Adel Surour - Academia.edu (original) (raw)

Papers by Adel Surour

Research paper thumbnail of Metallic Ores in North Africa: New Results and Achievements in the Post-2016 Era

Regional geology reviews, 2024

Research paper thumbnail of Geochemistry of island arc assemblage in the Eastern Desert of Egypt and the role of Pan-African magmatism in crustal growth of the Arabian–Nubian Shield: A review

Acta geochimica, Feb 29, 2024

Research paper thumbnail of Updating Geological Information About Selected Non-metallic Ore Deposits in North Africa

Regional geology reviews, 2024

Research paper thumbnail of Mafic and felsic magmatism in the Wadi Kalalat area, South Eastern Desert, Egypt: mineralogy, geochemistry and geodynamic evolution during the Neoproterozoic in the Nubian Shield

Research paper thumbnail of Geochemistry and petrogenesis of dyke swarms in NW Sinai, Egypt: a case of transition from compressional to extensional regimes during the late Neoproterozoic

Research paper thumbnail of Effect of thermal metamorphism on structure and chemistry of serpentine polymorphs in ophiolitic serpentinites

Journal of Marine Science: Research & Development, Aug 25, 2016

T Doce River (-19.6o; -39.8o), with a watershed of 83.400 km2 and an annual net discharge of 1300... more T Doce River (-19.6o; -39.8o), with a watershed of 83.400 km2 and an annual net discharge of 1300m3s-1, represents one of the biggest rivers in Brazil. Along its 853 km there are 228 counties, which are supplied with its waters. The mouth of the Doce River is located at the estuary of Regência, an almost pristine area known by its beaches and where many fishermen get their subsistence. The adjacent continental shelf is narrow (~35km) and is part of one of the most important South Atlantic ecosystems, the archipelago of Abrolhos, which together with the Vitoria-Trindade ridge presents a complex bathymetry, which forces the meandering of the southward Brazilian current and the formation of the Vitoria eddy. Among the Brazilian rivers, the Doce river presents the highest net concentration of suspended particulate matter (SPM, 386,25 mg l-1) and the associated plume extends far north or south depending of the continental shelf preferential flow. The mean shelf circulation is southwards during the spring/summer seasons, presenting a complete reversal during the autumn/winter seasons or during events a cold front passages, becoming northwards. The Brazilian western boundary currents flow at the slope, and to the north of 22oS the circulation between 100-3000 m of the water column is roughly northward. On 5th November 2015 an accident involving a rupture of one of the ore dams of SAMARCO, a Brazilian mining company joint-venture between Vale and the English-Australian BHP Billiton, released 55x106 m3 of toxic-mud into the Doce riverbed. Seventeen days later the mud reached the ocean increasing significantly the SPM concentration of the Doce river plume. Based on a historical (2007-2014) dataset (SPM, currents, tides, waves) collected at numerous stations at the Abrolhos Bank and a realistic numerical simulation performed with the regional ocean modeling system (ROMS) we were able to investigate the seasonal behavior of the plume of the Doce river and infer its influence in the Abrolhos region prior and after the SAMARCO dam accident.

Research paper thumbnail of Historiography and FTIR spectral signatures of beryl crystals from some ancient Roman sites in the Eastern Desert of Egypt

Environmental Earth Sciences, Nov 16, 2020

Beryl (mostly emerald) was mined in Egypt since Antiquity, particularly the so-called "Cleopatra'... more Beryl (mostly emerald) was mined in Egypt since Antiquity, particularly the so-called "Cleopatra's Mines" in the Eastern Desert were a major source of emerald in the world during the Roman era in northeast Africa. Emerald from the Nugrus belt is located at Sikait, Um Sleimat, Um Addebbaa and Um Kabu areas where the ancient mines are confined structurally and genetically to "schist-type" deposits as a part of the Neoproterozoic ophiolitic mélange. At Homret Mikpid and Homr Akarem occurrences, non-gem beryl occurs in greisinized granites, pegmatites and quartz veins. Fourier transform infrared (FTIR) spectroscopy is able to distinguish Egyptian emeralds from non-gem beryls. Different types of H 2 O molecules and OH-groups can be identified in all especially at ~ 3435-3480 cm −1 as an indication of X-site occupancy of Na and vacancy (□) and to the Y-site M 2+ and M 3+ cation distribution. High wavenumber bands > 3600 cm −1 , e.g. at ~ 3865-3988 cm −1 are characteristics of non-gem beryl only. Structural CO 2 molecules are seen in both emerald and beryl at ~ 2360 cm −1. About 97-99% (at a wavelength range of 335-611 nm.) infrared reflectance of non-gem beryl is much higher (97-99%) whereas it never exceeds ~ 88% (at ~ 360 nm) in emerald.

Research paper thumbnail of Metasomatized peridotite xenoliths from the cretaceous rift-related Natash volcanics and their bearing on the nature of the lithospheric mantle beneath the southern part of the Eastern Desert of Egypt

Research paper thumbnail of Metasomatised serpentinite at the contact with anorogenic granite from the Neoproterozoic ophiolites in the Eastern Desert of Egypt

European Journal of Mineralogy, Dec 20, 2019

Research paper thumbnail of Mineralogical and Geochemical Constraints on the Postcollisional Mafic Magmatism in the Arabian-Nubian Shield: An Example from the El-Bakriya Area, Central Eastern Desert, Egypt

The Journal of Geology, May 1, 2022

Research paper thumbnail of Cu–Mn–Fe alloys and Mn-rich amphiboles in ancient copper slags from the Jabal Samran area, Saudi Arabia: With synopsis on chemistry of Fe–Mn(III) oxyhydroxides in alteration zones

Journal of African Earth Sciences, 2015

Research paper thumbnail of A new occurrence of garnetiferous skarn rocks in Saudi Arabia: a case study from Bahrah area, Jeddah–Makkah Al Mukaramah highway

Arabian Journal of Geosciences, Dec 22, 2009

Research paper thumbnail of Genesis of Neoproterozoic Au-bearing volcanogenic sulfides and quartz veins in the Ar Rjum goldfield, Saudi Arabia

Ore Geology Reviews, Apr 1, 2014

Research paper thumbnail of The Bi’r Tawilah deposit, central western Saudi Arabia: Supergene enrichment of a Pan-African epithermal gold mineralization

Journal of African Earth Sciences, 2014

Research paper thumbnail of Fluid-related modifications of Cr-spinel and olivine from ophiolitic peridotites by contact metamorphism of granitic intrusions in the Ablah area, Saudi Arabia

Journal of Asian Earth Sciences, May 1, 2016

Research paper thumbnail of Origin of hydrous alkali feldspar-silica intergrowth in spherulites from intra-plate A2-type rhyolites at the Jabal Shama, Saudi Arabia

Journal of African Earth Sciences, Mar 1, 2016

Research paper thumbnail of Yukonite-like alteration products (Ca-Fe arsenate and As-rich Fe-oxyhydroxide) formed by in situ weathering in granodiorite, Bi'r Tawilah gold prospect, Saudi Arabia

European Journal of Mineralogy, Feb 11, 2013

Samples from drilling of the Bi'r Tawilah gold prospect in Saudi Arabia reveal the occurrence of ... more Samples from drilling of the Bi'r Tawilah gold prospect in Saudi Arabia reveal the occurrence of a CaFe arsenate phase, which is similar in appearance and chemistry to yukonite. Upon weathering of a granodiorite host, oxidation of arsenopyrite (0-25 m deep) leads to the formation of a very peculiar brown, amorphous to very poorly crystalline aggregate with cellular-like texture. This mixture consists of CaFe arsenate and arsenic-rich ferric oxyhydroxide resulting from the oxidation of arsenopyrite. It is intergrown with colloform ferric oxyhydroxide, the latter resulting from the oxidation of pre-existing pyrite. The EMPA analyses indicate that the Ca-rich domain contains the maximum As 2 O 5 content (up to 22.3 wt%) whereas the colloform ferric oxyhydroxide contains the highest amount of Fe 2 O 3 among the sample studied (60.8-63.1 wt%) associated to higher H 2 O content (31.4-33.2 wt%) than in the case of common goethite and lepidocrocite. As far as typical yukonite, scorodite or arsenosiderite are absent in the studied weathered granodiorite, it is believed that oxidation took place at elevated pH (.7) and temperature up to $75 C. The source of Ca 2þ can be derived from alteration of plagioclase in the granodiorite but its possible derivation from strongly corroded marble bands cannot be discarded. It is evident that availability of Ca 2þ and high pH buffered by the dissolution of calcite in the marble, in addition to the prevailing temperature upon weathering, played important roles in the formation of these pseudomorphs at Bi'r Tawilah.

Research paper thumbnail of Microfabrics and microchemistry of sulfide ores from the 640 FW-E level at the Al Amar gold mine, Saudi Arabia

Journal of Microscopy and Ultrastructure, 2013

Research paper thumbnail of Crystal structure analyses of four tourmaline specimens from the Cleopatra's Mines (Egypt) and Jabal Zalm (Saudi Arabia), and the role of Al in the tourmaline group

American Mineralogist, Mar 25, 2010

Fe-rich "oxydravite" and dravite from the Late Proterozoic ophiolitic mélange of the Arabo-Nubian... more Fe-rich "oxydravite" and dravite from the Late Proterozoic ophiolitic mélange of the Arabo-Nubian Shield, located in Egypt and Saudi Arabia, were structurally and chemically characterized by using crystal structure refinement based on single-crystal X-ray diffraction data, electron microprobe analysis, and Mössbauer spectroscopy. Structural formulae obtained by optimization procedures indicate disordering of Al, Mg, and Fe 2+ over the Y and Z sites, and an ordering of Fe 3+ at Y. The disordering can be explained by the substitution mechanisms 2

Research paper thumbnail of Opaque Mineralogy as a Tracer of Magmatic History of Volcanic Rocks: an Example from the Neogene-Quaternary Harrat Rahat Intercontinental Volcanic Field, North Western Saudi Arabia

Acta Geologica Sinica-english Edition, Oct 1, 2013

Research paper thumbnail of Metallic Ores in North Africa: New Results and Achievements in the Post-2016 Era

Regional geology reviews, 2024

Research paper thumbnail of Geochemistry of island arc assemblage in the Eastern Desert of Egypt and the role of Pan-African magmatism in crustal growth of the Arabian–Nubian Shield: A review

Acta geochimica, Feb 29, 2024

Research paper thumbnail of Updating Geological Information About Selected Non-metallic Ore Deposits in North Africa

Regional geology reviews, 2024

Research paper thumbnail of Mafic and felsic magmatism in the Wadi Kalalat area, South Eastern Desert, Egypt: mineralogy, geochemistry and geodynamic evolution during the Neoproterozoic in the Nubian Shield

Research paper thumbnail of Geochemistry and petrogenesis of dyke swarms in NW Sinai, Egypt: a case of transition from compressional to extensional regimes during the late Neoproterozoic

Research paper thumbnail of Effect of thermal metamorphism on structure and chemistry of serpentine polymorphs in ophiolitic serpentinites

Journal of Marine Science: Research & Development, Aug 25, 2016

T Doce River (-19.6o; -39.8o), with a watershed of 83.400 km2 and an annual net discharge of 1300... more T Doce River (-19.6o; -39.8o), with a watershed of 83.400 km2 and an annual net discharge of 1300m3s-1, represents one of the biggest rivers in Brazil. Along its 853 km there are 228 counties, which are supplied with its waters. The mouth of the Doce River is located at the estuary of Regência, an almost pristine area known by its beaches and where many fishermen get their subsistence. The adjacent continental shelf is narrow (~35km) and is part of one of the most important South Atlantic ecosystems, the archipelago of Abrolhos, which together with the Vitoria-Trindade ridge presents a complex bathymetry, which forces the meandering of the southward Brazilian current and the formation of the Vitoria eddy. Among the Brazilian rivers, the Doce river presents the highest net concentration of suspended particulate matter (SPM, 386,25 mg l-1) and the associated plume extends far north or south depending of the continental shelf preferential flow. The mean shelf circulation is southwards during the spring/summer seasons, presenting a complete reversal during the autumn/winter seasons or during events a cold front passages, becoming northwards. The Brazilian western boundary currents flow at the slope, and to the north of 22oS the circulation between 100-3000 m of the water column is roughly northward. On 5th November 2015 an accident involving a rupture of one of the ore dams of SAMARCO, a Brazilian mining company joint-venture between Vale and the English-Australian BHP Billiton, released 55x106 m3 of toxic-mud into the Doce riverbed. Seventeen days later the mud reached the ocean increasing significantly the SPM concentration of the Doce river plume. Based on a historical (2007-2014) dataset (SPM, currents, tides, waves) collected at numerous stations at the Abrolhos Bank and a realistic numerical simulation performed with the regional ocean modeling system (ROMS) we were able to investigate the seasonal behavior of the plume of the Doce river and infer its influence in the Abrolhos region prior and after the SAMARCO dam accident.

Research paper thumbnail of Historiography and FTIR spectral signatures of beryl crystals from some ancient Roman sites in the Eastern Desert of Egypt

Environmental Earth Sciences, Nov 16, 2020

Beryl (mostly emerald) was mined in Egypt since Antiquity, particularly the so-called "Cleopatra'... more Beryl (mostly emerald) was mined in Egypt since Antiquity, particularly the so-called "Cleopatra's Mines" in the Eastern Desert were a major source of emerald in the world during the Roman era in northeast Africa. Emerald from the Nugrus belt is located at Sikait, Um Sleimat, Um Addebbaa and Um Kabu areas where the ancient mines are confined structurally and genetically to "schist-type" deposits as a part of the Neoproterozoic ophiolitic mélange. At Homret Mikpid and Homr Akarem occurrences, non-gem beryl occurs in greisinized granites, pegmatites and quartz veins. Fourier transform infrared (FTIR) spectroscopy is able to distinguish Egyptian emeralds from non-gem beryls. Different types of H 2 O molecules and OH-groups can be identified in all especially at ~ 3435-3480 cm −1 as an indication of X-site occupancy of Na and vacancy (□) and to the Y-site M 2+ and M 3+ cation distribution. High wavenumber bands > 3600 cm −1 , e.g. at ~ 3865-3988 cm −1 are characteristics of non-gem beryl only. Structural CO 2 molecules are seen in both emerald and beryl at ~ 2360 cm −1. About 97-99% (at a wavelength range of 335-611 nm.) infrared reflectance of non-gem beryl is much higher (97-99%) whereas it never exceeds ~ 88% (at ~ 360 nm) in emerald.

Research paper thumbnail of Metasomatized peridotite xenoliths from the cretaceous rift-related Natash volcanics and their bearing on the nature of the lithospheric mantle beneath the southern part of the Eastern Desert of Egypt

Research paper thumbnail of Metasomatised serpentinite at the contact with anorogenic granite from the Neoproterozoic ophiolites in the Eastern Desert of Egypt

European Journal of Mineralogy, Dec 20, 2019

Research paper thumbnail of Mineralogical and Geochemical Constraints on the Postcollisional Mafic Magmatism in the Arabian-Nubian Shield: An Example from the El-Bakriya Area, Central Eastern Desert, Egypt

The Journal of Geology, May 1, 2022

Research paper thumbnail of Cu–Mn–Fe alloys and Mn-rich amphiboles in ancient copper slags from the Jabal Samran area, Saudi Arabia: With synopsis on chemistry of Fe–Mn(III) oxyhydroxides in alteration zones

Journal of African Earth Sciences, 2015

Research paper thumbnail of A new occurrence of garnetiferous skarn rocks in Saudi Arabia: a case study from Bahrah area, Jeddah–Makkah Al Mukaramah highway

Arabian Journal of Geosciences, Dec 22, 2009

Research paper thumbnail of Genesis of Neoproterozoic Au-bearing volcanogenic sulfides and quartz veins in the Ar Rjum goldfield, Saudi Arabia

Ore Geology Reviews, Apr 1, 2014

Research paper thumbnail of The Bi’r Tawilah deposit, central western Saudi Arabia: Supergene enrichment of a Pan-African epithermal gold mineralization

Journal of African Earth Sciences, 2014

Research paper thumbnail of Fluid-related modifications of Cr-spinel and olivine from ophiolitic peridotites by contact metamorphism of granitic intrusions in the Ablah area, Saudi Arabia

Journal of Asian Earth Sciences, May 1, 2016

Research paper thumbnail of Origin of hydrous alkali feldspar-silica intergrowth in spherulites from intra-plate A2-type rhyolites at the Jabal Shama, Saudi Arabia

Journal of African Earth Sciences, Mar 1, 2016

Research paper thumbnail of Yukonite-like alteration products (Ca-Fe arsenate and As-rich Fe-oxyhydroxide) formed by in situ weathering in granodiorite, Bi'r Tawilah gold prospect, Saudi Arabia

European Journal of Mineralogy, Feb 11, 2013

Samples from drilling of the Bi'r Tawilah gold prospect in Saudi Arabia reveal the occurrence of ... more Samples from drilling of the Bi'r Tawilah gold prospect in Saudi Arabia reveal the occurrence of a CaFe arsenate phase, which is similar in appearance and chemistry to yukonite. Upon weathering of a granodiorite host, oxidation of arsenopyrite (0-25 m deep) leads to the formation of a very peculiar brown, amorphous to very poorly crystalline aggregate with cellular-like texture. This mixture consists of CaFe arsenate and arsenic-rich ferric oxyhydroxide resulting from the oxidation of arsenopyrite. It is intergrown with colloform ferric oxyhydroxide, the latter resulting from the oxidation of pre-existing pyrite. The EMPA analyses indicate that the Ca-rich domain contains the maximum As 2 O 5 content (up to 22.3 wt%) whereas the colloform ferric oxyhydroxide contains the highest amount of Fe 2 O 3 among the sample studied (60.8-63.1 wt%) associated to higher H 2 O content (31.4-33.2 wt%) than in the case of common goethite and lepidocrocite. As far as typical yukonite, scorodite or arsenosiderite are absent in the studied weathered granodiorite, it is believed that oxidation took place at elevated pH (.7) and temperature up to $75 C. The source of Ca 2þ can be derived from alteration of plagioclase in the granodiorite but its possible derivation from strongly corroded marble bands cannot be discarded. It is evident that availability of Ca 2þ and high pH buffered by the dissolution of calcite in the marble, in addition to the prevailing temperature upon weathering, played important roles in the formation of these pseudomorphs at Bi'r Tawilah.

Research paper thumbnail of Microfabrics and microchemistry of sulfide ores from the 640 FW-E level at the Al Amar gold mine, Saudi Arabia

Journal of Microscopy and Ultrastructure, 2013

Research paper thumbnail of Crystal structure analyses of four tourmaline specimens from the Cleopatra's Mines (Egypt) and Jabal Zalm (Saudi Arabia), and the role of Al in the tourmaline group

American Mineralogist, Mar 25, 2010

Fe-rich "oxydravite" and dravite from the Late Proterozoic ophiolitic mélange of the Arabo-Nubian... more Fe-rich "oxydravite" and dravite from the Late Proterozoic ophiolitic mélange of the Arabo-Nubian Shield, located in Egypt and Saudi Arabia, were structurally and chemically characterized by using crystal structure refinement based on single-crystal X-ray diffraction data, electron microprobe analysis, and Mössbauer spectroscopy. Structural formulae obtained by optimization procedures indicate disordering of Al, Mg, and Fe 2+ over the Y and Z sites, and an ordering of Fe 3+ at Y. The disordering can be explained by the substitution mechanisms 2

Research paper thumbnail of Opaque Mineralogy as a Tracer of Magmatic History of Volcanic Rocks: an Example from the Neogene-Quaternary Harrat Rahat Intercontinental Volcanic Field, North Western Saudi Arabia

Acta Geologica Sinica-english Edition, Oct 1, 2013