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search.filters.applied.f.access: openAccess × Author: Tsukamoto, Sumiko × Has files: Yes × Subject: Late Pleistocene × WGL Institute: LIAG ×

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    K-feldspar pIRIR150 dating of the Late Pleistocene sediments in the NW Khangai Mountains (Mongolia) using a standardized dose-response curve approach
    (Lausanne : Frontiers Media, 2023) Li, Yan; Tsukamoto, Sumiko; Klinge, Michael; Sauer, Daniela; Frechen, Manfred
    K-feldspar luminescence dating has been widely applied to constrain the timing of Quaternary sedimentation in different environments. However, the measurements are time-consuming. Meanwhile, anomalous fading and partial bleaching are the two potential problems inducing dating uncertainty. In this study, sand-size K-feldspar grains extracted from 32 luminescence samples from the northern slope of the Khangai Mountains, Mongolia, were dated using the post-infrared (IR) infrared stimulated luminescence protocol (pIRIR150. subscript shows the second stimulation temperature). The standardized dose-response curves (sDRCs) for luminescence dating, which could improve the measurement efficiency, were constructed. The K-feldspar luminescence chronology has been established after careful investigations of fading correction and bleaching degree of the signals. The sDRCs and individual DRC yield consistent ages, indicating that sDRCs are applicable for luminescence dating with an improvement in measurement efficiency. The fading corrected ages using the two fading correction models are generally in agreement. Based on age comparisons between the radiocarbon dates, the fading corrected pIRIR150 and IR50 ages, the pIRIR150 signal was not fully bleached for several samples. In contrast, some IR50 ages were overestimated due to fading over-correction. The investigated profiles have documented the sedimentary information since the last deglaciation.
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    Luminescence Dating of Fluvial Deposits from the Weser Valley, Germany
    (Warsaw : De Gruyter, 2015) Roskosch, Julia; Tsukamoto, Sumiko; Frechen, Manfred
    Luminescence dating was applied on coarse-grained monomineralic potassium-rich feld-spar and polymineralic fine-grained minerals of five samples derived from fluvial deposits of the Riv-er Weser in northwestern Germany. We used a pulsed infrared stimulated luminescence (IRSL) single aliquot regenerative (SAR) dose protocol with an IR stimulation at 50°C for 400 s (50 μs on-time and 200 μs off-time). In order to obtain a stable luminescence signal, only off-time IRSL signal was rec-orded. Performance tests gave solid results. Anomalous fading was intended to be reduced by using the pulsed IRSL signal measured at 50°C (IR50), but fading correction was in most cases necessary due to moderate fading rates. Fading uncorrected and corrected pulsed IR50 ages revealed two major fluvial aggradation phases during the Late Pleistocene, namely during marine isotope stage (MIS) 5d (100 ± 5 ka) and from late MIS 5b to MIS 4 (77 ± 6 ka to 68 ± 5 ka). The obtained luminescence ages are consistent with previous 230Th/U dating results from underlying interglacial deposits of the same pit, which are correlated with MIS 7c to early MIS 6.