic interaction. Fault displacement profiles revealed complimentary displacement distribution between interacting overlapping conjugate faults. In competent rock units (Middle Eocene limestone), this interaction resulted in the formation of horsts and grabens relay zones, while in incompetent rock units (Middle Miocene soft marl and sandy limestone), this interaction resulted in a series of en echelon plunging anticlines and synclines (accommodation folds). Several transfer faults marked by points of local displacement minima were also identified, forming a distinctive zigzag pattern in map view that is characteristic of the Cairo-Suez District. Curved fault traces represent another form of fault linkage in the study area. Fault displacement profiles indicated two different growth mechanisms, either as the result of bilateral growth of two along-strike faults, or the intersection of previously isolated and differently oriented fault segments.

Active tectonic structures in northeastern Egypt: a geospatial analysis using structural, remote sensing, and seismic data

The seismotectonic activity in Northeastern Egypt is intimately related to the active tectonic structures (mainly faults) which deform the region and induce intraplate seismicity. The present contribution is a new attempt to integrate structural, remote sensing, and seismic data, and implement a reliable geospatial analysis to investigate and assess the nature of the relation between tectonic structures and seismotectonic activity in the Cairo–Suez district which is an active seismic source zone in Northeastern Egypt. The achieved remote sensing and GIS-based geospatial analysis introduces valuable information on the frequency, orientation, and density of investigated tectonic fault trends. The spatial distribution of earthquakes epicenters which recorded during the period (1997–2016) with magnitude (ML ≥ 3.0) is evidently interrelated with the detected tectonic trends, and normal faulting with subordinate shear component is the most focal mechanisms indicated from the analyzed seismic events. The depth analysis of the studied earthquakes suggests a “hard linkage” between the major rift-boundary faults in the northern Gulf of Suez rift and the tectonic trends in the southern domain of the Cairo–Suez district, and thus indicates seismic activity on relatively deeper crustal levels. Most of the studied earthquakes have occurred on the WNW–ESE to NW–SE oriented faults in predominantly extensional to transtensional stress regime, which indicating the WNW to NW tectonic trend as an active fault trend. The intraplate seismotectonic activity in Northeastern Egypt is highly controlled by two active tectonic boundaries, the Red Sea–Gulf of Suez rift and Aqaba–Dead Sea transform (to the east) and the Pelusium Shear System (PSS, to the west). Any reliable hypothetical model explaining the seismotectonic setting in such region would consider the Cairo–Suez district as a large transfer zone transmitting the “far-field” stresses northwestward to the PSS with an effective mechanism keeping the within-plate WNW–ESE, NW–SE, and E–W tectonic trends highly prone to rejuvenation and seismic rupture.

Present-Day Stress Field in Egypt Based on a Comprehensive and Updated Earthquake Focal Mechanisms Catalog

The present-day stress field in Egypt has been investigated on the basis of updated earthquake focal mechanism catalog covering the period from 1951 to 2017. Our catalog contains 234 focal mechanisms compiled from previous studies in addition to 22 new source mechanism solutions achieved in this study. According to the distribution of the recent earthquake epicentres, Egypt is divided into nine seismotectonic regions. The available fault plane solutions in Egypt demonstrate a spatial variability of source mechanisms, which categorize the study area into three groups. The first group includes Dahshour, Beni Suef, Cairo-Suez district, Northern-Central Gulf of Suez and Southern Gulf of Suez, which characterized by pure normal faulting mechanism to normal faulting with strike-slip component. Pure strike-slip faulting has clearly characterised Aswan and Gulf of Aqaba regions in the second group. However, the third group, which contains Abu Dabbab and the northern Egyptian continental margin, is characterized by thrust and strike-slip faulting. To calculate the orientation of the principle stress axes and the shape ratio we have applied the stress inversion technique. The present-day stress regime shows a variability of the tectonic stresses including extensional tectonic, transtensional and strike-slip. The transtensional stress regime with a maximum horizontal extensional NNE stress axis represents the dominant stress field pattern in Egypt. The results exhibit a good agreement with the tectonic settings and recent deformations in Egypt.

Middle Eocene larger benthic foraminifera from Egypt and their similarity to the southern tethyan provinces

This study aims to record the Middle Eocene larger benthic foraminifera from an outcrop exposed in the Cairo–Suez district, Egypt, and to discuss their geographic distribution along the southern Tethys. This succession is subdivided, from base to top, into the Observatory and Qurn formations. The recorded foraminiferal assemblage includes Dictyoconus aegyptiensis, Rhabdorites malatyaensis, R. minima, Idalina cuvillieri and Pseudolacazina schwagerinoides. Due to the absence of Nummulites species, two local larger benthic foraminiferal biozones are established Dictyoconus aegyptiensis and Idalina cuvillieri - Pseudolacazina schwagerinoides. In terms of paleobiogeography, a great similarity is noticed between the Egyptian foraminiferal assemblage and those of Libya, Oman, Iran and Turkey. Consequently, this indication supports foraminiferal migration along the southern Tethys.

Source mechanisms and simulation of ground motions of 18 and 22 July 2014 Suez earthquakes

ABSTRACTOn 18th and 22nd of July, 2014, two felt earthquakes have occurred in the northeastern part of Egypt (Cairo-Suez District) near Suez city with magnitude ML = 4.3 and ML = 4.0 respectively. The datasets used involves the two earthquakes recorded by Egyptian National Seismic Network (ENSN) and regional seismic stations (Jordan and Cyprus) to obtain the focal mechanism. A stochastic method is used to obtain high-frequency ground motion synthetics based on local site effect using 5 sites ambient noise (Microtremor) measurements to obtain the resonance frequency of the sediments. The ground motion parameters of (PGA), (PGV), (PGD) and spectral accelerations (SA) of the two earthquakes are obtained. The results show that the maximum value of the peak ground acceleration is observed at the site no. 1 (Northwest the apex of the Suez Gulf) due to near source-site distance and local site conditions (H/V = 4.4), while the minimum value is observed at the site no. 5 (Southwest of the small Bitter Lake) due to a large distance from the source (H/V = 2.10). The damped pseudo-acceleration was applied for the simulation at damping (0.5%, 1%, 5%, 10% and 20%). These results indicated, the efficiency and the importance of the local site conditions on strong ground motions.

Paleobiogeographic implications of the Middle Eocene ostracods from Cairo–Suez district, Egypt

The main targets of this paper are to examine the Middle Eocene ostracod assemblages collected from a succession exposed in the Cairo–Suez district, Egypt and to detect their paleobiogeographical implications. The studied succession is subdivided into two rock units: the Observatory and Qurn formations, in ascending order. The analysis of the ostracod assemblages led to the identification of 18 species, none of which is new. Three local biozones are established, Digmocythere ismaili - Xestoleberis kenawyi Assemblage Zone, Grinioneis moosi - Loxoconcha pseudopunctatella Assemblage Zone and Cativella qurnenis - Soudanella triangulata Assemblage Zone. The multivariate analyses indicate that there are three distinct bioprovinces, one of them represents the North Africa bioprovince, including Egypt, Libya, and Tunisia. The second bioprovince represents the Middle East, including Jordan and Israel. The third represents the West Africa bioprovince, including Senegal, Togo, Ivory Coast and Nigeria. Therefore, this deduction supports a migration of Eocene ostracods along the southern Tethys.

Geological mapping of the Central Cairo-Suez District of Egypt, using space-borne optical and radar dataset

The Central Cairo-Suez District (CCSD) has a special urban extension, particularly the fast growth of the new Cairo and New Administration Capital of Egypt (NACE). Accurate discrimination of the lithology and surface and near-surface structures will be a valuable contribution to the geotechnical characterization of the foundation rocks and geohazards. The present work utilizes remote sensing datasets; including Phased Array L-band Synthetic Aperture Radar (PALSAR-2) scenes, Landsat-8 OLI/TIRS data and high-resolution images of Google Earth accompanied with field work to update the geological map and highlighting the information on the spatial lithological distribution and the faulting history of the CCSD. Radar data is utilized to make use of its penetration capabilities to image the possible near-surface structures and rock contacts. The PALSAR-2 data improved the surface and shallow structural imaging around Gebel Oweibed and in other selected subsets. The NW-striking shear faults in Quaternary sediments were recognized for the first time. Their recent activation has been proved by the recent seismic events. The False Color Composites (FCC), Band ratios (BR), Decorrelation Stretch (DS) image processing techniques have been successfully applied to differentiate between sandstones, shales, marls, carbonates, basalts, and gravels which represent eight lithological units of Middle Eocene to Quaternary time. The results were enhanced and mapped by supervised classification with accuracy assessment exceeding 88%. Integration of remote sensing data, previous mapping, and field check resulted in a more accurate mapping of the study area with new important modifications.

Sequence stratigraphy and biozonation of the Upper Eocene Anqabiya Formation, Gebel Anqabiya, Egypt

Few studies on bio-sequence stratigraphy of the late Eocene succession in the study area have published so far. Accordingly, an exposed section of the Anqabiya Formation at Gebel Anqabiya along Cairo–Suez district of Egypt, was examined in detail to determine its foraminiferal and nannoplankton assemblages and to produce a sequence stratigraphic classification. We reveal that in this section, foraminifera and calcareous nannoplankton are generally rare, with relatively poor to moderate preservation, and restricted to certain horizons. Nineteen species of planktonic foraminifera and 24 species of calcareous nannoplankton were identified, leading to the classification of two planktonic foraminiferal zones (Globigerinatheka semiinvoluta Zone E14 and Globigerinatheka index Zone E15) and one calcareous nannoplankton zone (NP19–20). Forty-seven species of benthic foraminifera were identified and quantitatively analyzed to determine changes in paleo-water depth. Three local benthic biofacies, the Elphidium biofacies, the Cibicides biofacies and the Uvigerina biofacies, were recognized, and six microfacies types were distinguished. These analyses indicate that the studied succession was deposited under shallow marine environmental conditions representing a single 3rd-order depositional sequence. The interpreted sea-level curve can be correlated with the global curves during the late Eocene, and the correlation suggests a sea-level rise during E14 Zone, followed by a sea-level fall in E15 zone.