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1.
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:
2.
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
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Saját polcon:
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