Rock surface luminescence dating has developed into a promising approach to constrain depositional ages of clasts. The prerequisites for its successful application are the precise determination of the clast-specific dosimetry and the sufficient pre-burial resetting of the luminescence signal into a certain depth beneath the clast-surface. Dosimetry of clasts is significantly influenced by the internal beta dose rate, which largely depends on grain-size range and internal potassium content of feldspar within rock slices. In the current study, six clasts are investigated from three distinct fluvial terraces of the Bruche River in north-eastern France. Previously published independent age control from sandy deposits of the terraces indicate depositional ages of similar to 12-14 ka for the youngest, similar to 27-35 ka forthe middle, and a minimum age of similar to 200 ka forthe oldest terrace. Clast-based multi-elevated-temperature post-IR infrared stimulated luminescence (pIR) ages show systematic deviations from age control, overestimating by similar to 50-150% for the youngest terrace, similar to 10-30% for the middle terrace, but confirming the minimum age for the oldest terrace. The present study provides methodological advancements by estimating grain-size range and Kcontent in feldspar grains within rock slices using mu-X-rayfluorescence and microprobe analysis, respectively. Modern clasts from the present riverbed indicate that high-temperature pIR signals retain significant residual ages in rock slices, ranging from similar to 2-3 ka for pIR110 over similar to 5-6 ka for pIR170 to similar to 8 ka for pIR225 signals, while IR50 residual ages remain negligible (<1 ka). This study also demonstrates the potential for using fully saturated rock slices from clast interiors to perform reliable fading correction. As the clast-based luminescence ages overestimate the corresponding ages derived from sandy deposits, this highlights the remaining limitations that must be considered for this approach.
Over the past decade, the use of portable optically stimulated luminescence (OSL) readers has expanded rapidly, enabling the recovery of latent stratigraphic information from bulk sediments of late Quaternary age. These applications assume that luminescence signals from sample aliquots are reproducible, yet no study has explicitly examined preparation strategies that optimize inter-aliquot consistency. Consequently, no standardized methods for sample preparation exist in portable OSL research. This study initiates this discussion by testing how aliquot preparation and sample size influence reproducibility. Four samples were collected from postglacial eolian dunes in Alberta, Canada. For each sample, 20 aliquots were prepared using four approaches, yielding 320 aliquots: (a) monogranular layers of equal volume portions (similar to 1.5 g), (b) monogranular layers of equal-weight (1.5 g), (c) monogranular layers mounted on double-sided adhesive segments of equal area (similar to 1.0 g), and (d) multilayer portions of equal weight (12.0 g). All aliquots were analyzed with a portable OSL reader. Statistical results showed that for blue-OSL signals, reproducibility varied both among samples and across preparation methods. However, multilayer aliquots prepared with equal weights (12 g) consistently produced the highest reproducibility, suggesting that larger grain populations enhance inter-aliquot consistency. For IRSL signals, no preparation method offered a clear advantage.
The rapid increase in tree-ring radiocarbon concentration of 12‰ between 774–775 CE marked the first confirmed cosmic-origin event identified through annual tree-ring records. Subsequent studies have in-dependently verified this signal in dendrochronologically dated material from multiple regions, confirm-ing its global nature. Since then, several comparable events have been identified across different peri-ods. These radiocarbon spikes are of particular importance because they provide precise annual tie-points that can significantly improve chronological resolution in fields such as archaeology and geology. In this paper, we present a simple method for detecting such events in high-resolution radiocarbon da-tasets.
The rapid increase in tree-ring radiocarbon concentration of 12 parts per thousand between 774-775 CE marked the first confirmed cosmic-origin event identified through annual tree-ring records. Subsequent studies have independently verified this signal in dendrochronologically dated material from multiple regions, confirming its global nature. Since then, several comparable events have been identified across different periods. These radiocarbon spikes are of particular importance because they provide precise annual tie-points that can significantly improve chronological resolution in fields such as archaeology and geology. In this paper, we present a simple method for detecting such events in high-resolution radiocarbon datasets.
Optical Stimulated Luminescence (OSL) screening has emerged as a significant advancement in the field of luminescence dating applications. The employed portable luminescence readers offer practical and efficient tools for on-site measurements. In contrast to traditional luminescence dating in the laboratory, which often involves analyzing enriched quartz or feldspar mineral separates, portable OSL readers typically measure infrared (IR) or blue post-IR OSL signals from unprocessed bulk material. Here, we present a new device series that can be used as a portable OSL reader for dating purposes and luminescence screening: the OSL Helios reader. The reader has already been used in luminescence laboratories as a bench-top device for dosimetry research for almost twenty years. It recently received significant upgrades for better versatility. Our contribution demonstrates the application of the OSL Helios reader for luminescence screening on a loess profile, where luminescence signal intensities were assessed for specific sedimentological layers. The profile was measured using different versions of the OSL Helios reader, and the results were compared to those of the SUERC reader, which is commonly used as a portable reader in applications. Additionally, standard passive dosimeters (Al2O3:C and BeO), as well as detectors considered for emergency dosimetry (NaCl), were measured to determine the sensitivity of Helios devices. We conclude that the Helios reader performs similarly to the SUERC reader in most standard situations and can be considered an additional option for portable luminescence reader application.
Late Quaternary landscape evolution in tropical environments, such as Indonesia, remains poorly constrained due to limited prior studies and mineral properties that are challenging for luminescence dating. In this study, singleand multi-grain luminescence measurements of quartz and K-feldspar were explored for fill terrace deposits at the Kampar Kanan River, Indonesia. Our objective is to develop a chrono-stratigraphic framework that allows the reconstruction of late Quaternary fluvial morpho-dynamics, including climatic change. Quartz measurements were made using blue and green stimulation and single-aliquot regenerative dose (SAR) and double SAR protocols. However, as none of the quartz signals were fast component-dominated, they were not used for dating. Infrared-stimulated luminescence of multiple grains of K-feldspar at 50 degrees C (IR50) and post-infrared infrared-stimulated luminescence at 225 degrees C (pIR50IRSL225) yielded sufficiently bright signal intensities for dating, and ages were calculated using either the average dose (ADM) or minimum age model (MAM). The luminescence chronology based on fading corrected pIR50IRSL225 data yields ages from Marine Isotope Stage (MIS) 6 or earlier to MIS 1. The chrono-stratigraphy indicates that the river was likely aggradational during climate transitions from wet to dry with the deposition of more gravelly material, and erosional during colder periods when overbank deposition of fines may have been coincident with increased vertical river erosion due to a stronger monsoon.
This study addresses the challenge of signal crosstalk in luminescence measurements from single sand-sized mineral grains, utilising Electron-Multiplying Charge-Coupled Devices (EMCCD) for imaging. Crosstalk, or signal interference between adjacent grains, may significantly hamper the accuracy of luminescence analysis of signals emitted by single mineral grains. The research aims to minimise crosstalk, thereby enhancing the integrity of the luminescence data from each grain. The effects of altering the aperture size and the spacing between grains on the sample disc are investigated using the 110 degrees C thermoluminescence (TL) peak of quartz as an example. Specifically, the introduction of a newly designed sample disc with increased spacing between grain holes shows promising results in mitigating signal overlap, as evidenced by the experimental data. In particular, we demonstrate that the new design dramatically decreases signal crosstalk, enabling reliable automatic data analysis with minimal interference. The study offers practical solutions for enhancing the reliability of single-grain based luminescence chronologies and dosimetric assessments. By minimising signal crosstalk, more precise and reliable analyses of thermoluminescence and OSL signals can be obtained. To demonstrate the potential of the new design, for the first time, we show the estimation of trap parameters of the 110 degrees C peak in quartz at a single-grain level using an EMCCD camera, comparing it with the lifetime of the electrons in the 110 degrees C trap measured directly through storage experiments.
This study introduces a new method for measuring uranium, thorium decay chains, and 40K in geological materials using NaI:Tl gamma spectrometry. The novel approach involves fitting data to model reference spectra via custom software, processing full mixed spectra to estimate pure component spectra quantifying radionuclides concentrations and evaluating their correlations. These correlations are crucial in calculating environmental dose rates for trapped charge dating. The methodology was validated using a Canberra InSpector 1000 spectrometer, with results cross-checked against high-resolution gamma spectrometry. With the use of the mu Rate web application, dose rates uncertainties were lowered by including correlated inputs, which results in improved precision in trapped charge dating.
The importance of the fast decaying signal of quartz for dating sediments is confirmed by years of research. In OSL dating, the single-aliquot regenerative-dose (SAR) protocol is applied to estimate age using quartz. The OSL signal measured in this protocol consists of components with different properties, particularly with different susceptibility to bleaching in sunlight. It is known how complicated it is to extract the fast decaying signal from other overlapping signals when blue light is used for stimulation. Decomposing OSL curves into components is unsuitable for dating purposes due to the challenges involved in handling many OSL curves for age estimation and obtaining consistent results across these curves. An OSL measurement method based on optical stimulation whilethe sample is heated, so-called thermally modulated OSL (TM-OSL), was recently implemented in the SAR protocol. Instead of the blue light (470 nm) typical in SAR (hereinafter referred to as SAR BLSL), red light (620 nm) is used for optical stimulation. In the protocol with TM-OSL measurement, the fast component is isolated and used for the OSL age determination. The advantage of this approach for a set of samples selected from various depositional environments is presented. The equivalent dose for the same samples was also determined using the SAR protocol that involved red light stimulation (620 nm, SAR RLSL) at an elevated temperature (230 degrees C). The obtained results by the protocols using red light (SAR TM-OSL and SAR RLSL) are compared with the ones determined using the SAR BLSL protocol. Using TM-OSL in the SAR protocol leads to more precise dating results. The shape of the TM-OSL curve forthe fast OSL component in quartz allows to identify in the TM-OSL a contribution from a signal of another origin. It prevents age underestimation by excluding from calculations the share of OSL components, which can be less stable.
The Żabinko exposure (western Poland) reveals the classic fluvio-aeolian succession known from studies in the European Sand Belt. Previous chronostratigraphic studies were mainly based on uncalibrated radiocarbon dates from organic sediments and thermoluminescence dating. The picture visible from these studies indicated a number of discrepancies between these methods. The new research in this exposure was based on optically stimulated luminescence (OSL) dating and calibrated radiocarbon dates. The results obtained indicate a general discrepancy between the results achieved by these two methods. While the radiocarbon dates provide some meaningful picture and allow correlation with previous studies, the results of OSL dating do not allow for a chronological model of sedimentary processes. The OSL dates show large inversions of the results and are clearly younger than the other dating results. Detailed analysis of OSL measurements shows radioactive disequilibrium and variability linked to differential stratification of sediments, significantly impacting the assessment of environmental dose rates. We believe that this atypical variability is presumably the result of postdepositional processes, such as changes in groundwater levels, chemical weathering and radionuclide migration.
In temperate regions trees typically exhibit growth sensitivity to climatic conditions during the growth season. Annual tree ring growth increments correlate with a variety of environmental factors. As an index of water use efficiency, (SC)-C-13 is a preferred proxy to allow accurate interpretation of environmental factors critical for the tree growth, including changes in climate patterns, variation in the ambient temperature and precipitation. We assumed that isotopic differences within individual tree rings are likely to produce seasonal isotope fluctuations in the chronology that might be interpreted as response to environmental impacts. To verify the assumption, we measured (SC)-C-13 in annual tree rings of Pinus Sylvestris L. split into 13 intra-annual segments each and checked (SC)-C-13 correlations with temperature, precipitation, the number of sunshine hours and relative air humidity. For the investigation, we chose a site in north-eastern Lithuania, Zarasai, located in boreal latitude and remote from industrial pollution sources. The methodology of the research was based on high coherence of (SC)-C-13 chronologies measured in the whole wood and alpha-cellulose extracted by means of two different methods. The experiment produced strong (SC)-C-13 correlations with hydrometeorological parameters, especially in the earlywood formed in June.
The Daxing’anling Mountains are vulnerable to extreme weather and ecological degradation. Forests in this region have been substantially affected by extreme events; however, the pattern of future forest change remains uncertain. To determine the trends and reasons for extreme climate change, reanalysis data were used to assess the potential forest degradation resulting from future extreme climate events. Using tree-ring width chronologies of Pinus sylvestris var. mongolica (1952-2015) and Larix gmelinii (Rupr.) Kuzen (1962-2015), we performed a comparative analysis of the relationships between radial growth of these two tree species and extreme indices based on Pearson correlations. The functions between extreme climate and tree ring width were then used in the LASSO algorithm. Using the CMIP6 models under the intermediate emission scenario (SSP2-4.5), we projected the tree ring width of the two species from 2015 to 2100 using calibrated meteorological fields. The tree-ring chronologies of both species were correlated negatively with extreme warm temperature indices and positively with extreme precipitation indices. P. sylvestris responded more significantly to extremely high temperature indices and precipitation, with a certain lag effect. L. gmelinii responded significantly to extremely cold temperature indices. Tree species specificity may explain why the two species show different growth–climate relationships. The growth of P. sylvestris may decrease during extreme climate change conditions, whereas the effect on L. gmelinii future growth is not significant. The predicted growth series in the 2015–2100 period showed that three abnormally high values, six abnormally low values, and one extreme abnormally low value occurred in P. sylvestris, whereas there were two extreme abnormally low values, four abnormally low values, and four abnormally high values in L. gmelinii. Our findings can help predict the resilience and sustainability of forest ecosystems in the face of extreme climate change and contribute to forest management strategies.
For modern fluvial systems, stage height, velocity, and cross-section help estimate a river’s discharge. However, understanding the amount and fluctuations of past discharges remains a challenge. The dimen-sions of the meander loops/oxbow lakes are directly proportional to the river’s discharge and the sedi-ment load type. Central West Bengal, India, has a complex network of numerous oxbow lakes as a rem-nant of the river Hooghly, a major distributary of the River Ganga. The present work revisits Schumm’s classic work to estimate river discharges from the meander loops and explores a potential proxy for es-timating past discharges. Thus, it is extended to reconstruct past climate using grain size data, facies analysis, and the dimension of the meander loops coupled with the luminescence chronology of oxbow lakes. The study reveals that the region received good rainfall during reported periods of intense mon-soon, and the increased discharge at different time intervals has given rise to numerous oxbow lakes. The discharge values have shown considerable fluctuations, rising to 15 to 20 times the current value and very few anomalously high, even up to 250 to 300 times, left unrecorded from other archives. The study shows the preservation of systematic growth of discharges and the meander loops with climate re-vealing events with anomalously high (and so highly disastrous) discharges at the scale of tens of thou-sands of years, usually missed from other archives. Results from Ichhamati and Hooghly River meander loops in West Bengal, India, indicate a manifold increase of discharges from the current during 1–1.5 ka (known as the Medieval Warm Period); around 2.2 ka and around 3.9 ka with low or gaps of enhanced monsoon, e.g., Little Ice Age and during 2.5–3.5 ka. This is an effort to show the potential of past mean-der loops to be explored well for comprehensive records.
Sediments in Józefów were deposited in a small lake in the Eemian Interglacial and Early Vistulian (MIS 5). They were then covered by periglacial mineral sediments during the Upper Pleniglacial and the Late Vistulian (MIS 2). These sediments were deformed by gelifluction and thermokarst processes. There is no traces of deposition from MIS 4 and MIS 3. Optically stimulated luminescence (OSL) dating confirmed the age of the sediments and enabled the reconstruction of the deposition phases and deformation of the lake infilling.
The study examines sedimentology, stratigraphy, and the impact of wildfires on aeolian and soil processes during the Late Glacial Termination in the Korzeniew site, central Poland. The site, within a parabolic dune's central and lee-slope area, presents stacked aeolian sand units intermixed with six charcoal-enriched palaeosols. Thirteen optically stimulated luminescence (OSL) dates on quartz and six radiocarbon dates establish the chronological framework, dating deposition processes. Initial aeolian sand deposition occurred towards the Late Pleniglacial's end. Climate amelioration during the Bølling interstadial led to permafrost thaw and gleyic soil formation, later overlain by migrating parabolic dunes from the older Allerød interstadial. Wildfires, influenced by vegetation cover, deposited charcoals on the dune's lee slope. These charcoals underwent pedogenic reworking amid episodes of aeolian sand deposition during the Allerød interstadial and Younger Dryas, stabilizing in the earliest Holocene. Wildfires significantly impacted local vegetation development and aeolian activity. Despite the warmth of the Allerød interstadial, increased fires correlated with expanding pine forests and their heightened fire susceptibility. Short-term climate shifts likely destabilized vegetation, fostering fire occurrences during the Allerød interstadial.
This research paper introduces a methodology for estimating overcounting resulting from uranium series radionuclides, with a specific focus on 222 Rn contamination. The method is demonstrated using the Quantulus 1220 TM spectrometer. Exponential fitting is employed for the calculations, utilizing a custom algorithm developed in MATLAB ® R2022b. The proposed method allows for the determination of the sample count rate correction, F 14 C and radiocarbon age without the need for additional chemical treatment or specialized electronics during liquid scintillation counting (LSC) measurements with the Quantulus 1220 TM spectrometer. However, the method does have certain limitations. It requires a significant number of cycles and extended measurement time per cycle, but it can be applied to samples with significant 222 Rn contamination that require rapid 14 C analysis.
Carbon black (CB) is produced through the incomplete combustion of biomass or thermal decomposition in an oxygen-deprived environment. Technical carbon black (TCB) primarily consists of elemental carbon and comes in various grades distinguished by surface area and nanostructure morphologies. However, TCB production raises sustainability concerns due to its reliance on non-renewable feedstock, significant CO2 emissions and high energy consumption. TCBs find extensive use as reinforcing fillers in the tire and rubber industries. Recent studies underscore the importance of eco-friendly alternatives. This research was carried out to monitor the renewability of the TCB samples by determining the 14C isotope concentration. Liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS) radiocarbon techniques were employed for measuring the 14C isotope concentration, while isotope ratio mass spectrometry (IRMS) corrected standardised isotope fractionation correction. The investigation revealed that the examined TCB samples contain extremely low 14C concentrations, measuring <1 per cent modern carbon (pMC). This finding raises concerns regarding potential environmental ramifications.
Sediments in Jozefow were deposited in a small lake in the Eemian Interglacial and Early Vistulian (MIS 5). They were then covered by periglacial mineral sediments during the Upper Pleniglacial and the Late Vistulian (MIS 2). These sediments were deformed by gelifluction and thermokarst processes. There is no traces of deposition from MIS 4 and MIS 3. Optically stimulated luminescence (OSL) dating confirmed the age of the sediments and enabled the reconstruction of the deposition phases and deformation of the lake infilling.
Loess-paleosol sequences (LPS) are an exceptional source of palaeoclimate data constituting an indirect record of changing environmental and climatic conditions that prevailed during loess deposition and early diagenesis. The Zaprężyn LPS (17°11′52″E, 51°14′44″N) is situated in the southern morphological edge of the Trzebnica Hills. This sequence provides an opportunity to reconstruct past climate conditions in this part of SW Poland. In this work, we used two sets of optically stimulated luminescence (OSL) dating from the Gliwice and Bayreuth laboratory to establish a chronological framework for this profile. The results of 14 C accelerator mass spectrometry (AMS) dating were also used. The dating results are accompanied by detailed analyses of grain-size distribution and colour. The applied methodology allowed us to distinguish four litho-pedotratigraphic units: modern soil S0, L1LL1 loess unit, L1LL2 loess unit and fossil S1 soil. The OSL dating results indicate an unconformity representing a time interval >30 ka between the L1LL1 and L1LL2 units. This unconformity explains the lack of a L1SS1 soil unit. In Zaprężyn LPS, the presence of the ice wedge pseudomorph in L1LL2 loess unit was recorded. Ice wedge pseudomorph approves the presens the permafrost conditions during the Lower Plenivistulian in Trzebnica Hills.
This paper presents comprehensive investigations of the morphological, sedimentological, and stratigraphic features in the lower Prosna River valley infill, situated in west-central Poland. At the Rokutów site, we identified two meander generations and an anastomosing system. Fluvial changes observed depict the response of the extraglacial river system to climate fluctuations post-last glaciation. Following valley aggradation, scouring erosion, reaching depths of 9–10 m, likely occurred during the Bølling Interstadial. ‘Great meanders’ emerged during the Allerød-Younger Dryas, persisting for around 1000 years, with an uncommon upstream rotation influenced by the sub-Quaternary surface slope. A lengthy stabilization phase, lasting 8000–10,000 years, characterized by an anastomosing system with gradual aggradation, followed the great meandering period. About 3600–3900 years ago, the valley shifted back to a fluvial system with small meanders, lasting 600–900 years. Subsequently, the River Prosna reverted to an anastomosing system, remaining so until the 19th–20th centuries when it transformed into a single-channel system through regulatory manipulation. Our research suggests that the evolution of the Prosna River differed from other rivers across Western and Central Europe, exhibiting a blend of anastomosing and meandering phases.
