Türkiye Jeoloji Bülteni

Abstract: Daday-Devrekani massif consists of metamorphic rocks of the European margin that are progressively sliced with slivers of oceanic crust emplaced prior to Aptian, and with the concurrent Cretaceous flysch. The uppermost slice consists essentially of Paleozoic sediments and Karakaya formation intruded by Early Jurassic granites. These are covered, post-tectonically, by a carbonate-flyschwedge of the back-arc basin, deposited on teh north-facing platform of the Black Sea, in the interval of Late Liassic to Lutetian.The overall solution for the Gondwana-Eurasia convergence frame seems to be constrained with the idea that a thin sliver of continental crust was rifted off the northern Gondwana during the Early Triassic and was progressively accreted to Europe by Early Tertiary.Paleogeographic setting of the Paleotethyan domain with respect to the Pontides seems a very significant point for elucidation of the evolutionary frame. Southward deepening paleomorphology of the Pontides for the Permo-Carboniferous period, restriction of the Karakayaformation (Permo-Triassic) to northern side of the Îzmir-Kars suture in addition to its being adjacent to the suture, suggest presence of anoceanic domain between Anatolids and Pontides for the late Paleozoic and earlier. A carbonate flysch wedge, being restricted to north of the suture and covering, post-tectonic ally, the Karakaya (Akgöl) formation, indicates very clearly that it is related to teh back-arc batin(The Black Sea) and not to the northern strand of Neotethys of Şengör and Yılmaz (1981).The ocean floor between the subduction zone and the edge of the continental crust, must have been retrocharriaged onto the European margin, very likely through the aid of paleo-transform faults. The consumption of the Paleotethys could be realised by a multi-stageand/or progressive recess of the subduction zone. The island arc also retreated accordingly. The old island arc system was up warped due tothe compression of the new system and was covered, post-tectonically, by the sediments of the back-arc basin. The compressive regimealso migrated southwards in accordance with the new island arc system and the elevated flysch provided sediments for the new fore-arc basin. Daday region is probably a good example of a continental margin that shows progressive folding and imbricate slicing of the deformed rocks with flysch sediments deposited concurrently.It may be outlined that the Paleotethyan domain, diving north under Eurasia, was consumed progressively between PermoCarboniferous and Early Tertiary.

Abstract: Istranca Massif consist of deep level granites and high grade gneises (Kırklareli Complex) of Precambrian and Hercynian age; various meta sedimentary rock of platform and pelagic types and meta-volcanic and plutonic rocks of basic affinity (IstrancaMetamorphic Belt) of Triassic-Jurassic age; and shallow level volcno-plutoni complex (Istranca Batholte) of late Cretaceous age.Kırklareli Complex thrusted northeastward over the Istranca Metamorphic Belt which extends in NW-SE direction. Istranca Batholite emplaced in a zone trending direction in the Istranca Metamorphic Belt.Istranca Cimmerian Orogenic Belt extends to the East Thracian-Circum Rhodope Cimmerian belt in the southeast, and to the KüreCimmerian belt in the east. Dobruca, Crimean, Southern Slope Cimmerian Orogenic belt form the northern cast o Black Sea today.Before the opening of the Black Sea basin, Circum Rhodope, Istranca and Küre regions in the south Dobruca, Crimea, SouthernSlope Cimmerian Orogenic belt are involved in a single Cimmerian basin. The Basin was opened as a consequence of the southeast wardmoving of Africa relative to the European platform due to the Atlantic opening. The orogenic belt was developed by the closing of theCimmerian basin during the pre late Jurassic time.Küre, Great Caucasian Southern Slope and Istranca Cimmerian orogenic belts involves massive sulfide deposits which were generated associated with bimodal (basalt-rhyolite) rift volcanism related with the opening of the Cimmerian basin.

Abstract: In the Mut-Ermenek-Silifke basin situated in the central Taurus belt, Palaeozoic and Mesozoic aged units and Tertiarysediments overlying unconformably them crop out.In the basin various organic geochemical features of samples collected from formations with a source rock character have beenstudied. On the basis of these features, petroleum generation potential of the source rocks in the basin have been interpreted

Abstract: Detailed mapping of the Sultandağları Massif between Bağkonak (Yalvaç) and Engilli (Akşehir) villages indicates the followingstratigraphic succesions. The lower epimelamorphics consist of the Lower (?) - Middle Cambrian Çaltepe Formation and Upper Cambrian - LowerOrdovician Sultandede Formation; they are unconformably overlain by the Middle - Upper Devonian Engilli Formation. The Engilli Formationconformably underlies the Lower - Upper Corbaniferous Kirazlı and Harlak Formations and Upper Carboniferous -Upper Permian deresinekFormation. The Triassic (?) Kocakızıl dolerite intruded in the whole autochthonous Paleozoic assemblage. The allochthonous Hoyran ophiolite andthe Upper Jurassic - Upper Cretaceous Hacıalabaz limestone blocks, believed to be a part of the Hoyran Nappe, were tectonically emplaced on to themassif. Alluvial fan and lacustrine sediments of Upper Miocene - Pliocene age, referred to the Bağkonak and Yankkaya Formations, respectively,unconformafbly overlie Pre-Cenozoic units. Later, they were covered by the Recent alluvial deposits.The Lower Paleozoic epimetamorphic core assemblage wes deformed by three phases of folding and gained type-2 and type-3 re- folded-fold sturctures during the Caledonian orgeny. While the Upper Paleozoic metasedimentary envelope of the massif was gaining NW -SE trending mesoscopic tectonit structures, the whole of the Paleozoic units underwent low grade regional metamorphism during the Hercinian orogeny. However, in the Mesozoic - Senozoic development of Taurides, the Alpine movements, which caused the development of;rifting (Triassic), overthrusting, nappe-tectonics (Late Eocene) and block-faulting (Late Miocene), gave the present tectonic appearance of` the Sultandağları Massif.

Abstract: This study is aimed to provide some new information on the stratigraphy, paleontology and structural features ofGürlevik limestone (Arpat, 1964) locating in the area to the southeast of Sivas. In this area, the carbonates era rich in benthic foraminifers of Thanetian such as: Daviesina danteli Smout, Rotalİa trochidlformis Lamarck, Mississippina blnkhorst! Reuss,Pseudolacazİna oeztemuerİ (Sirel). They are thought to be deposited in the shallow-low energy marine environment. It has been determined that Gürlevik limestone shows the lateral transition to Tecer formation (inan ve înan, 1987) according to their paleontogic,stratigraphic and structural charecters. Based on these determinations, it is concluded that both these units should be named as Tecer formation. 

Abstract: In this investigation, biostratigraphica stud has been done in the filysh formation which is cropped out between Orhouye-Memlik villages (NW Ankara) based on Nannoplankton. In this studied area, two stratigraphic sections were measured and seventyumples were collected lithologically by sandstone, sandy siltstone, siltstone, claystone and marl. In the samples, sixty-five Nannoplankton species have been determined and Lithraphidites quadratus Zone has been distinguished. This zone is shown, the Uppermost Middle Maastrichtian and Upper Maastrichtian age. 

Abstract: 1>ıe subject of this research ıs to study the isolated left P4 of Proticlitherium intermedium found within the membre ofDutludere beU>ngmg lo the formation of Bayraktepe (Çanakkale).I*he Protictitherium intermedium is recorded from the coarse grained sandstone, reddish in colour, locally presenting pebbles andwith a thickness of one meter On the other hand, the Bunolistnodon sp., Listnodon splendens, Dorcatherium sp. are also observed within the same level.l"hc age of this specimen is probably the late Astarasian, according to the continental mammifercus stages.

Abstract: The topography of the Atticocycladic massif has previously been assumed to be primarily the result of erosion. However detailed field work has shown that the topography is tectonically controlled and is the reuslt of small dispslip displacements on twosets of high angle faults.In order to account for the juxtaposition of the various rock types in the field, previous workers have invoked the existence ofnappe structures and major unconformities. In this paper the existence of such structures is questioned and it is suggested that these juxtapositions can be accounted for by relatively small movements on high-angle faults. The recognitin of these important fault sets considerable simplifies the structure of the Atticocycladic massif.These faults are widespread and it is thought that a considerable amount of vertical movement is associated with tehm. These important faults are not immediately apparent on the areal photographs because movement on the two sets inhitbits the formation of longlinear fault traces.