Quaternary Geochronology最新文献

{"title":"Direct dating of an ancient stone causeway at Karlslunde, Sjælland, Denmark: A combined approach using luminescence from the surfaces of granitic cobbles and coarse grains from disaggregated heated rocks","authors":"W.K. Thompson ,&nbsp;J. Christensen ,&nbsp;A.S. Murray ,&nbsp;M. Autzen","doi":"10.1016/j.quageo.2024.101549","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101549","url":null,"abstract":"<div><p>In 2017 part of an ancient stone causeway was uncovered at Karlslunde on the island of Sjælland, Denmark. With no artefacts found at the site, optically stimulated luminescence dating of coarse grains, grains derived from disaggregated rocks, and surficial rock chips obtained directly from granitic road cobbles were used to determine the time of construction. Some granitic road cobbles were visibly disaggregating at the time of excavation, and laboratory measurements revealed surprising strong fast component dominated quartz sensitivity from these samples. It was concluded that some of the rocks used in the causeway had been heated, presumably prior to incorporation in the structure. Dose recovery plateau experiments using sedimentary quartz and quartz grains recovered by gently disaggregating heated rocks suggested the use of a 220/180 °C preheat/cut-heat combination (DR ratio 0.999 ± 0.018; n = 40); this reduced the risk of thermal transfer in these young samples. IRSL signals were used for rocks that could not be disaggregated. The L/T burial profiles obtained from two unheated rocks (1 granite, 1 felsic gneiss) indicated they had been exposed for sufficient time for us to be confident of obtaining accurate IRSL ages. The post-IR IRSL₁₈₀ signals were also measured in these two cobbles; the bleaching front was shallow and the signal was only sufficiently reset to allow accurate determination of D_e on one rock. After subtracting a residual, the dose recovery ratio results for the unheated rocks post-IR IRSL₁₈₀ and IR₅₀ were 1.006 ± 0.012 (n = 10) and 0.937 ± 0.007 (n = 10), respectively. In total 8 ages were accepted; 4 coarse grained sediment quartz ages from an unexcavated part of the road surface, 2 fading corrected IR₅₀ ages from surface slices from non-disaggregated cobbles, and 2 quartz ages from disaggregated (apparently heated) cobbles. IRSL signals from the sedimentary and heated samples were used primarily to assess the degree of resetting of the quartz blue-stimulated OSL; both the post-IR IRSL and IR₅₀ signals significantly over-estimated the quartz age. However, the sedimentary quartz ages, the heated cobble quartz ages and the fading corrected IR₅₀ ages from the unheated road cobbles, are consistent and likely reflect a construction age of ∼2ka ago.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101549"},"PeriodicalIF":2.7,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000530/pdfft?md5=2b190eaf42d3a5c7fc7045f78125f031&pid=1-s2.0-S1871101424000530-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141084618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescence dating of cobbles buried in moraines from the source area of the Litang River (Konglongluo Valley), eastern Tibetan Plateau","authors":"Kunmei Yang ,&nbsp;Xianjiao Ou ,&nbsp;Yang Li ,&nbsp;Geraint Jenkins ,&nbsp;Pan Yao ,&nbsp;Daobin Tang ,&nbsp;Yantian Xu ,&nbsp;Jinming Xie ,&nbsp;Lanhua Zeng ,&nbsp;Xiangjun Liu","doi":"10.1016/j.quageo.2024.101547","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101547","url":null,"abstract":"<div><p>Moraine deposits are difficult to date using conventional luminescence techniques, especially such deposits without glaciofluvial sand lenses incorporated within the feature. Recently developed rock surface luminescence burial dating has shown the potential for constraining heterogeneous glacial till sediments. However, the wider applicability of the luminescence dating of cobbles obtained from moraine deposits needs to be tested. Thirty-one buried granite cobbles from different generations of terminal moraines of the last deglaciation moraine series in the source area of the Litang River, eastern Tibetan Plateau, were collected. Eight cosmogenic nuclide ¹⁰Be exposure ages were generated from eight boulders obtained from the ridges of two moraines, to provide an external age control. A post-IR₅₀ IRSL₂₂₅ single aliquot regenerative dose (SAR) protocol was applied to measure the luminescence signal from rock slices. The IRSL₅₀ L_n/T_n-depth profiles from 23 cobbles showing surface age plateaus (up to 12 mm), indicating that the material was well-bleached prior to deposition. The depth of the bleaching front is variable between individual cobbles from the same deposit. Three distinct methods were employed to observe and correct for any anomalous fading present. We observe age agreement from different cobbles collected from the same moraine deposits, illustrating the reproducibility at our selected locations. The luminescence ages of burial cobbles (15.5 ± 2.1 ka to 20.0 ± 1.6 ka) align with geomorphic relationships and ¹⁰Be exposure ages. Particularly, the age of cobbles from one of the moraines (20.0 ± 1.6 ka) is consistent with independent ¹⁰Be exposure ages (18.6 ± 1.2 ka) of boulders from the same moraine. This study demonstrates the applicability of the luminescence dating of moraine deposits, using cobbles, and provides deeper insights of the last deglaciation in the eastern Tibetan Plateau.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101547"},"PeriodicalIF":2.7,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141094924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orbital global change drove fluvial aggradation and incision in Tibetan upper Mekong river: Chronological perspectives","authors":"Yinjun Zhou ,&nbsp;Junfeng Han ,&nbsp;Qinjing Shen ,&nbsp;Yantian Xu ,&nbsp;Yaling Tao ,&nbsp;Penghui Lin ,&nbsp;Yuansen Lai ,&nbsp;Yixuan Wang ,&nbsp;Zhongping Lai","doi":"10.1016/j.quageo.2024.101546","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101546","url":null,"abstract":"<div><p>The Tibetan Plateau (TP), often known as the “Asia Water Tower”, is the source region of several continental-scale rivers. However, due to the extremely difficult access and harsh living conditions in the interior plateau, fluvial processes in the headwaters of these large rivers and their connections to global climate changes remain unknown. In this study, the luminescence (using both quartz and K-feldspar) and AMS ¹⁴C dating techniques were employed to date the four terraces of the Zado Basin in order to elucidate the aggradation and incision history of the initial intermontane basin in the headwater of the Mekong River. One sample from the upper part of T4 terrace (which features a 12 m thick gravel layer, the base of which is unexposed) provides a K-feldspar pIR₅₀IR₂₂₅ age of 125 ± 10 ka, indicating that the initial deposition of this terrace could predate marine isotope stage (MIS) 5. Considering the margin of error, this age also suggests that the onset of incision on T4 terrace during the climate transition from MIS 6 (glacial) to early MIS 5 (interglacial). This incision likely occurred due to increased meltwater and precipitation, causing the Mekong carving into the bedrock for more than 50 m. Eight luminescence samples are collected from T3 terrace (26.5 m in thickness) with ages ranging from 83 ± 7.6 ka to 22.3 ± 1 0.2 ka, indicating T3 formation/aggradation from late MIS 5 to the Last Glacial Maximum (LGM), possibly owing to reduced precipitation and enhanced sediment supply from intensive glacial activities. At around 22 ka, the Mekong once again shifted towards incision, crafting the T3 terrace, situated roughly 28 m above the current floodplain. This incision event was recorded by two luminescence samples from a sandy lens located at the top of gravel layer of T3, with OSL ages of about 22 ka. Floodplain samples from T2 and T1, dated at 16 ka and 2.8 ka respectively, demonstrate that from the last deglaciation to the Holocene, the Mekong continued its downward incision. This erosion developed two cut and fill terraces at elevations of 22 m and 11 m above the present floodplain, likely due to increased precipitation and enhanced vegetation at that time. Overall, the glacial–interglacial climate changes were the most likely driving force behind fluvial processes in the upper Mekong basin since the Late Pleistocene, with aggradation occurring during the glacial period while incision in deglacial and interglacial periods, suggesting a close link between the fluvial geomorphic evolution and orbital-scale climate changes.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101546"},"PeriodicalIF":2.7,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141097778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A formation record of modern Nitraria tangutorum nebkhas on the Ordos Plateau of northern China based on optically stimulated luminescence dating","authors":"Yue Du ,&nbsp;Ruijie Lu ,&nbsp;Luo Ma ,&nbsp;Xiaokang Liu ,&nbsp;Dongxue Chen ,&nbsp;Yingna Liu","doi":"10.1016/j.quageo.2024.101550","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101550","url":null,"abstract":"<div><p>Nebkhas, as special biologically mediated aeolian landforms, play an important role in indicating regional aeolian activities and aeolian environmental changes. The Ordos Plateau is located in arid and semiarid regions of northern China that have a wide distribution of <em>Nitraria tangutorum</em> nebkhas. There are few chronological records of nebkha formation, so the history of the formation and evolution of nebkhas in the plateau is still unclear. In addition, the optically stimulated luminescence (OSL) dating method, which has been widely used in the dating of Holocene aeolian sediments, has not yet been applied to the dating of nebkha sediments in the Ordos Plateau. In this study, OSL methods were used to discuss the formation age and relevant aeolian activities of <em>Nitraria tangutorum</em> nebkhas in the Ordos Plateau. The results demonstrated that (1) the coarse-grained quartz OSL signals of nebkha sediments were insensitive and thus were inapplicable by the single aliquot regenerative (SAR) protocol. (2) The luminescence characteristics of the K-feldspar fraction and internal checks of the post-infrared infrared-stimulated (pIRIR) dating indicated that the pIR₅₀IR₁₇₀ protocol with 200 °C of preheating was applicable for D_e determinations of nebkha sediments. (3) The residual doses of the pIRIR₁₇₀ signals ranging from 0.02 to 0.14 Gy should be considered when calculating D_e values. (4) Bayesian age-depth models were used for the <em>Nitraria tangutorum</em> nebkha sedimentary sequences. The formation of nebkhas occurred during a relatively dry climate period accompanied by strong aeolian activity. That ∼0.38 ka was the main growth period of <em>Nitraria tangutorum</em> nebkhas. This study is the first report of the formation age of nebkhas of more than one hundred years in the region.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101550"},"PeriodicalIF":2.7,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141090669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Amino acid dating of pleistocene mammalian enamel from the river thames terrace sequence: A multi-taxon approach","authors":"M.R. Dickinson ,&nbsp;K. Scott ,&nbsp;N.F. Adams ,&nbsp;A.M. Lister ,&nbsp;K.E.H. Penkman","doi":"10.1016/j.quageo.2024.101543","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101543","url":null,"abstract":"<div><p>Amino acid geochronology can provide effective relative dating frameworks for the Pleistocene and has enabled correlation of terrestrial deposits to the global climatic fluctuations described by the marine oxygen isotope record. Using methods developed for the analysis of intra-crystalline amino acids in tooth enamel, we aimed to construct an enamel-based amino acid geochronology for the terrace deposits in the valley of the River Thames in southern Britain using different mammalian taxonomic groups: elephant, horse and bison. To achieve this, chiral amino acid analysis was applied to 58 elephantid, 21 horse and 15 bison teeth from 10 horizons in the Upper Thames Valley, three in the Lower Thames Valley and one from a Thames tributary in the Lea Valley. We evaluate differences in the rates of amino acid breakdown between the taxa and establish which species are similar enough to enable comparison for relative dating purposes. The relative dating of the river terrace deposits is in good agreement with the terrace stratigraphy, biostratigraphy, and other independent estimates of age for all three taxonomic groups. These frameworks demonstrate the potential of enamel-based amino acid geochronologies for relative dating of Middle–Late Pleistocene deposits in the UK, and establish an aminostratigraphic framework from which the dating of other tooth material can be refined. Enamel offers an opportunity to evaluate the age of sites where shell material is absent or poorly preserved. It can also, crucially, provide direct relative dating of mammalian fossils, which are often the focus of study in terms of their evolution, distributional changes or extinction. Direct dating negates the risk that the mammal fossils themselves might be reworked, or of different ages to shell, sediments or other dated material in the same deposits; it also enables archived samples with insecure provenance (e.g. from early 17th-19th century collections) to be directly dated.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101543"},"PeriodicalIF":2.7,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000475/pdfft?md5=f58ea1c2b545abfa9fc16637bbfab9db&pid=1-s2.0-S1871101424000475-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141090668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigations on single and multi-grain optically stimulated luminescence (OSL) sensitivity and electron spin resonance (ESR) signals in quartz derived from sandstones: Insights on provenance of quartz in ancient depositional systems","authors":"Aditi K. Dave ,&nbsp;Daniela Constantin ,&nbsp;Relu D. Roban ,&nbsp;Mihai N. Ducea ,&nbsp;Cristian Panaiotu ,&nbsp;Alida Timar-Gabor","doi":"10.1016/j.quageo.2024.101548","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101548","url":null,"abstract":"<div><p>Trapped charge techniques of luminescence and electron spin resonance (ESR) are classic tools for dating Quaternary deposits. Over the past decade, these techniques have been routinely applied to investigate provenance and/or the sedimentary history of quartz grains based on their different luminescence and ESR characteristics. Of these, optically stimulated luminescence (OSL) sensitivity is one of the most widely investigated parameter for luminescence-based provenance approach. A majority of studies on this parameter are based on evaluation of multi-grain quartz OSL sensitivity of the samples. This is particularly concerning because single-grain quartz luminescence studies have shown that the luminescence signal of a multi-grain aliquot is contributed by less than ∼1–10% of the total grains. Since the sole criteria for discrimination of sources based on luminescence sensitivity relies on its intensity, therefore the results based on multi-grain analysis will most likely be skewed depending on the ‘proportion’ and ‘brightness’ of a few grains. This demands a need to evaluate the potential of single-grain quartz OSL sensitivity in provenance studies. In this study, we investigate single and multi-grain quartz OSL sensitivity from compositionally different sandstones with well-characterised sources based on U–Pb zircon ages. We further complement this analysis with characterisation of ESR centres commonly used in quartz provenance, namely E′₁ and [AlO₄]⁰ centres. Our study shows that single-grain quartz OSL sensitivity can help distinguish between sediments that have a predominant input from a single source as compared to those with contribution from multiple sources, which otherwise cannot be inferred from multi-grain studies. Moreover, our results on characterisation of quartz-based ESR intensity of E′₁ and saturated [AlO₄]⁰ centres successfully differentiates between sandstones and further complements the luminescence-based characterisation.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101548"},"PeriodicalIF":2.7,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000529/pdfft?md5=a9fa2253ce41097997626715a74ab80a&pid=1-s2.0-S1871101424000529-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141084063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescence and thermometry studies of plant opal phytoliths","authors":"Joel Q.G. Spencer ,&nbsp;David C.W. Sanderson ,&nbsp;Mikaela Rader ,&nbsp;Scott K. Fitzgerald ,&nbsp;Charlie L. Rex ,&nbsp;Myroslav Sprynskyy ,&nbsp;Richard A. Staff","doi":"10.1016/j.quageo.2024.101544","DOIUrl":"10.1016/j.quageo.2024.101544","url":null,"abstract":"<div><p>We have investigated the luminescence properties of plant opal phytoliths to assess their suitability for determination of age and/or thermometric information from soil and sediment sequences. This study examined a &lt;2.37 gcm⁻³ density fraction in parallel with quartz grains from samples collected from alluvial terraces. We observed comparable optically stimulated luminescence (OSL) from the phytolith fraction to the quartz, and thermoluminescence (TL) with broader peaks and continuum to higher temperatures. Scanning electron microscopy (SEM) data suggested the presence of opal clasts and contaminant minerals. To better understand the luminescence from opal phytoliths we analyzed a suite of biogenic materials including very pure diatoms, phytoliths, and quartz reference materials. We observe low sensitivity but measurable OSL signals in all the materials analyzed, and infrared stimulated luminescence (IRSL) signals with fast decay rates exceeding those of more typical feldspars in some of the purer materials. TL signals are similar to those observed for glasses and suggests dose response might extend beyond quartz saturation levels. Preliminary investigations of OSL dose response show very promising growth characteristics for opal phytolith samples and all other biogenic silica materials analyzed.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101544"},"PeriodicalIF":2.7,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141024069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A luminescence dating study of the upper part of the loess-palaeosol sequence at kuldara, Khovaling Loess Plateau, Tajikistan","authors":"J.-P. Buylaert ,&nbsp;A. Challier ,&nbsp;E.P. Kulakova ,&nbsp;N.A. Taratunina ,&nbsp;K.J. Thomsen ,&nbsp;A.O. Utkina ,&nbsp;P.M. Sosin ,&nbsp;O.A. Tokareva ,&nbsp;A.A. Anoikin ,&nbsp;T.U. Khujageldiev ,&nbsp;C. Karayev A ,&nbsp;N.K. Ubaydulloev ,&nbsp;A.S. Murray ,&nbsp;R.N. Kurbanov","doi":"10.1016/j.quageo.2024.101545","DOIUrl":"10.1016/j.quageo.2024.101545","url":null,"abstract":"<div><p>The aim of this study was to develop an independent luminescence chronology for the upper part of the important Loess Palaeolithic site at Kuldara (Khovaling Loess Plateau, Tajikistan). We applied high sampling-depth resolution (n = 85) luminescence dating to the upper ∼26 m of the sequence from loess L4 to pedocomplex PC0. Luminescence characteristics of the post-IR₂₀₀ IRSL₂₉₀ signal from coarse-silt polymineral grains are satisfactory (reproducible growth and good dose recovery). Comparison with quartz OSL for samples &lt;50 ka and results from modern analogues (Challier et al. these proceedings) shows that the pIRIR_200,290 signal is, as expected, sufficiently bleached at deposition. The luminescence chronology extends back to ∼250 ka and shows distinct erosional hiatuses ranging in duration from ∼15 ka to a full glacial-interglacial cycle (∼100 ka); some of these breaks were not identifiable in the field. We suggest an upper dating limit of 2.5xD_c; this yields minimum ages of ∼300 ka for this material. Dust Accumulation Rates (DAR) are reconstructed for the Late Pleistocene (from ∼100 to ∼40 ka) and reveal, next to several minor dust accumulation peaks, two major peaks at the end of MIS5 (∼75 ka) and at MIS3b (∼40 ka). We conclude that detailed post-IR₂₀₀ IRSL₂₉₀ dating of loess-palaeosol sequences in Tajikistan is necessary to exploit fully the potential of this important terrestrial (dust) record.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101545"},"PeriodicalIF":2.7,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000499/pdfft?md5=71ee15bb221dab24f621ac008065bcc0&pid=1-s2.0-S1871101424000499-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141052400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of De values from Late Pleistocene alluvial deposits on the coast of Galicia (NW Spain) using BayLum or Analyst-based procedures","authors":"Carlos Arce-Chamorro ,&nbsp;Guillaume Guérin","doi":"10.1016/j.quageo.2024.101540","DOIUrl":"10.1016/j.quageo.2024.101540","url":null,"abstract":"<div><p>The coastal sedimentary record of Galicia (NW Spain) is important to study sea-level oscillations during the Late Quaternary. The alluvial deposits preserved in the Ria de Coruña and Ria de Arousa are remnants of fluvial valleys flooded by the sea during the successive Pleistocene and Holocene transgressions. A first chronological study by Optical Stimulated Luminescence (OSL)- revealed a fast-component dominated, but dim OSL signal emitted by quartz from this area. Equivalent dose distributions, as obtained with the Analyst software, yielded large overdispersion values, which were negatively correlated to the potassium concentration in the sediment, thus suggesting the influence of beta dose rate heterogeneities. Nevertheless, for most samples many aliquots were considered in saturation, leading to a palaeodose and age underestimation – regardless of the model choice for age calculation. In this paper, we present new analyses using the open-source R package BayLum, as the so-called saturated aliquots may be incorporated in age calculation. Thus, we test this model performance and more commonly used models in retrieving large doses. Then, we discuss the implications for age calculation for these continental sediments formed during the Late Pleistocene.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101540"},"PeriodicalIF":2.7,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S187110142400044X/pdfft?md5=d145af138dc41482113dca132cd885a4&pid=1-s2.0-S187110142400044X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141056295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luminescence dating of Late Pleistocene sea level change and cryogenesis in the northern Caspian region (Chernyy Yar section)","authors":"N. Taratunina ,&nbsp;J.-P. Buylaert ,&nbsp;A. Murray ,&nbsp;T. Yanina ,&nbsp;I.D. Streletskaya ,&nbsp;R. Kurbanov","doi":"10.1016/j.quageo.2024.101538","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101538","url":null,"abstract":"<div><p>During the Quaternary sedimentation in the southern part of the Caspian Lowland was influenced significantly by the Caspian Sea. This is expressed both in accumulation of marine/lagoon sediments as a result of transgressive phases, as well as erosion of sediments, which leads to an incompleteness in the geological record. The most detailed record of Later Quaternary sedimentation is found in the Lower Volga region, where a series of Caspian Sea transgressions, Volga River alluvium and loess-palaeosol series provide an excellent archive of the evolution of the climate and landscapes of the past. We have studied one of the reference sections, at Chernyy Yar, in which a series of major stages of regional sedimentations is recorded. Description of the Late Quaternary sediments and luminescence dating allowed us to obtain, for the first time, a detailed chronostratigraphy for the southern part of the Lower Volga. Our results show that the quartz OSL and feldspar pIRIR_50,290 signals were sufficiently bleached before deposition and uncertainties in bleaching have a negligible impact on the reliability of the luminescence ages. The new luminescence chronology described here, based on quartz OSL and K-feldspar pIRIR₂₉₀ ages, suggests five major stages during the Late Quaternary: (1) a stable alluvial sedimentation of the Volga River between 130 and 105 ka (MIS 5e/d), when the thick Chernyyar alluvial suite formed regionally during the Late Khazarian transgression of the Caspian Sea; (2) a stage when the retreat of the Khazarian transgression formed a very broad floodplain about 85 ka ago, and promoted Volga channel incision. New findings shows that the Atelian regression – a major event in the Late Quaternary of the Caspian Sea – began after ∼60 ka; (3) subaerial sedimentation during MIS 4 with evidence of cryogenic processes at ∼40 ka, reliably dated for the first time in this southern part of the East European Plain; (4) about 24 ka ago, the largest Late Quaternary Khvalynian transgression reached the Chernyy Yar; (5) after the subsequent regression at ∼14–15 ka some part of the marine record was eroded and the Holocene kastanozem soil formed.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101538"},"PeriodicalIF":2.7,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000426/pdfft?md5=0760e0b67864b5c401c608f272a5b120&pid=1-s2.0-S1871101424000426-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140951826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}