On the dose dependency of the bleachable and non-bleachable components of IRSL from K-feldspar: Improved procedures for luminescence dating of Quaternary sediments |
| |
| Institution: | 1. Nordic Laboratory for Luminescence Dating, Department of Geoscience, Aarhus University, Risø Campus, Roskilde, DK, 4000, Denmark;2. Center for Nuclear Technologies, Technical University of Denmark, DTU Risø Campus, Roskilde, DK, 4000, Denmark;3. Institute of Applied Geology, University of Natural Resources and Life Sciences, Peter Jordan-Str. 82, Vienna A, 1190, Austria;1. Department of Science, Systems and Models, Roskilde University, Denmark;2. Nordic Laboratory for Luminescence Dating, Department of Geoscience, Aarhus University, Denmark;3. Center for Nuclear Technologies, Technical University of Denmark, DTU Risø Campus, Denmark;4. Institute for Ancient Near Eastern Archaeology, Free University Berlin, Germany;5. DNRF Centre “Glass and Time,” Department of Science, Systems and Models, Roskilde University, Denmark;1. Institute of Earth Surface Dynamics, University of Lausanne, Geopolis, 1015 Lausanne, Switzerland;2. Department of Earth Sciences, ETH, 8092 Zürich, Switzerland;3. Netherlands Centre for Luminescence dating & Soil Geography and Landscape group, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands;1. Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark;2. Center for Nuclear Technologies, Technical University of Denmark, DTU Risø Campus, Roskilde, Denmark;3. Nordic Laboratory for Luminescence Dating, Department of Geoscience, Aarhus University, Risø Campus, Roskilde, Denmark;1. Department of Chemical and Geological Sciences, University of Cagliari, Cagliari, Italy;2. Nordic Laboratory for Luminescence Dating, Department of Geoscience, University of Aarhus, DTU Risø Campus, Roskilde, Denmark;3. Center for Nuclear Technologies, Technical University of Denmark, Risø Campus, Denmark;4. Institute for Biometeorology, National Research Council of Italy, Sassari, Italy;5. Department of Architecture, Design and Planning, University of Sassari, Sassari, Italy;6. CNR-Institute of Geosciences and Earth Resources, CNR, Via Moruzzi 1, 56124 Pisa, Italy;1. Centre for Archaeological Science, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522, Australia;2. Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China |
| |
| Abstract: | The infrared (IR) stimulated luminescence (IRSL) and post-IR IRSL (pIRIR) signals from K-feldspar can, for convenience, be divided into two components, bleachable and ‘non-bleachable’, where the latter corresponds to the ‘residual’ signal observed in sunlight-bleached samples. In this paper, we examine the non-bleachable component of IRSL of K-feldspar for several sedimentary samples from across Eurasia. We observed a large variability in the residual doses among these samples after prolonged exposure to sunlight. By employing multiple elevated temperature (MET) IR stimulations at 50–300 °C, we show that the residual dose increases systematically with stimulation temperature, attaining values as high as ～50 Gy at 300 °C, even after several hours to tens of hours of exposure to unfiltered sunlight. We examined two samples in detail and found that the bleachable and non-bleachable components produced different dose response curves. Pulse annealing studies showed that the non-bleachable component is more stable than the bleachable component, suggesting that a preheat procedure cannot eliminate the non-bleachable component. Additional experiments revealed that the non-bleachable component is dose dependent. Owing to this dose dependency, we demonstrate mathematically and empirically that the simple subtraction of a residual dose from the measured equivalent dose (De) – which is the most common approach employed (if any residual dose is subtracted at all) – will result in underestimation of the actual De. We present a method to correct for the dose dependency of the residual dose, which can improve the accuracy of either MET-pIRIR or pIRIR age estimates for samples in which the non-bleachable component represents a significant fraction of the measured signals. |
| |
| Keywords: | Potassium feldspar Infrared stimulated luminescence Post-IR IRSL MET-pIRIR Residual dose |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
