Optically Stimulated Luminescence Ages Research Articles

Paleostorm redeposition and post-glacial coastal chronology in the eastern Baltic Sea, Latvia

The 494 km long Latvian coast consists of sandy sediments, which serve as an excellent proxy for past coastal events and environment. Our study explores these understudied sediments along the western coast of the Gulf of Riga and combines two sand quartz-wise methods: optically stimulated luminescence (OSL) dating and grain microtextures. We provide a new chronology and microsedimentary results to trace post-glacial storm events and discuss correlations within the Baltic Sea region and elsewhere in Europe. OSL ages reveal a wide time span between 10.38 ± 0.61 ka and 1.04 ± 0.05 ka BP, but their inconsistency in the profiles along with the onshore position of landforms and gravelly horizons argues for sediment relocation due to storm action. A first paleostorm phase is dated to between 7.6 ± 1.2 ka and 4.63 ± 0.27 ka, corresponding with a transgression of the Littorina Sea and the Holocene Thermal Maximum, and with a roughly estimated vertical sediment redeposition above 5 m similar with the recent storms in the region. Sedimentary record from microstudy supports intense storm activity, especially in sediments redeposited after 6.07 ± 0.51 ka, and it is seen through an increased number of cracked quartz grains, shiny grains and fresh surfaces combined with a limited number of V-shaped marks. Weaker storm action, recorded by a lower share of cracked grains in the sediments, occurred between 7.6 ± 1.2 ka and 6.07 ± 0.51 ka.A second storm phase occurred at 1.44 ± 0.21 ka, corresponding with the post-Littorina, again with a performance of a weaker storm. Apart from the palaeostorm records, the beach ridges developed between 5.16 ± 0.33 ka and 4.47 ± 0.31 ka along with drier conditions when aeolian deposition took place twice: at 4.63 ± 0.27 ka and 1.55 ± 0.10 ka.

Climate-driven versus anthropogenic induced erosion of the last 3000 years from an ancient lake in the Southern Phokis Plain (Desfina), Greece

The timing and causes for erosional events at the Kastrouli (Greece) archeological site – a Late Myceneaen with reuse in later periods – are presented. Two borehole sediment cores (max 6 m depth), collected from the footsteps of the settlement hill plain, were studied. Sedimentary analysis and luminescence dating techniques investigate and identify periods of soil aggradation in this record. Moreover, optically stimulated luminescence (OSL) dating confirmed the concept of an ancient lake during Kastrouli settlement times. Macroscopic overview of the stratigraphic structure for each core, included lithological and textural evaluation of the core sediments, assessments of grain size, and determination of the geochemical and mineralogical composition of the sediments. X-ray powder diffraction (XRPD), X-ray fluorescence (XRF), and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) techniques were applied for the mineralogical and geochemical analysis. OSL ages from seven sediment horizons spanned from the Ottoman period to archaic times. All lithological findings correlate with the results of the electrical tomography survey conducted in same area. Extrapolation of the Logarithmic fitting of the data back in time of prehistoric Late Mycenaean era of Kastrouli verifies a lake deeper than 10 m, with a considerable enhancement in soil aggradation of 1.2 cm/year. Attempts to dry out the area are evidenced by the hydraulic works found in two engineering sinkholes. Sedimentation changes had occurred in the local environment over the last 2500 years, and soil aggradation underwent significant fluctuations in the two studied cores. The Roman period (a wet period) and the Byzantine period experienced high aggradation rates. By contrast, soil aggradation rates in southern Phokis (Kastrouli region) have remained exceedingly low from the Ottoman era (circa 13th century) to the present. In the context of the Phokis case study, it appears that the sedimentation rates, driven by climate, have strengthened anthropogenic activities.

Sedimentation rate changes across the Chinese Loess Plateau from luminescence dating of Malan loess in the Sanmen Gorge

Abstract The Chinese Loess Plateau (CLP), recognized as the world's largest loess plateau, has been a subject of ongoing debate regarding the continuity of its sedimentary loess sequence due to its intricate depositional environment. In this study, we conducted dating on a 9.8-m-long Malan loess core obtained from the Sanmen Gorge in the southern CLP using optically stimulated luminescence (OSL). The OSL dates indicate loess deposition between 52.4 and 11.3 ka, with no apparent hiatus on a millennial scale, and a sedimentation rate (SR) exhibiting six distinct episodes. Additionally, a comprehensive review of 613 OSL ages from 18 sections at 14 sites across the CLP was conducted. The results reveal loess deposition at most sites shows no apparent hiatus on a millennial scale over the past 60 ka, except for two specific locations. High SR episodes during Marine Isotope Stage (MIS) 3 across the CLP were attributed to heightened dust emissions from the source region and an enhanced dust deposition efficiency, while MIS 2 deposits were influenced by an intensified East Asian winter monsoon. Low SR episodes during MIS 1 at most sites were likely associated with reduced atmospheric transportation and pedogenesis. Spatially heterogeneous SR variations across the CLP might be influenced by local depositional environments.

OSL and radiocarbon dating of core TBF-1 on the outer shelf of the East China Sea and implications for late Quaternary stratigraphic correlation

It is crucial to establish a robust chronology for understanding late Quaternary sedimentation processes and environment changes in response to sea-level fluctuation on shelves. The shelf of the East China Sea (ECS) is featured by huge terrigenous sediment input and striking land -sea interaction during the late Quaternary. However, there remains controversy in chronostratigraphic rebuilding of transgression and regression deposits during eustatic-glacial cycles, mainly due to a lack of reliable dating data. In this study, an extensive comparison of 17 optically stimulated luminescence (OSL) and 15 AMS 14C ages from core TBF-1 (upper 40 m) provides a constraint in chronostratigraphic reconstruction since Marine Isotope Stage (MIS) 5. OSL ages range from 9.5 ± 0.7 to 67.3 ± 4.8 ka at depths from 2.00 to 28.00 m, while 14C ages range from 6645 to 41435 cal a BP at depths from 0.02 to 17.52 m. Regression analysis demonstrates a high level of agreement between OSL and 14C ages, with r2 values of 0.91 and 0.90, respectively. For Holocene sediments (U1), both OSL and 14C methods are applicable in tidal sand ridges, however, it should be noted that 14C ages may exhibit a young bias of up to 3 ka. For pre-Holocene sediments (U6-U2), OSL ages are robust within saturation limitation of OSL signal (De up to ca. 166 Gy), cross-checked by feldspar post-IR IRSL (pIRIR) dating protocol. Nevertheless, the shell 14C ages (11620 and 10390 cal a BP at depths of 13.95–14.56 m) in Last Glacial Maximum (LGM) fluvial sediments of U2 are significantly underestimated, because of their susceptibility to recrystallization and overgrowth, resulting in carbon exchange with environment. While the peaty layer's14C age in deltaic deposition (17.50 m, U5) was determined to be 36420 cal a BP, coincided with OSL age of 39.6 ± 3.9 ka. The chronostratigraphy since MIS 5 for core TBF-1 exhibits a significant correlation with previously published cores SFK-1, DZQ4, and DH02, on the ECS outer shelf. Through the evaluation of those underestimated 14C ages and saturated OSL ages, we re-elucidated the primary sedimentary facies and their respective formation periods. This sedimentary stratigraphic illustration exhibits significant consistency with eustatic-glacial cycles. The renewed chronological framework for ECS shelf allows better correlation between the late Quaternary sedimentary evolution and the land-sea interaction on open shelves dominated by siliciclastic sedimentation.

Optical dating of charcoal kiln remains from WWII: A test of accuracy

The majority of relic charcoal kilns in Europe are more recent than 1650 CE and cannot be precisely dated using radiocarbon dating (14C). Quartz-based optically stimulated luminescence (OSL) dating of the sediments associated with the kiln remains has been suggested as a viable alternative. Owing to the lack of reliable and sufficiently precise independent age information, however, it remains to be established whether OSL dating can yield accurate ages for post-1650 CE features. This is explicitly investigated in this study by applying a commonly adopted quartz OSL methodology to three relic charcoal kilns which are known to have been constructed and operated between December 1941 and March/April 1942 CE.We first document the quartz luminescence characteristics and show through procedural tests that the adopted single-aliquot regenerative dose procedure should be appropriate for equivalent dose determination. Four samples collected from the uppermost part of the charcoal-rich layers in the three features yield the youngest optical ages and are considered coeval. Their average age is 1928 ± 13 CE (95% probability), which matches the independent age reasonably well. The precision associated with the individual OSL ages ranges between 7 and 14% (1 sigma total uncertainty) and it might ideally be possible to establish relative chronologies with a higher time resolution. Finally, we briefly discuss our entire set of OSL ages in relation to future strategies for sampling charcoal kilns remains. In general, we conclude that OSL dating can be particularly advantageous to help resolving chronometric issues that pertain to post-1650 CE relic charcoal kilns.

Dating the Neanderthal environment: Detailed luminescence chronology of a palaeochannel sediment core at the Palaeolithic site of Lichtenberg in the Lower Saxony, northern Germany

Northern Germany is famous for its numerous Neanderthal (Middle Palaeolithic) archaeological sites and well-preserved palaeoclimate records. Nevertheless, our understanding of how hominins responded to climate fluctuations and adapted to changing environments in this region remains limited because there are only a few reliable, highly-resolved chronological frameworks of long stratigraphic successions. Most of the Middle Palaeolithic sites in this region lack a reliable chronostratigraphy beyond the radiocarbon dating range. In this study, we present a high-resolution optically stimulated luminescence (OSL) chronology derived from a ∼21 m long sediment core (Li-BPa) that was drilled in close proximity to the known Neanderthal site of Lichtenberg. Quartz OSL dating was applied to the upper 6.5 m of the core. Subsequently, the obtained quartz OSL ages were compared with feldspar post-infrared (IR) IRSL (pIRIR) measured at 290 °C (pIRIR290), pulsed IR50 (pre-pIRIR225), and pulsed pIRIR225 ages to select a suitable feldspar signal to date older samples. A comparison of the quartz and feldspar ages indicates that only fading-corrected pulsed IR50 (pre-pIRIR225) and pIRIR225 ages agree well with quartz OSL ages. Finally, the age framework of the sediment sequence was established based on the 11 quartz OSL ages and 23 fading-corrected pulsed IR50 (pre-pIRIR225) and pulsed pIRIR225 ages. The resulting Bacon age-depth model agrees with litho- and biostratigraphic designations, indicating that the whole sequence was deposited between ca. 275 ka and ca. 24 ka, corresponding to the Saalian to Weichselian periods.

Optically‐Stimulated‐Luminescence Ages and Paleo‐Environmental Implications of Relict Frost Wedges in North–Central Bohemia, Czech Republic

ABSTRACTRelict frost wedges are widespread and valuable indicators of past environmental conditions that have been extensively dated across central and western European lowlands over the past few decades, but their timing in the Czech Republic is poorly known. Here, we present optically‐stimulated‐luminescence (OSL) ages for seven relict frost wedges situated at four study sites in north–central Bohemia, Czech Republic (49.9992–50.4956°N, 13.3736–16.0011°E, 230–350 m above sea level). The OSL ages indicate that the frost wedges developed during two phases in marine isotope stage 2: an older phase that peaked at 23.6 ± 2.9 ka and a younger phase that peaked at 16.1 ± 1.3 ka. Both phases probably experienced cold, dry and windy conditions that were mostly associated with <0°C mean annual air and ground temperatures and the presence of at least discontinuous permafrost, which is in line with similar central and western European records and other paleo‐environmental archives. The new OSL ages constitute the first extended dataset on the timing of frost wedges in this undersampled area between the Fennoscandian and Alpine ice sheets, which is essential for reconstructing past permafrost extents and climate conditions, as well as for validating models of past permafrost dynamics in central Europe.

Combined different luminescence dating approaches on fluvial gravel deposits from the southern upper Rhine graben

In recent years, luminescence dating has witnessed significant advancements to overcome its traditional boundaries. However, methodological challenges persist when dating high-energy fluvial gravel deposits in proglacial settings, because partial bleaching and the scarcity of sand lenses complicate luminescence age estimation through conventional approaches. To address these issues, using rock surfaces of large clasts may overcome the limited availability of sand layers in some deposits and allow clast specific assessment of luminescence signal resetting at the time of deposition through the analyses of bleaching profiles. The Hartheim gravel pit in the southern Upper Rhine Graben of southwest Germany features a sedimentary succession deposited by distal braided river meltwater streams reworked during the late Pleistocene. Different luminescence approaches have been applied to sand lenses, the sandy matrix of gravel deposits and crystalline cobbles. Quartz optically stimulated luminescence (OSL) ages range between ∼19 and 22 ka, which represents the time just after the last glaciation maximum in the region. The OSL ages of the sandy matrix of ∼24–27 ka are in an agreement with the previous estimates, as these are from a stratigraphic lower position. However, post-IR infrared stimulated luminescence (pIRIR) ages of sand layer and sandy matrix both are some 3–6 ka older than the OSL ages, despite being internally very consistent. Luminescence depth profiles show that the signal was deeply reset in some cobbles, whereas in others only the IRSL signal in the surface layer appears to have been reset. The cobble IRSL ages show a relatively large spread, and it remains uncertain, if this is caused by incomplete bleaching or it reflects dosimetric issues. Nevertheless, overall, our results underscore the potential of rock surface luminescence dating to date fluvial deposits from the Upper Rhine Graben and similar settings.

Chronology by luminescence and radiocarbon on core sediments from the northeastern pearl river plain and implications for delta process

Accurate dating is the basis for deciphering eustatic and climatic changes on deltaic sedimentary processes. In the Pearl River Delta (PRD) plain of south China, scarce robust chronology hinders the detailed interpretation of sedimentary history. In this study, quartz optically stimulated luminescence (OSL) (21 samples), feldspar post-IR IRSL (pIRIR) (4 samples) and radiocarbon (14C) (2 samples) dating were applied to obtain detailed chronological framework of core SXG06 (23-m long to bedrock) from the northeastern PRD. SXG06 consists an upper marine unit (M1) and a lower marine unit (M2), separated by a terrestrial unit (mottled clay, T1). For M1, quartz OSL and 14C samples yielded ages from 5.2 ± 0.3 to 0.32 ± 0.02 ka. The sample on top of T1 produced a quartz OSL age of 35 ± 2 ka. For other 12 samples in T1 and M2, quartz OSL signals reached saturation and generated minimum ages (>51 ka). For these the saturated quartz OSL samples, feldspar pIR50IR250 provides an age range of 123 ± 7–105 ± 7 ka. The compilation of all the above ages and previous sedimentology data reveals that: (1) M2 was formed during marine transgression of Marine Isotope Stage (MIS) 5; (2) A hiatus with an age gap of between ∼35 ka and ∼5 ka was observed, which might be due to the low sea level and resultant weathering scouring; (3) Initial M1 deposits from the northeastern PRD postdated the central and southern PRD by ∼3 ka, indicating delayed delta development in the northeastern PRD during the Holocene. (4) SXG06 experienced slow deposition 0.3 m/ka in ∼5–3 ka because of the coevally decreased sediment supply, followed by accelerated deposition rate of 3 m/ka after ∼3 ka associated with strengthen human activity.

Chronology of core sediments from the south coastal Bohai Sea of eastern Asia and its implications for sedimentary history

The Shandong Peninsula along the coastal Bohai Sea in China is a vast alluvial plain formed by the Yellow River. It is an ideal place for investigating the evolution of landform in a river–sea interaction area where chronology is key. However, detailed optically stimulated luminescence (OSL) chronology studies of cores are still limited and have mainly concentrated on the Yellow River Delta, while they are scarce on the south coast of the Bohai Sea. In this study 16 OSL samples were collected from the upper 32 m of core DZK01 (192 m in depth) to establish a chronological framework using quartz OSL. Results indicated that the quartz OSL ages ranged from 217 ± 19 ka to 1.63 ± 0.14 ka, and we believe they were the minimum ages when De > ca. 200 Gy owing to OSL signal saturation. Our dating results reveal two sedimentary hiatuses with age gaps of 71–37 ka and 37–9.5 ka. Holocene sediments are located above a depth of 11.8 m with an onset age of approximately 9.5 ± 0.6 ka. Based on the sedimentary facies and dating results, no transgression sediment has been observed during marine isotopic stage (MIS) 3. This sedimentary sequence pattern is consistent with global sea-level change. We also summarized the extents of three transgressions around the Bohai Sea, and found very different patterns for different part of the coasts, e.g., in the north, the west, and the south. This requires further investigation.

High-resolution luminescence-dated sediment record for the last two glacial-interglacial cycles from Rodderberg, Germany

The Rodderberg Volcanic Complex (RVC) is well-known for the long climate record archived in its crater basin, which lasts for several glacial-interglacial cycles. However, a detailed chronological framework is still lacking. Here, we perform high-resolution luminescence dating on a 72.8 m-long sediment core with the optically stimulated luminescence (OSL) signal from fine-grained (4–11 μm) quartz and three kinds of post-infrared infrared (pIRIR) stimulated luminescence signals from fine-grained polymineral fractions. Together with magnetic susceptibility, grain size and quartz OSL sensitivity measurements, a numerical age framework is built for the upper half of the sediment core. Quartz OSL ages align well with pIRIR ages for the last 45 ka, but they underestimate in relation to pIRIR ages for ages beyond 45 ka. The three pIRIR signals, including the pIRIR signal at 225 °C (pIRIR225), the pulsed pIRIR signal at 150 °C (pulsed pIRIR150) and the multi-elevated-temperature pIRIR at 250 °C (MET-pIRIR250), yield consistent ages up to ca. 250 ka at a sediment depth of 37.5 m. Below that depth, dating limits of the protocols are reached. Nevertheless, our results indicate that sediments below 37.5 m predate Marine Isotope Stage (MIS) 7. Altogether, obtained ages reveal continuous dust accumulation during MIS 7 and MIS 6. One erosional event happened at the end of the Eemian (MIS 5e), which eroded the Eemian soil. The sedimentation rate during the Weichselian glacial period is tenfold lower compared to the sedimentation rate observed during MIS 7–6. This low sedimentation rate likely arises from the cessation of slope wash effects and the occurrence of various wind erosional events alternating with dust deposition as the basin is filled by dust. A notably high sedimentation rate is observed at the transition from MIS 6 to the Eemian, marked by the deposition of a 7 m-thick loess layer between 135 and 129 (±5) ka. This high sedimentation rate could be attributed to intensified slope wash and solifluction processes resulting from the thawing of permafrost at the time of deglaciation. Alternatively, it might be a signature of Heinrich event 11, during which strong winds brought large amounts of dust into the basin within a short time.

Correlations between quartz OSL dose-response curve and TL glow curve characteristics, and their implications for equivalent dose estimation

Optically stimulated luminescence (OSL) dating of quartz using the single-aliquot regenerative-dose (SAR) procedure requires construction of dose-response curves (DRCs). The shapes of DRCs and their characteristic saturation doses (D0 values) are well-known to be highly variable between samples and among individual grains from the same sample, but the factors that control DRC characteristics are imperfectly understood. Here we report correlations between OSL DRC shapes and thermoluminescence (TL) glow curve characteristics for a sample of quartz from northern Australia. Individual grains were measured using the SAR procedure and one of two preheat temperatures (160 °C and 260 °C), and grouped according to similarities in their DRC shapes. Grains from each DRC group were then physically transferred onto a separate disc for TL measurement as a multi-grain aliquot. A strong correlation was observed between DRC group and laboratory-irradiated TL glow curve shapes, along with some differences between the two preheats. Irrespective of the selected preheat, earlier saturating DRC groups are associated with the most intense 110 °C TL signal, and the least intense 325 °C TL signal, which corresponds to the main OSL trap. Later saturating DRC groups generally show the opposite trend. There are also trends within other regions of the glow curve and DRC group, such as prominent TL responses at 140–160 °C, 220–240 °C and 390–410 °C. We assessed the effect on the accuracy of equivalent dose (De) estimation using an associated radiocarbon age as an independent cross-check of the OSL ages for the DRC groups. De over- and under-estimates were obtained for some DRC groups. Most notably, grains preheated to 160 °C displayed a pattern of De values which decreased with an increase in D0. We relate this to variable concentrations of charge at the ∼230 °C TL trap prior to regenerative dose OSL measurements. OSL ages for most DRC groups preheated to 260 °C are close to the radiocarbon age, as are those of later saturating DRC groups preheated to 160 °C; the latter DRC groups have the smallest TL signals at ∼230 °C relative to the TL peak at 325 °C. The results of this study suggest that correlations between single-grain De and D0 values can occur due to underlying differences in the TL characteristics of grains with different DRC shapes. In the absence of independent age control and prior to measuring multi-grain aliquots of quartz, we recommend that OSL dating practitioners screen their samples for any single-grain patterns of De as a function of DRC shape, to determine the optimal SAR measurement conditions and data-analysis procedures for De estimation.

Post-glacial small delta process uncovered by luminescence and radiocarbon chronology of core sediments from coastal South China Sea

Reliable chronology is crucial for reconstructing delta processes. The past decades witnessed a boost of dating works on the most economically influential large deltas (i.e., subaerial area >1000 km2), but chronology remains lacking on many small deltas (i.e., subaerial area <1000 km2) that are also densely populated and economically active. Luohe River Delta (LRD) in the coastal South China Sea is such a small delta, whose evolution concerns hundreds of thousands of people, and literally no reliable dating results have been reported to support research of its processes. Herein, dating work combining radiocarbon (14C) on mollusk shells and quartz Optically Stimulated Luminescence (OSL) methods were performed on core LFZK06 from LRD, to test applicability of both methods by age comparison and to establish a chronological framework, using Bayesian age-depth models, of LRD for the first time. 14C ages are systematically c. 0.5–1 ka younger than OSL ages from the same depths. Such young bias of 14C ages in LRD contrasts with previously observed overestimated 14C results in the nearby Pearl River Delta (PRD), likely due to the distinction in bedrock types between Luohe River (granites and sandstones only) and Pearl River (limestone prevalence causing hardwater effect) drainages. Ages of core LFZK06 span from 57 ± 7 ka to 3.42 ± 0.05 cal ka BP and contain a hiatus between 57±7–11.9 ± 1.7 ka. Holocene deltaic sequence of the core shows three-stage sedimentary processes: (1) rapid deposition of prodelta/delta front sediments at 10.2‐0.4+0.5 ka–7.7‐0.3+0.4 ka related to rapid sea level rise, (2) hiatus during 7.7‐0.3+0.4 ka–5.7‐0.8+0.5 ka likely due to reduced sediments input or river channel migration, (3) rapid accumulation of delta plain sediments during 5.7‐0.8+0.5 ka–3.42‐0.85+0.42 ka reflecting depocenter shift toward core location. Moreover, changes of quartz OSL sensitivity were detected, indicative of sediment provenance transition. A change in sediment source from nearby granite weathering towards fluvial long-transported materials occurred at a depth of 24.7 m, with low quartz OSL sensitivity in the gravelly layer below (11.9 ± 1.7 ka) and one magnitude higher quartz OSL sensitivity in prodelta deposits above (10.2‐0.4+0.5 ka).

Underestimated single-aliquot quartz OSL ages of Late-Pleistocene sediments due to the dominance of medium component

Optically stimulated luminescence (OSL) dating technique has increasingly been employed to establish chronologies for coastal deposits since the Late Pleistocene. However, the commonly used single-aliquot quartz OSL dating method may yield inaccurate ages due to factors such as partial bleaching, luminescence characteristics, and the age limit of quartz. In this study, taking the Yangtze River Delta (YRD) as an example, single-aliquot and single-grain OSL dating using varying grain-sized quartz and K-feldspar were cross-checked to establish appropriate dating method for Late-Pleistocene sediments in coastal areas. The quartz OSL signals of the upper 24 m Holocene sediments were dominated by the fast component, and the ages obtained through OSL and AMS 14C ages agree. Conversely, the lower 24–91 m section, representing the last glacial-interglacial cycle, reveals a notable underestimation of quartz OSL ages, with a maximum underestimation of 250%, attributed to the influence of signal components. For samples within the dating limit of quartz (less than 70 ka), the single-grain method effectively mitigates the issue associated with the signal component. Single-grain K-feldspar technique proves valuable for accurately determining the age of those older sediments exceeding 70 ka. Through cross-checking between different OSL dating methods, sediments initially attributed to marine isotope stage (MIS) 3 (36–60 ka) are re-identified as deposited during MIS 5 (80–130 ka). This study highlights the necessity of assessing the variability in luminescence characteristics before applying a single OSL dating protocol to all samples from different sedimentary facies within a single core.

Tectonic geomorphology and Quaternary slip history of the Fuyun fault, southwestern Altai Mountains, central Asia

The northwest-trending Altai Mountains of central Asia expose a complex network of thrust and strike-slip faults that are key features accommodating intracontinental crustal shortening related to the Cenozoic India-Asia collision. In this study, we investigated the Quaternary slip history of the Fuyun fault, a right-lateral strike-slip fault bounding the southwestern margin of the Altai Mountains, through geologic mapping, geomorphic surveying, and optically stimulated luminescence (OSL) geochronology. At the Kuoyibagaer site, the Fuyun fault displaces three generations of Pleistocene–Holocene fill-cut river terraces (i.e., T3, T2, and T1) containing landslide and debris-flow deposits. The right-lateral offsets are magnified by erosion of terrace risers, suggesting that river course migration has been faster than slip along the Fuyun fault. The highest Tp2 terrace was abandoned in the middle Pleistocene (150.4 ± 8.1 ka uppermost OSL age) and was displaced 145.5 +45.6/–12.1 m along the Fuyun fault, yielding a slip rate of 1.0 +0.4/–0.1 mm/yr since the middle Pleistocene. The lower Tp1 terrace was abandoned in the late Pleistocene and aggraded by landslides and debris flows in the latest Pleistocene–Holocene (36.7 ± 1.6 ka uppermost OSL age). Tp1 was displaced 67.5 +14.2/–6.1 m along the Fuyun fault, yielding a slip rate of 1.8 +0.5/–0.2 mm/yr since the late Pleistocene. Our preferred minimum slip rate of ~1 mm/yr suggests the Fuyun fault accommodates ~16% of the average geodetic velocity of ~6 mm/yr across the Altai Mountains. Integration of our new Fuyun slip rate with other published fault slip rates accounts for ~4.2 mm/yr of convergence across the Chinese Altai, or ~70% of the geodetic velocity field.

Millennial-scale fluctuations of palaeo-ice margin at the southern fringe of the last Fennoscandian Ice Sheet

Abstract. The paper presents the first terrestrial record of millennial-scale palaeo-ice margin oscillations at the southern fringe of the last Fennoscandian Ice Sheet (FIS) during the last glacial cycle. The study area is located in northern Poland close to the last FIS maximum limit. The chronology and dynamics of palaeo-ice margin oscillations at the southern fringe of the FIS are based on combined luminescence and 10Be surface exposure dating. Optically stimulated luminescence (OSL) was used to date sandy deposits (fluvioglacial sediments and aeolian deposits filling fossil periglacial wedges) intercalating basal till layers. The most likely age of the tills was constrained by Bayesian modelling of the sequence of OSL ages and lithostratigraphy. 10Be surface exposure dating was used on erratic boulders left during the final retreat of the last FIS and resting on the surface of glacial landforms. Our results, which are mainly based on OSL chronology and Bayesian modelling, indicate millennial-scale oscillations of the last FIS in northern Poland between ∼19 and ∼17 ka. The last FIS retreated and re-advanced over a relatively short period of time (2–3 ka), leaving lithostratigraphic records (basal tills) of three ice re-advances over a millennial-scale cycle: 19.2±1.1, 17.8±0.5 and 16.9±0.5 ka. Despite 10Be surface exposure ages obtained for 14 erratic boulders being poorly clustered, the main mode of age distribution occurs at ∼18 ka and indicates a possible signal of the ice sheet retreat after one of the re-advances. We explore the dynamics of these oscillations and compare the proposed cycles of the southern FIS advances and retreats with existing patterns of the last deglaciation and millennial-scale fluctuations of the last FIS inferred from marine records.

Coastal Evolution of Satingpra Peninsula, Songkhla Province: Implications for Understanding Songkla Lagoon Formation

Songkhla Lagoon has been studied for decades, but there is no clear evidence of its origin. As a barrier to the lagoon, the Satingpra Peninsula plays a crucial role in understanding its formation. Eleven sediment samples from sand ridges and tidal flats on the Satingpra Peninsular were collected and analysed for granulometry and geochronology. Both coarse-grained and fine-grained quartz-rich fractions were utilised to prepare samples of aliquots. The optically stimulated luminescence (OSL) dating was performed using the single-aliquot regenerative dose method for a determined (deposited) age. In addition, previous research, geological surveys and geochronological data were combined to explain their formation in this region. The OSL ages in the present study indicated that the late Holocene regression occurred between 0.36 and 3.27 ka (ka stands for 1,000 years). Integrated with previous studies, recorded ages dating back to the mid-Holocene sea level rise (ca. 6.5 ka) and the subsequent late-Holocene decline, indicate that both the old lagoon and middle beach ridge exhibit a sand ridge formation that runs parallel to the shoreline, extending from the south to the north. The middle sand, in this study, formed from about 3.02 to 1.5 ka ago resulting in the lagoon being isolated from the sea during that time. The lagoonal tide led the deposition as the present tidal flat from 3.3 to 1.7 ka. About 2.19 ka ago, the inner and middle ridges formed due to wind-driven processes influenced by a dry climate. This was followed by a continued sea level regression, leading to the formation of the outer ridge around 1.5 ka ago when the sea level was 1.4 m below the present sea level. However, it’s essential to consider this sea level data in relation to the tectonic and human-induced land motions in the surrounding area. HIGHLIGHTS OSL ages, based on average dose model at the Northern Satingpra Peninsula were 1.04 - 3.27 ka. The old sand ridges of the Satingpra Peninsula prograde northward after mid Holocene sea level highstand. Paleo sea level based on wind-wave sediments contact was 1.4 m lower than present day at 1.46 ka. GRAPHICAL ABSTRACT

Flood events in the lower reaches of the Yellow River: OSL and radiocarbon dating on the Anshang site

The lower reaches of the Yellow River have witnessed numerous episodes of flooding and considerable shifts in its course. Examining flood records within the Yellow River basin offers invaluable insights into ancient human settlements, agricultural practices, trade routes, and technological advancements of ancient Chinese civilizations. However, dating these fluvial sediments poses a considerable challenge due to either the scarcity of organic material for radiocarbon (14C) dating or the potential incomplete bleaching of sediments for optically stimulated luminescence (OSL) techniques. This study focused on the Anshang site located in Henan Province, we obtained OSL ages from distinct grain size fractions of quartz and cross-verified them with independent acceleration mass spectrometry (AMS) 14C ages. The findings revealed that both coarse quartz grains (CG) and medium quartz grains (MG) underwent complete bleaching in silt-dominated flood deposits and shallow lacustrine deposits. Conversely, the OSL ages of CG and MG quartz were notably overestimated by approximately 3–6 ka in silty clay-dominated flood deposits. Upon comparing the OSL ages with AMS 14C ages, it was evident that bulk organic matter AMS 14C ages aligned with CG OSL ages in shallow lacustrine deposits, but they appeared older than CG OSL ages in flood deposits. However, the AMS 14C ages from plant demonstrated good consistency. Consequently, we successfully identified flood-lacustrine sediments dating back to approximately ∼13 ka, ∼8–3 ka, ∼2.6 ka, ∼1 ka, and the last few hundred years, aligning well with historical documentation and earlier research. The regional evidence presented herein enhances our understanding of the applicability of OSL dating and AMS 14C dating in fluvial-lacustrine sediments. Armed with these new ages, we constructed a reference chronology for archaeological localities situated in the fluvial sediments of the lower reaches of the Yellow River.

Combined optically stimulated luminescence and radiocarbon dating of aeolian dunes in Arctic Sweden

AbstractMultiple parabolic sand dune fields formed in Arctic Sweden after the last deglaciation, facilitated by an abundance of loose glaciofluvial sediment, limited vegetation cover and strong winds. Following initial stabilisation, these dunes underwent repeated reworking after fire events, as evidenced by the presence of buried soils, charcoal layers and redeposited sands in the dune stratigraphy. These reworking events may be driven by wider climate forcing; however, to date, no chronological framework exists for this activity in Sweden. As such, here, we apply quartz optically stimulated luminescence (OSL) dating of Arctic Swedish sand dunes using two dunes at the sites of Vastakielinen and Jorggástat. Resultant double‐SAR (single aliquot regenerative dose) quartz OSL ages are in good agreement with independent ages provided by 14C dating of charcoal fragments recovered from charcoal layers within the dunes, and we conclude that the chosen protocol is generally well suited for dating aeolian reworking of dune sediments in Arctic Sweden. While feldspar contamination limits precise age assignment for initial dune movement, our results nonetheless suggest repeated and long‐lasting aeolian activity in Arctic Sweden throughout the Holocene and, although there are differences in detail, further suggest some general trends in terms of dune stability and reworking over Arctic Fennoscandia.

Origin and depositional background of the Holocene black soil in Northeast China: Evidence from grain-size analysis and optically stimulated luminescence dating

The fertile Holocene black soil of Northeast China make it a major grain producing region, however, this soil is increasingly vulnerable to erosion. Knowledge of the origin and depositional background of the black soil in Northeast China can provide a reference for the conservation of the soil resources of this region. To this end, we examined the grain-size characteristics of the Holocene black soil across the plains in Northeast China, and we conducted optically stimulated luminescence (OSL) dating of the underlying stratum. The western Holocene black soils have a bimodal grain-size distribution similar to that of the sandy loess deposits on the Chinese Loess Plateau. In contrast, the eastern Holocene black soils mostly have a trimodal grain-size distribution similar to that of reworked loess in flood plains. From west to east, the median grain size and the sand content gradually decrease from >120 μm to <20 μm and from >80 % to <20 %, respectively. This eastward fining trend is consistent with the prevailing westerly winds during the dust storm season, indicating a wind-blown origin for the black soil material which was transported primarily from the adjacent sandy lands. Furthermore, our OSL ages reveal that the underlying stratum of the Holocene black soil was primarily deposited during the last glacial period, with the relatively wide depositional age range of 2–65 ka. This suggests unstable geomorphological conditions in Northeast China prior to the formation of the black soil, which may have resulted from the enhanced erosion and decreased vegetation cover.