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    Eski Konya Gölü doğu kıyı sedimentlerindeki fosil molluska kavkılarının esr tekniğiyle analizi ve tarihlendirilmesi
    (Selçuk Üniversitesi, 26.06.2018) Ekici, Gamze; Sayın, Ülkü
    Konya Closed Basin is one of the important centers of Turkey in terms of agricultural and industrial productions. Old Konya Lake, located in the Konya Closed Basin, has expanded and narrowed several times due to climatic changes during the Quaternary period and completely dried up about 6 thousand years ago. In the basin, the lacustrine sediments of the Quaternary period are uninterrupted and well preserved. In this thesis study, 4 locations (Adakale, Sazlıkpınar, İsmil, Hotamış Lake) were determined in the eastern part of the Konya Closed Basin in order to illuminate the Quaternary period of the Old Konya Lake and stratigraphic sections were measured from these locations. After sedimentological and paleontological evaluations, lacustrine shells (Dreissena iconica, Valvata piscinalis, Bithynia tentaculate, Unio pictorum), which are observed intensively in these locations, are analyzed and dated in detail by Electron Spin Resonance (ESR) technique. The ESR spectra of natural and irradiated specimens recorded under different spectrometer conditions were examined and the types of paramagnetic centers in the structure of samples were determined and the characteristics of these centers were revealed. Dose response and kinetic studies were carried out to determine the parametric centers' dependence on radiation dose and thermal stability. Paramagnetic centers that are sensitive to radiation and determined to be stable have been used for ESR dating studies. In this study, 24 mollusc shell samples taken from the eastern part of Konya Lake were dated for the first time with ESR technique and the stratigraphically matched ages were obtained. In addition, some samples were dated with 14C and Th/U dating techniques. The ESR ages obtained between 6.3 ± 0.5 and 138 ± 38 thousand years for four locations were used to interpret the paleogeographic and paleoclimatic characteristics of the basin for geological and physical evaluation. This study is supported by TUBITAK project, with the number 114Y237
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    The Importance of Pre-Annealing Treatment for ESR Dating of Mollusc Shells: A Key Study for Ismil in Konya Closed Basin/Turkey
    (AMER INST PHYSICS, 2018) Ekici, Gamze; Sayin, Ulku; Aydin, Hulya; Isik, Mesut; Kapan, Sevinc; Demir, Ahmet; Engin, Birol
    In this study, Electron Spin Resonance (ESR) spectroscopy is used to determine the geological ages of fossil mollusc shells systematically collected from two different geological splitting at Ismil Location (37.72769 degrees N, 33.17781 degrees E) in eastern part of Konya. According to the assessment of obtained ESR ages, the importance of pre-annealing treatment emphasize in the case of g=2.0007 dating signal is overlapped with the other signals arisen from short lived radicals that cause the wrong age calculation. To overcome this problem, the samples are pre-annealed at 180 degrees C for 16 minutes and, in this case ESR ages are recalculated for g=1.9973 dating signal. Dose response curves are obtained using 1.9973 signals after pre-annealing treatments for each samples. ESR ages of samples are obtained in the range of 138 +/- 38 ka and 132 +/- 30 ka (Upper Pleistocene) according to the Early Uranium Uptake model and the results are in good agreement with the estimated ages from stratigraphic and paleontological correlation by geologists. Thus, it is suggested that especially in the case of g=2.0007 dating signal cannot been used due to superimposition case, the signal with 1.9973 g value can be used for dating after pre-annealing treatment. The results reports the first ESR ages on shells collected from Ismil Location and highlight the importance of pre-annealing treatment. This study is supported by TUBITAK 114Y237 research project.