Faulting, mass-wasting and deposition in an active dextral shear zone, the Gulf of Saros and the NE Aegean Sea, NW Turkey   总被引：1，自引：1，他引：0  

Timur Ustaömer  Erkan Gökaşan  Hüseyin Tur  Tolga Görüm  Fatma Gül Batuk  Doğan Kalafat  Hakan Alp  Berkan Ecevitoğlu  Halim Birkan 《Geo-Marine Letters》2008,28(3):171-193

Structural, mass-wasting and sedimentation processes along an active dextral shear zone beneath the Gulf of Saros and the NE Aegean Sea were investigated on the basis of new high-resolution swath bathymetric data and multi-channel seismics. A long history of dextral shearing operating since the Pliocene culminated in the formation of a NE-SW-trending, ca. 800-m-deep basin (the so-called inner basin) in this region, which is bordered by a broad shelf along its northern and eastern sides and a narrow shelf at the southern side. The western extension of the North Anatolian Fault Zone (the Ganos Fault) cuts the eastern shelf along a narrow deformation zone, and ends sharply at the toe of the slope, where the strain is taken up by two NE-SW-oriented fault zones. These two fault zones cut the basin floor along its central axis and generate a new, Riedel-type pull-apart basin (the so-called inner depression). According to the bathymetric and seismic data, these basin boundary fault zones are very recent features. The northern boundary of the inner depression is a through-going fault comprising several NE-SW- and E-W-oriented, overlapping fault segments. The southern boundary fault zone, on the other hand, consists of spectacular en-echelon fault systems aligned in NE–SW and WNW–ESE directions. These en-echelon faults accommodate both dextral and vertical motions, thereby generating block rotations along their horizontal axis. As the basin margins retreat, the basin widens continuously by mass-wasting of the slopes of the inner basin. The mass-wasting, triggered by active tectonics, occurs by intense landsliding and channel erosion. The eroded material is transported into the deep basin, where it is deposited in a series of deep-sea fans and slumps. The high sedimentation rate is reflected in an over 1,500-m-thick basin fill which has accumulated in Pliocene–Quaternary times.  相似文献   

Producing forest fire susceptibility map via multi-criteria decision analysis and frequency ratio methods     

Arca  Deniz  Hacısalihoğlu  Mercan  Kutoğlu  Ş. Hakan 《Natural Hazards》2020,104(1):73-89

Natural Hazards - Located in the Mediterranean basin, one of the world’s leading places in terms of forest fires, Turkey is one of the countries where forest fires are experienced very often...  相似文献   

A comparative predictive analysis of weighted overlay,weighted sum and fuzzy logic for mineral prospectivity mapping of precious and base metal mineralizations at north-east of Gümüşhane city,NE Turkey     

Önder Kayadibi  Doğan Aydal 《国际地球制图》2019,34(5):539-559

The study area located south of the Eastern Pontide metallogenic belt (NE Turkey) has an important potential for valuable and base metallic minerals. Geological, tectonic, geochemical, hydrothermal alteration, mineralogical and fluid inclusion characteristics of ore formations in the region have been studied in detail. The purpose of this study is to combine and analyse the acquired spatial data layers in a geographic information system (GIS) environment using knowledge-driven approaches and to identify prospective areas in terms of mineralization. Moreover, evaluating the performance of different knowledge-driven mineral probability modelling results comparatively and quantitatively constitutes the other goal of the study. As a result, in addition to the known mineralization locations, a number of new prospective and favourable areas have been identified for future detailed studies. In addition, it has been found that the mineral predictive map generated using fuzzy logic-OR method produces the best and successful results compared to others.  相似文献   

Late Quaternary evolution of the Çanakkale Strait region (Dardanelles, NW Turkey): implications of a major erosional event for the postglacial Mediterranean-Marmara Sea connection   总被引：2，自引：2，他引：0  

Erkan Gökaşan  Hüseyin Tur  Mustafa Ergin  Tolga Görüm  Fatma Gül Batuk  Nurcan Sağcı  Timur Ustaömer  Ozan Emem  Hakan Alp 《Geo-Marine Letters》2010,30(2):113-131

Seismic and bathymetric data from the Çanakkale Strait and its extensions onto the shelves of the Marmara and Aegean seas indicate that the strait was formed mainly by an erosional event. Four seismic units are observed on seismic profiles. The lower two of these (units 4 and 3) constitute the basement of a regionally widespread erosional unconformity (ravinement), which developed during marine isotope stage 2 (MIS 2). The two upper units (units 2 and 1), which overlie the ravinement surface, form a higher-order sequence. Sequence stratigraphic analysis indicates that units 2 and 1 deposited as lowstand and highstand systems tracts respectively, since the end of MIS 2. The transgressive systems tract is represented by a major erosional event which occurred throughout the Çanakkale sill area when the Mediterranean-Marmara Sea connection and, hence, the Çanakkale Strait was formed. The existence of the erosive ?arköy Canyon along the shelf edge of the southern Marmara Sea demonstrates that the flow direction causing the erosion was from south to north, thus proving that it was produced by Mediterranean water flowing over the sill into the Marmara Sea basin.  相似文献   

The influence of hazardous liquid waste on the permeability of earthen liners   总被引：1，自引：0，他引：1  

K. Kayabalı  M. Mollamahmutoğlu 《Environmental Geology》2000,39(3-4):201-210

 Permeability and its susceptibility to changes with time or exposure to chemicals are major factors in selection of earthen liners for use in hazardous liquid-waste containment systems. Earthen liners often consist of mixtures including both granular soil and fine matrix. Six different solid mixtures were tested to investigate the influence of hazardous liquid waste on their permeability. The granular part of the mixtures included sand and crushed natural zeolite, whereas the matrix was composed of bentonite and microcement. Highly acidic solutions, bases, leather industry leachate and municipal waste leachate were used as permeants. Of the mixtures tested, only two mixtures performed well against the attack of chemicals. The testing method was the falling head system with the compaction mold permeameter. The period of experiments varied from two to eight weeks. Received: 24 September 1998 · Accepted: 5 January 1999  相似文献   

大庆头台地区扶余油层无效缝的形成与分布   总被引：1，自引：0，他引：1  

陈建文 《地学前缘》2000,7(4):391-402

:在研究大庆头台地区扶余油层微裂缝的基础上给出了无效缝的概念 ,从研究与无效缝形成有关的成岩作用入手 ,研究了成岩作用中的演化及无效缝的形成 ,论述了微裂缝形成期次、成藏期、次生矿物作用及无效缝形成期次的匹配关系。阐述了无效缝的形成机理、影响因素及在扶余油层中的分布特征。通过对无效缝的研究 ,揭示了无效缝的形成与发展对大庆头台地区扶余油层产油能力和储油能力的影响。本研究对特低渗透裂缝型油田的开发具有一定的指导意义。  相似文献   

Research on limestone decay in a polluting environment, I˙stanbul-Turkey     

A. Tuğrul  H.Ì. Zarif 《Environmental Geology》1999,38(2):149-158

 I˙stanbul, the capital of the east Roman, Byzantine and Ottoman Empires embraces two continents, one arm reaching out to Asia, the other to Europe. It is therefore, a rich city in terms of monuments and historical cites. Shell limestones of Upper Miocene age are used as building stone in the majority of the monuments in I˙stanbul because of their attractiveness, availability and workability. The durability characteristics of the limestones are examined, and those factors that are responsible for atmospheric weathering are discussed, in a humid and marine environment with important problems of urban pollution, specifically due to traffic. In the present study weathering of the building stones were first examined in situ by macroscopic observations. The weathering that developed as a result of environmental effects since this limestone was first used in historical monuments has been affected 0.1–1.5 cm deep from the surface. The weathered facing stone of Şehzade Mehmed Mosque in I˙stanbul is undergoing a program of progressive replacement. During this study, samples were taken from this monument where the shell limestone was used. The stone surface was principally examined by means of Scanning Electron Microscopy (SEM). Petrographical and mineralogical analyses were made by using optical microscopy and X-ray diffraction method. The physico-chemical properties of these rocks control their weathering behaviour and reactivity. Major and trace element analyses and the effect of deterioration on the physical properties of the limestones (unit weight, porosity and water absorption) have also been investigated. Studies on the samples implies that weathering on the stone surface caused important variations on the physical characteristics of the rock. Received: 11 February 1998 · Accepted: 18 August 1998  相似文献   

Spatial Heating Monthly Degree-Day Features and ClimatologicPatterns in Turkey     

M. Kadıoğlu  Z. Şen  L. Gültekin 《Theoretical and Applied Climatology》1999,64(3-4):263-269

Summary  Degree-days as a measure of accumulated temperature deviations from a base temperature have many practical applications in various human related activities such as home cooling, heating, plant growth in agriculture and power generation in addition to energy requirement. Long temperature records are necessary for their reliable estimations at given stations. In this paper, degree-day measure has been applied to monthly temperature records for systematically changed base temperature values from − 25 °C to + 35 °C with 5 °C increments at 255 meteorology stations in Turkey. The results are represented in the form of spatial degree-day distribution maps, which are then related to various climatic, meteorological and topographic features of Turkey. For instance, free surface water bodies in forms of surrounding seas, lakes and rivers insert retardation in the expansion of heating degree-days over large regions. On the other hand, cold air penetration from polar regions in the northeastern Turkey originating from Siberia appears at moderate base temperature heating degree-days. Received August 20, 1998 Revised June 21, 1999  相似文献   

Geological evolution of the Gulf of Saros,NE Aegean Sea     

Çağatay  M. N.  Görür  N.  Alpar  B.  Saatçılar  R.  Akkök  R.  Sakınç  M.  Yüce  H.  Yaltırak  C.  Kuşcu  I. 《Geo-Marine Letters》1998,18(1):1-9

 The Gulf of Saros is an Upper Miocene transtensional basin in NW Anatolia, formed by the interaction between the North Anatolian Fault and the N-S extensional tectonic régime of the Aegean. The present configuration of the basin evolved mainly during the Plio-Quaternary under the increased activity of the North Anatolian Fault. During the late Miocene-late Quaternary, no sedimentation took place on the shelves. After this long hiatus, an important change in tectonic style about 0.2 Ma BP allowed sedimentation to resume in the gulf. Received: 14 February 1997 / Revision received: 12 November 1997  相似文献   

Stochastic Modeling of the Van Lake Monthly Level Fluctuations in Turkey     

Z. Şen  M. Kadioğlu  E. Batur 《Theoretical and Applied Climatology》2000,65(1-2):99-110

Summary  Planning, design, construction and operation of lakeshore structures require information about the future likely extremes of the lake levels at a given risk percentage. Alternative future likely synthetic sequences can be numerically generated provided that the underlying generating mechanism of the lake level fluctuation phenomenon is identified. Simple linear and periodic nonlinear models are used for modeling the deterministic part in the lake level records. Linear trend is eliminated from the original lake level historic data by regression line technique. The nonlinear part needs two stages for its identification. First Fourier series is applied to model interannual periodicities in the lake level fluctuation series and then monthly standardization procedure is applied for seasonal periodic nonlinear component modeling. A second order Markov model is found suitable for the remaining stochastic parts. The application of the methodology is presented for the Lake Van monthly level data in eastern Turkey. Suitable models are identified and their parameters are estimated for trend, periodic and stochastic parts. Likely, synthetic lake levels are generated by the stochastic model and hence lake level extreme values are depicted for the next 2, 6, 12, 24, 60 and 120 months with risk calculations. Such risk calculations take into account the stochastic characteristics of the lake level fluctuations only. The deterministic parts as linear trends and periodicities are added to the stochastic extreme events for the actual simulation of the lake levels. The model presented in this paper is not for time prediction of future lake levels but rather for the simulation of possible equally likely extreme lake level value occurrences over any desired future period. Received April 22, 1998/Revised July 28, 1999  相似文献