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001-es BibID:	BIBFORM124594
Első szerző:	Daoud, Abazar M. A. (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
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