Türkiye Jeoloji Bülteni

Abstract: In this study, we have investigated the geological evolution of Tertiary sedimentary rocks between Bertiz-Süleymanlıand Kılavuzlu region in the north of Kahramanmaraş.The data wich are obtained from studies in north and south of the investigated area, indicate that a divergent regime exist betweenArabian and Taurus plates and which starts at Jurassic and continues in  the Lower Cretaceous time and point out a subduction regime thatbegins with the Valanginian age. It is clear that the continuity of this subduction of the Arabian plate moves toward the north untill theMaastrihtian. There are different opinions related with the geological evolution beginning with the Maastrichtian to the Miocene period.However, since the Miocene epoch a peripheral basin has been developed in the region. The sediments which have accumulated in thisperipheral basin that developed between Arabian plate and Taurus platform show different sequential arrangements in the northern andthe southern of the basin. The change of stratigraphic position and depositional environments in space and time point out at least sevencompression / thurust movements since the Upper Cretaceous epoch in the region.

Abstract: The Eastern Pontian arc developed on the sialic basement represents magmatic provences variable in time and spaceduring the Mesozoic and Cenozoic epochs.In the Eastern Black Sea coast tholeiitic volcanism which began in the Lias, turns in tholeiitic/calc-alkaline volcanism in the UpperCretaceous; calc-alkaline volcanism in the Eocene, and alkaline volcanism in the Neogene to make complete successive island arc magmaseries in time.On the other hand, in the contemporaneous volcanic rocks, increasing of K content toward south, cause spatial changes in the arcmagmatism. The Malm-Lower Cretaceous rapid subsidence events in the inter arc/back-arc rift basins which are formed in the Lias, are characterizedby passing from the platform carbonate facies to the olistostromal turbiditic deep marine facies.In the back-arc basins to the south, Bayburt, Kelkit, Amasya regions, this epoch mentioned above, corresponds to the time of theformation of the ophiolitic olistostromal melange.Basaltic rocks, which constitute ophiolitic melange have within plate and mid ocean ridge/island arc affinities (poligenetic ophioliteconcept).This melange is in turn overlain by the high K calc-alkaline andesite with pyroclast and the Upper Cretaceous rudist-bearing limestonesin the Bayburt, Maden area.In the Everek Hanları district these Upper Cretaceous limestones are accompained with a formation with couldn`t be exactly definedgeologically by now and were mapped as ophiolitic series with tectonic contact, and so this caused contradictory interpretations. Duringour field study we observed that the formation mentioned above is rested unconformably on the erosional surface of the Upper Cretaceouslimestones and comprise the low TİO2 leucite-bearing alkaline basalts intercalated with the continental red colour cross bedding detritusand is overlain by the Paleogene turbidites with the basement conglomerates.This formation defined geologically was called Everek Hanları Formation.The calc-alkaline and low TiO2 alkaline volcanism (shoshonitic) which cover the ophiolitic melange with sedimentary origin are strongevidence to imply that this melange formed in the back-arc geotectonic environment. We have similar geologic observation in Amasya.Manifestation of this leucite-bearing volcanism which of approximately 60 m.y. of age, in the northern part of the Eastern Pontian arcalong the Black Sea coast in the Neogene, imply that the high K volcanism regressed together with the arc magmatism toward thetrench during the Cenozoic time just as known in the Nortwestern America.On the other hand, contemporaneous magmatism and subsidence events are suggestive that mantle uprising had the main role inthese concept in the Eastern Pontian arc/back-arc geotectonic environments.

Abstract: This investigation held in Ödemiş submassive has pointed out once more that the leptites have to be included in the general sequence of the Menderes Massive. These originally volcanic rocks which have the thickness ranging from 20-25 meters to a few kilometers are formed a guide horizon between schist and gneiss. Hard, unoriented and violet colored leptites contain pyroxene-rich old basic vein rocks.The studies of chemical analyses show that the original rocks of leptite are in the composition rhyolite-dasite, dominant calcalkaline generation, sialic in origine and metamörphic equivalent of island arc volcanites. 

Abstract: Pyroclastics exposed in the northern and northeastern parts of Çiftehan, present a complex structure together with alteratedbasaltic and andesitic volcanics. Pyroclastics were generally formed as tuff, agglomerate and volcanic breccia and intersected by trachyteand basaltic dikes extending in the east-west direction.According to their mineralogical composition, the volcanics wich are generally spilitized are of calkalkaline character. Their regionalsetting and major and some trace element constituahts show that the volcanics could be produced from a maturated island arc volcanism.

Abstract: Çavdar-Demirtepe iron ore body is situated 26 km. Southheast of Söke-Aydın. It is the most important iron ore body in theMenderes massif.Lithological formations of the basement are para origin in the investigated area. Original sedimentary rocks were sandstones, mudstone,and argillaceous sandstones. Schists and gneisses were formed by metamorphoses of these rock units.In all rock formations mineralizations (disseminated, highly disseminated and massive kinds) were formed under similar conditions.

Abstract: The seismic data elucidated especially the Upper Miocene and Plio-Quatemary units in detail. However, the deep seismicinformation is not so clear because of acoustic masking of the evaporitic high velocity layers.In the both Antalya and Mersin Basins the evaporitic units, which are seen locally in the shape of diapiric features, are marked by theboundary of the non-evaporitic units where laterally change occurs.The seismic data suggest that the Antalya and Mersin Basins are controled technically by the vertical movements. Especially, thesubsidence has played a main role and, novadays, that is still active.Several opinions have been proposed by the authors, concerning the evolution of those basins. In general, the region doesn`t fit in withan ideal plate tectonic`s model, so the opinions remain controversial. 

Abstract: Up to now the various evolution models have been put forward for the Western Anatolia from the interpretations of geological, sesismological and remote sensing data. Here, a new probable model was proposed from the results of the data analysis and theoretical model studies over the Bouguer gravity data where the older models were examined too.The faulting mechanisms for the Western Anatolia were obtained to be belong to the faults of having vertical and strike-slip componentes of a region of typical tensional tectonics as being determined from teh earthguake focal mechanism solutions. After the dataanalysis processe, the gravity data show a general increase in values from east to west where this is indicative of upper matle uplift towards the Aegean Sea and the crust is being 30 km thick on average unden the Aegean Sea while it reahes about 35-40 km determinedfrom the power spectrum evaluations have been thought to have connections with the magmatic intrusions and this proposal has beensupported with the magnetic data. The region which hs manya geophysical signatures belongs to the typical tensional continental areas,shows resemblances with the Basin and Range region of North America of having similar characteristics.When all the available data being interpreted together, a probable evolution model of the Western Anatolia would be assumed tobe progressed according to the N-S tensional tectonics. According to the above evolution model, the grabens of Gediz and B Mendereswere thought to be formed ak E-W trending continental rift systems

Abstract: In this paper, Caprinids from the Cenomanian limestones of the Westren Taurus, have been determined for the first timein Turkey. 12 left valve sections of Caprina schiosensis species, have simple, oval-shaped canals in the palial canal area. These canalsare narrow in posterior part, but large in anterior part. The dorsal part and cardinal area of 4 right valve sections of Neocaprina sp., havenot been preserved. The anterior accessory canals are large, rectangular ; the posterior accessory canals are small, oval or rectangular. Theanterior shell wall is without canals. Ventral caren is present. 2 valve sections of Ichthyosarcolites sp. are triangular in shape, carenshave not been developed. 

Abstract: In this research, the. remain of right mandibular fragment with M2, M3 in, situ of Hippopotamus which was found atReşadiye are investigated. As a result .of this research» it is. justified, that this teeth belonge to Hippopotamus, amphibius. LINNAEUS ofPliyo-Pleistocene age.