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1.
001-es BibID:
BIBFORM124594
Első szerző:
Daoud Abazar Mohamed Ahmed (földtudományi kutató, geológus, geográfus)
Cím:
Petrography and diagenesis of barite concretions from Wadi Halfa, Sudan / Abazar Mohamed Ahmed Daoud, Kadry Nasser Sediek, Mohamed Ahmed Rashed, Ahmed Mohamed Elsharief, Abdelaziz Mohamed Elamein, Péter Rózsa
Dátum:
2024
Megjegyzések:
During the detailed geological observation of the sedimentary outcrops around the region of Wadi Halfa in Northern Sudan, discoidal-shaped concretions of barite were found. The lithofacies of these sedimentary outcrops, ♭Wadi Halfa Formation', contain sediments of continental, glacial and marine environments including trough and planner cross bedded sandstone, fine and massive mudstone facies intercalated with some marine fossils marked by a thin layer of oolitic ironstone and large petrified tree trunks. The vertical lithofacies of barite concretions comprises fine to medium yellowish to grayish sandstone overlain by a poorly sorted pinkish coarse-grained sandstone layer which contains barite concretions varying in size and shape. The discoidal-shaped barite concretions were found penetrating the bedding planes of sandstone. The upper part of these concretions is associated with fine-grained sandstone, while the lower part corresponds to coarse-grained sandstone. The framework of the barite concretions is composed primarily of very angular to angular monocrystalline (43.7%) and polycrystalline (11.5%) quartz grains, smaller amount of fledspars and heavy minerals (1.5%). Barite serves as the main cementing material, constituting 42% of the composition. The average porosity of most samples is 3%. Detailed petrographic analysis suggests that their original porosity has been reduced by cementation (44.1%) rather than compaction processes (0.6-5.2%). However, the origin of the concretions and the source of the barium remains unresolved. Moreover, quartz grains of these concretions are highly pure, they show much higher purity than quartz occurring in the embedding sandstone. The barite in the study area may formed during the Permian era (250 million years ago) when Mediterranean ocean waters covered the northern part of Sudan. Barite precipitated and crystallized from seawater around the quartz grains similarly to Oklahoma (USA), Egypt, Morocco and Australia. Understanding the original sources of these concretions may guide the exploration for other metallic minerals and petroleum. Additionally, barite holds significant economic potential due to its variuos applications across different industries and engineering projects, including its use in shielding against radiation in high-radiation environments and its critical role in medical applications.
ISBN:
978-963-8321-61-9
Tárgyszavak:
Természettudományok
Földtudományok
előadáskivonat
könyvrészlet
Megjelenés:
Ahány kő, annyi történet 14. Kőzettani és Geokémiai Vándorgyűlés Előadás- és poszterkivonatok / szerk. Buday Tamás, Csámer Árpád, McIntosh Richard William, Molnár Kata, Virág Attila. - p. 32. -
További szerzők:
Sediek, Kadry N.
Rasheed, Mohammed
Elsharief, Ahmed M.
Elamein, Abdelaziz M.
Rózsa Péter (1956-) (petrográfus)
Internet cím:
Szerző által megadott URL
Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon:
2.
001-es BibID:
BIBFORM124596
Első szerző:
Daoud Abazar Mohamed Ahmed (földtudományi kutató, geológus, geográfus)
Cím:
Petrography, Diagenesis and Paragenesis of Wadi Halfa Oolitic Ironstone Formation, North Sudan / Daoud, Abazar M. A., Rashed M. A. A., Kadry N. Sediek, Elamein A. M., Elsharief A. M.
Dátum:
2021
ISSN:
2054-7412
Megjegyzések:
Utilizing petrography, diagenesis and paragenesis are the major step to study the sediments of Wadi Halfa Oolitic Ironstone Formation for their origin and economic potential. Petrographical analysis of Wadi Halfa Oolitic Ironstone Formation were carried out depending on the investigation of six vertical lithofacies profiles from the region of Wadi Halfa. The petrographic classification of sandstone samples of Wadi Halfa Oolitic Ironstone Formation according to mineral composition (quartz, lithic fragments, and feldspars) are classified as quartzarenite 66.7%, sub lithic arenite 20.9% and subarkose 12.5%. The provenance of the sandstone revealed that all sample were derived mainly from interior stable craton. The stable craton offered good environments for detrital constitution to be recycled and transported for relatively long-distance. The present study adopted an intergranular pressure solution (IGV) diagram for IGV values more than 50 percent for all studied samples indicating that more of their original porosity has been destroyed cementation rather than by compaction processes for most samples.
Tárgyszavak:
Természettudományok
Földtudományok
idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Petrography
Diagenesis
Paragenesis
Wadi Halfa
Lithofacies and Intergranular pressure solution (IGV)
Megjelenés:
Advances in Image and Video Processing. - 9 : 3 (2021), p. 591-607. -
További szerzők:
Rasheed, Mohammed
Sediek, Kadry N.
Elamein, Abdelaziz M.
Elsharief, Ahmed M.
Internet cím:
Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon:
3.
001-es BibID:
BIBFORM124597
Első szerző:
Daoud Abazar Mohamed Ahmed (földtudományi kutató, geológus, geográfus)
Cím:
The geotechnical properties of the oolitic ironstone formation, Wadi Halfa, North Sudan / Abazar, M. A. Daoud, Rashed, M. A., Elsharief, A. M., Kadry, N. Sediek, Elamein, A. M.
Dátum:
2020
ISSN:
2006-9766
Megjegyzések:
Wadi Halfa Oolitic Ironstone Formation (WHOIF) covers large areas around Wadi Halfa border town in Northern Sudan. The detrital framework grains of sandstone of WHOIF are composed of sub-angular to sub-rounded quartz grains followed by feldspars, lithic fragments, micas and heavy minerals. The dominant cementing materials are iron oxides, carbonate cement, and some clay minerals. Twelve block samples were carefully selected and collected from six sites to represent different parts of vertical lithofacies sections of the studied formation. The petrographical characteristics of the specimens were first studied and the specimens were then subjected to laboratory tests to determine some of their basic physical and engineering properties. The physical tests constituted unit weight, specific gravity and water absorption. The measured engineering properties included uniaxial compressive strength (UCS) and ultra-sonic pulse velocity (UPV). The UCS and UPV were measured for specimens parallel and perpendicular to the bedding planes of the studied samples. The geotechnical study shows that the UCS values of WHOIF generally range from strong 83.7 MPa to very strong 153.7 MPa for perpendicular direction to bedding planes. Very good statistical correlation coefficient was developed between UCS and UPV. Good correlation was obtained between water absorption, porosity and UPV. These relations indicated that a decrease in void ratio and porosity resulted in an increase in UCS and UPV. An increase in water absorption of sandstone yielded a decrease in ultrasonic pulse velocity and uniaxial compressive strength.
Tárgyszavak:
Természettudományok
Földtudományok
idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Wadi Halfa Oolitic ironstone formation
lithofacies
uniaxial compressive strength
ultrasonic pulse velocity
Megjelenés:
Journal of Geology and Mining Research. - 12 : 1 (2020), p. 25-34. -
További szerzők:
Rashed, M. A.
Elsharief, Ahmed M.
Sediek, Kadry N.
Elamein, Abdelaziz M.
Internet cím:
Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon:
4.
001-es BibID:
BIBFORM124595
Első szerző:
Daoud Abazar Mohamed Ahmed (földtudományi kutató, geológus, geográfus)
Cím:
Barite Concretions in Wadi Halfa Oolitic Ironstone Formation, North Sudan / Abazar M. A. Daoud, Rashed M. A., Kadry N. Sediek, Elamein A. M., ElshariefA. M.
Dátum:
2020
ISSN:
2454-7352
Megjegyzések:
During our examination of the outcrops of the sedimentary formations in northern Sudan, we found discoidal-shape grains of the heavy mineral, barite in a sandstone of the Wadi Halfa Oolitic Ironstone Formation, which was recorded by all the earlier workers as a reworked sandstone. Petrography-wise, the framework of the sandstone consists of very angular to angular quartz grains, in which monocrystalline grains dominate over polycrystalline grains. Barite is the main cementing material of this sandstone, which occurs as concretions. Barite concretions indicate that more of the original porosity has been destroyed by cementation rather than by compaction processes with the inter-granular porosity being reduced mainly due to cementation. The origin of these concretions, as a cementing material in the sandstone, is ascribed to the reaction of Ba with some soluble sulfate to form the extremely insoluble heavy barite that appears as rounded concretions. The sulfur of the sulfate may be from the hydrothermal fluids related to submarine volcanism and/or biogeochemical processes. The deposition of these concretions might have taken place not long after the formation of the sandstone. The source of the barium, however, remains an unsolved problem. Further work is needed to interpret the origin and occurrence of these concretions along the region of Wadi Halfa.
Tárgyszavak:
Természettudományok
Földtudományok
idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Barite concretions
Wadi Halfa oolitic ironstone
cementation
Sudan
Megjelenés:
Journal of Geography, Environment and Earth Science International. - 24 : 5 (2020), p. 51-64. -
További szerzők:
Rashed, M. A.
Sediek, Kadry N.
Elamein, Abdelaziz M.
Elsharief, Ahmed M.
Internet cím:
Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon:
5.
001-es BibID:
BIBFORM124179
Első szerző:
Daoud Abazar Mohamed Ahmed (földtudományi kutató, geológus, geográfus)
Cím:
Relationship between petrography and geomechanical properties of the sandstone: A case study from Wadi Halfa, North Sudan / Daoud, Abazar M. A.; Abdelkader, Mohamed M.; Sediek, Kadry N.; Elsharief, Ahmed M.; Rashed, Mohamed A.; Elamein, Abdelaziz M.; Abdalrahiem, Khaled O.; Rózsa, Péter
Dátum:
2024
ISSN:
2062-0810 2063-4269
Megjegyzések:
The investigation of the effect of petrography and diagenetic features on the geomechanical properties of the sandstone and their relationship to rock failure are of vital importance for different construction projects. The present study involves analyzing multi-vertical lithofacies profiles around the region of Wadi Halfa, North Sudan. The sandstone is dominantly composed of monocrystalline quartz grains (60%) accompanied by some polycrystalline quartz, feldspars, lithic fragments, micas, and heavy minerals. Iron oxides are the main type of cementing materials (14%), with some (2%) of carbonates and clay minerals. The average porosity of all studied samples is 12%. The compressive strength ranges widely, influenced by weathering, grain size, cementing materials, and bedding planes. The uniaxial compressive strength is more influenced by wetting when the load is parallel to bedding planes. Sandstone anisotropy is suggested by a U-shaped curve, with lower values at 458 and higher values at 908 and 08. The geomechanical behavior of rocks masses in Wadi Halfa was evaluated through a combination of field and laboratory analyses which revealed a variable Rock Mass Rating (RMR) ranging from 58 to 92 and a Geological Strength Index (GSI) ranging from 33 to 61.
Tárgyszavak:
Természettudományok
Földtudományok
idegen nyelvű folyóiratközlemény hazai lapban
folyóiratcikk
sandstone
compressive strength
anisotropy
post-specimen failure
softness coefficient
RMRGSI
Megjelenés:
International Review of Applied Sciences and Engineering. - [Epub ahead of print] (2024), p. 1-17. -
További szerzők:
Abdelkader, Mohamed M.
Sediek, Kadry N.
Elsharief, Ahmed M.
Rasheed, Mohammed
Elamein, Abdelaziz M.
Abdalrahiem, Khaled O.
Rózsa Péter (1956-) (petrográfus)
Internet cím:
Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon:
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