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    Geochemical Evidences of Paleoenvironmental Changes in Late Quaternary Lacustrine Sediments of the Konya Closed Basin (Konya, Turkey)
    (Springer International Publishing Ag, 2019) Orhan, Hukmu; Delikan, Arif; Demir, Ahmet; Kapan, Sevinc; Olgun, Kemal; Ozmen, Ayhan; Sayin, Ulku
    Important geochemical evidence reflecting Quaternary climatic changes was obtained by evaluating geochemical data from 51 samples and datings from 3 samples by ESR method from sediments of a 7-m-deep trench in Great Konya lake area at the southwest of Adakale village (Konya, Turkey). The geochemical data indicate that the study area was influenced, four times, by a climate having strong precipitation, which caused strong erosion and high detrital input between 25,276 +/- 1732-year BP and approximately 50,000-year BP. These periods correspond to climatic changes during the last glacial periods, the warm climate of D-O-2, D-O-5, D-O-6 and D-O-14 events and the cold climate of H2, H3, H4 or H5 and H6 events.
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    Paramagnetic characterization of fossil mollusc shells at eastern part of the old Konya lake: its importance for EPR dating
    (Oxford Univ Press, 2023) Ekici, Gamze; Sayin, Ulku; Isik, Mesut; Kapan, Sevinc; Demir, Ahmet; Aydin Karaaslan, Hulya; Delikan, Arif
    Fossil mollusc shells are used for dating geological materials because they are well preserved throughout geological time. In this study, the radicals in the structure of fossil mollusc shells (Dreissena iconica, Valvata piscinalis, Bithynia tentaculate, Unio pictorum) collected from the Eastern Part of Old Konya Lake in Turkiye were investigated by EPR technique. For all fossil shells, microwave and temperature dependence of the signals were examined, and the signals suitable for dating are discussed. Characteristic features of intrinsic and impurity-related radicals were identified and the importance of paleontological evaluation of molluscs to get a reliable equivalent dose in EPR dating studies was emphasised.
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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.