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Yayın Preliminary results towards the equivalence of transformed continuous-wave Optically Stimulated Luminescence (CW-OSL) and linearly-modulated (LM-OSL) signals in quartz(Versita, 2011-09) Kitis, George; Polymeris, George S.; Güneç Kıyak, Nafiye; Pagonis, VasilisThe present paper presents a comparative experimental study of two commonly measured Optically Stimulated Luminescence (OSL) signals in quartz. The experimental study measures both the continuous wave OSL (CW-OSL) and the linearly modulated (LM-OSL) signals from the same quartz sample for a range of stimulation temperatures between 180 and 280A degrees C, while the former is transformed to pseudo LM-OSL (ps LM-OSL). A computerized deconvolution curve analysis of the LM-OSL and ps LM-OSL signals was carried out, and the contributions of several OSL components to the initial OSL signal (0.1 s) were shown to be independent of the stimulation temperature used during the measurement. It was also found that the composite OSL (0.1 s) signal consists mainly of the first two OSL components present in the OSL curves. The equivalence of the ps LM-OSL (transformed CW-OSL) and of LM-OSL measurements was also examined by an appropriate choice of the experimental stimulation times, and of the stimulation power of the blue LEDs used during the measurement.Yayın Luminescence ages of feldspar contaminated quartz from fluvial terrace sediments(Wind-J Wojewoda Publ Co, 2008-01-01) Güneç Kıyak, Nafiye; Erturaç, Mehmet KorhanThis study focuses on obtaining luminescence ages in feldspar contaminated quartz from well-developed fluvial terraces of the Yesilirmak (Iris) river located inside the eastern North Anatolian Fault Shear Zone (NAFZ). We applied a technique based on conventional single-aliquot regenerative-dose (SAR) protocol, modified with an IR pre-treatment to reduce the OSL contribution from feldspar for accurately measuring the dose in quartz. All investigated samples showed an ability to measure a beta dose given in the laboratory, a so called dose recovery test. The dependence of the equivalent dose on thermal treatment was also examined. Dose rate calculations were based on spectral analysis of gamma measurements by a field spectrometer on site. The efforts to establish a chronology using the IR modified SAR technique produced reliable dose results in stratigraphic order. Results were reproducible and grouped broadly between 35-109 ka for Bektemur, 32-36 ka for Kizilca, 19-47 ka for Aksalur and 35-44 ka for Sahinkaya. Obtained results show that the studied area was controlled by tectonic activities within the last 50 ka and the sample Aksalur 2 was the loess deposit formed by aeolian activity.
