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Articles 601 - 630 of 917
Full-Text Articles in Earth Sciences
Porosity-Permeability And Textural Parameters Of The Palaeogene Forearc Sedimentary Fill On Lemnos Island, Ne Greece, Angelos Maravelis, Avraam Zelilidis
Porosity-Permeability And Textural Parameters Of The Palaeogene Forearc Sedimentary Fill On Lemnos Island, Ne Greece, Angelos Maravelis, Avraam Zelilidis
Turkish Journal of Earth Sciences
The Palaeogene forearc sedimentary fill on Lemnos Island, NE Greece, was examined to determine reservoir characteristics and textural parameters. During this time interval the studied area was the site of accumulation of submarine fans that underlie shelf deposits, with tectonic activity responsible for the shallowing upward trend. Turbidites were deposited in both inner (slope fan facies) and outer parts (basin floor fan facies) of the submarine fan system and consist of alternating sandstone and mudstone beds. Sandstones occur in both complete and incomplete Bouma sequences while shelf deposits have been interpreted as storm-surge deposits on the deeper parts of shelves. …
An Active Composite Pull-Apart Basin Within The Central Part Of The North Anatolian Fault System: The Merzifon-Suluova Basin, Turkey, Fuat Bora Rojay, Ali̇ Koçyi̇ği̇t
An Active Composite Pull-Apart Basin Within The Central Part Of The North Anatolian Fault System: The Merzifon-Suluova Basin, Turkey, Fuat Bora Rojay, Ali̇ Koçyi̇ği̇t
Turkish Journal of Earth Sciences
The North Anatolian Fault System (NAFS) that separates the Eurasian plate in the north from the Anatolian microplate in the south is an intracontinental transform plate boundary. Its course makes a northward convex arch-shaped pattern by flexure in its central part between Ladik in the east and Kargı in the west. A number of strike-slip basins of dissimilar type and age occur within the NAFS. One of the spatially large basins is the E-W-trending Merzifon-Suluova basin (MS basin), about 55 km long and 22 km wide, located on the southern inner side of the northerly-convex section of the NAFS. The …
The Palu-Uluova Strike-Slip Basin In The East Anatolian Fault System, Turkey: Its Transition From The Palaeotectonic To Neotectonic Stage, Serap Çolak, Ercan Aksoy, Ali̇ Koçyi̇ği̇t, Murat İnceöz
The Palu-Uluova Strike-Slip Basin In The East Anatolian Fault System, Turkey: Its Transition From The Palaeotectonic To Neotectonic Stage, Serap Çolak, Ercan Aksoy, Ali̇ Koçyi̇ği̇t, Murat İnceöz
Turkish Journal of Earth Sciences
The East Anatolian fault system (EAFS) is the 80-km-wide, 700-km-long, NE-trending sinistral strike-slip fault system forming a seismically very active intracontinental transfom fault boundary. It is located between Karlıova County in the northeast and Karataş-Samandağ counties in the southwest, and forms the southeastern boundary of the Anatolian platelet. The Palu-Uluova basin is one of several strike-slip basins located along the EAFS. It is surrounded by several push-ups such as the Karaömerdağı, Mastardağı and Askerdağı push-ups caused by the complexities peculiar to strike-slip faulting. The Palu-Uluova basin consists of three sub-sections: two are NE-trending strike-slip sub-basins, the Uluova and the Palu-Kumyazı …
The Early−Middle Palaeozoic Oceanic Events Along The Southern European Margin: The Deli Jovan Ophiolite Massif (Ne Serbia) And Palaeo-Oceanic Zones Of The Great Caucasus, Guram Zakariadze, Stevan Karamata, Sergei Korikovsky, Aleksei Ariskin, Shota Adamia, Tamar Chkhotua, Sergei Sergeev, Natasha Solov'eva
The Early−Middle Palaeozoic Oceanic Events Along The Southern European Margin: The Deli Jovan Ophiolite Massif (Ne Serbia) And Palaeo-Oceanic Zones Of The Great Caucasus, Guram Zakariadze, Stevan Karamata, Sergei Korikovsky, Aleksei Ariskin, Shota Adamia, Tamar Chkhotua, Sergei Sergeev, Natasha Solov'eva
Turkish Journal of Earth Sciences
The paper deals with the Middle Palaeozoic oceanic events on the northern margin of the Eastern Mediterranean Hercynides. The Balkan-Carpathian Ophiolite Belt (BCO) and palaeo-oceanic zones of the Great Caucasus, all framing the East European Platform from the south, are correlated. The BCO palaeo-oceanic complex was widely thought to be a Late Precambrian-earliest Cambrian oceanic thrust sheet (563±5 Ma), a part of the South European Palaeo-oceanic Suture. The geochronological studies carried out on gabbroic series of the Deli Jovan Massif (BCO, NE Serbia), showed, however, that they are of much younger (Early Devonian) age: (a) Sm-Nd mineral isochron age of …
Geology And Hydrocarbon Systems In The Western Black Sea, Georgi Georgiev
Geology And Hydrocarbon Systems In The Western Black Sea, Georgi Georgiev
Turkish Journal of Earth Sciences
This paper presents the author's integrated regional studies during the last decade. The main purpose is to present an overall understanding of the geological structure, sedimentary basins and hydrocarbon systems of the whole Western Black Sea Zone (WBSZ). This study is based on original data from boreholes, seismic and gravity-magnetic surveys and hydrocarbon accumulations. Many geophysical borehole data obtained for WBSZ during the last 3-4 decades were interpreted mostly at a national level using different approaches, terminology and nomenclature for the same or similar lithostratigraphic and tectonic units. Therefore, a unified approach to interpretation of borehole-seismic data and correlation of …
Tectonics Of The Strandja Massif, Nw Turkey: History Of A Long-Lived Arc At The Northern Margin Of Palaeo-Tethys, Boris Natalin, Gürsel Sunal, Muharrem Satir, Erkan Toraman
Tectonics Of The Strandja Massif, Nw Turkey: History Of A Long-Lived Arc At The Northern Margin Of Palaeo-Tethys, Boris Natalin, Gürsel Sunal, Muharrem Satir, Erkan Toraman
Turkish Journal of Earth Sciences
The Strandja Massif, Thrace Peninsula, NW Turkey, forms an important link between the Balkan Zone of Bulgaria, which is usually correlated with Variscan orogen in Central Europe, and the Pontides, where Cimmerian structures are the most prominent. The massif is composed of a Palaeozoic basement and a Triassic metasedimentary cover. The basement is made of various granite gneisses, paragneisses, and schists that are intruded by large plutons of monzonitic metagranites. Detrital zircon studies have revealed Ordovician (433 and 446 Ma) and Carboniferous (305 Ma) ages of the metasedimentary rocks. The isotopic age of the granite gneisses is 308-315 Ma (Carboniferous, …
Palaeoflora And Climate Of Lignite-Bearing Lower−Middle Miocene Sediments In The Seyitömer And Tunçbilek Sub-Basins, Kütahya Province, Northwest Turkey, Mehmet Serkan Akki̇raz, Funda Akgün, Torsten Utescher, Volker Wilde, Angela Anneliese Bruch, Volker Mosbrugger, Sari̇ye Duygu Üçbaş
Palaeoflora And Climate Of Lignite-Bearing Lower−Middle Miocene Sediments In The Seyitömer And Tunçbilek Sub-Basins, Kütahya Province, Northwest Turkey, Mehmet Serkan Akki̇raz, Funda Akgün, Torsten Utescher, Volker Wilde, Angela Anneliese Bruch, Volker Mosbrugger, Sari̇ye Duygu Üçbaş
Turkish Journal of Earth Sciences
Lower-Middle Miocene successions from Kütahya province (Seyitömer and Tunçbilek sub-basins) were analyzed to reconstruct the palaeoclimate and vegetation of the period. A rich coniferous forest formed the dominant components among sporomorphs and consisted mainly of undeterminable Pinaceae, Pinus haploxylon type, Pinus diploxylon type, Picea, Cedrus, Cathaya, Keteleeria and Podocarpus. Pollen data also indicate the presence of some fern taxa (Osmunda, Polypodiaceae, Schizeaceae) Selaginella and Lycopodium. Cupressaceae frequently occur in all samples from both sub-basins, and form part of the mixed forest assemblage. Two woody plants Castanea-Castanopsis and evergreen Quercus predominate in the assemblages as well. The reconstruction of palaeoclimate is …
Dating Subduction Events In East Anatolia, Turkey, Oberhaensli Roland, Bousquet Romain, Osman Candan, Aral Okay
Dating Subduction Events In East Anatolia, Turkey, Oberhaensli Roland, Bousquet Romain, Osman Candan, Aral Okay
Turkish Journal of Earth Sciences
Metamorphic studies in the cover sequences of the Bitlis complex allow the thermal evolution of the massif to be constrained using metamorphic index minerals. Regionally distributed metamorphic index minerals such as glaucophane, carpholite, relics of carpholite in chloritoid-bearing schists and pseudomorphs after aragonite in marbles record a LT-HP evolution. This demonstrates that the Bitlis complex was subducted and stacked to form a nappe complex during the closure of the Neo-Tethys. During late Cretaceous to Cenozoic evolution the Bitlis complex experienced peak metamorphism of 1.0-1.1 GPa at 350-400°C. During the retrograde evolution temperatures remained below 460°C. 39Ar/40Ar dating of white mica …
The Kemer Metamorphic Complex (Nw Turkey): A Subducted Continental Margin Of The Sakarya Zone, Mesut Aygül, Gülteki̇n Topuz, Aral Okay, Muharrem Satir, Hans Peter Meyer
The Kemer Metamorphic Complex (Nw Turkey): A Subducted Continental Margin Of The Sakarya Zone, Mesut Aygül, Gülteki̇n Topuz, Aral Okay, Muharrem Satir, Hans Peter Meyer
Turkish Journal of Earth Sciences
High-pressure and ultrahigh-pressure metamorphic rocks crop out widely in the northern Aegean. In many instances their ages and tectonic setting are poorly constrained. Here we report newly discovered high-pressure rocks of continental crustal origin and of Late Cretaceous age southwest of the Marmara Sea. They occur at the contact between the Rhodope-Strandja Zone in the north and the Sakarya Zone in the south. The Kemer Metamorphic Complex is composed mainly of mica schist, calcschist and marble with minor metabasite and serpentinite. The mica schists contain garnet, phengite (3.30-3.44 c.p.f.u), (±) paragonite, albite, epidote, calcite, chlorite and titanite. The high-pressure metamorphic …
Chromite-Hosted Silicate Melt Inclusions From Basalts In The Stravaj Complex, Southern Mirdita Ophiolite Belt (Albania), Izabella Havancsàk, Friedrich Koller, Jànos Kodolànyi, Csaba Szabò, Volker Höck, Kujtim Onuzi
Chromite-Hosted Silicate Melt Inclusions From Basalts In The Stravaj Complex, Southern Mirdita Ophiolite Belt (Albania), Izabella Havancsàk, Friedrich Koller, Jànos Kodolànyi, Csaba Szabò, Volker Höck, Kujtim Onuzi
Turkish Journal of Earth Sciences
The Stravaj ophiolite compex, part of the western Mirdita ophiolite belt in Albania, is located east of the Shpati massif, and west of the Shebenik massif. The Stravaj ophiolite sequence itself consist of MOR-related and subduction-related volcanic rocks (Hoeck et al. 2007) formed by pillow lavas and various dykes. The deeper units are formed by gabbros and plagioclase-bearing peridotites. The pillow lavas are intersected by basaltic dykes with a rather primitive composition. The studied basaltic dyke contains former relics of olivine, fresh spinel and clinopyroxene phenocrysts in a glassy groundmass. The silicate phases are strongly altered. The spinels appear as …
Aspects Of Final Disposal Of Radioactive Waste In Germany, Guido Bracke
Aspects Of Final Disposal Of Radioactive Waste In Germany, Guido Bracke
Turkish Journal of Earth Sciences
Safe disposal of radioactive waste is required in all countries using nuclear power, radioactive materials in medicine and in industry or research. This contribution presents an overview of the strategy of final disposal of radioactive waste and summarizes the procedure and present status in Germany. It is concluded that the safe disposal of radioactive waste is feasible but that the public demand for safety has to be met by applying a stepwise, transparent, and traceable development procedure for a repository in a safety case to obtain regulatory and public approval.
Early Oligocene Continental Climate Of The Palaeogene Basin (Hungary And Slovenia) And The Surrounding Area, Boglarka Erdei, Torsten Utescher, Lilla Hably, Julia Tamás, Anita Roth-Nebelsick, Michaela Grein
Early Oligocene Continental Climate Of The Palaeogene Basin (Hungary And Slovenia) And The Surrounding Area, Boglarka Erdei, Torsten Utescher, Lilla Hably, Julia Tamás, Anita Roth-Nebelsick, Michaela Grein
Turkish Journal of Earth Sciences
This paper concentrates on the Early Oligocene palaeoclimate of the southern part of Eastern and Central Europe and gives a detailed climatological analysis, combined with leaf-morphological studies and modelling of the palaeoatmospheric CO_2 level using stomatal and \delta^1^3C data. Climate data are calculated using the Coexistence Approach for Kiscellian floras of the Palaeogene Basin (Hungary and Slovenia) and coeval assemblages from Central and Southeastern Europe. Potential microclimatic or habitat variations are considered using morphometric analysis of fossil leaves from Hungarian, Slovenian and Italian floras. Reconstruction of CO_2 is performed by applying a recently introduced mechanistic model. Results of climate analysis …
Late Miocene Palaeoclimate And Ecosystem Dynamics In Southwestern Bulgaria − A Study Based On Pollen Data From The Gotse-Delchev Basin, Dimiter A. Ivanov, Torsten Utescher, A. Rahman Ashraf, Volker Mosbrugger, Vladimir Bozukov, Nadezhda Djorgova, Evgenia Slavomirova
Late Miocene Palaeoclimate And Ecosystem Dynamics In Southwestern Bulgaria − A Study Based On Pollen Data From The Gotse-Delchev Basin, Dimiter A. Ivanov, Torsten Utescher, A. Rahman Ashraf, Volker Mosbrugger, Vladimir Bozukov, Nadezhda Djorgova, Evgenia Slavomirova
Turkish Journal of Earth Sciences
A profile 63 m thick in the Late Miocene in the Gotse-Dechev Basin (SW Bulgaria) was sampled for pollen analysis in the Kanina opencast mine. The exposed sequence comprises a basal unit with brown coal-clay cycles and clayey/siliciclastic cover layers partly representing a lacustrine facies. A total of 60 pollen samples were analysed, but quantitative data are confined to 30 polleniferous samples. The palynological analysis carried out provides data about the composition and structure of the fossil vegetation. The main vegetation type was a mixed mesophytic forest dominated by Carya, Fagus, Betula, Quercus, and Ulmus. Accessory elements included Magnolia, Corylopsis, …
Palaeoclimatic Estimates For The Late Pliocene Based On Leaf Physiognomy From Western Yunnan, China, Sanping Xie, Sun Bainian, Jinyu Wu, Zhicheng Lin, Defei Yan, Liang Xiao
Palaeoclimatic Estimates For The Late Pliocene Based On Leaf Physiognomy From Western Yunnan, China, Sanping Xie, Sun Bainian, Jinyu Wu, Zhicheng Lin, Defei Yan, Liang Xiao
Turkish Journal of Earth Sciences
Based on leaf physiognomy of the Late Pliocene Tuantian megaflora from the Mangbang Formation of Tengchong County in western Yunnan, a quantitative reconstruction of palaeoclimate was performed with Leaf Margin Analysis (LMA) methodology and the Climate-Leaf Analysis Multivariate Program (CLAMP). The latter produced the following parameters: mean annual temperature (MAT) from 17.2 to 17.7°C; warmest month mean temperature (WMMT) from 25 to 25.5°C; coldest month mean temperature (CMMT) from 9.5 to 10.8°C; length of growing season (GRS) from 9.5 to 9.7 months; growing season precipitation (GSP) from 1834.3 to 1901.2 mm; mean monthly growing season precipitation (MMGSP) from 222.4 to …
Palaeoclimate Estimates For Selected Leaf Floras From The Late Pliocene (Reuverian) Of Central Europe Based On Different Palaeobotanical Techniques, Christine Thiel, Stefan Klotz, Dieter Uhl
Palaeoclimate Estimates For Selected Leaf Floras From The Late Pliocene (Reuverian) Of Central Europe Based On Different Palaeobotanical Techniques, Christine Thiel, Stefan Klotz, Dieter Uhl
Turkish Journal of Earth Sciences
To provide quantitative palaeoclimate estimates based on different palaeobotanical techniques for three contemporaneous Pliocene leaf floras, we applied the Coexistence Approach (CoA), leaf margin analysis (LMA), the Climate Leaf Analysis Multivariate Program (CLAMP) and the European Leaf Physiognomic Approach (ELPA). Furthermore, we compared recently published estimates from an additional locality with our data. The leaf physiognomic techniques yield lower mean annual temperatures than the CoA, which is most likely caused by taphonomic biases. Due to these potential biases we are in favour of the CoA as the most reliable method, and its palaeotemperature estimates show similar temperatures for all localities. …
Sedimentary Properties Of The Middle−Upper Eocene Formations In Çardak, Burdur And İncesu, Sw Turkey, Ezher Toker, Mehmet Serkan Akki̇raz, Fuzuli̇ Yağmurlu, Funda Akgün, Sefer Örçen
Sedimentary Properties Of The Middle−Upper Eocene Formations In Çardak, Burdur And İncesu, Sw Turkey, Ezher Toker, Mehmet Serkan Akki̇raz, Fuzuli̇ Yağmurlu, Funda Akgün, Sefer Örçen
Turkish Journal of Earth Sciences
The integration of sedimentological, palynological and palaeontological data in three different outcrops in SW Turkey provides a clearer understanding of the palaeoenvironments in an area between the Çardak-Dazkırı Basin and the Isparta region during the Middle-Late Eocene. In this study, the Çardak-Dazkırı (Başçeşme Formation), Burdur (Varsakyayla Formation) and Isparta (Kayıköy Formation) areas have been studied for facies and facies associations. These formations contain alluvial fan, fan delta, shelf and related marine deposits. Detailed field observations allowed 34 lithofacies and 10 facies associations to be identified. The palynomorph assemblages in the Başçeşme and Varsakyayla formations contain biostratigraphically important taxa such as …
Discovery Of A Mississippian Reef In Turkey: The Upper Viséan Microbial-Sponge-Bryozoan-Coral Bioherm From Kongul Yayla (Taurides, S Turkey), Julien Denayer, Markus Aretz
Discovery Of A Mississippian Reef In Turkey: The Upper Viséan Microbial-Sponge-Bryozoan-Coral Bioherm From Kongul Yayla (Taurides, S Turkey), Julien Denayer, Markus Aretz
Turkish Journal of Earth Sciences
For the first time, a Mississippian reef is described from Turkey. This microbial-sponge-bryozoan-coral bioherm has been discovered in the Central Taurides (South Turkey), at Kongul Yayla located between Hadim and Taşkent. The bioherm contains a rich and diversified fauna: sponges and rugose corals are of particular interest. The bioherm shows four main facies reflecting distinct growth stages from the base to the top: (1) the basal bioclastic beds, (2) the core facies formed of framestone comprising rugose corals, lithistid sponges, fistuliporid bryozoans and microbial boundstone, (3) the crest facies with large colonies of cerioid rugose corals and chaetetid sponges, and …
Neotectonic Characteristics Of The İnönü-Eskişehir Fault System In The Kaymaz (Eskişehir) Region: Influence On The Development Of The Mahmudiye-Çifteler-Emirdağ Basin, Azad Selçuk, Yaşar Ergün Gökten
Neotectonic Characteristics Of The İnönü-Eskişehir Fault System In The Kaymaz (Eskişehir) Region: Influence On The Development Of The Mahmudiye-Çifteler-Emirdağ Basin, Azad Selçuk, Yaşar Ergün Gökten
Turkish Journal of Earth Sciences
The İnönü-Eskişehir Fault System (İEFS) is a NW- to WNW-trending zone of active deformation about 15-25 km wide, 400 km long and characterized predominatly by strike-slip faulting. In this study, the Yörükkaracaören (SE of Eskişehir)-Sivrihisar section of the İEFS was investigated. The system consists of three fault zones, namely the Alpu Fault Zone (AFZ), the Eskişehir Fault Zone (EFZ) and the Orhaniye Fault Zone (OFZ) in the study area. The EFZ is made up mostly of N30°W-trending right-lateral strike-slip fault segments with normal components. However, the AFZ and OFZ are composed of E-W-trending normal and NE- to NW-trending strike-slip fault …
Late Palaeozoic To Cenozoic Evolution Of The Black Sea-Southern Eastern Europe Region: A View From The Russian Platform, Anatoly Nikishin, Peter Ziegler, Sergey Bolotov, Pavel Fokin
Late Palaeozoic To Cenozoic Evolution Of The Black Sea-Southern Eastern Europe Region: A View From The Russian Platform, Anatoly Nikishin, Peter Ziegler, Sergey Bolotov, Pavel Fokin
Turkish Journal of Earth Sciences
A synthesis of the Late Palaeozoic to Cenozoic evolution of the Black Sea region and the southern parts of the East European Platform (EEP) is presented. During Carboniferous to Early Permian times the Cordillera-type Euxinus Orogen evolved along the southern margin of the EEP in response to progressive closure of the Rheic and Palaeotethys oceans and the accretion of Gondwana-derived continental terranes. Permian development of the north-dipping Palaeotethys subduction system along the southern Pontides margin of these terranes was accompanied by important compressional intraplate deformation on the EEP. The Mesozoic to Palaeogene evolution of the southern parts of the EEP, …
Cenozoic Volcanism Of The Caucasian Mobile Belt In Georgia, Its Geological-Petrological Peculiarities And Geodynamic Conditions, Bezhan Tutberidze
Cenozoic Volcanism Of The Caucasian Mobile Belt In Georgia, Its Geological-Petrological Peculiarities And Geodynamic Conditions, Bezhan Tutberidze
Turkish Journal of Earth Sciences
The Caucasian mobile belt is situated in the area of Late Cenozoic collision of the large Afro-Arabian and Eurasian lithospheric plates. Extensive volcanic activity in the Georgian part of the Caucasian mobile belt took place during the Late Miocene-Holocene. Five volcanic regions have been identified in Georgia; each of them reveals in a greater or lesser degree similarity of tectonic and magmatic processes. Volcanic products are represented by basaltic, doleritic, andesitic basaltic, andesitic dacitic, rhyolitic lavas and their pyroclastics with andesites and dacites prevailing. Using petrochemical and geochemical data the volcanics can be divided into two main rock groups: calc-alkaline …
Ion Probe U-Pb Dating Of The Central Sakarya Basement: A Peri-Gondwana Terrane Intruded By Late Lower Carboniferous Subduction/Collision-Related Granitic Rocks, Petek Ayda Ustaömer, Ti̇mur Ustaömer, Alastair Robertson
Ion Probe U-Pb Dating Of The Central Sakarya Basement: A Peri-Gondwana Terrane Intruded By Late Lower Carboniferous Subduction/Collision-Related Granitic Rocks, Petek Ayda Ustaömer, Ti̇mur Ustaömer, Alastair Robertson
Turkish Journal of Earth Sciences
Ion probe dating is used to determine the relative ages of amphibolite-facies meta-clastic sedimentary rocks and crosscutting granitoid rocks within an important 'basement' outcrop in northwestern Turkey. U-Pb ages of 89 detrital zircon grains separated from sillimanite-garnet micaschist from the Central Sakarya basement terrane range from 551 Ma (Ediacaran) to 2738 Ma (Neoarchean). Eighty five percent of the ages are 90-110% concordant. Zircon populations cluster at ~550-750 Ma (28 grains), ~950-1050 Ma (27 grains) and ~2000 Ma (5 grains), with smaller groupings at ~800 Ma and ~1850 Ma. The first, prominent, population (late Neoproterozoic) reflects derivation from a source area …
Late Cretaceous-Eocene Geological Evolution Of The Pontides Based On New Stratigraphic And Palaeontologic Data Between The Black Sea Coast And Bursa (Nw Turkey), Zahi̇de Özcan, Aral Okay, Ercan Özcan, Aynur Hakyemez, Sevi̇nç Altiner
Late Cretaceous-Eocene Geological Evolution Of The Pontides Based On New Stratigraphic And Palaeontologic Data Between The Black Sea Coast And Bursa (Nw Turkey), Zahi̇de Özcan, Aral Okay, Ercan Özcan, Aynur Hakyemez, Sevi̇nç Altiner
Turkish Journal of Earth Sciences
The Late Cretaceous-Eocene geological evolution of northwest Turkey between the Black Sea and Bursa was studied through detailed biostratigraphic characterization of eleven stratigraphic sections. The Upper Cretaceous sequence in the region starts with a major marine transgression and lies unconformably on a basement of Palaeozoic and Triassic rocks in the north (İstanbul-type basement) and on metamorphic rocks and Jurassic sedimentary rocks in the south (Sakarya-type basement). Four megasequences have been differentiated in the Late Cretaceous-Eocene interval. The first one, of Turonian to Late Campanian age, is represented by volcanic and volcanoclastic rocks in the north along the Black Sea coast, …
The Unaz Formation: A Key Unit In The Western Black Sea Region, N Turkey, Okan Tüysüz, İsmai̇l Ömer Yilmaz, Lilian Svabenicka, Sabri̇ Ki̇ri̇ci̇
The Unaz Formation: A Key Unit In The Western Black Sea Region, N Turkey, Okan Tüysüz, İsmai̇l Ömer Yilmaz, Lilian Svabenicka, Sabri̇ Ki̇ri̇ci̇
Turkish Journal of Earth Sciences
The Pontide magmatic belt in the Western Pontides, which developed in response to the northward subduction of the northern branches of the Tethys Ocean, consists of two different volcanic successions separated by an Upper Santonian pelagic limestone unit, the Unaz Formation. The first period of volcanism and associated sedimentation started during the Middle Turonian and lasted until the Early Santonian under the control of an extensional tectonic regime, which created horst-graben topography along the southern Black Sea region. The lower volcanic succession, the Dereköy Formation, was deposited mainly within these grabens. This extensional period probably represents the rifting of magmatic …
Testing Alternative Tectono-Stratigraphic Interpretations Of The Late Palaeozoic−Early Mesozoic Karakaya Complex In Nw Turkey: Support For An Accretionary Origin Related To Northward Subduction Of Palaeotethys, Alastair Robertson, Ti̇mur Ustaömer
Testing Alternative Tectono-Stratigraphic Interpretations Of The Late Palaeozoic−Early Mesozoic Karakaya Complex In Nw Turkey: Support For An Accretionary Origin Related To Northward Subduction Of Palaeotethys, Alastair Robertson, Ti̇mur Ustaömer
Turkish Journal of Earth Sciences
Lower Carboniferous-Upper Triassic rocks of the Karakaya Complex exposed E-W across Turkey are critical to reconstructions of Palaeotethys in the Eastern Mediterranean region. Despite decades of research, the origin and emplacement of the Karakaya Complex remains controversial because it is mapped either as an overall stratigraphic succession of sedimentary olistostromes or as a stack of thrust sheets and mélange. Tectonic models include a continental rift, a back-arc rift, a marginal oceanic basin, and an accretionary prism formed by subduction of a wide ocean. Subduction is seen as either northwards or southwards. To test the alternatives, the various litho-tectonic units and …
Petrogenesis Of Late Cretaceous Adakitic Magmatism In The İstanbul Zone (Çavuşbaşı Granodiorite, Nw Turkey), Sabah Yilmaz Şahi̇n, Namik Aysal, Yildirim Güngör
Petrogenesis Of Late Cretaceous Adakitic Magmatism In The İstanbul Zone (Çavuşbaşı Granodiorite, Nw Turkey), Sabah Yilmaz Şahi̇n, Namik Aysal, Yildirim Güngör
Turkish Journal of Earth Sciences
The Çavuşbaşı granodiorite intrudes Ordovician sedimentary rocks in the western part of the İstanbul Zone (NW Turkey). The intrusion is made up mainly of granodiorite, and subordinate tonalite and quartz diorite, and has a granular texture and some special mixing textures such as antirapakivi, blade-shaped biotite, acicular apatite, spongy cellular dissolution/melting plagioclase textures. The main mafic minerals are hornblende and biotite. U-Pb in-situ dating of zircons from two samples via SHRIMP yielded weighted age values of ~68 Ma, suggesting emplacement during the Late Cretaceous. Geochemically the Çavuşbaşı granodiorite resembles adakites with high Sr/Y and La/Yb ratios, low Y and HREE …
Neotectonic Evolution Of An Actively Growing Superimposed Basin In Western Anatolia: The Inner Bay Of İzmir, Turkey, Bora Uzel, Hasan Sözbi̇li̇r, Çağlar Özkaymak
Neotectonic Evolution Of An Actively Growing Superimposed Basin In Western Anatolia: The Inner Bay Of İzmir, Turkey, Bora Uzel, Hasan Sözbi̇li̇r, Çağlar Özkaymak
Turkish Journal of Earth Sciences
İzmir Bay is an actively growing shallow marine basin controlled by active faults trending NE, NW, N-S and E-W, in the West Anatolian Extensional Province. The bay of İzmir is a lazy L-shaped superimposed basin which is topographically divided into an E-W-trending inner bay and a NW-trending outer bay. The Inner Bay of İzmir is an asymmetric graben structure approximately 5-7 km wide and 25 km long containing (i) upper Cretaceous-Palaeocene basement, (ii) an older succession of lower to upper Miocene basin fill, overlain with angular unconformity by (iii) a younger Plio-Quaternary basin fill. The older succession contain a 0.5- …
Faulting And Stress Distribution In The Bolu Pull-Apart Basin (North Anatolian Fault Zone, Turkey): The Significance Of New Dates Obtained From The Basin Fill, Ergun Gökten, Ramazan Demi̇rtaş, Volkan Özaksoy, Erdal Herece, Baki̇ Varol, Uğur Temi̇z
Faulting And Stress Distribution In The Bolu Pull-Apart Basin (North Anatolian Fault Zone, Turkey): The Significance Of New Dates Obtained From The Basin Fill, Ergun Gökten, Ramazan Demi̇rtaş, Volkan Özaksoy, Erdal Herece, Baki̇ Varol, Uğur Temi̇z
Turkish Journal of Earth Sciences
The Bolu Basin in northwestern Turkey, situated in the western part of the North Anatolian Fault Zone (NAFZ), displays the neotectonic features of a pull apart basin. The long axis of the basin extends east-west, parallel to the fault zone and Bolu city, situated in the central part of this basin, was extensively damaged during the 17 August 1999 M= 7.4 and 12 November 1999 M= 7.2 earthquakes. The master strand of the North Anatolian Fault Zone cuts through the basin close to its southern edge and movement on this strand has caused tilting of the basin floor towards the …
The North Anatolian Fault On The Hersek Peninsula, Turkey: Its Geometry And Implications For The 1999 İzmit Earthquake Rupture Propagation, Özgür Kozaci, Erhan Altunel, Scott Lindvall, Charles Brankman, William Lettis
The North Anatolian Fault On The Hersek Peninsula, Turkey: Its Geometry And Implications For The 1999 İzmit Earthquake Rupture Propagation, Özgür Kozaci, Erhan Altunel, Scott Lindvall, Charles Brankman, William Lettis
Turkish Journal of Earth Sciences
The western termination of the 1999 İzmit earthquake still remains as an intriguing problem for researchers and the people residing around the Sea of Marmara. There have been numerous offshore mapping and modelling studies performed in the Gulf of İzmit. However, the main debate about the western termination of the 1999 İzmit surface rupture is linked to the Hersek Peninsula and corresponding fault geometry. We focused our efforts at resolving the fault geometry on the Hersek Peninsula by applying geological mapping, geomorphic analyses, palaeoseismic trenching and geophysical surveys. Our studies reveal that the North Anatolian Fault forms a restraining stepover …
Western Termination Of The Mw 7.4, 1999 İzmit Earthquake Rupture: Implications For The Expected Large Earthquake In The Sea Of Marmara, Gülsen Uçarkuş, Zi̇yadi̇n Çakir, Rolando Armijo
Western Termination Of The Mw 7.4, 1999 İzmit Earthquake Rupture: Implications For The Expected Large Earthquake In The Sea Of Marmara, Gülsen Uçarkuş, Zi̇yadi̇n Çakir, Rolando Armijo
Turkish Journal of Earth Sciences
The Mw 7.4, August 17, 1999 İzmit earthquake ruptured a ~100-km-long onshore section of the North Anatolian Fault (NAF) in the eastern Marmara region, causing the loss of more than 20,000 people and extensive destruction. The western termination and total length of the earthquake rupture is still a matter of debate because the surface rupture goes offshore in the Gulf of İzmit after displaying a coseismic displacement of ~5 m. Such a considerable slip implies that the fault rupture must definitely continue some distance westward on the sea floor, but where exactly it terminated is difficult to determine. This issue …
Geochemical And Sr-Nd Isotopic Characteristics Of Post-Collisional Calc-Alkaline Volcanics In The Eastern Pontides (Ne Turkey), Abdullah Kaygusuz, Mehmet Arslan, Wolfgang Siebel, Cüneyt Şen
Geochemical And Sr-Nd Isotopic Characteristics Of Post-Collisional Calc-Alkaline Volcanics In The Eastern Pontides (Ne Turkey), Abdullah Kaygusuz, Mehmet Arslan, Wolfgang Siebel, Cüneyt Şen
Turkish Journal of Earth Sciences
Major, trace element, K-Ar age and Sr-Nd isotopic data are presented for the Eocene Torul volcanics in the eastern Pontide orogenic belt (NE Turkey). The studied rocks are composed of basaltic andesitic, andesitic, trachyandesitic, and minor trachydacitic lavas associated with their pyroclastics. These rocks contain plagioclase (An2-44), hornblende (Mg#= 0.78-0.98), clinopyroxene (Wo43-46 En41-43 Fs10-15), biotite, quartz, and minor sanidine phenocrysts. K-Ar ages on hornblendes ages range from 43.99 (±2.59) to 33.45 (±2.32) Ma, within the Middle to Late Eocene. The volcanic rocks show calc-alkaline affinities and have medium to high K contents. They are enriched in large ion lithophile (LILE) …