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result(s) for
"Farahat, Esam S."
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Integrating multi-source remote sensing, field work, and petrography for automatic lithological mapping and mineralization potential in the Gabal El-Faraid, Egypt
2026
The Gabal El-Faraid Group, in the Egyptian Southeastern Desert, comprises Neoproterozoic lithologies and structurally controlled mineralization zones that require an integrated exploration approach. This study integrates multi-source remote sensing data with detailed field observations, structural analysis, and petrographic investigations to improve lithological differentiation and delineate mineralization-related structures. Results indicate a potential structural-control spatial association among shear zones, hydrothermal alteration zones, and mineralization, suggesting their potential role in controlling mineralization. Support Vector Machine (SVM) and Random Forest (RF) algorithms have been used to best delineate lithological rock units of the study area. Accurate lithological mapping was achieved using an SVM applied to combined Sentinel-2 and ALOS PALSAR datasets, yielding an overall accuracy of 92.67%, a Kappa coefficient of 0.8928, and an F1-score of 88.64%. Six spectral mineral indices, like argillic, clay, ferrous silicates, ferrugination, hydroxyl, and phyllic alterations, have been emphasized using the hyperspectral PRISMA dataset. Exposed rocks comprise metavolcanics, metagabbro-diorite, tonalite-granodiorite, monzogranite, syenogranite, pegmatite, and late basic dikes, representing a multiphase magmatic sequence spanning arc-related to post-collisional stages. Structural investigations indicate a polyphase deformation history comprising four major events (D1-D4). The earliest phase (D1) is characterized by penetrative foliation, stretching lineation, and low-angle thrusting associated with nappe transport during intra-oceanic arc accretion. D2 reflects large-scale folding and regional shortening related to arc-to-continent collision. The D3 phase records transpressional strike-slip shearing, reactivating earlier structures and facilitating magma ascent, whereas D4 is marked by brittle faulting and jointing linked to post-orogenic uplift and extensional tectonics. Lineament analysis from PALSAR data highlights dominant NW-SE and NE-SW trends that closely correspond to field-measured fabrics and shear zones. Integration of field and remote sensing datasets demonstrates that late-stage deformation (D3-D4) exerted strong structural control over pegmatite emplacement, quartz veining, and hydrothermal alteration, with a main set trending WNW to NW and a less prominent set with pronounced ENE and NNW trends, emphasizing the role of inherited Pan-African structures in localizing mineralization. High-priority prospective zones in the studied granites were derived from integrated datasets, which were systematically combined in ArcGIS using a fuzzy-logic overlay. The detected zones are labeled as very high, high, moderate, low, and very low based on their potential for rare-metal mineralization. The integrated datasets can be applied to similar areas in the Eastern Desert of Egypt and across the entire Arabian-Nubian Shield (ANS).
Journal Article
Petrogenesis and Tectonic Implications of the Cryogenian I-Type Granodiorites from Gabgaba Terrane (NE Sudan)
by
Adam, Munir M. A.
,
Lv, Xinbiao
,
Abdel Rahman, Abdel Rahman A.
in
Asthenosphere
,
Biotite
,
Composition
2023
The widely distributed granitic intrusions in the Nubian Shield can provide comprehensive data for understanding its crustal evolution. We present new bulk-rock geochemistry and isotopic (zircon U-Pb and Lu-Hf) data from the Haweit granodiorites in the Gabgaba Terrane (NE Sudan). The dated zircons presented a 206Pb/238U Concordia age of 718.5 ± 2.2 Ma, indicating that they crystallized during the Cryogenian. The granodiorites contain both biotite and amphibole as the main mafic constituents. The samples exhibit metaluminous (A/CNK = 0.84–0.94) and calc-alkaline signatures. Their mineralogical composition and remarkable low P2O5, Zr, Ce, and Nb concentrations confirm that they belong to I-type granites. They exhibit subduction-related magma geochemical characters such as enrichment in LILEs and LREEs and depletion in HFSEs and HREEs, with a low (La/Yb)N ratio (3.0–5.9) and apparent negative Nb anomaly. The positive Hf(t) values (+7.34 to +11.21) and young crustal model age (TDMC = 734–985 Ma) indicates a juvenile composition of the granodiorites. The data suggest that the Haweit granodiorites may have formed from partially melting a juvenile low-K mafic source. During subduction, the ascending asthenosphere melts might heat and partially melt the pre-existing lower crust mafic materials to generate the Haweit granodiorites in the middle segment of the Nubian Shield.
Journal Article
Red Sea rift-related Quseir basalts, central Eastern Desert, Egypt: Petrogenesis and tectonic processes
by
Hauzenberger, Christoph
,
Farahat, Esam S.
,
Ali, Shehata
in
Asthenosphere
,
Basalt
,
Crystallization
2017
Mineral and whole-rock chemistry of Red Sea rift-related Tertiary basalts from south Quseir city, central Eastern Desert of Egypt is presented to investigate their petrogenesis and relationship to tectonic processes. The south Quseir basalts (SQB) are classified as high-Ti (TiO
2
>2 wt.%) subalkaline transitional lava emplaced in an anorogenic tectonic setting. Their Mg# varies from 48 to 53 indicating the evolved nature of the SQB. Pearce element ratios suggest that the SQB magmas evolved via fractional crystallization of olivine + clinopyroxene ± plagioclase, but the absence of Eu anomalies argues against significant plagioclase fractionation. Clinopyroxene compositions provide evidence for polybaric fractionation of the parental mafic magmas. Estimated temperatures of crystallization are 1015 to 1207 °C for clinopyroxene and 1076 to 1155 °C for plagioclase. These values are interpreted to result from early stage crystallization of clinopyroxene followed by concurrent crystallization of clinopyroxene and plagioclase. The incompatible trace element signatures of the SQB (La/Ba = 0.08–0.10 and La/Nb = 0.89–1.04) are comparable to those of ocean island basalts (OIB) generated from an asthenospheric mantle source unaffected by subduction components. Modeling calculations indicate that the SQB primary magmas were derived from ~4–5% partial melting of a garnet-bearing lherzolite mantle source. The NE Egyptian basaltic volcanism is spatially and temporally related to Red Sea rifting and to the local E–W striking faults, confirming a relationship to tectonic activity. Our results suggest that the extensional regime associated with Red Sea rifting controlled the generation of the Egyptian basalts, likely as a result of passive upwelling of asthenospheric mantle.
Journal Article
Petrogenesis and Tectonic Evolution of I- and A-Type Granites of Mount Abu Kibash and Tulayah, Egypt: Evidence for Transition from Subduction to Post-Collision Magmatism
by
Sami, Mabrouk
,
Fathy, Douaa
,
Abart, Rainer
in
Alkalis
,
Aluminum oxide
,
Biological fertilization
2024
The Neoproterozoic granitic rocks of Mount Abu Kibash and Tulayah in the central Eastern Desert of Egypt are of geodynamic interest and provide us with important information about the evolution and growth of the northern part of the Arabian–Nubian Shield (ANS) continental crust. They are primarily composed of granodiorites and syenogranites based on new field, mineralogical, and geochemical analyses. The granodiorites are marked by an enrichment of LILEs such as Sr, K, Rb, Ba compared to HFSEs like Nb, Ta, Ti and show a higher concentration of LREEs relative to HREEs. This composition suggests a subduction-related setting and aligns with the characteristics of subducted I-type granites in the ANS. Chemistry of the analyzed primary amphiboles in the investigated granodiorites support a calc-alkaline nature, mixed source and subduction-related setting. The granodiorites represent an early magmatic phase in this setting, likely formed from a mix of mantle-derived mafic magmas and lower crust material, with subsequent fractional crystallization. On the other hand, syenogranites exhibit high SiO2 (72.02–74.02 wt%), total alkali (7.82–8.01 wt%), and Al2O3 (13.79–14.25 wt%) levels, suggesting their derivation from peraluminous (A/CNK > 1) parental magmas. Their REE-normalized patterns are flat with a pronounced negative Eu anomaly, typical of post-collisional A2-type granites worldwide. These rocks originated from the partial melting of a juvenile lower crustal source (tonalite) in a post-collisional setting, driven by lithospheric delamination that facilitated mantle upwelling and underplating to the lower crust. Interaction between the upwelled mantle and lower crust led to fertilization (enrichment with HFSE and alkalis) of the lithosphere before partial melting. Fractional crystallization coupled with less considerable crustal assimilation are the main magmatic processes during the evolution of these rocks. The transition from subduction to post-collisional setting was accompanied by crustal uplifting, thickening and extensional collapse of ANS continental crust that caused emplacement of large masses of A-type granites in the northern ANS.
Journal Article
An Occurrence of Pyroxmangite in the NYF Granitic Pegmatite of the Gabal El-Bakriya Intrusion, Arabian–Nubian Shield
2025
We report here, for the first time on the Nubian Shield, the western half of the Arabian–Nubian Shield (ANS), pegmatite-hosted pockets with a unique mineralogy, including pyroxmangite. It represents the second discovery on the ANS, where the first one was at Jabal Aja on the Arabian Shield, the eastern half of the ANS. One of the most remarkable aspects of pyroxmangite is its rarity and the potential economic value of its use in jewelry and decorative applications. Pegmatites are associated with A-type granites of the Gabal El-Bakriya intrusion (GEBI), Eastern Desert, Egypt. Mineralized pegmatites occur at the margin of the alkali-feldspar granite and exhibit gradational contacts with the host rocks. The pegmatites were emplaced as plugs and dikes within the intrusion and along its periphery. Pyroxmangite appears as coarse-grained, massive black aggregates or as disseminated crystals. The pegmatites are composed of K-feldspars and quartz, with subordinate amounts of albite, micas, and mafic minerals. Accessory phases include monazite-(Ce), zircon, fergusonite, xenotime, fluorite, pyrochlore, allanite, thorite, bastnäsite, samarskite, cassiterite, beryl, and pyrochlore. Pyroxmangite-bearing assemblages consist essentially of pyroxmangite and garnet, with accessory pyrochroite, quartz, zircon, magnetite, and fluorite. Geochemically, the pegmatites are highly evolved, with elevated SiO2 content (76.51–80.69 wt.%) and variable concentrations of trace elements. They show significant enrichment in Nb (Nb > Ta), Y, REE, Zr, Th, U, and F, consistent with NYF-type pegmatites. REE contents range from 173.94 to 518.21 ppm, reflecting diverse accessory mineral assemblages. Tectonically, the pegmatites crystallized in a post-collisional setting, representing a late-stage differentiate of the A-type GEBI magma. Mineralization is concentrated in the apical and marginal zones of the granitic cupola and is dominated by barite, fluorite, Nb-Ta oxides, REE minerals, and uranium-bearing phases. The highly evolved granites, greisens, pegmatites, and quartz-fluorite veins of the GEBI have a high economic potential, deserving further exploration.
Journal Article
Molecular Detection of Influenza A and B Viruses in Four Consecutive Influenza Seasons 2015–16 to 2018–19 in a Tertiary Center in Western Saudi Arabia
by
Alshamrani, Majid
,
Alsaeed, Moneerah S.
,
Azhar, Esam I.
in
Health risks
,
Influenza
,
Influenza A
2021
Introduction
Influenza infection poses a significant public health threat. The core for disease prevention and control relies on strengthened surveillance activities, particularly in Saudi Arabia, the country that hosts the largest annual mass gathering event worldwide. This study aimed to assess the molecular and seasonal pattern of influenza virus subtypes in western Saudi Arabia to inform policy decisions on influenza vaccine.
Methods
This cross-sectional study was conducted at King Abdulaziz Medical City, western Saudi Arabia. Medical records and surveillance database of laboratory-confirmed influenza cases were reviewed from October 2015 to 2019. A panel of real-time polymerase chain reactions was performed to detect influenza A and B. Extracted RNA from a subset of positive samples was used to determine influenza A subtypes and influenza B lineages.
Results
This study included a total of 1928 patients with laboratory-confirmed influenza infections. Influenza peaks were observed in October each season, with variant predominant strains. Influenza virus subtypes co-circulate with no reports of co-infection. Influenza A(H3N2) was reported in 42% of the cases, then influenza B (30.7%) and influenza A(H1N1)pdm09 (27.3%). Healthcare workers represented 9.4% of the cases. One-third of the cases (30.4%) were admitted to the hospital with a median admission duration of 4 days. The influenza B viruses were subtyped in 218 cases. Victoria lineage was predominant (64.1%) in 2015 and 2016; however, Yamagata was predominant in the next two consecutive seasons (94.4% and 85.4%, respectively).
Conclusion
The burden due to influenza B may be underestimated with an observed vaccine mismatch. A quadrivalent influenza vaccine is recommended to reduce the health impact associated with influenza B infections. Molecular surveillance of the influenza viruses should be enhanced continuously for a better understanding of the influenza activity and assessment of vaccine effectiveness.
Journal Article
How did the first year of the COVID-19 pandemic affect urology practice in Arab countries? A cross-sectional study by the Arab Association of Urology research group
by
Hamri, Saeed Bin
,
Elmohamady, Basheer
,
El-Dakhakhny, Amr S.
in
Coronaviruses
,
COVID-19
,
COVID-19 diagnostic tests
2022
Objective:
The aim of this study was to assess of the effect of coronavirus disease 2019 (COVID-19) pandemic on urology practice in the Arab world during the first year of the crisis.
Methods:
An Internet-based questionnaire was created and sent out via email to members of the Arab Association of Urology (AAU) using ‘Google Forms’. The survey assessed participants’ demographics in terms of age, gender, country of origin, type of practice and position. Impacts of COVID-19 on urological practice were assessed in terms of the changes in hospital policies regarding consultations, and elective and emergency surgical cases. Moreover, impacts of COVID-19 on urologists were assessed.
Results:
A total of 255 AAU members across 14 Arab countries (Emirates, Egypt, Saudi Arabia, Iraq, Jordan, Algeria, Kuwait, Yemen, Qatar, Lebanon, Libya, Oman, Sudan and Syria) completed the survey; 4% were female urologists. Consultations at outpatient clinics were closed or restricted to emergency cases or replaced by telemedicine in almost 15%, 40% and 25% of hospitals, respectively. Elective surgeries were stopped or reduced to under 25% of surgical capacity in >10% and about 25% of hospitals, respectively. Almost 90% (228) reported changes in the policy for emergency theatres. Nearly 65% of hospitals offered preoperative COVID-19 testing to patients and 50% of hospitals provided personal protective equipment (PPE) to their urologists. Of 99% (253) who reported a change in urological education, 95% relied on online webinars. About 56% of respondents had their own private practice, of whom 91% continued private practice during the crisis. About 38% of participants reported exposure to intimidation (75% emotional, 20% verbal and 5% physical).
Conclusion:
The COVID-19 pandemic resulted in major changes in hospitals’ policies regarding outpatient consultations, elective and emergency operative cases, and the shift to telemedicine. Arab urologists have been facing major challenges either in both the governmental or the private sectors, and some of them were exposed to emotional, verbal and even physical intimidation.
Journal Article