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Dorra Tanfous Amri Mourad Bédir Mohamed Soussi Hajer Azaiez Lahoussine Zitouni M. Hédi Inoubli Kamel Ben Boubaker 《Comptes Rendus Geoscience》2005,337(7):703-711
Seismic and sequence stratigraphy analyses, petroleum-well control and surface data studies of the Majoura–El Hfay region in the Central Atlas of Tunisia had led to identify and calibrate Jurassic seismic horizons. Seismic stratigraphic sections, seismic tectonics analyses, isochron and isopach mapping of Jurassic sequences show a differentiated structuring of platform and depocentre blocks limited by deep-seated NE–SW, north–south east–west and NW–SE faults intruded by Upper Triassic salt. The early salt migration seems to have started by the platform fracturing during the Lower Liassic rifting event. These movements are fossilized by thickness variations of Jurassic horizons, aggrading and retrograding onlap and toplap structures between subsiding rim-syncline gutters and high platform flanks intruded by salt pillows and domes. The salt migration is also attested by Middle and Upper Jurassic space depocentre migrations. Around the Majoura–El Hfay study blocks bounded by master faults, Triassic salt have pierced the Cretaceous and Tertiary sedimentary cover in a salt diapir extrusion and salt wall structures. To cite this article: D. Tanfous Amri et al., C. R. Geoscience 337 (2005). 相似文献
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Dorra Mahdi Randa Ben Abdallah Nouri Hatira Ali Tlili Hédi Ridha Chaftar Fakher Jamoussi 《Arabian Journal of Geosciences》2013,6(11):4347-4355
The Oued Belif 48 and Koudiat El Halfa 5 borehole samples have been analysed in order to reveal the mineralogical composition of the Triassic successions and their burial history within the geological evolution of the Tethysian southern margin. Oued Belif 48 borehole belongs to Nefza district which is a part of the “Nappe zone” (Tellian unit, north-western Tunisia). Koudiat El Halfa 5 borehole crosses the Koudiat El Halfa diapir (north–west of the north–south axis, Central Atlas). In this paper, the burial degree of evaporitic Triassic samples was determined by the “illite crystallinity” index and by the evolution of the other phyllosilicates, essentially chlorite, talc and illite/chlorite and illite/smectite mixed layers. The studied samples of the two boreholes are characterized by the presence of abundant clay minerals. The <2-μm grain-size fraction of the samples is mostly composed of illite, chlorite and smectite and may contain a slight percentage of swelling layers (illite/smectite and illite/chlorite). The illite crystallinity value measured on ethylene glycol solvated oriented mounts of the Oued Belif 48 samples oscillates globally between 1 and 2.5 characterizing the epizonal zone with a range of 300–400 °C temperatures. The measures of Koudiat El Halfa 5 samples crystallinity index show a value ranging from 2 to 4, which indicates the anchizone and early epizone burial stage (temperatures around 200 °C). These data can be explained by Miocene magmatic activities characterizing the Triassic material of Nefza district and also by burial phenomena effects. 相似文献
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Dorra Gargouri Maher Gzam Adel Kharroubi Younes Jedoui 《Environmental Earth Sciences》2018,77(10):381
The urbanized coastal zones are frequently faced to various pollutant discharges mainly in the shoreline. The quantification of the pollution level was mainly based on sea-water analysis. However, in this environment, the sediment characterization, using quality indicators, may constitute an accurate approach. The latter can be particularly appropriate to define heavy metals pollution degree. Chemical analyses of Cd, Cu, Zn, and Fe were undertaken for a total of 45 surface marine sediment samples of Gabes city coast. There is a significant extension of pollution, strongly influenced by the dominant longshore current. The studied sediments were found usually enriched with Cu, Cd, and Zn. These anthropogenic heavy metals have identical behavior and similar distribution. These metals did not show any correlations with Fe chosen as natural tracer. The multi-element indices used permitted to conclude that 70% of sampling sites are highly affected by heavy metal contamination and associated with very high ecological risk. These indices use a simple contamination factor, which, however, would not take account of the sedimentary inputs and the complex sediment behavior. Consequently, modified indices, employing enrichment factor, were used and demonstrated better to assess pollution and ecological risk. 相似文献
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Dorra Tanfous Hakim Gabtni Hajer Azaiez Mohamed Soussi Mourad Bedir 《Arabian Journal of Geosciences》2012,5(3):513-524
A gravity and seismic analysis was conducted over and around Jebel Es Souda-Hmaeima, located on the eastern border of the Tunisian Mountains between the Atlasic block to the west and the Pelagian Block to the east, as part of a study to investigate the subsurface structures. These data, together with outcrop geology, well data, and measurements of physical properties of rock samples, were integrated with a new interpretation of the tectonic model of Jebel Es Souda-Hmaeima anticline. This structure represents a backfolded anticline associated with a steep east-vergent thrust above a blind thrust fault along the base of Triassic formations. The proposed model emphasizes the role of transpressional deformation along deep-seated basement faults and has implications for petroleum generation, migration, and entrapment in central Tunisia. 相似文献
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Elkhayam M. Dorra Peter J. Stafford Ahmed Y. Elghazouli 《Bulletin of Earthquake Engineering》2013,11(4):1217-1257
The Egyptian economy and culture are centralized in the Greater Cairo region. Thus, it is essential that the built environment is able to withstand the possible earthquake events that may occur, and to continue to operate and function. Failure to do so would result in significant economic losses. This study presents the latter stages of a multi-tiered probabilistic earthquake loss estimation model for Greater Cairo and builds upon previous studies of the seismic hazard. In order to assess possible damage to the built environment, and the resulting economic losses, the vulnerability of the built environment is first evaluated. Through the use of satellite images, Egypts building census, previous studies and field surveys, a building-stock inventory is compiled. This building inventory is classified according to structural type and height, and is geocoded by district. Using existing fragility curves, the vulnerability of the building stock is assessed. In addition, the vulnerability of both the electricity and natural gas networks are assessed, through the use of fragility curves, cut sets and an evaluation of the supply networks. Based on the assessment of direct losses, the losses associated with building damage far exceed those associated with the considered network infrastructure. A macro-economic model is developed that takes into account damage to the built environment and provides estimates of indirect economic losses, as well as enabling the identification of the optimal recovery process. Using this model, it is shown that the indirect losses can exceed direct losses for extreme scenarios where the economy is brought to a near standstill. The framework developed and presented herein can be extended to include more networks, and is also applicable to other regions. 相似文献
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Dorra Tanfous Amri Ferid Dhahri Mohamed Soussi Hakim Gabtni Mourad Bédir 《Journal of Earth System Science》2017,126(7):104
The Gafsa and Chotts intracratonic basins in south-central Tunisia are transitional zones between the Atlasic domain to the north and the Saharan platform to the south. The principal aim of this paper is to unravel the geodynamic evolution of these basins following an integrated approach including seismic, well log and gravity data. These data are used to highlight the tectonic control on the deposition of Jurassic and Lower Cretaceous series and to discuss the role of the main faults that controlled the basin architecture and Cretaceous–Tertiary inversion. The horizontal gravity gradient map of the study area highlights the pattern of discontinuities within the two basins and reveals the presence of deep E–W basement faults. Primary attention is given to the role played by the E–W faults system and that of the NW–SE Gafsa fault which was previously considered active since the Jurassic. Facies and thickness analyses based on new seismic interpretation and well data suggest that the E–W-oriented faults controlled the subsidence distribution especially during the Jurassic. The NW–SE faults seem to be key structures that controlled the basins paleogeography during Late Cretaceous–Cenozoic time. The upper Triassic evaporite bodies, which locally outline the main NW–SE Gafsa fault, are regarded as intrusive salt bodies rather than early diapiric extrusions as previously interpreted since they are rare and occurred only along main strike-slip faults. In addition, seismic lines show that Triassic rocks are deep and do not exhibit true diapiric features. 相似文献
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Nedia Ghannem Dorra Gargouri Mohamed Moncef Sarbeji Chokri Yaich Chafai Azri 《Environmental Earth Sciences》2014,72(9):3419-3427
Concentrations of several heavy metals (Pb, Cr, Cd, Cu, Zn and Fe) in surface sediment were determined to investigate the distributions and the metallic pollution status in Sfax–Chebba coastal area (southeast of Tunisia). Sediment samples were collected from 20 locations, representing three different site groups (i.e., site I: urban zone, site II: pre-urban zone and site III: rural zone). Heavy metal contents were analyzed by Atomic Absorption Spectrometry. The obtained results showed that generally, heavy metal concentrations in the coastal sediments near Sfax city (urban zone) were higher than those at other stations because of the anthropogenic activities. These concentrations exceeded the threshold effect levels. This was confirmed by the chemometric approaches (enrichment factors, geoaccumulation index and principal component analysis) which showed a significant impact of multiple anthropogenic sources. Moderate to extremely severe enrichment of sediments in terms of Pb, Cr, Cd, Cu and Zn were shown to exist in site I. Severe enrichment by Cd was also observed in other sites. Based on the geoaccumulation index, Pb, Cr, Cd, Cu and Zn can be considered as unpollutants to extreme pollutants. 相似文献
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