Osama Khairy - Academia.edu (original) (raw)

Papers by Osama Khairy

Research paper thumbnail of Geochemical characteristics and genesis of niobium–yttrium–fluorine granite pegmatite from Hmrat El Sorwhyia area, North Eastern Desert, Egypt

Applied earth science, Jun 17, 2024

Research paper thumbnail of Deciphering the multistage magmatic processes in the Nuqara caldera, the northern Egyptian <scp>Nubian‐Shield</scp>: Insights from zircon morphology and geochemistry

˜The œIsland arc/˜The œisland arc, 2024

Research paper thumbnail of Ediacaran anorogenic alkaline magmatism and wolframite mineralization linked to mantle plume activity in the north Arabian-Nubian Shield (Egypt)

Chemie der Erde, Apr 1, 2024

Research paper thumbnail of Petrogenesis and geochemistry of the successive granitic events in the eastern Arabian Shield: implications for tectonic evolution and crustal thickening

International Journal of Earth Sciences

There is ongoing debate around the origin of successive granitic magmatic events in transitional ... more There is ongoing debate around the origin of successive granitic magmatic events in transitional stages from compressional to extensional tectonic settings in orogens. In the eastern part of the Arabian Shield, the late Cryogenian–Ediacaran magmatism of the transitional stage contributed to the growth of the Ad-Dawadmi terrane. The late Neoproterozoic Abt schist Formation, which is found throughout the Ad-Dawadmi terrane, is intruded by batholiths of the Najirah granitoids (~ 641 Ma) followed by the Khurs granite of the Ar Ruwaydah Suite (~ 612 Ma). A switch in geodynamic regime from post-collision to intra-plate extension was attended by the Hadbet Tayma alkali granites. This study utilizes petrology and whole-rock geochemistry to decipher the genesis of these three granitic intrusive events. The Najirah granitoids are metaluminous, late-orogenic, I-type granitoids generated from magma derived by partial melting of lower crustal mafic rocks. The younger Khurs granite of the Ar Ruwaydah suite reflects a post-orogenic setting and has predominantly peraluminous nature with S-type granite characteristics, supporting an origin by partial melting of the metagraywacke crust. A fnal anorogenic magmatic event produced a suite of A-type (A2-subtype) alkaline granites of Hadbet Tayma, which formed after the termination of the accretion and microplate amalgamation phase of the northern East African Orogeny (EAO). These three successive magmatic events provide evidence for a range of magmatic sources in the thickened crust of the eastern Arabian Shield, reflecting its tectonic evolution over time.

Research paper thumbnail of A newly recorded Cryogenian-Ediacaran Dokhan Volcanic caldera with resurgent uplift in the Arabian-Nubian Shield, southwest Safaga, Egypt

Research paper thumbnail of Petrogenesis and geochemistry of the successive granitic events in the eastern Arabian Shield: implications for tectonic evolution and crustal thickening

International Journal of Earth Sciences, 2023

There is ongoing debate around the origin of successive granitic magmatic events in transitional ... more There is ongoing debate around the origin of successive granitic magmatic events in transitional stages from compressional to extensional tectonic settings in orogens. In the eastern part of the Arabian Shield, the late Cryogenian–Ediacaran magmatism of the transitional stage contributed to the growth of the Ad-Dawadmi terrane. The late Neoproterozoic Abt schist Formation, which is found throughout the Ad-Dawadmi terrane, is intruded by batholiths of the Najirah granitoids (~ 641 Ma) followed by the Khurs granite of the Ar Ruwaydah Suite (~ 612 Ma). A switch in geodynamic regime from post-collision to intra-plate extension was attended by the Hadbet Tayma alkali granites. This study utilizes petrology and whole-rock geochemistry to decipher the genesis of these three granitic intrusive events. The Najirah granitoids are metaluminous, late-orogenic, I-type granitoids generated from magma derived by partial melting of lower crustal mafic rocks. The younger Khurs granite of the Ar Ruwaydah suite reflects a post-orogenic setting and has predominantly peraluminous nature with S-type granite characteristics, supporting an origin by partial melting of the metagraywacke crust. A fnal anorogenic magmatic event produced a suite of A-type (A2-subtype) alkaline granites of Hadbet Tayma, which formed after the termination of the accretion and microplate amalgamation phase of the northern East African Orogeny (EAO). These three successive magmatic events provide evidence for a range of magmatic sources in the thickened crust of the eastern Arabian Shield, reflecting its tectonic evolution over time.

Research paper thumbnail of Genetic link between uranium mineralization and the emplacement of limited intrusion adjacent to alkaline granites, Abu Hamr area, north Eastern Desert, Egypt

Arabian Journal of Geosciences, Mar 1, 2018

The recorded uranium mineralization is genetically related to the U content and structural settin... more The recorded uranium mineralization is genetically related to the U content and structural setting of syenogranitic dyke that occurs near alkaline granites, Abu Hamr area, north Eastern Desert of Egypt. The associated abnormal level of radioactivity exhibits maximum equivalent uranium (eU) of 155.6 parts per million (ppm) with an average of 54 ppm while the maximum of eTh reaches up to 235 ppm with average content of 120 ppm. The nearby alkaline granites of Gabal Abu Hamr show a normal distribution of eU and eTh resembling that of normal granites (4 ppm eU and 8 ppm eTh). Radioactive anomalies can be interpreted as successive concentrations of U-Th, which are related to magmatic processes of syn-shearing syenogranite dyke formation followed by hydrothermal redistribution during the emplacement, and then supergene enrichment. Testing of uranium equilibrium has revealed major chemical U addition to both the syenogranitic dyke and, to less extent, the alkaline granites. The rare-earth element (REE) patterns display pronounced enrichment of light REEs and heavy REEs of the syenogranitic dyke in contrast to the alkaline granites, which might have attributed to the subsequent hydrothermal circulation. The studied dyke is also characterized by well-developed U, Th, and Pb enrichments. Post-magmatic hydrothermal activity is evident from the presence of dark violet fluorite with inclusion of U and Th minerals, in addition to the presence of zircon crystals with overgrowth, xenocrystic cores, REE replacements, and spatially inclusions of allanite-(Ce) with irregularly distributed patchy overgrowths of U and Th.

Research paper thumbnail of Early Ensimatic Stage of the Arabian-Nubian Shield

Springer eBooks, 2021

The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned ... more The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned with the processes of ocean closure, subduction, orogenesis and crustal growth, in relation to the assembly of Gondwanaland in the late Neoproterozoic. Other valuable published works deal with the earlier development of the Arabian-Nubian Shield in the light of the configuration of Rodinia (assembly and rifting) and the Mozambique Ocean. Progress in modern geochronological and structural data from the Arabian-Nubian Shield reveals that some of the Arabian-Nubian Shield rocks were derived from older crustal material and were affected by tectonic events of the early ensimatic stage of the Mesoproterozoic Rodinia breakup. The studies of Arabian-Nubian Shield ophiolites and related melange rock units, representing remnants or fragments of earliest simatic (mafic-ultramafic) lithosphere, provide essential constraints on the oceanic realm predating the accretionary and collisional stages of the Arabian-Nubian Shield (~780–600 Ma). Understanding the complete tectonic evolution of the Arabian-Nubian Shield requires providing special attention to the structural, petrological, geochemical and geochronological characteristics of its early primitive stage during the Rodinia breakup.

Research paper thumbnail of A newly recorded Cryogenian-Ediacaran Dokhan Volcanic caldera with resurgent uplift in the Arabian-Nubian Shield, southwest Safaga, Egypt

Research paper thumbnail of New insights into Cryogenian arc granitoids hosting Th-U mineralized Ediacaran syenogranite dikes, Ra’s Abdah area in the northern Egyptian Nubian Shield: Constraints from U‐Pb ages and zircon geochemistry

Precambrian Research, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of Petrogenesis and tectonic evolution of late Pan-African granitiods in the El Regita area, Central Southern Sinai, Egypt: With a synopsis about Th–U distribution and Cu mineralization

Journal of African Earth Sciences, 2021

The Late Precambrian intrusives in the El Regita area, central Southern Sinai at the northernmost... more The Late Precambrian intrusives in the El Regita area, central Southern Sinai at the northernmost Arabian-Nubian Shield, signify the typical evolutionary Pan-African magmatic stages. Geochemical and mineralogical variation from calc-alkaline (I-type) quartz-monzonite and granodiorite to later mostly A-type monzogranite, syenogranite, and alkali-feldspar granite, indicates high fractionation and extensive magmatic differentiation of the same parent melt, derived from the mantle–crust interaction above the subducted oceanic plate influenced by partial melting processes. The compositional variation is linked to the tectonic evolution from regional compressional deformation to the continental crust's relaxation. The mineralogy of the studied granitoids, which are analogous to similar rocks that crop out in the North-Eastern Desert of Egypt, is consistent with the view that the Sinai region is an eastern extension of the northern Eastern Desert. Results from all geothermometers of the studied granitoids expected decreasing oxygen fugacity in the magma following temperature decrease. Based on the Al-in-hornblende geobarometer, the (I-type) granitoids represents hydrated granites emplaced at lower crustal levels than the monzogranite-syenogranite plutons. The El Regita area is characterized by structurally controlled mesothermal copper mineralization which has epi-genetic origin and is mainly related to the emplacement of granitoids in the late-collisional stage. Abnormal radioactivity levels in the El Regita area are structurally controlled and connected to highly sheared granodiorites. After leaching, uranium was redistributed and finally fixed or adsorbed by Fe-oxyhydroxides to form immobile secondary U-bearing minerals.

Research paper thumbnail of Early Ensimatic Stage of the Arabian-Nubian Shield

The Geology of the Arabian-Nubian Shield, 2021

The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned ... more The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned with the processes of ocean closure, subduction, orogenesis and crustal growth, in relation to the assembly of Gondwanaland in the late Neoproterozoic. Other valuable published works deal with the earlier development of the Arabian-Nubian Shield in the light of the configuration of Rodinia (assembly and rifting) and the Mozambique Ocean. Progress in modern geochronological and structural data from the Arabian-Nubian Shield reveals that some of the Arabian-Nubian Shield rocks were derived from older crustal material and were affected by tectonic events of the early ensimatic stage of the Mesoproterozoic Rodinia breakup. The studies of Arabian-Nubian Shield ophiolites and related melange rock units, representing remnants or fragments of earliest simatic (mafic-ultramafic) lithosphere, provide essential constraints on the oceanic realm predating the accretionary and collisional stages of the Arabian-Nubian Shield (~780–600 Ma). Understanding the complete tectonic evolution of the Arabian-Nubian Shield requires providing special attention to the structural, petrological, geochemical and geochronological characteristics of its early primitive stage during the Rodinia breakup.

Research paper thumbnail of Geology and Radioelements Potentiality of Phanerozoic Trachytes of Wadi Al-Owayrishah and Its Surroundings, Central Eastern Desert, Egypt ‎

Trachyte rocks of Wadi Al-Owayrishah and its surroundings crop out in the form of sheets and dyke... more Trachyte rocks of Wadi Al-Owayrishah and its surroundings crop out in the form of sheets and dykes. ‎They are striking and dipping in a concordant manner with the primary and secondary structures of the ‎enclosing host rocks. The trachyte rocks may be related to the rifting event that produced monogenetic ‎volcanoes of basaltic rocks and/or alkaline felsic rocks. Radioactive minerals associated with trachytes are ‎mainly represented by secondary minerals. Concentrations of radioactive minerals are essentially controlled ‎by distribution of amygdales and phyenocrysts. The main sources of uranium anomalies in the study area ‎are trachytes themselves, superheated solutions and hydrothermal solutions. The anomalies are controlled by ‎low permeability of country rocks in contact (siltstones), as well as the presence of iron oxyhydroxides ‎alteration as assistance agent for uranium adsorption, fixation and accumulation. Secondary uranium ‎minerals such as uranophane and uranium-bearing mi...

Research paper thumbnail of Petrogenesis and tectonic evolution of late Pan-African granitiods in the El Regita area, Central Southern Sinai, Egypt: With a synopsis about Th–U distribution and Cu mineralization

Journal of African Earth Sciences, 2021

Research paper thumbnail of TZT: a windows program for calculating zircon crystallization temperature based on Ti-in-zircon thermometry

Earth Science Informatics, 2021

A Free Windows software has been programmed by Visual Basic-2012 under the Windows platform. The ... more A Free Windows software has been programmed by Visual Basic-2012 under the Windows platform. The program allows users to calculate the zircon crystallization temperature. The designed program employs a simple scoring algorithm to measure the zircon crystallization temperature based on the function of titanium-in-zircon thermometry (Watson and Harrison, 2005). During data entry, the input data option includes letters (upper case or lower case), numbers and even symbols. The obtained results are saved into output separate and editable Microsoft Excel sheet. The saved sheet can be used for data editing during opened existing file option. The results accuracy is validated by comparing with analyses taken from the literature and showing no considerable differences between the both results.

Research paper thumbnail of Narrow-band imaging: a new tool for evaluation of head and neck squamous cell carcinomas. Review of the literature

Acta otorhinolaryngologica Italica : organo ufficiale della Società italiana di otorinolaringologia e chirurgia cervico-facciale, 2008

Head and neck squamous cell carcinoma of the upper aerodigestive tract is well known for its freq... more Head and neck squamous cell carcinoma of the upper aerodigestive tract is well known for its frequently late presentation and diagnosis at an advanced stage. In addition, it is well recognized that it may arise in multiple sites, either synchronously or metachronously. Thus it should be imperative to endoscopically screen the upper aerodigestive tract of patients at risk for head and neck squamous cell carcinoma with a new diagnostic tool, especially due to the fact that early lesions are very difficult to detect even by multiple passes with a standard endoscopy, if they are < or = 1 cm in diameter. Lugol chromoendoscopy, which is mainly used in the oesophagus, is not suitable for the head and neck region due to severe mucosal irritation. Herein, narrow-band imaging is described, a diagnostic tool already proved as a useful screening method in other endoscopic fields, and its application in the early detection of head and neck squamous cell carcinoma is reviewed, as reported by p...

Research paper thumbnail of Using Portable Gamma‐Ray Spectrometry for Testing Uranium Migration: A Case Study from the Wadi El Kareim Alkaline Volcanics, Central Eastern Desert, Egypt

Acta Geologica Sinica-english Edition, 2018

The 300±20 Ma anomalously radioactive trachytes of Wadi El Kareim, central Eastern Desert, are a ... more The 300±20 Ma anomalously radioactive trachytes of Wadi El Kareim, central Eastern Desert, are a significant example of U-mineralization related to the alkaline volcanics in Egypt. Extensive portable gamma-ray spectrometric data has been utilized to identify geological factors controlling uranium mobility in the geological units along the three detailed study locations of Kab Al-Abyad, South Wadi (W) Al-Tarafawy and W. Al-Farkhah; their eTh/eU ratios averaging around 4.1, 3.7 and 5.6 respectively. Quantitative analysis with the integration of mobility maps and geological studies suggest two systems controlling U-migration within the geological units (confined system and unconfined system). In the confined system, the syngenetically formed U have experienced mobility after leaching and are redistributed in the presence of an incorporation carrier during transportation (probably as carbonate complexes). Then the retardant for uranium is achieved by sorption or by coprecipitation with ...

Research paper thumbnail of Egyptian Hammamat molasse basins and their relations to arc collision stages: Implications for radioactive elements mineralization potential

Research paper thumbnail of Genetic link between uranium mineralization and the emplacement of limited intrusion adjacent to alkaline granites, Abu Hamr area, north Eastern Desert, Egypt

Arabian Journal of Geosciences

Research paper thumbnail of Ra’s Abdah of the north Eastern Desert of Egypt: the role of granitic dykes in the formation of radioactive mineralization, evidenced by zircon morphology and chemistry

Research paper thumbnail of Geochemical characteristics and genesis of niobium–yttrium–fluorine granite pegmatite from Hmrat El Sorwhyia area, North Eastern Desert, Egypt

Applied earth science, Jun 17, 2024

Research paper thumbnail of Deciphering the multistage magmatic processes in the Nuqara caldera, the northern Egyptian <scp>Nubian‐Shield</scp>: Insights from zircon morphology and geochemistry

˜The œIsland arc/˜The œisland arc, 2024

Research paper thumbnail of Ediacaran anorogenic alkaline magmatism and wolframite mineralization linked to mantle plume activity in the north Arabian-Nubian Shield (Egypt)

Chemie der Erde, Apr 1, 2024

Research paper thumbnail of Petrogenesis and geochemistry of the successive granitic events in the eastern Arabian Shield: implications for tectonic evolution and crustal thickening

International Journal of Earth Sciences

There is ongoing debate around the origin of successive granitic magmatic events in transitional ... more There is ongoing debate around the origin of successive granitic magmatic events in transitional stages from compressional to extensional tectonic settings in orogens. In the eastern part of the Arabian Shield, the late Cryogenian–Ediacaran magmatism of the transitional stage contributed to the growth of the Ad-Dawadmi terrane. The late Neoproterozoic Abt schist Formation, which is found throughout the Ad-Dawadmi terrane, is intruded by batholiths of the Najirah granitoids (~ 641 Ma) followed by the Khurs granite of the Ar Ruwaydah Suite (~ 612 Ma). A switch in geodynamic regime from post-collision to intra-plate extension was attended by the Hadbet Tayma alkali granites. This study utilizes petrology and whole-rock geochemistry to decipher the genesis of these three granitic intrusive events. The Najirah granitoids are metaluminous, late-orogenic, I-type granitoids generated from magma derived by partial melting of lower crustal mafic rocks. The younger Khurs granite of the Ar Ruwaydah suite reflects a post-orogenic setting and has predominantly peraluminous nature with S-type granite characteristics, supporting an origin by partial melting of the metagraywacke crust. A fnal anorogenic magmatic event produced a suite of A-type (A2-subtype) alkaline granites of Hadbet Tayma, which formed after the termination of the accretion and microplate amalgamation phase of the northern East African Orogeny (EAO). These three successive magmatic events provide evidence for a range of magmatic sources in the thickened crust of the eastern Arabian Shield, reflecting its tectonic evolution over time.

Research paper thumbnail of A newly recorded Cryogenian-Ediacaran Dokhan Volcanic caldera with resurgent uplift in the Arabian-Nubian Shield, southwest Safaga, Egypt

Research paper thumbnail of Petrogenesis and geochemistry of the successive granitic events in the eastern Arabian Shield: implications for tectonic evolution and crustal thickening

International Journal of Earth Sciences, 2023

There is ongoing debate around the origin of successive granitic magmatic events in transitional ... more There is ongoing debate around the origin of successive granitic magmatic events in transitional stages from compressional to extensional tectonic settings in orogens. In the eastern part of the Arabian Shield, the late Cryogenian–Ediacaran magmatism of the transitional stage contributed to the growth of the Ad-Dawadmi terrane. The late Neoproterozoic Abt schist Formation, which is found throughout the Ad-Dawadmi terrane, is intruded by batholiths of the Najirah granitoids (~ 641 Ma) followed by the Khurs granite of the Ar Ruwaydah Suite (~ 612 Ma). A switch in geodynamic regime from post-collision to intra-plate extension was attended by the Hadbet Tayma alkali granites. This study utilizes petrology and whole-rock geochemistry to decipher the genesis of these three granitic intrusive events. The Najirah granitoids are metaluminous, late-orogenic, I-type granitoids generated from magma derived by partial melting of lower crustal mafic rocks. The younger Khurs granite of the Ar Ruwaydah suite reflects a post-orogenic setting and has predominantly peraluminous nature with S-type granite characteristics, supporting an origin by partial melting of the metagraywacke crust. A fnal anorogenic magmatic event produced a suite of A-type (A2-subtype) alkaline granites of Hadbet Tayma, which formed after the termination of the accretion and microplate amalgamation phase of the northern East African Orogeny (EAO). These three successive magmatic events provide evidence for a range of magmatic sources in the thickened crust of the eastern Arabian Shield, reflecting its tectonic evolution over time.

Research paper thumbnail of Genetic link between uranium mineralization and the emplacement of limited intrusion adjacent to alkaline granites, Abu Hamr area, north Eastern Desert, Egypt

Arabian Journal of Geosciences, Mar 1, 2018

The recorded uranium mineralization is genetically related to the U content and structural settin... more The recorded uranium mineralization is genetically related to the U content and structural setting of syenogranitic dyke that occurs near alkaline granites, Abu Hamr area, north Eastern Desert of Egypt. The associated abnormal level of radioactivity exhibits maximum equivalent uranium (eU) of 155.6 parts per million (ppm) with an average of 54 ppm while the maximum of eTh reaches up to 235 ppm with average content of 120 ppm. The nearby alkaline granites of Gabal Abu Hamr show a normal distribution of eU and eTh resembling that of normal granites (4 ppm eU and 8 ppm eTh). Radioactive anomalies can be interpreted as successive concentrations of U-Th, which are related to magmatic processes of syn-shearing syenogranite dyke formation followed by hydrothermal redistribution during the emplacement, and then supergene enrichment. Testing of uranium equilibrium has revealed major chemical U addition to both the syenogranitic dyke and, to less extent, the alkaline granites. The rare-earth element (REE) patterns display pronounced enrichment of light REEs and heavy REEs of the syenogranitic dyke in contrast to the alkaline granites, which might have attributed to the subsequent hydrothermal circulation. The studied dyke is also characterized by well-developed U, Th, and Pb enrichments. Post-magmatic hydrothermal activity is evident from the presence of dark violet fluorite with inclusion of U and Th minerals, in addition to the presence of zircon crystals with overgrowth, xenocrystic cores, REE replacements, and spatially inclusions of allanite-(Ce) with irregularly distributed patchy overgrowths of U and Th.

Research paper thumbnail of Early Ensimatic Stage of the Arabian-Nubian Shield

Springer eBooks, 2021

The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned ... more The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned with the processes of ocean closure, subduction, orogenesis and crustal growth, in relation to the assembly of Gondwanaland in the late Neoproterozoic. Other valuable published works deal with the earlier development of the Arabian-Nubian Shield in the light of the configuration of Rodinia (assembly and rifting) and the Mozambique Ocean. Progress in modern geochronological and structural data from the Arabian-Nubian Shield reveals that some of the Arabian-Nubian Shield rocks were derived from older crustal material and were affected by tectonic events of the early ensimatic stage of the Mesoproterozoic Rodinia breakup. The studies of Arabian-Nubian Shield ophiolites and related melange rock units, representing remnants or fragments of earliest simatic (mafic-ultramafic) lithosphere, provide essential constraints on the oceanic realm predating the accretionary and collisional stages of the Arabian-Nubian Shield (~780–600 Ma). Understanding the complete tectonic evolution of the Arabian-Nubian Shield requires providing special attention to the structural, petrological, geochemical and geochronological characteristics of its early primitive stage during the Rodinia breakup.

Research paper thumbnail of A newly recorded Cryogenian-Ediacaran Dokhan Volcanic caldera with resurgent uplift in the Arabian-Nubian Shield, southwest Safaga, Egypt

Research paper thumbnail of New insights into Cryogenian arc granitoids hosting Th-U mineralized Ediacaran syenogranite dikes, Ra’s Abdah area in the northern Egyptian Nubian Shield: Constraints from U‐Pb ages and zircon geochemistry

Precambrian Research, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of Petrogenesis and tectonic evolution of late Pan-African granitiods in the El Regita area, Central Southern Sinai, Egypt: With a synopsis about Th–U distribution and Cu mineralization

Journal of African Earth Sciences, 2021

The Late Precambrian intrusives in the El Regita area, central Southern Sinai at the northernmost... more The Late Precambrian intrusives in the El Regita area, central Southern Sinai at the northernmost Arabian-Nubian Shield, signify the typical evolutionary Pan-African magmatic stages. Geochemical and mineralogical variation from calc-alkaline (I-type) quartz-monzonite and granodiorite to later mostly A-type monzogranite, syenogranite, and alkali-feldspar granite, indicates high fractionation and extensive magmatic differentiation of the same parent melt, derived from the mantle–crust interaction above the subducted oceanic plate influenced by partial melting processes. The compositional variation is linked to the tectonic evolution from regional compressional deformation to the continental crust's relaxation. The mineralogy of the studied granitoids, which are analogous to similar rocks that crop out in the North-Eastern Desert of Egypt, is consistent with the view that the Sinai region is an eastern extension of the northern Eastern Desert. Results from all geothermometers of the studied granitoids expected decreasing oxygen fugacity in the magma following temperature decrease. Based on the Al-in-hornblende geobarometer, the (I-type) granitoids represents hydrated granites emplaced at lower crustal levels than the monzogranite-syenogranite plutons. The El Regita area is characterized by structurally controlled mesothermal copper mineralization which has epi-genetic origin and is mainly related to the emplacement of granitoids in the late-collisional stage. Abnormal radioactivity levels in the El Regita area are structurally controlled and connected to highly sheared granodiorites. After leaching, uranium was redistributed and finally fixed or adsorbed by Fe-oxyhydroxides to form immobile secondary U-bearing minerals.

Research paper thumbnail of Early Ensimatic Stage of the Arabian-Nubian Shield

The Geology of the Arabian-Nubian Shield, 2021

The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned ... more The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned with the processes of ocean closure, subduction, orogenesis and crustal growth, in relation to the assembly of Gondwanaland in the late Neoproterozoic. Other valuable published works deal with the earlier development of the Arabian-Nubian Shield in the light of the configuration of Rodinia (assembly and rifting) and the Mozambique Ocean. Progress in modern geochronological and structural data from the Arabian-Nubian Shield reveals that some of the Arabian-Nubian Shield rocks were derived from older crustal material and were affected by tectonic events of the early ensimatic stage of the Mesoproterozoic Rodinia breakup. The studies of Arabian-Nubian Shield ophiolites and related melange rock units, representing remnants or fragments of earliest simatic (mafic-ultramafic) lithosphere, provide essential constraints on the oceanic realm predating the accretionary and collisional stages of the Arabian-Nubian Shield (~780–600 Ma). Understanding the complete tectonic evolution of the Arabian-Nubian Shield requires providing special attention to the structural, petrological, geochemical and geochronological characteristics of its early primitive stage during the Rodinia breakup.

Research paper thumbnail of Geology and Radioelements Potentiality of Phanerozoic Trachytes of Wadi Al-Owayrishah and Its Surroundings, Central Eastern Desert, Egypt ‎

Trachyte rocks of Wadi Al-Owayrishah and its surroundings crop out in the form of sheets and dyke... more Trachyte rocks of Wadi Al-Owayrishah and its surroundings crop out in the form of sheets and dykes. ‎They are striking and dipping in a concordant manner with the primary and secondary structures of the ‎enclosing host rocks. The trachyte rocks may be related to the rifting event that produced monogenetic ‎volcanoes of basaltic rocks and/or alkaline felsic rocks. Radioactive minerals associated with trachytes are ‎mainly represented by secondary minerals. Concentrations of radioactive minerals are essentially controlled ‎by distribution of amygdales and phyenocrysts. The main sources of uranium anomalies in the study area ‎are trachytes themselves, superheated solutions and hydrothermal solutions. The anomalies are controlled by ‎low permeability of country rocks in contact (siltstones), as well as the presence of iron oxyhydroxides ‎alteration as assistance agent for uranium adsorption, fixation and accumulation. Secondary uranium ‎minerals such as uranophane and uranium-bearing mi...

Research paper thumbnail of Petrogenesis and tectonic evolution of late Pan-African granitiods in the El Regita area, Central Southern Sinai, Egypt: With a synopsis about Th–U distribution and Cu mineralization

Journal of African Earth Sciences, 2021

Research paper thumbnail of TZT: a windows program for calculating zircon crystallization temperature based on Ti-in-zircon thermometry

Earth Science Informatics, 2021

A Free Windows software has been programmed by Visual Basic-2012 under the Windows platform. The ... more A Free Windows software has been programmed by Visual Basic-2012 under the Windows platform. The program allows users to calculate the zircon crystallization temperature. The designed program employs a simple scoring algorithm to measure the zircon crystallization temperature based on the function of titanium-in-zircon thermometry (Watson and Harrison, 2005). During data entry, the input data option includes letters (upper case or lower case), numbers and even symbols. The obtained results are saved into output separate and editable Microsoft Excel sheet. The saved sheet can be used for data editing during opened existing file option. The results accuracy is validated by comparing with analyses taken from the literature and showing no considerable differences between the both results.

Research paper thumbnail of Narrow-band imaging: a new tool for evaluation of head and neck squamous cell carcinomas. Review of the literature

Acta otorhinolaryngologica Italica : organo ufficiale della Società italiana di otorinolaringologia e chirurgia cervico-facciale, 2008

Head and neck squamous cell carcinoma of the upper aerodigestive tract is well known for its freq... more Head and neck squamous cell carcinoma of the upper aerodigestive tract is well known for its frequently late presentation and diagnosis at an advanced stage. In addition, it is well recognized that it may arise in multiple sites, either synchronously or metachronously. Thus it should be imperative to endoscopically screen the upper aerodigestive tract of patients at risk for head and neck squamous cell carcinoma with a new diagnostic tool, especially due to the fact that early lesions are very difficult to detect even by multiple passes with a standard endoscopy, if they are < or = 1 cm in diameter. Lugol chromoendoscopy, which is mainly used in the oesophagus, is not suitable for the head and neck region due to severe mucosal irritation. Herein, narrow-band imaging is described, a diagnostic tool already proved as a useful screening method in other endoscopic fields, and its application in the early detection of head and neck squamous cell carcinoma is reviewed, as reported by p...

Research paper thumbnail of Using Portable Gamma‐Ray Spectrometry for Testing Uranium Migration: A Case Study from the Wadi El Kareim Alkaline Volcanics, Central Eastern Desert, Egypt

Acta Geologica Sinica-english Edition, 2018

The 300±20 Ma anomalously radioactive trachytes of Wadi El Kareim, central Eastern Desert, are a ... more The 300±20 Ma anomalously radioactive trachytes of Wadi El Kareim, central Eastern Desert, are a significant example of U-mineralization related to the alkaline volcanics in Egypt. Extensive portable gamma-ray spectrometric data has been utilized to identify geological factors controlling uranium mobility in the geological units along the three detailed study locations of Kab Al-Abyad, South Wadi (W) Al-Tarafawy and W. Al-Farkhah; their eTh/eU ratios averaging around 4.1, 3.7 and 5.6 respectively. Quantitative analysis with the integration of mobility maps and geological studies suggest two systems controlling U-migration within the geological units (confined system and unconfined system). In the confined system, the syngenetically formed U have experienced mobility after leaching and are redistributed in the presence of an incorporation carrier during transportation (probably as carbonate complexes). Then the retardant for uranium is achieved by sorption or by coprecipitation with ...

Research paper thumbnail of Egyptian Hammamat molasse basins and their relations to arc collision stages: Implications for radioactive elements mineralization potential

Research paper thumbnail of Genetic link between uranium mineralization and the emplacement of limited intrusion adjacent to alkaline granites, Abu Hamr area, north Eastern Desert, Egypt

Arabian Journal of Geosciences

Research paper thumbnail of Ra’s Abdah of the north Eastern Desert of Egypt: the role of granitic dykes in the formation of radioactive mineralization, evidenced by zircon morphology and chemistry

Research paper thumbnail of Early Ensimatic Stage of the Arabian-Nubian Shield

The Geology of the Arabian-Nubian Shield, 2021

The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned ... more The majority of geological investigations that deal with the Arabian-Nubian Shield are concerned with the processes of ocean closure, subduction, orogenesis and crustal growth, in relation to the assembly of Gondwanaland in the late Neoproterozoic. Other valuable published
works deal with the earlier development of the Arabian-Nubian Shield in the light of the configuration of Rodinia (assembly and rifting) and the Mozambique Ocean. Progress in modern geochronological and structural data from the Arabian-Nubian Shield reveals that some of the Arabian Nubian Shield rocks were derived from older crustal material and were affected by tectonic events of the early ensimatic stage of the Mesoproterozoic Rodinia breakup. The studies of Arabian-Nubian Shield ophiolites and related mélange rock units, representing remnants or fragments of earliest simatic (maficultramafic) lithosphere, provide essential constraints on the oceanic realm predating the accretionary and collisional stages of the Arabian-Nubian Shield (*780–600 Ma). Understanding the complete tectonic evolution of the Arabian-Nubian Shield requires providing special attention to the structural, petrological, geochemical and geochronological characteristics of its early primitive stage during the Rodinia breakup.