Stratigraphic architecture of the fluvio-lacustrine deposits, Bathan Formation, Al-Rehaili area, North Jeddah, Saudi Arabia     

Ibrahim M. Ghandour  Hamad A. Al-Washmi 《Arabian Journal of Geosciences》2013,6(4):995-1010

A siliciclastic-dominated succession (～11 m thick) underlying Harrat Rahat, belonging to the Miocene–Pliocene Bathan Formation is recently exposed at Al-Rehaili area, North Jeddah, Saudi Arabia. It covers a wide spectrum of grain sizes varying from clay-rich mudstones to cobble grade conglomerate and consists of a variety of facies vary from fluvial to marginal and open lacustrine deposited in a half-graben basin formed along the eastern margin of the extensional Red Sea Basin. Field-based sedimentologic investigation enables to identify ten facies grouped into three facies associations (A–C). The depositional history is subdivided into two stages. The first stage represents deposition in gravel to sand-dominated fluvial system sourced from a southern source and grade northward into lacustrine delta and open lacustrine setting. The second stage on the other hand includes deposition of fluvial channels running in E–W direction with attached bank sand bar. Sequence stratigraphic interpretations of the lacustrine deposits enable to identify three unconformity-bounded sequences (SQ_1–3). The basal sequence is incomplete, consisting of three aggradationally to progradationally stacked delta plain and delta front parasequences. The second sequence is sharply and erosively overlying a red paleosol bed that defines the upper boundary of the first sequence. It includes two system tracts; upward-fining and deepening lacustrine offshore mudstones of the transgressive system tracts unconformably overlain by red paleosol of the regressive systems tracts. The top of this sequence is delineated at the sharp transgressive surface of erosion at the base of delta mouth bar deposits of sequence 3. Changes in the accommodation and sedimentation rates by basin subsidence under the influence of tectonics and sediment compaction and loading as well as climatic oscillation between semi-arid to arid conditions were the major controls on the fluvio-lacustrine sedimentation and their facies distribution. Tectonic reorganization of the drainage system resulted in the formation of E–W flowing fluvial streams in the second stage.  相似文献   

Eruptive history of the Barombi Mbo Maar, Cameroon Volcanic Line, Central Africa: Constraints from volcanic facies analysis     

Boris Chako Tchamabé  Dieudonné Youmen  Sébastien Owona  Issa  Takeshi Ohba  Károly Németh  Moussa Nsangou Ngapna  Asobo N. E. Asaah  Festus T. Aka  Gregory Tanyileke  Joseph V. Hell 《Central European Journal of Geosciences》2013,5(4):480-496

his study presents the first and detail field investigations of exposed deposits at proximal sections of the Barombi Mbo Maar (BMM), NE Mt Cameroon, with the aim of documenting its past activity, providing insight on the stratigraphic distribution, depositional process, and evolution of the eruptive sequences during its formation. Field evidence reveals that the BMM deposit is about 126m thick, of which about 20m is buried lowermost under the lake level and covered by vegetation. Based on variation in pyroclastic facies within the deposit, it can be divided into three main stratigraphic units: U₁, U₂ and U₃. Interpretation of these features indicates that U₁ consists of alternating lapilli-ash-lapilli beds series, in which fallout derived individual lapilli-rich beds are demarcated by surges deposits made up of thin, fine-grained and consolidated ash-beds that are well-defined, well-sorted and laterally continuous in outcrop scale. U₂, a pyroclastic fall-derived unit, shows crudely lenticular stratified scoriaceous layers, in which many fluidal and spindle bombs-rich lapilli-beds are separated by very thin, coarse-vesiculatedash-beds, overlain by a mantle xenolith- and accidental lithic-rich explosive breccia, and massive lapilli tuff and lapillistone. U3 displays a series of surges and pyroclastic fall layers. Emplacement processes were largely controlled by fallout deposition and turbulent diluted pyroclastic density currents under “dry” and “wet” conditions. The eruptive activity evolved in a series of initial phreatic eruptions, which gradually became phreatomagmatic, followed by a phreato-Strombolian and a violent phreatomagmatic fragmentation. A relatively long-time break, demonstrated by a paleosol between U₂ and U₃, would have permitted the feeding of the root zone or the prominent crater by the water that sustained the next eruptive episode, dominated by subsequent phreatomagmatic eruptions. These preliminary results require complementary studies, such as geochemistry, for a better understanding of the changes in the eruptive styles, and to develop more constraints on the maar’s polygenetic origin.  相似文献   

Possibility of investigation of the microstreams and associations by the radiotomographic method     

O. I. Evdokimov  T. K. Filimonova  V. V. Sidorov  Rasim Amer Ali 《Earth, Moon, and Planets》1995,68(1-3):267-275

This article contains the tomographic problem's solution of the radiants distribution study by the meteor radar data. It was received the distribution of meteors velocities for the parts of celestial sphere with angular dimensions 10° × 10° and 1° × 1°. Was shown that the angular dimensions of most of radiants are equal 1° – 3° and larger part of the sporadic background looks like a totality of microstreams.  相似文献   

Oil spill sorption using carbonized pith bagasse: trial for practical application   总被引：2，自引：1，他引：1  

M. Hussein  A. A. Amer  I. I. Sawsan M.Sc. 《International Journal of Environmental Science and Technology》2008,5(2):233-242

In the present work, an attempt was made to provide an efficient, easily deployable method of cleaning up oil spills and recovering of the oil. Carbonized pith bagasse, a relatively abundant and inexpensive material is currently being investigated as an adsorbent to remove contaminants “oil” from water. Fibers extracted from bagasse and carbonized at 300 °C were found to have a high performance for sorption and recovery of light, heavy oils and even the viscous ones. The physical properties of pith bagasse were investigated using scanning electronic microscope to show the inner and the outer surface and the cross section area of the pith bagasse and thermo gravimetric analyzer to investigate the degradation profile of the pith bagasse. The carbonized pith bagasse was packed into a polypropylene bag and its sorption behavior was studied. A comparison was made between the prepared pad and the commercial sorbents show that the pad containing carbonized pith bagasse has higher sorption capacity in comparison to the commercial sorbents. The pad exhibited high oil retention ability and a high selectivity for the oils over the water. The pad showed a possibility of reuse for eight times. The sorption capacity of the pads containing carbonized pith bagasse was found to increase with increasing the time of sorption till it reaches the maximum value at the time of sorption equal to 60 min.  相似文献   

Development of ground-shaking maps for the Sultanate of Oman   总被引：1，自引：1，他引：0  

Eser Çaktı  Issa El-Hussain  Karin Şeşetyan  Ahmed Deif  Ufuk Hancılar  Ghazi Al-Rawas  Yaver Kamer  Khalifa Al-Jabri 《Natural Hazards》2016,82(2):1357-1373

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A new hypothesis about the surface circulation in the eastern basin of the mediterranean sea   总被引：3，自引：1，他引：3  

Najwa Hamad  Claude Millot  Isabelle Taupier-Letage 《Progress in Oceanography》2005,66(2-4):287

In time, the circulation of the Atlantic Water (AW) in the eastern basin of the Mediterranean Sea has been described differently, according to two major representations. The historical one, which began with the scheme from Nielsen in 1912 and has been refined up to the 1980s, favours a counterclockwise circulation in the whole basin, with AW flowing in its southern part as a broad flow off Libya and Egypt (from the Ionian to the Levantine subbasins), then continuing along Middle-East and Turkey before flowing back westwards. The more recent one, issued in the 1990s, favours a clockwise circulation in the northern part of the Ionian continuing offshore across the basin from the Cretan to the central part of the Levantine as the so-called “Mid-Mediterranean Jet”. This jet is depicted then as splitting both clockwise in the southeastern part of the basin and counterclockwise off Turkey (where this representation agrees with the former). Because the recent representation cannot be considered as a refinement of the historical ones, we have been interested in understanding why a given data set available to everybody is interpreted in such different ways.In the Algerian subbasin, the combined use of satellite infrared images and a significant amount of in situ data sets (hydrology and both Eulerian and Lagrangian current measurements) allowed us to solve a similar controversy. Therefore, we examined the circulation features in the eastern basin, undertaking the detailed analysis of 1000 daily and weekly composite images spanning the period 1996–2000, and of monthly composite images available since 1985. Whenever in situ observations were available, we have confronted them with the satellite thermal signatures and have shown that both are consistent. This paper focuses on the overall (basin scale) results while the detailed ones are published in an other paper. The new scheme we propose is basically a refined version of the historical ones: the circulation of AW is counterclockwise in the whole eastern basin but it is more constrained alongslope than previously thought, and the broadening historically schematised appears to be due to intense mesoscale eddies mainly generated by the instability of this circulation.  相似文献   

Integrating international linguistic minorities in emergency planning at institutions of higher education     

Abukhalaf  Amer Hamad Issa  von Meding  Jason 《Natural Hazards》2021,109(1):845-869

Natural Hazards - Research concerning the behavior of international linguistic minorities at institutions of higher education during disasters is very limited. Many international groups suffer from...  相似文献   

Solidification of Tank Bottom Sludge   总被引：1，自引：0，他引：1  

Ramzi A. Taha  Yahia E.-A. Mohamedzein  Amer A. Al-Rawas  Yahya Al-Suleimani 《Geotechnical and Geological Engineering》2010,28(1):15-25

Tank bottom oily sludge (S) is collected from tank bottoms during cleaning operations and contaminated soil is collected after spills and leakages. Disposal of tank sludge is a significant item of tank maintenance for producers, refiners and transporters of petroleum materials. The objective of this paper is to investigate the use of various additives in the solidification of tank bottom sludge. The sludge was solidified using various combinations of additives including ordinary Portland cement (OPC), cement by-pass dust (CBPD) and quarry fines (QF). Geotechnical and leachability properties of the mixtures were determined. The use of OPC alone as a solidifying agent yielded the best results. This was followed by blends S:OPC:QF of 1:0.5:1.5 and S:CBPD of 1:2. Economically, the latter two mixtures would be considered more cost-effective in solidifying the sludge as the additives are waste by-product materials. The Toxicity Characteristic Leaching Procedure (TCLP) results indicated that no extracts exceeded the threshold TCLP limits established by U.S. Environmental Protection Agency (USEPA). The solidified material can be used in construction of roads, embankments and landfill layers.  相似文献   

Leachate Mound Changes in Landfills Due to Changes in Percolation by a Cap     

Issa S. Oweis  Gopal C. Biswas 《Ground water》1993,31(4):664-674

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Participatory groundwater management in Jordan: Development and analysis of options     

Mohamed?ChebaaneEmail author  Hazim?El-Naser  Jim?Fitch  Amal?Hijazi  Amer?Jabbarin 《Hydrogeology Journal》2004,12(1):14-32

Groundwater over-exploitation has been on the rise in Jordan. Competing demands have grown in the face of perennial water shortages, a situation which has been exacerbated by drought conditions in the past decade. This paper reports findings of a project in which management options to address over-exploitation were developed for one of Jordans principal aquifer systems, the Amman-Zarqa Basin. Options for addressing the situation were developed through a participatory approach that involved government officials and various public and private sector interest groups. Particular efforts were made to involve well irrigators, who are likely to be heavily impacted by the changes required to reduce groundwater pumping to a sustainable level. With information obtained from a rapid appraisal survey as well as from interviews with farmers, community groups, government officials, and technical experts, an extensive set of options was identified for evaluation. Based on integrated hydrogeologic, social, and economic analysis, five complementary management options were recommended for implementation. These included the establishment of an Irrigation Advisory Service, buying out farm wells, placing firm limits on well abstraction and irrigated crop areas, exchanging treated wastewater for groundwater, and measures to increase the efficiency of municipal and industrial water use. Various combinations and levels of these options were grouped in scenarios, representing possible implementation strategies. The scenarios were designed to assist decision makers, well owners and other stakeholders in moving gradually towards a sustainable abstraction regime. Social and economic aspects of each option and scenario were analyzed and presented to stakeholders, together with a summary of legal, institutional and environmental ramifications. Combining scientific analysis with a participatory approach in the Amman Zarqa Basin groundwater management was devised as a prototype to be used in the management of other groundwater basins in Jordan. This participatory management approach would also be useful in other parts of the world that are experiencing similar groundwater over-exploitation problems.Résumé La surexploitation des eaux souterraines prend de limportance en Jordanie. Les demandes en concurrence ont augmenté face à des déficits permanents deau, situation qui a été exacerbée par la sécheresse de la dernière décennie. Cet article rend compte de laboutissement dun projet dans lequel des options de gestion portant sur la surexploitation ont été développées pour lun des principaux systèmes aquifères de Jordanie, le bassin dAmman Zarqa. Des options pour aborder cette situation ont été développées grâce à une approche participative qui implique des fonctionnaires du gouvernement et des groupes dintérêts variés des secteurs public et privé. Des efforts particuliers ont été faits pour impliquer les irrigants utilisant des puits, qui sont probablement ceux qui ont le plus fort impact sur les changements attendus permettant de remettre le système en équilibre. À partir des informations obtenues de campagnes rapides dévaluation, telles que des réunions de communautés et des entrevues avec des experts techniques du gouvernement, un large jeu doptions a été identifié pour lévaluation. Basées sur une analyse hydrogéologique, sociale et économique, cinq options complémentaires de gestion ont été recommandées pour la réalisation. Ce sont la création dun Service Consultatif dIrrigation, achetant les puits agricoles, fixant des limites fermes aux prélèvements des puits et aux zones irriguées, échangeant les eaux usées traitées avec des eaux souterraines, et la mise en place de mesures pour accroître lefficacité des usages collectifs et industriels. Des combinaisons et des niveaux variés de ces options ont été regroupés en scénarios, présentant les stratégies possibles de mise en uvre. Les scénarios ont été mis au point pour assister les décideurs, les propriétaires de puits et les autres acteurs pour atteindre progressivement un régime de prélèvement durable. Les aspects sociaux et économiques de chaque option et de chaque scénario ont été analysés et présentés aux acteurs, en même temps quun résumé des ramifications légales, institutionnelles et environnementales. En combinant une analyse scientifique à une approche participative du bassin dAmman Zarqa, la gestion des eaux souterraines a été imaginée comme un prototype pouvant être utilisé pour la gestion dautres bassins aquifères de Jordanie. Il peut également être utile à dautres régions du monde qui sont concernées par des problèmes similaires de surexploitation des eaux souterraines.Resumen La sobreexplotación de las aguas subterráneas ha ido en aumento en Jordania, donde las demandas en competición han crecido frente a una escasez perenne de agua, situación que ha sido agravada por el estado de sequía de la última década. Este artículo presenta los hallazgos de un proyecto en el que se han desarrollado opciones de gestión para hacer frente a la sobreexplotación en uno de los principales sistemas acuíferos de Jordania: la cuenca de Ammán-Zarga. Se ha elaborado opciones para afrontar la situación mediante un enfoque participativo que incluye a personal del gobierno y a diversos grupos de interés de los sectores público y privado. En particular, se ha intentado involucrar a los regantes que se sirven de aguas subterráneas, quienes tienen más probabilidad de ser directamente afectados por los cambios requeridos para devolver el sistema a un balance equilibrado. A partir de la información obtenida en rápidas campañas de valoración, así como de encuentros con la comunidad y entrevistas con los expertos técnicos del gobierno, se ha identificado un amplio conjunto de opciones para su evaluación. Basándose en un análisis integrado de los aspectos hidrogeológicos, sociales y económicos, se ha recomendado la implementación de cinco opciones complementarias de gestión: establecimiento de un Servicio Asesor de Riego; adquisición de pozos de granjas; imposición de límites estrictos en las extracciones de pozos y superficies de riego; substitución de las aguas subterráneas con aguas residuales depuradas; y medidas para incrementar la eficiencia de los usos municipales e industriales del agua. Se ha agrupado varias combinaciones y niveles de dichas opciones en escenarios, representando estrategias posibles de implementación. Los escenarios han sido diseñados para ayudar a los gestores en la toma de decisiones, a los propietarios de pozos y a otros agentes para que se vaya consiguiendo de forma gradual un régimen de extracciones sustentable. Se ha analizado los aspectos sociales y económicos de cada opción y de cada escenario, presentándolos a los diversos agentes, además de generar un resumen de ramificaciones legales, institucionales y medioambientales. Se ha concebido la combinación de un análisis científico con un enfoque participativo en la cuenca de Ammán-Zarga como un prototipo de gestión de las aguas subterráneas que puede ser aplicado a la gestión de otras cuencas en Jordania. También sería útil en otros lugares del mundo que estén experimentando problemas similares de sobreexplotación de los recursos hídricos subterráneos.Abbreviations and acronyms AED Academy for Educational Development - ARD Associates in Rural Development - AZB Amman–Zarqa Basin - ECC Economic Consultative Council - GMCC Groundwater Management Consultative Committee - GMF Groundwater Management Fund - GIS Geographic Information System - HDH Hashmiya–Dulayl–Hallabat - IAS Irrigation Advisory Service - JICA Japanese International Cooperation Agency - M&I Municipal and Industrial - MOA Ministry of Agriculture - MWI Ministry of Water and Irrigation - NCARTT National Center for Agricultural Research and Technology Transfer - NGO Non-governmental Organization - O&M Operations and Maintenance - RA Rapid Appraisal - RS Remote Sensing - UFW Unaccounted for Water - USAID United States Agency for International Development - WAJ Water Authority of Jordan - WEPIA Water Education & Public Information Activity - WRPS Water Resource Policy Support  相似文献