Book of Abstracts - DLED2025 Heidelberg, Germany

Book of Abstracts DLED 2025 14-16 November 2025 Heidelberg, Germany     Book of Abstracts DLED 2025, Heidelberg, Germany 14-16 November 2025 The authors of the abstracts assume full responsibility for the information provided herein. However, mistakes can happen, and they come without any guarantee. Photos: Sebastian Kreutzer, Sylvia Knörr, 2025 DLED Logo Design: Volker Schniepp, 2025 Publisher: Institute of Geography, Heidelberg University, Germany via zenodo.org DOI: https://doi.org/10.5281/zenodo.17840763 Copyright: This document is distributed under CC BY-NC 4.0 licence conditions. However, the DLED logo and the photos are not covered by this licence, and any further distribution beyond this document requires written consent from the copyright holders. This includes, but is not exclusive to, modification and usage as training data. [Heidelberg, Germany, Monday, 15 December 2025] Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 2 of 51 Back to the roots – 30th anniversary of the German Luminescence and ESR conference in Heidelberg Under the motto “Back to the roots”, the German Luminescence and ESR dating (Deutsche Lumineszenzund ESR Datierung – DLED) community met 14th–16th November 2025 in Heidelberg – the place where, after the fall of the Berlin wall and the opening of the Inner German border, the Freiberg and the Heidelberg luminescence laboratories first met informally to discuss recent developments of the radiometric dating techniques. Afterwards, the meeting became officially established as an annual conference that is meanwhile regularly attended by researchers not only from Germany, but also from Austria, Switzerland and Poland. This year, our meeting started with a pre-conference R workshop on November 13th, 2025, at the Institute of Geography, Heidelberg University, given by Thomas Kolb and Dirk Mittelstraß, which was well attended, especially by young researchers. The following two days, we were guests in the building of the Heidelberg Academy of Sciences at the foot of the romantic Heidelberg castle ruin. We welcomed more than 45 participants, including a few ALUMNis (Abstinent Luminescence Nerds), and enjoyed 16 oral and 16 poster contributions showing the dynamic evolution of the radiometric dating techniques, and hands-on sessions on sample preparation, environmental gamma dose rate measurements with a novel cadmium zinc telluride (CZT) detector, and portable OSL profiling like in the Nebraska Sand Hills. Frank Preusser contributed a special talk on the upper age limit of MET IRSL SAR dating on feldspar, and Ashok Singhvi, via video, reviewed 45 years of progress in luminescence dating, both adding to the overall success of the meeting. The final session focused on possible future activities like recruiting young researchers and incorporating AI in the data analysis generated by the radiometric dating techniques. The traditional DLED hiking led us on a misty Sunday morning from the Academy building up to the castle ruin and further up the Neckar Valley to Neckargemünd, from where a visit to the famous find site of the Homo heidelbergensis at Mauer was organized. There, Sebastian Kreutzer addressed the early days of radiofluorescence dating by Matthias Krbetchek and Günther A. Wagner, and its importance for the chronological placement of the prehistoric jaw. At the find site and in the Prehistoric Museum in the town hall of Mauer, Ms Sylvia Knörr gave an instructive guided tour before the participants came together for a final outdoor farewell sausage. Photo: Sebastian Kreutzer, 2025 Photo: Sylvia Knörr, 2025 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 3 of 51 Thanks to financial support from Freiberg Instruments, Risø DTU, and µDose, the conference fees could be kept low, especially for junior scientists, while providing good food throughout the meeting. We thank all participants for contributing to a successful meeting! See you next year in Tübingen, Jutta Asmuth, Marco Colombo, Sebastian Kreutzer, Annette Kadereit Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 4 of 51 Table of contents [T1] Advancing terrestrial surface air temperature reconstruction using feldspar thermoluminescence palaeothermometry ............................................................................................ 6 [T2] Climatic and anthropogenic drivers of Holocene Black Soil redistribution in North-eastern China 7 [T3] Can we progress pIR-IRSL SAR and MET-IRSL SAR by progressively elevating the temperature? ...................................................................................................................................... 9 [T4] How old are the Nazca Lines? .............................................................................................. 11 [T5] Signal-Depth Profiling of Rock Surfaces with a reader-mounted EMCCD Camera: a Tool for Tracking Clast Movement and Understanding Geomorphic Processes? ........................................... 12 [T6] Insights from luminescence dating for unravelling the sedimentation context of the shaman site from Bad Dürremberg ............................................................................................................... 14 [T7] OSL-thermochronology Reveals Rapid Exhumation at Icy Point, Alaska ........................... 16 [T8] Improving the estimation of high natural luminescence doses using OTOR solutions ......... 17 [T9] Biases in minimum dose estimates of modern samples ......................................................... 18 [T10] Progress Towards Reproducible Luminescence Data Analysis: The REPLAY Project ........ 19 [T11] Uncertainty assessment in retrospective physical dosimetry ................................................ 21 [T12] Where is the upper dating limit of MET post-IR IRSL in the Alpine Foreland and the Upper Rhine Graben? ................................................................................................................................. 22 [T13] Reminiscing five decades of cohabitation with luminescence dating .................................... 23 [T14] Assessing the stability of Infrared Photoluminescence signals .............................................. 25 [T15] Determining the geochemical composition of single grains using µ-XRF ............................. 26 [T16] Environmental gamma dose rate measurements using cadmium zinc telluride (CZT) detectors 27 [P1] Revisiting ESR dating of zircons .......................................................................... 28 [P2] Assessment of Quartz OSL Signal Characteristics in Central Iran’s Aeolian Sediments: Implications for dating .................................................................................. 30 [P3] A high-resolution chronology based on OSL dating and Bayesian Modelling of alluvial deposits from Upper Franconia (Bavaria, Germany) .......................................... 31 [P4] The ARENICOLA project: Radiofluorescence images digested by digital sandworms 32 [P5] Multi-methodological age dating of clay exploitation in the Lateglacial channel of the Bergstraßenneckar between Viernheim and Mannheim (southwest Germany) .......... 33 [P6] Are the star dunes of modern ages in Erg Chebbi, South-East Morocco? ............ 35 [P7] OSL rock surface burial dating of megalith structures in the Dzhungar Mountains - Kazakhstan .................................................................................................................... 36 [P8] Towards standardized determination and normalization of saturation plateaus in Luminescence Rock Surface Dating ................................................................................. 37 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 5 of 51 [P9] Sensitivity-Weighted Signal Dominance in Fine-Grain Quartz: A Hypothesis on Apparent Bleaching Efficiency ......................................................................................... 38 [P10] Analysis of natural radioactivity distribution in aeolian sediment quartz grains and its impact on dose rate in OSL dating ............................................................................. 39 [P11] Evaluation of α, β, and γ Environmental Dose Rate Measurement Precision in 200 mg Samples Using the µDOSE+ System ......................................................................... 41 [P12] Chronostratigraphy of Pleistocene terraces of the middle Neckar using Luminescence dating ........................................................................................................ 43 [P13] Applicability of pOSL age estimates for the reconstruction of hydroclimate change based on shoreline dunes in sub-humid to semi-arid south-east Australia ....................... 44 [P14] The Middle Würmian marker horizon at Baix and Collias (Rhône Rift Valley, France) – is it coeval with the Gräselberg Soil in Germany? .......................................... 47 [P15] Luminescence dating of offshore and onshore tsunami deposits from the Shetland Islands (UK) .................................................................................................................... 49 [P16] Machine Learning-Based Classification of Single Quartz Grains for Luminescence Dating 51 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 6 of 51 [T1] Advancing terrestrial surface air temperature reconstruction using feldspar thermoluminescence palaeothermometry Salome Oehler1,*, Pontien Niyonzima1, Georgina E. King1, Rabiul H. Biswas2, Frédéric Herman2, Rosemary Nalwanga3, Maxime Bernard1, Christoph Schmidt1 1University of Lausanne, Institute of Earth Surface Dynamics, Lausanne, Switzerland 2Indian Institute of Technology Kanpur, Department of Earth Sciences, Kanpur, India 3Makerere University, College of Natural Sciences, Department of Zoology, Entomology and Fisheries Sciences, Kampala, Uganda *Corresponding author: [Salome Oehler: [email protected]] In recent years, a new tool for terrestrial surface air temperature reconstruction (< 30 °C) has been proposed, exploiting the sensitivity of low-temperature thermoluminescence (TL) signals of feldspar (200–300 °C) to terrestrial temperature fluctuations over geological timescales [1]. Palaeotemperatures can be inferred by projecting the trapped charge population of these feldspars back in time through modelling the trapped charge response to fluctuating temperatures. This involves adaptation of various time-resolved relative temperature records, such as Greenland ice sheet δ18O data, speleothem-, or pollen records as priors to the model. The routine application of TL palaeothermometry is hindered by the lack of routine measurement procedures, specifically for estimating the kinetics of growth, and sufficient method validation. This contribution thus presents our attempt to establish a robust measurement protocol for growth kinetics of Kand Na-feldspar by assessing the reliability of different single and multiple aliquot protocols. We further present the current state of validation using samples of known thermal history from the KTB and MIZ-1 boreholes and show first results of surface air temperature reconstructions at several northern hemispheric study sites. We ultimately aim to improve our understanding of the last glacial maximum climate and climate sensitivity by assessing terrestrial temperatures reconstructed for two altitudinal and one latitudinal transect across the Euro-African northern hemisphere. Keywords: thermoluminescence, temperature sensing, palaeothermometry, last glacial maximum, climate sensitivity References [1] Biswas, R.H., Herman, F., King, G.E., Lehmann, B., Singhvi, A.K., 2020. Surface Paleothermometry using low-temperature thermoluminescence of feldspar. Clim. Past 16, 2075–2093. https://doi.org/10.5194/cp-16-2075-2020 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 7 of 51 [T2] Climatic and anthropogenic drivers of Holocene Black Soil redistribution in North-eastern China Xumin Pan1, 2, 4, *, Marijn van der Meij2, Tony Reimann2, Fei Yang3, 4, Hao Long1, 4, Ganlin Zhang1, 3, 4, * 1Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, China 2Institute of Geography, University of Cologne, Germany 3Institute of Soil Science, Chinese Academy of Sciences, China 4University of Chinese Academy of Sciences, China *Corresponding author: [Xumin Pan: [email protected]-koeln.de; Ganlin Zhang: [email protected]] Fertile black soils in northeastern China have undergone severe degradation from agricultureinduced erosion [1], despite cultivation beginning only ca 130 years ago [2], providing a unique setting to separate humanfrom climate-driven erosion. However, disentangling and quantifying the relative intensities of anthropogenic versus climatic drivers remains challenging due to overlapping signals in colluvial soil archives. We investigated the singlegrain post-infrared infrared stimulated luminescence (pIRIR) signal of feldspars from 19 samples from three profiles along a hillslope catena and compared them with other soil properties and geochronometers to trace soil redistribution and reconstruct Holocene erosion phases. Erosion intensity was highest on the backslope and decreased at the summit. Upslope truncation supplied colluvial deposits and enhancing the burial of organic carbon at the toeslope. Apparent luminescence ages reveal upslope profiles thinning toward parent material. The active mixing zones (at 20 cm) was dated to ca 3 ka (summit) and 15 ka (backslope). A depth–age inversion at 60 cm in the toeslope profile indicates a rapid increase in erosion beginning after 1250 and 1780 CE (±2σ) and continuing to the present, coinciding with the onset of regional agricultural activity. The deeper colluvium (60–180 cm) records earlier sedimentation, likely driven by natural soil creep. Compared with the natural depositional rates (0.10–0.13 m ka-1), the modern anthropogenic rates (3.4-5.0 m ka-1) are approximately 26-50 times higher, underscoring the dominant role of human activity in soil redistribution during the Holocene. Keywords: Black soils, luminescence, feldspar, soil erosion, Cs-137, soil organic carbon References [1] Wen, Y., Kasielke, T., Li, H., Zepp, H., Zhang, B., 2021. A case‐study on history and rates of gully erosion in Northeast China. Land Degrad. Dev. 32, 4254–4266. https://doi.org/10.1002/ldr.4031 [2] Liu, X., Lee Burras, C., Kravchenko, Y.S., Duran, A., Huffman, T., Morras, H., Studdert, G., Zhang, X., Cruse, R.M., Yuan, X., 2012. Overview of Mollisols in the world: Distribution, land use and management. Can. J. Soil Sci. 92, 383–402. https://doi.org/10.4141/cjss2010-058 Acknowledgement We thank Assoc. Prof. Jingran Zhang for providing the environmental dose rate report. We are grateful to Yibei Chen for soil description and 137Cs measurements, and to Xiangqi Kong Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 8 of 51 for 137Cs measurements. Special thanks go to Yue Huang, Yunpeng Hong, and Lili Liu for their help with sample preparations. We also thank Guanglong Liang and Dr. Aimin Zhang for their assistance in the field. Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 15 of 51 [3] Landesmuseum für Vorgeschichte. (n.d.). Die ›Schamanin‹ von Bad Dürrenberg. https://www.landesmuseum-vorgeschichte.de/dauerausstellung/menschenwechsel/die-schamanin-von-badduerrenberg; last access: 2025-11-27. [4] Murray, A. S., & Wintle, A. G. (2000). Luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol. Radiation Measurements, 32(1), 57–73. https://doi.org/10.1016/S1350-4487(99)00253-X Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 16 of 51 [T7] OSL-thermochronology Reveals Rapid Exhumation at Icy Point, Alaska Yicheng Pu1, Jintang Qin1,*, Jie Chen1, Gongming Yin1, Richard O. Lease2 1State Key Laboratory of Earthquake Dynamics and Forecasting, Institute of Geology, China Earthquake Administration, Beijing, China 2U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska 99508, USA *Corresponding author: [Jintang Qin: [email protected]] The coupled influence of tectonic activity and climate forcing on landscape evolution represents a frontier in geodynamic research. The Icy Point region in southeastern Alaska is an ideal site for studying this problem, where geomorphic development is controlled by the Fairweather strike-slip fault system – a structure that accommodates interactions between the Yakutat, Pacific, and North American plates. This fault exhibits a unique geometry in the study area: it transitions northwards along-strike from pure strike-slip to a transpressional regime dominated by contraction. This transition results in a ca 2 km rightstep restraining double bend, extending over 30 km with an interlimb angle of less than 25°. Previous apatite (U-Th)/He studies revealed extremely rapid exhumation rates of 5-10 km Myr-1 since ca 0.8 Ma, interpreted as a consequence of tectonically driven regional rock uplift. To quantitatively deconvolve the relative contributions of tectonic uplift and climatically modulated erosion, this study employs OSL-thermochronology on siltstone samples from the Icy Point region. Leveraging its enhanced sensitivity to lower temperatures, this approach provides new insights into exhumation events within the upper ca 2 km of the crust over the last ca 300,000 years. Keywords: OSL-thermochronology, Icy Point at Alaska, Tectonic-climate interactions Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 17 of 51 [T8] Improving the estimation of high natural luminescence doses using OTOR solutions Barbara Mauz1,*, Sebastian Kreutzer2, John L. Lawless3 1Paris Lodron University of Salzburg, Salzburg, Austria 2Institute of Geography, Heidelberg University, Heidelberg, Germany 3Department of Redwood Scientific, Pacifica, CA, USA *Corresponding author: [Barbara Mauz: [email protected]] While highly desired, it remains a challenge to determine high natural doses. The challenge is to project a natural dose close to saturation to a dose-response curve generated with high laboratory doses. The single saturating exponential (SSE) function mostly delivers poor fits to this type of dose response. In order to understand the poor fit and associated De underestimation, we employ analytical expressions derived from the OTOR model (one trap one recombination centre [1]) and from the OTORX model (extended OTOR [2]). We compare OTOR and SSE fits for high-dose quartz and feldspar samples and use a theoretical approach to explain the results. Our explanations focus on the physically meaningful constants [3] obtained from the OTOR fit functions, i.e., the characteristic saturation dose D63% and the retrapping ratio R. Well-bleached fine-grained polymineral and monomineral feldspar and quartz samples irradiated up to ca 5000 Gy were used and measured using the pIRIR225 and OSL-SAR protocols. We show that the widely reported De underestimation of high natural doses is an inherent bias of the SSE. Furthermore, we show that an exponential saturating dose-response curve must be constructed to accurately determine the values of the fit parameters. Using such long DRCs, we find R values that are specific for feldspar and quartz, and this, in turn, explains the inability of the SSE function to describe the dose response close to saturation. References [1] Pagonis, V., Kitis, G., Chen, R., Sep 2020. A new analytical equation for the dose response of dosimetric materials, based on the Lambert W function. J. Lumin. 225, 117333 https://doi.org/10.1016/j.jlumin.2020.117333 [2] Lawless, J. L., Timar-Gabor, A., 2024. A new analytical model to fit both fine and coarse-grained quartz luminescence dose response curves. Rad. Meas. 170, 107045 https://doi.org/10.1016/j.radmeas.2023.107045 [3] Kitis, G., Polymeris, G.S., Peng, J., 2025. Determining equivalent dose for optically stimulated luminescence (OSL) dating with physically meaningful dose response curves. Quat Geochron. 88, 101671 https://doi.org/10.1016/j.quageo.2025.101671 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 18 of 51 [T9] Biases in minimum dose estimates of modern samples W. Marijn van der Meij1,2*, Gerard B.M. Heuvelink2 1Institute of Geography, University of Cologne, Germany 2Soil Geography and Landscape group, Wageningen University and Research, Netherlands *Corresponding author: [Marijn van der Meij: [email protected]] Luminescence dating determines the time since soil or sediment grains were last exposed to daylight. In samples where not all grains have been sufficiently exposed during their last transport, the luminescence dose distributions often contain two components: a younger component reflecting the moment of most recent exposure and an older component representing inherited doses from earlier exposures. The Minimum Age Model [1] or Minimum Dose Model (MDM) is widely used to estimate the parameters describing the dose distributions of these partly bleached samples and derive a representative burial dose. Despite its common use, many users are unfamiliar with the statistical background of the MDM, which is essential for recognizing its limitations. One of these limitations arises when the MDM is applied to modern samples that can contain near-zero or even negative doses. In these cases, the usual log-transformation of the data cannot be performed, and the MDM is instead applied to the measurements and their errors in their natural units (Gy) [2]. In natural units, measurement uncertainty generally increases with dose. This proportional error gives higher doses a wider range of potential values, making it difficult for the unlogged MDM to determine whether a grain belongs to the younger or the older component. In this presentation, we will first explain the statistical basis of the MDM. Then, we will show how applying the unlogged MDM can result in a systematic bias in parameter estimation, leading to an overestimation of the palaeodose of partly bleached modern samples. Keywords: OSL, age modelling, MAM, bias References [1] Galbraith, RF, Roberts, RG, Laslett, GM, Yoshida, H, and Olley, JM, 1999. Optical dating of single and multiple grains of quartz from Jinmium rock shelter, northern Australia: part I, experimental design and statistical models, Archaeometry, 41, 339–364, https://doi.org/10.1111/j.1475-4754.1999.tb00987.x [2] Arnold, LJ, Roberts, RG, Galbraith, RF, and DeLong, SB, 2009. A revised burial dose estimation procedure for optical dating of young and modern-age sediments, Quaternary Geochronology, 4, 306–325, https://doi.org/10.1016/j.quageo.2009.02.017 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 19 of 51 [T10] Progress Towards Reproducible Luminescence Data Analysis: The REPLAY Project Marco Colombo1,*, Sebastian Kreutzer1, Konrad Tudyka2,8, Svenja Riedesel3, Margret C. Fuchs4, Michael Dietze5, Loïc Martin6, Christoph Schmidt7, Thomas Kolb8 1Institute of Geography, Heidelberg University, Heidelberg, Germany 2Institute of Physics, Silesian University of Technology, Poland 3Institute of Geography, University of Cologne, Cologne, Germany 4Helmholtz Institute Freiberg for Resource Technology, Helmholtz-Zentrum Dresden-Rossendorf, Freiberg, Germany 5Division of Earth Sciences and Geography, RWTH Aachen, Aachen, Germany 6Innsbruck Quaternary Research Group, University of Innsbruck, Innsbruck, Austria 7Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland 8Department of Geography, Justus-Liebig-University Giessen, Giessen, Germany *Corresponding author: [Marco Colombo: [email protected]] Accessible and transparent software tools for luminescence data analysis are undoubtedly beneficial to the reproducibility and reliability of dating results. As discipline boundaries are extended through the application of machine-learning-driven approaches on increasingly larger datasets, access to user-friendly discipline-specific software tools is paramount. Within the luminescence dating community, several applications and scripts have evolved predominantly within the ecosystem of the statistical programming environment R. One such application is the R package ‘Luminescence’ [1]. Established 13 years ago, and with now 24 developers, it has demonstrated some success in fostering a community-driven, reproducible, and open research software framework through a bottom-up approach. However, open-access R code does not automatically guarantee transparency and reproducibility. Additionally, R scripts can be challenging, especially for newcomers, and even large language models can only generate code with meaningful context if the training data is high-quality and complete. Within the software project REPLAY, we have made a new push towards usability and considerably intensified our efforts to enhance the userfriendliness and robustness of luminescence data analysis with R. As a first step, throughout the past year, we have fully implemented the FAIR principles (Findability, Accessibility, Interoperability, and Reusability) for research software, improved the stability and code quality of ‘Luminescence’, and initiated the refactoring of ‘RLumShiny’ [2] as its graphical user interface. Our presentation will spotlight key milestones and implemented quality measures (e.g., automated testing, snapshots, usability measures). While the underlying technical aspects are indeed intriguing, the primary focus will be on reproducibility aspects, user-visible modifications, and practical benefits for everyday work in the trapped-charge dating community. Keywords: data analysis, R, reproducibility, software, luminescence Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 20 of 51 References [1] Kreutzer, S., Burow, C., Dietze, M., Fuchs, M.C., Schmidt, C., Fischer, M., Friedrich, J., Mercier, N., Philippe, A., Riedesel, S., Autzen, M., Mittelstrass, D., Gray, H.J., Galharret, J.-M., Colombo, M., Steinbuch, L., de Boer, A.-M., 2025. Luminescence: Comprehensive luminescence dating data analysis. v1.1.1. https://doi.org/10.32614/CRAN.package.Luminescence [2] Burow, C., Wolpert, U.T., Kreutzer, S., Colombo, M., 2025. RLumShiny: “Shiny” applications for the R package “Luminescence.” v0.2.5. https://doi.org/10.32614/CRAN.package.RlumShiny Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 21 of 51 [T11] Uncertainty assessment in retrospective physical dosimetry Clemens Woda*, Vladislava Fokina Federal Office for Radiation Protection (BfS), Neuherberg, Germany *Corresponding author: [Clemens Woda: [email protected]] Uncertainty assessment, whether in luminescence dating or in retrospective dosimetry using luminescence methods, is a key element for quantitative dose measurement. In retrospective physical dosimetry, personal items such as chip cards, smartphones, and low-cost electronic gadgets can be used as fortuitous dosimeters to estimate the individual radiation exposure following a radiological accident, nuclear emergency, or malevolent use of ionizing radiation [1]. Several European laboratories active in this kind of research are organized in EURADOS (European Radiation Dosimetry Group) and RENEB (Running the European Network in Biological and Retrospective Physical Dosimetry) to be able to respond to a mass-casualty radiological incident in Europe. Within the Working Group on retrospective dosimetry in EURADOS, a current activity is the harmonization of uncertainty assessment and determination of detection limits across all methods, biological or physical. This presentation will give an overview of the uncertainty budget of a TL/OSL dose measurement of ceramic substrates of electronic components in personal items, with an emphasis on the methodology currently used at BfS, but which is open for a critical review. Starting from the “classical” uncertainty assessment of a single OSL measurement [2, 3], the uncertainty is then propagated through the measurement of a calibration curve and finally by correcting for (anomalous) fading. Next to the classical error propagation, Monte Carlo methods are also used, as well as practical approaches to consider larger-than-expected scatter of data points around the calibration curve. An outlook on the possible use of Bayesian methods within the Working Group is also given. Keywords: TL/OSL, Uncertainty assessment, retrospective dosimetry, fading References [1] Fattibene, Paola et al., 2023. Reflections on the future developments of research in retrospective physical dosimetry, Physics Open, 14. 100132. https://doi.org/10.1016/j.physo.2022.100132 [2] Galbraith R., 2014. A further note on the variance of a background-corrected OSL count. Ancient TL 32 (1), 1-4. https://doi.org/10.26034/la.atl.2014.477 [3] Li, B. 2007. A note on estimating the error when subtracting background counts from weak OSL signals. Ancient TL, 25, 9–14. https://doi.org/10.26034/la.atl.2007.402 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 22 of 51 [T12] Where is the upper dating limit of MET post-IR IRSL in the Alpine Foreland and the Upper Rhine Graben? Frank Preusser Sedimentary Geology and Quaternary Research, University of Freiburg, Albertstr. 23b, 79104 Freiburg, Germany *Corresponding author: [Frank Preusser: [email protected]-freiburg.de] The upper limit of feldspar luminescence dating has been an issue of long debate. It is in principle determined by four factors: 1) signal saturation level, 2) thermal signal stability (lifetime), 3) non-thermal signal stability (anomalous fading), and 4) dose rate. While it has been shown that the thermal signal stability would presumably allow dating back to some million years, determining signal saturation level and the rate of anomalous fading is not straightforward. Presented and discussed here is the experience of dating samples with ages >>100 ka from the Upper Rhine Graben (and elsewhere), in particular when compared to independent age estimates. Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 23 of 51 [T13] Reminiscing five decades of cohabitation with luminescence dating Ashok Kumar Singhvi Institute for Marine Research, Shantou University, 243, Daxue Road,515063, Shantou Corresponding author: Ashok Kumar Singhvi [[email protected]m] The discovery of luminescence from solids is now nearing its Quadricentennial anniversary. Its derivative, the luminescence dating, is completing its platinum jubilee, and it is a time appropriate to recount and applaud landmark contributions, milestones, and people in this journey. This journey has been a classic example of a synergistic mutualism between Geosciences and Physics – each one rigorously informing the other. The groups of Martin Aitken at Oxford and Vagn Mejdahl at Risø contributed to the development through, a) instruments for reliable and reproducible measurements; b) understanding the physics of mineral luminescence and their dependence on irradiation and type; c) computation of natural radiation dose in nature with spatially heterogeneous distribution of radioactivity and radiation types; d) experimental protocols and e) the estimation of errors. These efforts made Thermoluminescence a secured dating method and a legally secured method for authenticity testing. G. Valladas, R. Visocekas and others (France), F. G. Houtermans and G.A. Wagner (Germany), I. Liritzis (Greece) made seminal contributions through novel applications. P. W. Levy, S. W. S. McKeever (USA), A. M Stoneham (UK), R. Chen (Israel), C. M. Sunta, and K. S., V. Nambi (India), provided insights through spectroscopy and modelling. Parallelly, applications of luminescence to meteoritics and lunar sciences grew, and interesting new applications ranging from classification of meteorites, to perihelion of orbits, terrestrial ages, and studies on lunar rocks were developed by S.A. Durrani (UK), Robert Walker, and D. W. Sears (USA) and many others [1]. Demonstration of Optically Stimulated Luminescence by D.W. Huntley and infrared stimulated luminescence from feldspars by Galina Hütt revolutionized luminescence dating and dosimetric applications. Automated TL-OSL readers and automated single-grain luminescence measurements developed by Lars Boetter-Jensen and Geoff Duller at Risø enabled methodological rigor through the ease of reproducible measurements, buttressed by analytical protocols by R. F. Galbraith and others. S. Kreutzer and J. Durcan provided open-access community software for data analytics. Presently, luminescence dating contributes ~4000+ publications annually to quaternary geology, earth surface processes, and archaeology using over ~ 800+ automated TL/OSL readers [2, 3]. I shall trace this journey of 8 decades, through my personal experience of five decades, provide examples from our work, identify recent developments, and discuss emerging possibilities. One of the novel possibilities will be to move away from our obsession with well-bleached and poorly bleached signals for dating to using the dispersion and discordance in them as proxies for geomorphic processes. In this, the use of multiple luminescence signals (TL, OSL, IR, PIRIRSL, and others) could also serve as a surrogate for basic scale to local scale events. Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 24 of 51 Keywords: Thermoluminescence, Optically Stimulated luminescence, Meteorites, Lunar rocks, Geomorphology, Quaternary References [1] D. W. G. Sears, K. Ninagawa, A. K. Singhvi, 2018. Glimmerings of the Past: The Luminescence Properties of Meteorites and Lunar Samples with an Emphasis on Applications, Create Space Independent Publishing Platform. [2] A.K. Singhvi, R.K. Kaushal, and S. Parida 2022. Luminescence dating and Quaternary Geology: The Indian Narrative, J. Paleontological Society of India. 67(1). 183-201. https://doi.org/10.1177/0971102320220114 [3] A.S. Murray, L. Arnold, J-P. Buylaert, G., Guérin, J. Qin, A.K. Singhvi, R. Smedley and K.J. Thomason, Optically Stimulated dating using Quartz. Nature Revis. https://doi.org/10.1038/s43586-021-00068 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 31 of 51 [P3] A high-resolution chronology based on OSL dating and Bayesian Modelling of alluvial deposits from Upper Franconia (Bavaria, Germany) Bastian Grimm1,*, Christian Zeeden2, Thomas Kolb1, Markus Fuchs1 1Department of Geography, Justus Liebig University Giessen, Gießen, Germany 2LIAG-Institute for Applied Geophysics, Hannover, Germany *Corresponding author: [Bastian Grimm: [email protected]-giessen.de] Reliable chronologies are fundamental for interpreting OSL datasets, yet complex depositional settings and age scatter often complicate age modelling. Bayesian approaches provide a powerful statistical framework to integrate individual OSL ages, incorporate stratigraphic constraints, and explicitly account for uncertainties. This enables the development of robust, transparent, and reproducible age models that provide a solid basis for geomorphological interpretations. We argue that such modelling frameworks are crucial for linking luminescence chronologies with geomorphological and environmental processes, and we highlight their potential for broader applications within Quaternary geochronology. Keywords: OSL dating, geochronology, Bayesian modelling, alluvial deposits Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 32 of 51 [P4] The ARENICOLA project: Radiofluorescence images digested by digital sandworms Dirk Mittelstaß1,2,*, Margret C. Fuchs2, Christoph Schmidt3, Sebastian Kreutzer1 1Institute of Geography, Heidelberg University, Heidelberg, Germany 2Helmholtz Institute Freiberg for Resource Technology (HIF), Freiberg, Germany 3Institute of Earth Surface Dynamics, University of Lausanne, Switzerland *Corresponding author: [Dirk Mittelstraß: [email protected]] Recent advances in instrumentation and methodology have markedly improved age accuracy in luminescence dating, yet most measurement protocols still rely on non-imaging photomultiplier systems. This limits data richness and requires chemical and physical sample treatment to ensure pure mineral fractions. Imaging detectors, though capable of grain-wise luminescence analysis applied in all kinds of measurement protocols, have been rarely used due to data processing challenges. The ARENICOLA project (DFG, #553815036) seeks to tackle these challenges by developing a new methodical framework centred around multi-spectral radiofluorescence (RF) images measured during beta-irradiation steps. RF signals are rich in information and can be recorded over extended periods with sufficient intensity, making them attractive for mineral identification and provenance fingerprinting. By acquiring RF images with highresolution CCD/CMOS detectors across the UV–visible–NIR spectrum, ARENICOLA will generate a comprehensive training dataset for natural mineral grains. Automated spectral deconvolution, grain segmentation, and signal component deconvolution will transform the RF signals of each grain into a well-defined set of parameters. Established and scientifically transparent machine learning approaches like partial-least squares (PLS) regression will then be used to create grain classification agents and enable provenance tracing based on mineralspecific luminescence properties. The project will deliver an open-source R package that integrates the image preprocessing and machine learning approaches into a user-friendly workflow, thereby lowering the methodological barrier to image-based single-grain dating and provenance analysis. The resulting framework will provide researchers with a powerful new tool for establishing precise chronologies of palaeoenvironmental change. In the presented poster, we will outline the planned data analysis workflow and present first insights into the challenges ahead. Keywords: Radiofluorescence, Spectra, Imaging, Machine Learning, R Packages Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 33 of 51 [P5] Multi-methodological age dating of clay exploitation in the Lateglacial channel of the Bergstraßenneckar between Viernheim and Mannheim (southwest Germany) Max Engel1*, Annette Kadereit1, Felix Henselowsky2, Manuel Herzog1, Barbara Tuczek3, Heinrich Thiemeyer4, Olaf Bubenzer1 1Institute of Geography, Heidelberg University, Im Neuenheimer Feld 348, 69120 Heidelberg, Germany 2Institute of Geography, Johannes Gutenberg University Mainz, Johannes-Joachim-Becher-Weg 21, 55099 Mainz, Germany 3Hessisches Staatsarchiv Darmstadt, Hessisches Landesarchiv, Karolinenplatz 3, 64289 Darmstadt, Germany 4Institute for Physical Geography, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt am Main, Germany *Corresponding author: [Max Engel: [email protected]] Linear vegetation anomalies in the crops at the Rindlache site in the channel of the Lateglacial Bergstraßenneckar (BSN) near Mannheim [1] identified in satellite images of the summer season motivated our investigation of potential (pre-)historical land use in this particular fluvial realm. The study is based on up to 1.7 m deep pits, sediment sampling, and laboratory analyses (grain-size distribution, CNS, loss-on-ignition, X-ray fluorescence analyses, morphoscopy of sand grains) as well as electrical resistivity tomography. The investigations reveal the presence of up to 12 ca 100 m long and up to 3.5 m wide parallel trenches cutting into the organic-rich and fine-grained natural strata, which result from silting-up of the abandoned BSN channel during the Holocene [1]. The trenches are filled with sand originating from nearby LGM to Lateglacial aeolian dune deposits on the Lower Rhine Terrace based on sedimentological and microscopic comparison of sand grains [2]. The sand infill and the remaining walls of fine-grained natural strata are covered and thus elevated by ca 40 cm of a mixture of anthropogenically deposited alluvial fine grains and sand (Dj sensu [3]). The trenches are ca 1.5 m deep and reach down to the clay-rich unit of the silting-up sequence of the BSN, which suggests that clay exploitation was the purpose of the trenching. Dating the clay exploitation relies on a multi-methodological approach involving luminescence dating, pedo-sedimentary features, modern anthropogenic relics, and, eventually, historical documents. Termini ante quem: A hollow brick embedded ca 35 cm below the surface and pushed into the sand infill could be identified as a survey point of the land consolidation Viernheim DF 459, thus providing a terminus ante quem of AD 1970/80s. No activities at the time of the Reich Labour Service in the 1930s were documented, rendering the trenching before that time likely. Termini post quem: The peat deposit at the Rindlache site, where the deepest part of the trenches cuts in, dates to 7920–7701 cal yr BP [1], thus giving a terminus post quem. The sand infilling included remains of a Bw horizon that had likely developed until middle Holocene times at the dune site before it was used for the refilling of the trenches. Optical stimulated luminescence (OSL) dating, using blue-light stimulated (BLSL) single aliquot regenerative (SAR) [4] quartz coarse-grain dating showed insufficient bleaching of the Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 34 of 51 material by delivering a wide range of equivalent doses corresponding to ca 21 ka to ca 300 a, in accordance with an LGM origin of the material and its redistribution/relocation in recent/historic times. In contrast to the alluvial deposits, the sand infilling did not show any hydromorphic features that had developed before the Rhine River regulation by Tulla AD 1817–1876 (AD 1865 Altrip). Both, termini ante and post quem consistently point to an age of the trenches somewhere between the second half of the 19th century and 1930. The search of documents in the historical archives of the state of Hesse at Darmstadt revealed files on land use in the area of Viernheim, which include official permits, directories of names of owners of land parcels, and, for the geographical allocation and matching of the historic plans with modern land parcel numbers, an atlas of the land parcels around the Rindlache site. Among these, we identified a license for a brickyard site exactly on the land parcel of the linear anomalies dated to 1st June 1865, providing detailed information on the conditions under which clay mining was granted by authorities. One of the requirements was immediate backfilling of the trenches, which is in accordance with the lack of any pedogenetic features at the boundary to the sand infill [2]. Keywords: Fluvial anthroposphere, Bergstraßenneckar, Clay mining, Incomplete bleaching References [1] Engel, M., Henselowsky, F., Roth, F., Kadereit, A., Herzog, M., Hecht, S., Lindauer, S., Bubenzer,O., Schukraft, G., 2022. Fluvial activity of the Lateglacial to Holocene “Bergstraßenneckar" in the Upper Rhine Graben near Heidelberg, Germany – first results. E&G Quaternary Science Journal, 71, 213–226. https://doi.org/10.5194/egqsj-71-213-2022 [2] Henselowsky, F., Kadereit, A., Herzog, M., Tuczek, B., Thiemeyer, H., Bubenzer, O., Engel, M., revised. Historical clay exploitation from palaeo-channel deposits of the Lateglacial “Bergstraßenneckar” in the Upper Rhine Graben, southern Germany. E&G Quaternary Science Journal. [3] Ad-hoc AG Boden, 2024. Bodenkundliche Kartieranleitung, 6th ed., two volumes. Schweizerbart, Hannover. [4] Murray, A. S. and Wintle, A. G.: Luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol, Radiation Measurements, 32, 57–73, https://doi.org/10.1016/s13504487(99)00253-x, 2000. Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 35 of 51 [P6] Are the star dunes of modern ages in Erg Chebbi, SouthEast Morocco? Manuel Herzog1,*, Annette Kadereit1,3, Olaf Bubenzer1,2 1Institute of Geography, Heidelberg University, Heidelberg, Germany 2Heidelber Centre for the Environment (HCE), Heidelberg University, Germany 3Laboratory for Luminescence Dating, Heidelberg University, Germany *Corresponding author: [Manuel Herzog, [email protected]] Star dunes, among the largest and most complex aeolian bedforms, have long been regarded as relics and morphologically stable under present-day climatic conditions. However, recent studies increasingly suggest that these dunes are dynamic features capable of rapid modification and movement in modern times [1-2]. This contribution examines the internal sedimentary facies and age structure of a major arm of a star dune in the Erg Chebbi, southeastern Morocco. Ground penetrating radar (GPR) surveys using a 350 MHz digital hyper-stacking antenna reveal distinct internal reflections and bounding surfaces consistent with downwind deposition under prevailing south–southwest winds. Four hand-auger cores [3] provided fifteen samples for optically stimulated luminescence (OSL) dating, analysed using the blue-light stimulated single-aliquot regenerative (SAR) protocol on quartz coarsegrains (125–212 µm) [4]. The results indicate early Holocene deposition at 9.58 ± 0.39 ka, followed by a middle Holocene phase between 6.85 ka and 7.57 ka, and a significant hiatus preceding the accumulation of modern dune sediments within the last millennium. These findings demonstrate that star dunes in the Erg Chebbi are indeed not inert geomorphic relics but active systems undergoing episodic reworking and vertical accretion. The combined GPR–OSL approach provides new insights into star dune evolution and highlights their sensitivity to environmental and climatic variability across Holocene timescales. Keywords: star dunes, Erg Chebbi, ground penetrating radar, optical stimulated luminescence References [1] Bristow S.C. and Duller G. (2024) Structure and chronology of a star dune at Erg Chebbi, Morocco, reveals why star dunes are rarely recognised in the rock record. Scientific Reports 14(1). https://doi.org/ 10.1038/s41598-024-53485-3 [2] Herzog M., Schmitt A., and Bubenzer O. (2024) Reconstructing star dune dynamics using ground penetrating radar – How movement shapes complex surface structures. Aeolian Research, 67-79. https://doi.org/10.1016/j.aeolia.2024.100920 [3] Bubenzer O. (2001) Manual coring equipment for the collection of stratified samples from dry sand dunes. Ancient TL 19(1): 1-3. https://doi.org/10.26034/la.atl.2001.326 [4] Murray A.S. and Wintle A.G. (2000) Luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol. Radiation Measurements 32(1). https://doi.org/10.1016/s1350-4487(99)00253-x Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 36 of 51 [P7] OSL rock surface burial dating of megalith structures in the Dzhungar Mountains - Kazakhstan Sarah Schaffer1,*, Michael Meyer1,*, Loic Martin1, Peter Tropper2, Michael Frachetti3 1Institute of Geology, University of Innsbruck, Innrain 52, Innsbruck, Austria 2Institute of Mineralogy, University of Innsbruck, Innrain 52, Innsbruck, Austria 3Department of Anthropology, Washington University, St. Louis, USA *Corresponding authors: [[email protected]; [email protected]] The Dzhungar Mountains in northern Tien Shan, Kazakhstan, are part of the Inner Asian Mountain Corridor, which extends from the Hindu Kush to the Altai. This corridor is significant for human migration and cultural exchange due to its water availability and ecological diversity. The Dzhungar Mountains contain several Bronze Age sites, including the Dali settlement complex and an adjacent circular megalithic structure several meters in diameter. Megaliths in Central Inner Asia are rare, undated, and understudied, leaving their chronological relationship to the Bronze Age unclear. Infrared Stimulated Luminescence rock surface burial dating (IRSL RSbD) is a new tool in quaternary geochronology and allows determining the burial age of rock surfaces since their last exposure to sunlight. The method is based on the fact that, over time, rock surfaces can store energy in the crystal lattice of rock-building minerals, such as feldspar, due to naturally occurring radiation. This energy can be read out as a luminescence signal upon infrared stimulation under laboratory conditions, allowing burial ages to be obtained. For dating the Dali megalith structure, we used infrared-stimulated luminescence of feldspar from the buried face of the granitic megalith boulders and complemented this with singlegrain OSL dating of the sediment beneath the boulders. This combined dating approach helps to establish a chronological framework for the Dali megalithic structure and assess its relationship to the Bronze Age timeline of the Inner Asian Mountain Corridor. Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 37 of 51 [P8] Towards standardized determination and normalization of saturation plateaus in Luminescence Rock Surface Dating Daniel Sperlich1,*, Arne Ramisch1, Michael Meyer1 1Department of Geology, University of Innsbruck, Austria *Corresponding author: [Daniel Sperlich: [email protected]bk.ac.at] Recent advancements in luminescence surface exposure and burial dating have resulted in its increasing application in a wide range of geological and archaeological settings. While the equations that describe signal propagation with depth and their associated parameters are well constrained in various dating models (Time-Depth model [1], Bleaching With Depth Model [2, 3], General-Order Kinetics Model [4]), the determination and normalization of the saturation plateau in luminescence-depth profiles have not yet been standardized. A review of recent literature is conducted, and the most common methods of normalizing the luminescence signal to saturation are identified. We test and quantitatively compare both existing and newly developed normalization approaches on various datasets from conventionally sliced cores as well as from 2D EMCCD imaging, and evaluate their respective effects on established dating model fitting. We present a standardized tool to normalize luminescence-depth profiles to saturation, suitable for a wide range of datasets and rock surface dating applications. Keywords: rock surface dating, luminescence depth-profiles, signal normalization to saturation References [1] Polikreti K, Michael CT, Maniatis Y, 2002. Authenticating marble sculpture with thermoluminescence. ATL 20:11–18. https://doi.org/10.26034/la.atl.2002.340 [2] Sohbati R, Murray AS, Chapot MS, et al., 2012. Optically stimulated luminescence (OSL) as a chronometer for surface exposure dating. Journal of Geophysical Research: Solid Earth 117:. https://doi.org/10.1029/2012JB009383 [3] Sohbati R, Murray A, Jain M, et al, 2011. Investigating the resetting of OSL signals in rock surfaces. Geochronometria 38:249–258. https://doi.org/10.2478/s13386-011-0029-2 [4] Freiesleben TH, Thomsen KJ, Jain M, 2023. Novel luminescence kinetic models for rock surface exposure dating. Radiation Measurements 160:106877. https://doi.org/10.1016/j.radmeas.2022.106877 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 38 of 51 [P9] Sensitivity-Weighted Signal Dominance in Fine-Grain Quartz: A Hypothesis on Apparent Bleaching Efficiency Benjamin Spitaler1,*, Micheal Meyer1 1Department of Geology, University of Innsbruck, Innrain 52, Innsbruck, Austria *Corresponding author: [Benjamin Spitaler: bena[email protected]] In multiand fine-grain OSL dating, the luminescence signal represents the combined response of hundreds to thousands of quartz grains, depending on the mask size used. Each grain can differ in optical sensitivity and bleaching history. Model studies [1] showed that in mixed populations, highly sensitive grains often dominate the total signal and shift the equivalent dose (De) towards their individual De value. This effect, usually seen as a systematic bias, might under certain conditions improve De estimates in heterogeneous finegrain samples such as glacial lake deposits. In alpine settings these deposits can contain a mixture of highly sensitive, well-bleached loess grains and low-sensitivity, poorly bleached glacial quartz [2]. Our initial work on alpine glacial lake sediments from the Late Pleistocene suggests that in fine-grain (4–11 µm) quartz samples, the bright, well-bleached grains dominate the composite OSL signal, despite the fact that up to ca 106 grains contribute to the net luminescence signal of each aliquot and the depositional proximity to glaciers. Similar to [2], we speculate that quartz OSL ages could be accurate in this specific sedimentary setting, which would otherwise be prone to age overestimation due to partial bleaching, due to the dominant influence of bright grains on the fine-grain quartz De values – a bias effect that we call “sensitivity weighting”. In fine-grain samples, testing this assumption remains challenging and is typically achieved via comparison of the quartz OSL ages with (i) independent age control, or (ii) systematic comparison with other harder-to-bleach signals such as the IR50 or pIR-IRSL signals and their respective feldspar ages. Here, we propose and elaborate on sediment mixing experiments using quartz fine-grain populations with known sensitivity contrasts in order to test and quantify this sensitivity weighting effect. Keywords: Optically Stimulated Luminescence (OSL), Fine-grain quartz, Sensitivity bias, Equivalent dose (DE), Partial bleaching, Multi-grain signal, Alpine glacial sediments, Loess, Sensitivity-weighted signal dominance References [1] Rhodes, E. (2007). Quartz Single Grain Osl Sensitivity Distributions: Implications for Multiple Grain Single Aliquot Dating. Geochronometria, 26, 19–29. https://doi.org/10.2478/v10003-007-0002-5 [2] Lukas, S., Preusser, F., Anselmetti, F. S., & Tinner, W. (2012). Testing the potential of luminescence dating of high-alpine lake sediments. Quaternary Geochronology, 8, 23–32. https://doi.org/10.1016/j.quageo.2011.11.007 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 39 of 51 [P10] Analysis of natural radioactivity distribution in aeolian sediment quartz grains and its impact on dose rate in OSL dating Joanna Rocznik1*, Zofia Zakrzewska1, Andrzej Wojtalak1, Fatima Pawełczyk1, Konrad Tudyka1, Grzegorz Poręba1 1Silesian University of Technology, Institute of Physics – CSE, Konarskiego 22B, Gliwice, Poland *Corresponding author: [Joanna Rocznik: [email protected]] In this work, we outline the methodology and present the results of our research on the distribution of natural radioactivity in typical dune sediments. This was done by conducting radioactivity measurements for two dominant fractions, 125-200 μm and 200-500 μm, of seven different dune samples, following different pretreatment or sample processing steps that are standard in luminescence dating procedures (Fig. 1). This approach allowed us to focus on changes in the dose rate values estimated using data from HRGS and μDOSE/μDOSE+ measurements, including measurements of light and heavy mineral samples which were possible due to the development of the μDOSE+ system capable of measuring samples as small as 200 mg, and draw conclusions about the distribution of radiation in the bulk sediment. Research is still ongoing; based on the results obtained so far, it can be concluded that for the dominant fractions in the samples, 125–200 μm and 200–500 μm, with quartz making up the majority component, chemical pretreatment has a significant impact on the activity of ²³⁸U, ²³²Th, and ⁴⁰K, and therefore, on dose rates; we observed a decrease in dose rate values as the pretreatment progressed. Furthermore, these values are strongly influenced by the light and heavy minerals present within the samples, with ⁴⁰K consistently contributing the most to their overall activity. Figure 1Figure 1. Graph of the three approaches used to conduct this study. Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 40 of 51 Keywords: dose rate, luminescence dating, environmental radioactivity, radioactivity distribution, aeolian sediments Acknowledgements Joanna Rocznik would like to acknowledge that this work is realised as a part of a research project number 2024/53/N/ST10/01996 funded by the National Science Centre. Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 47 of 51 [P14] The Middle Würmian marker horizon at Baix and Collias (Rhône Rift Valley, France) – is it coeval with the Gräselberg Soil in Germany? Daniela Sauer1,*, Nora Pfaffner1, Sebastian Kreutzer2, Olivier Moine3, Annette Kadereit2 1Department of Physical Geography, University of Göttingen, 37077 Göttingen, Germany 2Heidelberg Luminescence Laboratory, University of Heidelberg, 69120 Heidelberg, Germany 3Laboratoire de Géographie Physique, CNRS-Université Paris 1-UPEC, 94320 Thiais, France *Corresponding author: [Daniela Sauer: [email protected]-goettingen.de] Loess palaeosol sections (LPSs) are important terrestrial archives for landscape reconstruction [1]. LPSs in the current Mediterranean and the temperate zone of Europe have been investigated in detail [e.g., 2, 3]; however, the transition zone remains underresearched. The Rhône Rift Valley is a natural corridor extending north–south from the currently temperate to the Mediterranean zone, with the present transition from temperate to Mediterranean near the city of Valence (approximately 45°N). Our field campaigns revealed that the loess deposits of the LPSs along the Rhône Rift Valley are often reworked, but still the LPSs exhibit a detailed stratigraphy, rendering them valuable terrestrial archives for past landscape reconstruction. During field investigations, we found that the 14 m thick LPS at Baix [4], [5], located ca 25 km SW of Valence (44.71°N; 4.47°E; 155 m a.s.l.) and the 8 m thick LPS Collias ca 100 km further to the south (43.95°N; 4.47°E; 100 m a.s.l.) each exhibit a brownish Calcic Cambisol remain associated with prominent basal carbonate nodules in the Middle Pleniglacial part (MIS 3). The preserved truncated Bw horizon is reworked in its uppermost part. The prominent and similar appearance at Baix and Collias makes this truncated Calcic Cambisol an ideal marker horizon for the Pleniglacial part of the LPSs along the Rhône Rift Valley. Luminescence dating helped to narrow down the time range of the soil development using post-IR60IR225 SAR dating [6, 7, 8, 9] of feldspar coarsegrains and a post-IR60IR225 SAR screening at Baix [10, 11] and BLSL SAR dating [12] of quartz coarse grains at Collias [13]. In both LPSs (Baix and Collias), luminescence dating resulted in a basal sediment deposition age of ca. 55 ka and a deposition age of ca 38 ka for the sediment overlying the marker horizon. Thus, formation of the Calcic Cambisol in the warm Greenland Interstadials (GIS) 14 to GIS 10 is likely, which roughly corresponds to the terrestrial interstadials Goulotte, Pile, and Charbon at La Grande Pile [14, 15]. According to the highly precise chronology at the site Nussloch in SW-Germany, the Baix Soil as Middle Würmian marker horizon of the Rhône Rift Valley may correspond to the bipartite Gräselberg Soil, whereby the Lower Gräselberg Soil was attributed to GIS 14 and the Upper Gräselberg Soil was attributed to GIS 12 [ 2]. Coeval evolution with the Middle Pleniglacial marker horizon in the Rhône Rift Valley seems likely, whereby the milder climate in the Rhône Rift Valley probably allowed for an extended period of soil formation (likely until GIS 10), compared to the cooler conditions in Germany. Keywords: loess-palaeosol sections, Gräselberg soil, luminescence dating, Rhône Rift Valley, France Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 48 of 51 References [1] Marković, S. B., Hambach, U., Catto, N., Jovanović, M., Buggle, B., Machalett, B., Zöller, L., Glaser, B., and Frechen, M.: Middle and Late Pleistocene loess sequences at Batajnica, Vojvodina, Serbia, Quatern. Int., 198, 255–266, https://doi.org/10.1016/j.quaint.2008.12.004, 2009. [2] Moine, O., Antoine, P., Hatté, C., Landais, A., Mathieu, J., Prud’homme, C, Rousseau, D.-D.: The impact of Last Glacial climate variability in west-European loess revealed by radiocarbon dating of fossil earthworm granules. Proceedings of the National Academy of Sciences of the United States of America, 114 (24), 6209-6214, https://doi.org/10.1073/pnas.1614751114, 2017. [3] Costantini, E. A., Carnicelli, S., Sauer, D., Priori, S., Andreetta, A., Kadereit, A., and Lorenzetti, R.: Loess in Italy: Genesis, characteristics and occurrence, Catena, 168, 14–33, https://doi.org/10.1016/j.catena.2018.02.002, 2018. [4] Suen, T.-Y., 1934. Le lœss de la vallée du Rhône, Lyon: Bosc frères, M. et L. Riou, PhD Thèse, Université de Lyon-Faculté des Lettres, 163 pp. [5] Mazenot, G., 1956. Recherches sur les faunes malacologiques du loess récent würmien et de divers limons terrestres 870 holocènes dans le sud-est de la France. Publications de la Société Linnéenne de Lyon 25 (1), 9–24. https://www.persee.fr/doc/linly_0366-1326_1956_num_25_1_7784. [6] Thomsen, K. J., Murray, A. S., Jain, M., and Bøtter-Jensen, L.: Laboratory fading rates of various luminescence signals from feldspar-rich sediment extracts, Radiation Measurements, 43, 1474–1486, https://doi.org/10.1016/j.radmeas.2008.06.002, 2008. [7] Thomsen, K., Murray, A., and Jain, M.: Stability of IRSL signals from sedimentary K-feldspar samples, Geochronometria, 38, 1–13, https://doi.org/10.2478/s13386-011-0003-z, 2011. [8] Buylaert, J. P., Murray, A. S., Thomsen, K. J., and Jain, M.: Testing the potential of an elevated temperature IRSL signal from K-feldspar, Radiation Measurements, 44, 560–565, https://doi.org/10.1016/j.radmeas.2009.02.007, 2009. [9] Buylaert, J. P., Jain, M., Murray, A. S., Thomsen, K. 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Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 49 of 51 [P15] Luminescence dating of offshore and onshore tsunami deposits from the Shetland Islands (UK) Dominik Brill1,*, Andreas Peffeköver1,2, Anja Zander1, Nel Nussberger3, Katharina Hess3, Stephan Opitz1, Sue Dawson4, Pedro J.M. Costa5,6, Tasnim Patel7, Philipp Kempf9, Isa Schön8, Vanessa M.A. Heyvaert9,10, Rikza Nahar10,11, Juliane Scheder9, Maarten Van Daele10, Marc De Batist10, Max Engel3,9,* 1Institute of Geography, University of Cologne, Cologne, Germany 2Department of Earth Sciences, Simon Fraser University, Burnaby, Canada 3Institute of Geography, Heidelberg University, Heidelberg, Germany 4Energy, Environment and Society, University of Dundee, Dundee, Scotland 5Department of Earth Sciences, University of Coimbra, Coimbra, Portugal 6Instituto Dom Luiz, University of Lisbon, Lisbon, Portugal 7Marine Ecology and Management (MARECO), Institute of Natural Sciences, Brussels, Belgium 8Freshwater Biology (FWB), Institute of Natural Sciences, Brussels, Belgium 9Geological Survey of Belgium, Institute of Natural Sciences, Brussels, Belgium 10Renard Centre of Marine Geology, Department of Geology, Ghent University, Ghent, Belgium 11Faculty of Industrial Technology, Sumatera Institute of Technology, South Lampung, Indonesia *Corresponding authors: [Dominik Brill: [email protected]; Max Engel: [email protected]] The Shetland Islands exhibit some of the most well-preserved Holocene tsunami deposits in the Atlantic Basin, representing the most important evidence for the regional long-term tsunami hazard in the North Sea and Norwegian Sea. In order to use information from the sedimentary record of tsunamis for coastal hazard management, the identification of their source as well as reliable dating of the events is crucial. To date, three tsunamis have been identified on the Shetland Islands based on tsunami deposits, i.e., the supraregional Storegga tsunami (8175–8120 cal. yr BP) as well as two smaller-scale tsunamis radiocarbon-dated to 5500 cal. yr BP and to ca. 1500 cal. yr BP [1], recently revised to ca. 1400 cal. yr BP [2]. Here, we present the very first luminescence ages of the early and late Holocene events from tsunami deposits preserved in both offshore and onshore records to cross-check and, given the advantages of luminescence dating [3], to potentially improve the existing radiocarbonbased event chronology. Offshore sediment cores used in this study were taken during cruise 2023/16 of the RV Belgica in 2023 in water depths of 36 m (Dury Voe) and 81 m (Basta Voe). Tsunami deposits were identified based on visual interpretation (sharp lower boundary, coarser grain size) and 2D µXRF mapping. Complex radiation fields and time-dependency of environmental dose rates in the offshore deposits are tackled by implementing representative water contents, site-specific internal K contents, modelled dose rates considering the effect of radioactive disequilibria and stratigraphic heterogeneity on the scale of gamma radiation. Despite the challenges related to incomplete signal resetting, robust luminescence-based chronologies could be achieved by combining single-grain K-feldspar dating with a pIRIR130 protocol and Bayesian age-depth modelling. Final luminescence chronologies presented are highly consistent and indicate evidence of the 8175–8120 cal. yr BP Storegga Tsunami (Dury Voe and Basta Voe) and of the 1400 cal. yr BP tsunami Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 50 of 51 (Dury Voe). The investigated onshore deposit at Dury Voe is a thin sand layer <5 cm bracketed by dystrophic peat reaching up to 400 m inland and up to 3.3 m above the current high-tide level [1]. Luminescence ages we regenerated for two samples at a proximal site very close to the present coast. Unlike the offshore cores, the onshore Dury Voe sand contains quartz with luminescence properties suitable for OSL dating. However, quartz required >50– 100 grains per aliquot, whereas feldspar supported single-grain measurements. Final ages show good agreement among different signals and aliquot sizes for both samples. The signals for all six dosimeters combined yielded mean ages of 1360±50 years and 1460±80 years for the two samples. Our preliminary results show that the application of luminescence dating to event deposits on Shetland faces challenges (radioactive disequilibria offshore, poor quartz-luminescence properties), nonetheless, it can still establish consistent event chronologies, corroborating and complementing pre-existing 14C data. With regards to the late Holocene tsunami deposit, the luminescence ages indicate an overall lower age than the initially assumed 1500 cal yr. BP [1]. This may be based on the advantage of directly dating the sedimentation process with luminescence, whereas 14C-based sandwich dates [1] are potentially associated with a time lag between the death of the dated organism and the sedimentation process, leading to age overestimation of the event [3]. Luminescence dating on Shetland is part of the NORSEAT and GEN-EX projects, both kindly funded by BELSPO (Belgian Science Policy Office). Keywords: Palaeotsunami research, Tsunami, Event deposits, Radioactive disequilibria References [1] Bondevik, S., Mangerud, J., Dawson, S., Dawson, A., Lohne, Ø., 2005. Evidence for three North Sea tsunamis at the Shetland Islands between 8000 and 1500 years ago. Quaternary Science Reviews, 24, 1757–1775. https://doi.org/10.1016/j.quascirev.2004.10.018 [2] Engel, M., Hess, K., Dawson, S., Patel, T., Koutsodendris, A., Vakhrameeva, P., Klemt, E., Kempf, P., Schön, I., Heyvaert, V.M.A., 2024. Sedimentary evidence of the Late Holocene tsunami in the Shetland Islands (UK) at Loch Flugarth, northern Mainland. Boreas, 53, 27–41. https://doi.org/10.1111/BOR.12635 [3] Brill, D., Tamura, T., 2020. Optically stimulated luminescence dating of tsunami and storm deposits. In: Engel, M., Pilarczyk, J., May, S.M., Brill, D., Garrett, E.G. (eds.), Geological records of tsunamis and other extreme waves. Elsevier, Amsterdam, pp. 705–727. https://doi.org/10.1016/B978-0-12-8156865.00032-8 Book of Abstracts DLED 2025 – Heidelberg, Germany © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License – CC-BY-NC | Page 51 of 51 [P16] Machine Learning-Based Classification of Single Quartz Grains for Luminescence Dating Marcin Młynarz1,*, Zofia Zakrzewska1,*, Grzegorz Poręba1, Julia Pluta1, Konrad Tudyka1 1Silesian University of Technology, Institute of Physics - Centre for Science and Education, ul. S. Konarskiego 22B, 44-100 Gliwice, Poland *Corresponding author: [Marcin Młynarz: [email protected]; Zofia Zakrzewska: [email protected]] The study explores the relationship between single-grain optically stimulated luminescence (OSL) signal intensity and quartz grain characteristics by combining OSL measurements, optical microscopy, and automated image analysis. Principal Component Analysis (PCA) and Uniform Manifold Approximation and Projection (UMAP) [1] were used to evaluate morphological variation among grains. By projecting morphological grain-level features into a lower-dimensional space, the study aims to assess whether meaningful patterns link OSL signal intensity to physical grain attributes. Keywords: UMAP, classification, luminescence, morphological properties References [1] Leland McInnes, John Healy, James Melville, UMAP: Uniform Manifold Approximation and Projection for Dimension Reduction, arXiv:1802.03426 [stat.ML] Pearson Karl, LIII. On lines and planes of closest fit to systems of points in space, Philosophical Magazine, https://doi.org/10.1080/14786440109462720