Heat flow and thermal evolution of the lithosphere of the Black Sea basin     

Yu. I. Galushkin  A. A. Shreider  A. A. Bulychev  Al. A. Shreider 《Oceanology》2006,46(2):274-291

In most of the studies devoted to the analysis of the thermal regime of the Black Sea basins, the high sedimentation rate is regarded to be the principal reason for the low values of the surface heat flow as compared to the deep flow. We used the basin modeling technique for a more detailed assessment of this issue with regard to the new geological and geophysical data on the age and structure of the sedimentary cover and basement of the Black Sea basins. The use of enhanced seismic data, together with a more accurate estimation of the age limits of the sedimentary sequences in the region, allowed us to refine the results of the previous studies. Based on the calculations performed for an actual cross section with actual properties of the sedimentary rocks under compaction and the basement rocks, it is shown that any version of the sedimentation and evolution of the basin compatible with the geological and geophysical data available lead to heat flow values that are significantly greater than those actually observed. Our analysis proves that the sedimentation alone, as was implied in the previous studies, cannot explain the decrease in the deep heat flow at the floor surface down to values of about 34 mW/m². It is shown that the temperature influence of the invasion of dense though heated waters of the Mediterranean Sea that occurred about 7000 years ago helps one to explain the low present-day heat flow values in the deep-water parts of the Western and Eastern basins of the Black Sea. The application of the basin modeling technique allowed us to pose a version of the thermal evolution of the lithosphere in the Western basin of the Black Sea compatible with the high heat flow at the end of the Cretaceous, with three stages of subsidence of the sea floor down to its present-day depths, and with the low heat flow values measured in the basin. According to the geophysical data, this version implies a relatively high-temperature present-day thermal regime in the basin’s lithosphere with a lithosphere thickness of about 60 km.  相似文献   

Parameters of the sediments of the deep-water basin of the Black Sea     

Al. A. Schreider  A. A. Schreider  A. A. Bulychev 《Oceanology》2007,47(6):848-856

The methodology and the first results of the computations of the volumes, masses, and growth rates of the sedimentary body of the buried Black Sea basin are presented. Their temporal evolution reflects the regional paleogeodynamics, in particular, the reorientation of the vector of the relative movement of the Arabian and Eurasian lithospheric plates and the related intensification of their collision in the late Miocene-Pliocene.  相似文献   

Intercomparison of Boron Isotope and Concentration Measurements. Part II: Evaluation of Results   总被引：3，自引：1，他引：3  

Roberto Gonfiantini  Sonia Tonarini  Manfred Grning  Alessandra Adorni‐Braccesi  Assad S. Al‐Ammar  Marcus Astner  Sebastien Bchler  Ramon M. Barnes  Randy L. Bassett  Alain Cocherie  Annette Deyhle  Andrea Dini  Giorgio Ferrara  Jrme Gaillardet  Judith Grimm  Catherine Guerrot  Urs Krhenbühl  Graham Layne  Damien Lemarchand  Anette Meixner  D. Jack Northington  Maddalena Pennisi  Eva Reitznerov  Ilia Rodushkin  Naoji Sugiura  Regina Surberg  Sabine Tonn  Michael Wiedenbeck  Samuel Wunderli  Yingkai Xiao  Thomas Zack 《Geostandards and Geoanalytical Research》2003,27(1):41-57

The Istituto di Geoscienze e Georisorse (IGG), on behalf and with the support of the International Atomic Energy Agency (IAEA), prepared eight geological materials (three natural waters and five rocks and minerals), intended for a blind interlaboratory comparison of measurements of boron isotopic composition and concentration. The materials were distributed to twenty seven laboratories - virtually all those performing geochemical boron isotope analyses in the world -which agreed to participate in the intercomparison exercise. Only fifteen laboratories, however, ultimately submitted the isotopic and/or concentration results they obtained on the intercomparison materials. The results demonstrate that interlaboratory reproducibility is not well reflected by the precision values reported by the individual laboratories and this observation holds true for both boron concentration and isotopic composition. The reasons for the discrepancies include fractionations due to the chemical matrix of materials, relative shift of the zero position on the δ¹¹B scale and a lack of well characterized materials for calibrating absolute boron content measurements. The intercomparison materials are now available at the IAEA (solid materials) and IGG (waters) for future distribution.  相似文献   

Towards developing a geoscientific approach to sustainable agricultural and rural development   总被引：3，自引：0，他引：3  

Dhia Al Bakri 《Environmental Geology》2001,40(4-5):543-556

 Conventional practices employed to achieve sustainable agricultural and rural development (SARD) tend to be subjective, focus on effects rather than causes, and have little diagnostic or predictive value. Consequently, many of the management options and solutions adopted to restore degraded natural resources are, often, economically unviable and environmentally unsustainable. These shortcomings are believed to be caused, partly, by overlooking or insufficiently recognizing the role and importance of geology to SARD. This paper demonstrates that geology is the most critical factor in the genesis of biophysical resources and in determining sustainability of agricultural and rural development. A case study from Australia shows how geological principles can be employed to obtain goals of ecological sustainability. A geologically-based model for cold temperate regions is provided to assist resource users and managers in understanding and predicting the genetic influence of geology on the inherent potential, constraint and resilience of the biophysical resources. Received: 7 January 2000 · Accepted: 23 May 2000  相似文献   

Triassic magmatism in the South Urals: Geochemistry,isotopic composition,and geodynamics     

Al. V. Tevelev  I. A. Kosheleva  M. A. Furina  B. V. Belyatskii 《Moscow University Geology Bulletin》2009,64(2):92-101

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Evolution of contourite systems in the late Cretaceous Chalk Sea along the Tornquist Zone     

Christian Hübscher  Mu'ayyad Al Hseinat  Matthias Schneider  Christian Betzler 《Sedimentology》2019,66(4):1341-1360

Based on integration of seismic reflection and well data analysis this study examines two major contourite systems that developed during the late Cretaceous in the southern Baltic Sea. The evolution of these Chalk Sea contourite systems between the Kattegat and the southern Baltic Sea started when Turonian to Campanian inversion tectonics overprinted the rather flat sea floor of the epeiric Chalk Sea. The Tornquist Zone and adjacent smaller blocks were uplifted and formed elongated obstacles that influenced the bottom currents. As a consequence of the inversion, the sea floor west of the Tornquist Zone tilted towards the north‐east, creating an asymmetrical sub‐basin with a steep marginal slope in the north‐east and a gentle dipping slope in the south‐west. A south‐east directed contour current emerged in the Coniacian or Santonian along the south‐western basin margin, creating contourite channels and drifts. The previously studied contourite system offshore Stevns Klint is part of this system. A second, deeper and north‐west directed counter‐flow emerged along and parallel to the Tornquist Zone in the later Campanian, but was strongest in the Maastrichtian. This bottom current moderated the evolution of a drift‐moat system adjacent to the elevated Tornquist Zone. The near surface Alnarp Valley in Scania represents the Danian palaeo‐moat that linked the Pomeranian Bay with the Kattegat. The previously studied contourite system in the Kattegat represents the north‐western prolongation of this system. This study links previous observations from the Kattegat and offshore Stevns Klint to the here inferred two currents, a more shallow, south‐east directed and a deeper, north‐west directed flow.  相似文献   

Characterization of a coastal aquifer basin using gravity and resistivity methods: a case study from Aqaba in Jordan     

Mohammad Al Farajat 《Acta Geophysica》2009,57(2):454-475

The southern basin of Aqaba forms coastal aquifer and comprises an area of about 90 km². Alluviums and Pleistocene deposits fill the basin bounded by Precambrian Granite Basement to the east and north. Hydrogeophysical investigations were carried out to investigate its groundwater potentials and characteristics. Direct modeling on Bouger and residual gravity revealed some local subsurface faults that form subbasins and sub-grabens in the body of the basin, each one of them is bounded by two to three faults. The spatial distribution of groundwater was found to be affected by the presence of the sub-basins and grabens. Geoelectrical layers have been vertically digitized and put in a four variable space-lattice, 2D slices of the different depths and 3D visualizations have been produced. The extents of seawater intrusion and zones of water qualities were delineated. The geoelectric inferred some local subsurface faults that were found in spatial correlation with those inferred from the gravity. A good combination was made between gravity and resistivity methods to confirm the 3D distribution of groundwater in the basin.  相似文献   

Performance Evaluation of a Full‐Scale Extended Aeration System in Al‐Bireh City,Palestine     

Rashed Al‐Sa'ed  Nayef Tomaleh 《洁净——土壤、空气、水》2012,40(11):1250-1256

Major challenges attributed to dysfunctional wastewater treatment facilities in developing countries include lack of commitment and poor informed decision making by the higher municipal administration. This paper presents how process monitoring and control during full scale operation ensures sustainability of civic infrastructures like Al‐Bireh wastewater treatment plant (AWWTP). It is written from the perspective of practical process selection to evaluate the performance of AWWTP, a single‐sludge nitrification–denitrification process with aerobic sludge stabilization. Process monitoring data (July 2000–April 2007) from available monthly operating reports were analyzed and evaluated. Additional data on microbiological analysis and information about facility unit operations were gathered through review of published local literature and interviews with AWWTP personnel. Influent and effluent data evaluated were the chemical oxygen demand (COD), biological oxygen demand (BOD), total nitrogen (TN), and total phosphorus (TP). Despite annual and seasonal variations in AWWTP influent for COD, BOD, TN, and TP, the Palestinian wastewater reuse requirements for restricted irrigation were met. Process design and proper facility operation have direct impacts on effluent quality. The study concludes that regardless of the design capacity and process type, adequate administrative and operational management dictate the sustainability of AWWTP and reuse schemes.  相似文献   

Out‐of‐plane seismic behaviour of rocking masonry walls     

Omar Al Shawa  Gianmarco de Felice  Alberto Mauro  Luigi Sorrentino 《地震工程与结构动力学》2012,41(5):949-968

The evaluation of the out‐of‐plane behaviour of unreinforced walls is one of the most debated topics in the seismic assessment of existing masonry buildings. The discontinuous nature of masonry and its interaction with the remainder of the building make the dynamic modelling of out‐of‐plane response troublesome. In this paper, the results of a shaking table laboratory campaign on a tuff masonry, natural scale, U‐shaped assemblage (façade adjacent to transverse walls) are presented. The tests, excited by scaled natural accelerograms, replicate the behaviour of external walls in existing masonry buildings, from the beginning of rocking motion to overturning. Two approaches have been developed for modelling the out‐of‐plane seismic behaviour: the discrete element method and an SDOF analytic model. Both approaches are shown to be capable of reproducing the experimental behaviour in terms of maximum rotation and time history dynamic response. Finally, test results and numerical time history simulations have been compared with the Italian seismic code assessment procedures. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Biocontrol of Meloidogyne javanica on Tomato Plants by Hypocrea lixii (the Teleomorph of Trichoderma harzianum)          下载免费PDF全文

Abdallah M. Elgorban  Mohamed A. Abdel‐Wahab  Ali H. Bahkali  Basheer A. Al‐Sum 《洁净——土壤、空气、水》2014,42(10):1464-1469

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