Evidence of extensive carbonate mounds and sublacustrine channels in shallow waters of Lake Van,eastern Turkey,based on high-resolution chirp subbottom profiler and multibeam echosounder data     

Deniz Cukur  Sebastian Krastel  M. Namık Çağatay  Emre Damcı  Aysegül Feray Meydan  Seong-Pil Kim 《Geo-Marine Letters》2015,35(5):329-340

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Significance of the Felsic Sub–Volcanics in Development of Related Au–Ag Deposits at Maden Village (Bolkar Mountain Region), South Turkey: Constraints from Whole–Rock Geochemistry,Geochronology and Pb-S Isotopes     

Sünger  A.  Akyıldız  M.  Nurlu  N. 《Geotectonics》2022,56(3):361-381

Geotectonics - The Horoz granitoid and related felsic sub–volcanics located in the Inner Tauride Belt are key igneous rocks for understanding and investigating the collision and closure...  相似文献   

Impact of climate change on meteorological and hydrological droughts for Upper Coruh Basin,Turkey     

Yılmaz  Muhammet  Alp  Harun  Tosunoğlu  Fatih  Aşıkoğlu  Ömer Levend  Eriş  Ebru 《Natural Hazards》2022,110(2):1039-1060

Natural Hazards - Environmental changes have led to non-stationary flood risks in coastal cities. How to quantitatively characterize the future change trend and effectively adapt is a critical...  相似文献   

A New Natural Secondary Reference Material for Garnet U-Pb Dating by TIMS and LA-ICP-MS     

Namık Aysal  Marcel Guillong  Tamara Bayanova  Mayuko Fukuyama  Nicole Leonard  İsak Yılmaz  Elif Varol  Fatma Şişman Tükel  Yusuf Kaan Kadıoğlu  Nurullah Hanilçi  Fulya Uzun  Ersin Kaygısız 《Geostandards and Geoanalytical Research》2023,47(2):297-310

Gem quality andradite-rich garnet (IUC-1), obtained from the Miocene trachyte dome near Ankara city (Turkey), has been identified as a potential natural secondary reference material for U-Pb dating. In this study, U-Pb dating was performed in five different laboratories using isotope dilution TIMS and laser ablation ICP-MS to determine the homogeneity of euhedral garnet crystals. The U-Pb ID-TIMS data for IUC-1 yielded ²⁰⁷Pb/²³⁵U and ²⁰⁶Pb/²³⁸U ages of 20.9 ± 0.4 and 20.6 ± 0.8 Ma respectively, and these values are consistent with U-Pb LA-ICP-MS analyses, in which different garnet crystals yielded ages of 20.8 ± 0.1, 20.7 ± 0.1, 20.7 ± 0.2 and 20.2 ± 0.1 Ma. An andradite (IUC-2) from the Serçeören wollastonite skarn (Turkey) can be used as a secondary reference material provided detailed imaging of the crystals is undertaken. ID-TIMS data yielded ²⁰⁷Pb/²³⁵U and ²⁰⁶Pb/²³⁸U ages of 20.4 ± 0.4 and 20.9 ± 1.0 Ma respectively, and yielded U-Pb ages on different grains of 20.5 ± 0.1, 20.7 ± 1.0, 20.8 ± 1.7 and 20.9 ± 1.6 Ma. The assigned weighted mean age of IUC-1 (20.4 ± 0.5 Ma, 2s) is proposed as a 2023 reference value. IUC-1 garnet is expected to contribute significantly to rapidly developing garnet geochronology in the near future.  相似文献   

Using tree-ring signals and numerical model to identify the snow avalanche tracks in Kastamonu,Turkey     

Nesibe Köse  Abdurrahim Aydın  Ünal Akkemik  Hüseyin Yurtseven  Tuncay Güner 《Natural Hazards》2010,54(2):435-449

Many parts of our planet are exposed to natural disasters such as snow avalanches, floods and earthquakes. Detailed knowledge on these natural disasters is crucial for human safety. On December 25–26, 1992, two avalanches occurred at Kayaarkası-Kastamonu in northern Turkey. The first avalanche took place at night of 25–26 December and caused no damage. The second avalanche took place at morning of 26 December, killed four people and did damage to properties. The purpose of the present study is to determine the effects of the snow avalanches on tree rings and to investigate the boundaries and velocities of the avalanches using a numerical simulation model and the tree-ring data. Increment cores from 71 trees in the avalanche-impacted area and the control site were sampled to obtain individual standard chronologies. In the analyses, trees were grouped as (1) heavily damaged by the avalanche, showing a decrease in tree-ring widths since the event, (2) trees heavily damaged by the avalanche, showing an increase in tree-ring widths a couple of years later the event and (3) trees that were not damaged by the avalanche. In this study, one of the most important results is the precise determination of the temporal and spatial patterns of the undocumented avalanche (the first avalanche) event. Avalanches were numerically simulated using dynamical avalanche simulation software ELBA+. Comparison of the simulation model with tree-ring analysis revealed valuable results about the boundaries of the zone of influence of the avalanches.  相似文献   

Fossil hunting in the Neolithic: Shells from the Taurus Mountains at Çatalhöyük,Turkey     

Daniella E. Bar‐Yosef Mayer  Burin Ak&#x;m Gümü  Yeim &#x;slamolu 《Geoarchaeology》2010,25(3):375-392

The Neolithic site of Çatalhöyük in Turkey contains thousands of mollusk shells, among them about 200 fossils. About 25 fossil gastropods and bivalvesoriginate in a Miocene fauna from the Mediterranean Tethys province, and are known from several localities in the Taurus Mountains, dating to the Miocene. The rest are scaphopods belonging to two species of Dentalium and dating to the Pliocene. The gastropods and bivalves were likely collected in the Karaman‐Mut Basin at adistance of about 50km from Çatalhöyük, while the scaphopods were brought from the Hatay Basin. Most of the fossil mollusks at the site were discovered in the upper phases, that is, late in the Pre‐Pottery Neolithic B sequence, and are associated with feasting activities. They may have been collected and brought to the site by the inhabitants as part of transhumance activities, or by visitors. © 2010Wiley Periodicals, Inc.  相似文献   

Dating faults by fission track dating of epidotes — an attempt     

M. Bar  Y. Kolodny  Y.K. Bentor 《Earth and Planetary Science Letters》1974,22(2):157-162

An attempt was made to determine the absolute age of faulting by measuring fission track ages of epidotes from mineralization veins along fault and joint planes. The method was applied to epidotes from along faults and fissures in the Sinai Peninsula, which cut Precambrian rocks. Most samples yield Tertiary ages (32-11 m.y.) An Early Cretaceous event is also recorded (120-103 m.y.). Samples from country rocks (igneous and metamorphic) give ages older than 325 m.y. The results are compatible with previous geological information, and suggest that the method can be potentially useful for dating faults.  相似文献   

An analysis of precipitation climatology in Jordan     

Q. Tarawneh  M. Kadıoğlu 《Theoretical and Applied Climatology》2003,74(1-2):123-136

Summary ?One of the most important features in analysing the climatology of any region is to study the precipitation and its periodicity of different harmonics in order to study the behavior of the observed data. In this study the amplitude of frequencies, phase angle and basic statistical parameters are calculated in order to depict spatial characteristics of precipitation over Jordan. Precipitation records of 17 stations were chosen according to climatic regions of Jordan. The first and second harmonic analyses explain more than 90% of the precipitation variation in Jordan effectively. The amplitudes of the first and second harmonic were calculated in order to describe the climatic regions in the country. The maximum amplitudes were found in the northern mountainous region. The phase angle representing the time of maximum rainfall is also used in the form of a contour chart. It is found that Jordan has its main rainfall season in winter with maximum around January. The coefficient of variation shows the high variability of rainfall of the country. Received February 4, 2002; revised August 1, 2002; accepted August 6, 2002  相似文献   

A simultaneous spectroscopic and photometric study of two eclipsing binaries: V566 Oph and V972 Her     

S. O. Selam  E. M. Esmer  H. V. Şenavcı  E. Bahar  O. Yörükoğlu  M. Yılmaz  Ö. Baştürk 《Astrophysics and Space Science》2018,363(2):34

In this study, we have performed simultaneous solutions of light and radial velocity curves of two eclipsing binary systems, V566 Oph and V972 Her. We observed both systems spectroscopically with a very recently installed spectrograph on the 40 cm telescope, T40, located in Ankara University Kreiken Observatory (AUKR), for the first time. We made use of the photometric data from the Hipparcos satellite for V972 Her, while we obtained the photometric observations of V566 Oph by using the 35 cm telescope, T35, located also in our observatory campus. We derived the absolute parameters for both systems and discussed their evolutionary states. In addition to the simultaneous analysis, we have also analyzed the change in mid-eclipse times for V566 Oph, and found cyclic variations, for which we have discussed light-time effect and magnetic activity as their potential origin, superimposed on a secular change due to a mass transfer between the components of the binary.  相似文献   

The influence of a heavily polluted urban river on the adjacent aquifer systems   总被引：2，自引：0，他引：2  

K. Kayabalı  M. Çelik  H. Karatosun  Z. Arıgün  A. Koçbay 《Environmental Geology》1999,38(3):233-243

 Ankara Creek is often subjected to overflowing of sewage caused by rainfall or direct discharge of raw sewage. Alluvial aquifers adjacent to Ankara Creek and its tributaries have considerable groundwater potential. The present status of groundwater quality is far from drinking water standards. Groundwater contamination in Ankara is suspected to be caused by Ankara Creek which is heavily polluted by raw sewage discharge, surface runoff and other common sources. In order to investigate the influence of heavily polluted Ankara Creek on the groundwater contamination in the adjacent alluvial aquifers, five sampling stations on Ankara Creek and 25 water wells were monitored during 1996. At five different sampling periods, water samples were collected from both surface water and groundwater. Chemical analyses of basic ions, pollution parameters and heavy metals in natural waters were carried out. The organic pollution prevails in Ankara Creek whereas total dissolved solids (TDS) and heavy metal concentrations are considerably low. Starting from the idea that Ankara Creek somewhat influences the groundwater quality and the contaminants in groundwater should attenuate with respect to distance, a series of water wells in a certain area, each having different distance from the creek, were examined using four pollution parameters. It is concluded that Ankara Creek barely influences the aquifer systems in connection. This is attributed to two reasons: rapid attenuation of contaminants due to dilution in groundwater and a blanket of very fine sized materials covering the bottom of Ankara Creek. Received: 28. April 1997 · Accepted: 23. February 1998  相似文献