Palynostratigraphy and paleoenvironmental significance of the Cretaceous succession in the Gebel Rissu-1 well,north Western Desert,Egypt     

Salah El Beialy  Maher El-Soughier  Sayed Abdel Mohsen  Haytham El Atfy 《Journal of African Earth Sciences》2011,59(2-3):215-226

Palynological investigation of the Cretaceous Abu Roash, Bahariya, Kharita, Alamein, Alam El Bueib and Betty formations, encountered in the Gebel Rissu-1 well, north Western Desert, Egypt yielded 27 species of pteridophytic spores, 24 of gymnosperm pollen, 25 of angiosperm pollen and 11 of dinoflagellate cysts in addition to some acritarchs, foraminiferal test linings and freshwater algae. This enabled us to recognize five miospore biozones arranged from youngest to oldest as: Classopollis brasiliensis–Afropollis cf. kahramanensis–Dichastopollenites ghazalataensis Assemblage Zone (Late Cenomanian); Elaterosporites klaszii–Sofrepites legouxae–Afropollis jardinus Assemblage Zone (Middle/Late Albian–Early Cenomanian); Pennipollis peroreticulatus–Duplexisporites generalis-Tricolpates Assemblage Zone (Early Aptian–Early Albian); Tucanopollis crisopolensis–Afropollis sp. Assemblage Zone (Barremian) and Appendicisporites cf. tricornitatus–Ephedripites spp. Assemblage Zone (Late Neocomian).The Early Cretaceous Kharita, Alam El Bueib and the Betty formations encountered in the Gebel Rissu-1 well are interpreted to indicate oxic proximal and distal shelf deposits, characterized by type III/IV, V kerogen, which is gas prone but having little potential to produce hydrocarbons. The Upper Cretaceous Abu Roash and Bahariya formations are characterized by a distal suboxic–anoxic and marginal dysoxic–anoxic environment, and their kerogen type III/II indicates gas/oil prone nature. The Bahariya and Kharita Albian–Cenomanian sediments in the present study witnessed the onset of a semi-arid to arid climate, with local or seasonal humid conditions, based on the continuous high abundance of the elaterates pollen and Afropollis-producing plants that inhabited the paleotropical humid coastal plains.  相似文献   

Coupling short-time sequencing batch reactor and coagulation–settling process for co-treatment of landfill leachate with raw municipal wastewater     

Ismail Trabelsi  Sourour Salah  Fayçal Ounaeis 《Arabian Journal of Geosciences》2013,6(6):2071-2079

The co-treatment of landfill leachate (LFL) with municipal wastewater (MWW) using shortcut sequencing batch reactor combined with coagulation–settling process (SBR + CS) was investigated. Four ratios of LFL to MWW volume (v/v) were used during experiments including the ratios 1:9, 2:8, 3:7 and 5:5. The average quality of the LFL was chemical oxygen demand (COD) of 20,800 mg L^?1 and NH₄-N of 2,645 mg L^?1. The SBR-treating LFL in six series where mixing aeration and settling phases were varied from 4 to 14 h was combined with coagulation (FeCl₃, Al₂(SO₄)₃) with an interval of 2 h. It was found that ratio (1:9) of leachate to MWW under aeration and mixing phase of 4 h with settling time of 1.5 h exhibited the highest ability to remove both COD and NH ₄ ⁺ -N, 99% and 85%, respectively. The short-time sequential batch reactor was tested for the treatment of raw LFL, and only 47% and 23% removal of COD and NH ₄ ⁺ -N, respectively, could be achieved.  相似文献   

Seismic anisotropy structure beneath the southeastern Mediterranean from shear-wave splitting   总被引：1，自引：0，他引：1  

Mohamed K. Salah 《Arabian Journal of Geosciences》2013,6(6):1717-1730

Analysis of seismic anisotropy in the crust and the uppermost mantle gives lots of information about the ambient mantle flow, stress state, and the dynamic processes inside the Earth. Thus, seismic anisotropy and its main distinctive features beneath the southeastern Mediterranean region are studied through the analysis of teleseismic shear-wave splitting observed at six broadband seismic stations belonging to the GEOFON and the MedNet. Although the number of the recording stations is small; a total of 495 splitting parameters are obtained, which revealed significant variations in the observed fast polarization directions beneath the study area. The stations in northern Egypt and Cyprus show fast velocity directions oriented roughly N–S to NNE–SSW, coincident with many previous results. A slightly different splitting pattern comprising NE–SW fast polarization directions is observed in the stations located along the Dead Sea fault in the southeastern Mediterranean; which are consistent with the current strike-slip motion between Africa and Arabia. In addition, NW–SE fast polarization directions are recognized in the latter group. The observed delay times vary greatly but their averages lie between 0.35 and 1 s. Although large-scale mechanisms, such as the absolute plate motion of Africa and Arabia towards Eurasia and the differential motion between Arabia and Africa can be invoked to predominantly explain the origin of anisotropic features, we suggest that density-driven flow in the asthenosphere is a possible additional cause of the wide range of the splitting pattern observed beneath some stations.  相似文献   

Palynological,palynofacies, paleoenvironmental and organic geochemical studies on the Upper Cretaceous succession of the GPTSW-7 well,North Western Desert,Egypt     

Salah Y. El Beialy  Haytham S. El Atfy  Michael S. Zavada  Essam M. El Khoriby  Ramadan H. Abu-Zied 《Marine and Petroleum Geology》2010

The present study of the Abu Roash and Bahariya formations in well GPTSW-7 refines our understanding of the subsurface Cretaceous of the north Western Desert of Egypt. Our investigations are based on the palynological analyses of 71 cuttings samples, of which 24 have also been analyzed for geochemistry, in addition to 3 sidewall cores analyzed for vitrinite reflectance (R_o).  相似文献   

Lower and Middle Pleistocene human settlements recorded in fluvial deposits of the middle Loire River Basin,Centre Region,France     

Jackie Despriée  Pierre Voinchet  Hélène Tissoux  Jean-Jacques Bahain  Christophe Falguères  Gilles Courcimault  Jean Dépont  Marie-Hélène Moncel  Sophie Robin  Marta Arzarello  Robert Sala  Laurent Marquer  Erwan Messager  Simon Puaud  Salah Abdessadok 《Quaternary Science Reviews》2011,30(11-12):1474-1485

This paper records the findings from c. 80 prehistoric sites that have been discovered in the alluvial deposits of the rivers Creuse, Cher, and Loir, tributaries of the middle Loire River, over the period since 1981. These deposits comprise river terrace aggradations formed during successive glacial–interglacial cycles which have recorded climate and environment during Quaternary time. The systematic dating of these river deposits by Electron Spin Resonance (ESR) applied to optically bleached sedimentary quartz has resulted in the establishment of a chronological framework for the evolution of these rivers during Lower and Middle Pleistocene (between 1.7 Ma and 130 ka). Evidence for Early Palaeolithic (Mode 1) industries with an in situ context (workshops, soils) in the highest aggradations indicates that Hominins were present in the study area, near the geographical centre of France (47°N), around 1.1 Ma. Examination of the sites indicates that Human occupations were located along valley bottom sites during temperate episodes. Subsequently, after a gap of several hundred thousand years industries with handaxes appear in the Middle Loire Basin in the interval between 700 and 600 ka, and then continuously from 400 ka. These two phases of settlement produced industrial assemblages with clear differences in their responses to the supplies of raw materials and in the modes of making flakes.  相似文献   

南京市地基稳定性区划图   总被引：1，自引：0，他引：1  

Bishir  S 罗国煜 《高校地质学报》1997,3(1):62-77

为了城市土地的合理使用，保证建筑物的安全，目前在城市岩土工程问题中对土地的合理利用研究和评价方法不断涌现。本文根据南京市的基岩岩性、地貌特征、覆盖层厚度和第四纪松散沉积物分布情况，划分为五个基本类型，各个分区具有不同的工程地质特征。  相似文献   

The genetic structure of Pandalus borealis in the Northeast Atlantic determined by RAPD analysis     

Martinez  Iciar; Aschan  Michaela; Skjerdal  Taran; Aljanabi  Salah M. 《ICES Journal of Marine Science》2006,63(5):840-850

  相似文献   

Seismic velocity and Poisson’s ratio tomography of the crust beneath southwest Anatolia: an insight into the occurrence of large earthquakes     

Mohamed K. Salah  Sakir Sahin  Cem Destici 《Journal of Seismology》2007,11(4):415-432

The western part of Anatolia is one of the most seismically and tectonically active continental regions in the world, and much of it has been undergoing NS-directed extensional deformation since the Early Miocene. In this study, we determine 3-D tomographic images of the crust under the southwestern part of the North Anatolian Fault Zone by inverting a large number of arrival time data of P and S waves. From the obtained P- and S-wave velocity models, we estimated the Poisson’s ratio structures for a more reliable interpretation of the obtained anomalies. Our tomographic results confirmed the major tectonic features detected by previous studies and revealed new structural heterogeneities related to the active seismotectonics of the studied area. High P-wave velocity anomalies are recognized near the surface, while at deeper crustal layers, low P-wave velocities are widely distributed. The crustal S-wave velocity and Poisson’s ratio exhibit more structural heterogeneities compared to the P-wave velocity structure. Microearthquake activity is intense along highly heterogeneous zones in the southwestern part, which is characterized by low to high P-wave velocity, low S-wave velocity, and high Poisson’s ratio anomalies. Large earthquakes are also concentrated in zones dominated by low velocities and low to high Poisson’s ratios. Results of the checkerboard and synthetic tests indicate that the imaged anomalies are reliable features down to a depth of 25 km. Moreover, they are consistent with many geological and geophysical results obtained by other researchers along the southwestern part of the North Anatolian Fault Zone. An erratum to this article can be found at  相似文献   

Intercomparison of Secondary Inorganic Aerosol Concentrations in the UK with Predictions of the Unified Danish Eulerian Model     

Salah S. Abdalmogith  Roy M. Harrison  Zahari Zlatev 《Journal of Atmospheric Chemistry》2006,54(1):43-66

Nitrate and sulphate concentrations were measured over the period January 2002–December 2003 on daily basis at two stations in the UK: a rural site (Harwell) and an urban site (Belfast). The measurements were compared with model results obtained by using the Unified Danish Eulerian Model (UNI-DEM), which was run using both a coarse resolution grid (50 km × 50 km surface cells) and a fine resolution grid (10 km × 10 km surface cells). The results from the comparison show reasonably good agreement between concentrations measured at the two stations and calculated by the model. This is achieved despite the absence of aqueous phase sulphur oxidation chemistry in the model. The model results were also used to predict the spatial distributions of nitrate and sulphate concentrations in the UK which agree well with observations. The contribution of mainland European emission sources and that of UK sources to pollution levels in the UK was estimated. The relative proportions differ substantially across the UK with the imported contribution to UK sulphate and nitrate typically in the range 20–45% and 35–65% respectively.  相似文献   

The Precambrian Terranes of Yemen and their Correlation with those of Saudi Arabia and Somalia: Implications for the Accretion of Gondwana     

Brian F. Windley  Martin J. Whitehouse  Douglas B. Stoeser  Salah Al-Khirbash  Mahfood A.O. Ba-Bttat  Ahmed Al-Ghotbah 《Gondwana Research》2001,4(2)

  相似文献