Pub Date : 2024-06-21DOI: 10.1016/j.quageo.2024.101568
Hao Ji , Chun-Ru Liu , Wen-Peng Li , Chuan-Yi Wei , Bhupati Neupane , Gong-Ming Yin
Assessing the adequate bleaching of quartz Electron Spin Resonance (ESR) signals at the time of deposition is essential for sediment ESR dating. In this study, we focus on the Datong volcanic group is situated in Datong City, Shanxi Province, and is among the most renowned volcanic groups in China. The eruption within the Datong volcanoes during a geological period resulted in extensive high-temperature lava flow that directly overlaid Quaternary lacustrine deposits and subjected the underlying lacustrine layers to high-temperature heating. Thus, an investigation of the field profile in the Yujiazhai area, southeast of the Datong Volcanic Group, shows a novel approach for assessing the bleaching extent of ESR centers. This is accomplished by comparison of the DE values of the Al and the Ti–Li centers in partly-heated layer sample. The result reveals that quartz Al and Ti–Li centers in the lacustrine sediments appear to undergo sufficient bleached during transportation and natural bleaching processes in the study area. Furthermore, this study provides insight into the chronology of volcanic eruption in the Yujiazhai area, estimating an eruption age of approximately 300 ka. This volcanic activity most likely corresponds to the third volcanic activity period in the Datong region.
评估沉积时石英电子自旋共振(ESR)信号的漂白程度对于沉积物的 ESR 测定至关重要。大同火山群位于山西省大同市,是中国最著名的火山群之一。大同火山群在某一地质时期的喷发造成了大面积的高温熔岩流,直接覆盖了第四纪湖相沉积,并使下伏湖相地层受到高温加热。因此,对大同火山群东南部于家寨地区野外剖面的调查显示了一种评估 ESR 中心漂白程度的新方法。这种方法是通过比较部分加热层样品中铝和钛锂中心的 DE 值来实现的。结果表明,在研究区域的运输和自然漂白过程中,湖沼沉积物中的石英铝和钛锂中心似乎经历了充分的漂白。此外,本研究还对余家寨地区的火山喷发年代学进行了深入研究,推测其喷发年代约为 300 ka。这一火山活动很可能与大同地区的第三次火山活动期相吻合。
{"title":"Evaluating signal bleaching of Al and Ti–Li centers in fluvio-lacustrine sediments of Datong, North China, and its implications for the volcanic eruption chronology","authors":"Hao Ji , Chun-Ru Liu , Wen-Peng Li , Chuan-Yi Wei , Bhupati Neupane , Gong-Ming Yin","doi":"10.1016/j.quageo.2024.101568","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101568","url":null,"abstract":"<div><p>Assessing the adequate bleaching of quartz Electron Spin Resonance (ESR) signals at the time of deposition is essential for sediment ESR dating. In this study, we focus on the Datong volcanic group is situated in Datong City, Shanxi Province, and is among the most renowned volcanic groups in China. The eruption within the Datong volcanoes during a geological period resulted in extensive high-temperature lava flow that directly overlaid Quaternary lacustrine deposits and subjected the underlying lacustrine layers to high-temperature heating. Thus, an investigation of the field profile in the Yujiazhai area, southeast of the Datong Volcanic Group, shows a novel approach for assessing the bleaching extent of ESR centers. This is accomplished by comparison of the D<sub>E</sub> values of the Al and the Ti–Li centers in partly-heated layer sample. The result reveals that quartz Al and Ti–Li centers in the lacustrine sediments appear to undergo sufficient bleached during transportation and natural bleaching processes in the study area. Furthermore, this study provides insight into the chronology of volcanic eruption in the Yujiazhai area, estimating an eruption age of approximately 300 ka. This volcanic activity most likely corresponds to the third volcanic activity period in the Datong region.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141483729","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}
The middle reaches of Yarlung Tsangpo, situated on the southern Tibetan Plateau, have experienced extensive river damming events due to glacier advances, resulting in the formation of several ancient dammed lakes. These palaeolakes offer invaluable insights into past hydrological and geomorphological dynamics on the Tibetan Plateau. In this study, we reported a newly identified ancient dammed lake, named the Xiaru palaeolake, located upstream of the Ganglai Gorge in the uppermost segment of the middle reaches of Yarlung Tsangpo, and conducted a pioneer chronological investigation of the lake using K-feldspar post-IR IRSL (pIRIR) dating. Quartz minerals from most lacustrine and fluvial sediments can not provide reliable ages characterized with low intensity and large inter-aliquot scatter in equivalent doses (De). In contrast, the K-feldspar exhibited much greater luminescence intensity and narrower De distribution using the pIRIR225 dating protocol. Residual, dose recovery, and fading tests demonstrated that the pIRIR225 signals are well bleached with a relatively low fading rate, making it a more suitable dosimeter for dating applications in the study area. The pIRIR225 ages, derived through single aliquots, standard growth curve (SGC), and single grain measurements, reveal a major phase of the Xiaru Lake between 24.1 ± 1.0 ka and 15.8 ± 1.1 ka, that commenced aligning with the global Last Glacial Maximum. Furthermore, one lacustrine sample dated to 29.9 ± 2.2 ka suggests the possibility of multiple damming events in Ganglai Gorge during the last glacial period, although further evidence is required for a comprehensive interpretation.
雅鲁藏布江中游位于青藏高原南部,由于冰川的推进,这里经历了大面积的堰塞湖事件,形成了多个古老的堰塞湖。这些古湖泊为了解青藏高原过去的水文和地貌动态提供了宝贵的资料。在本研究中,我们报告了位于雅鲁藏布江中游最上游岗来峡谷上游的一个新发现的古堰塞湖,命名为夏鲁古湖泊,并利用 K 长石后红外 IRSL(pIRIR)测年对该湖泊进行了首次年代学调查。大多数湖泊和河流沉积物中的石英矿物无法提供可靠的年代,其特点是等效剂量(De)强度低、等效剂量间散度大。相比之下,使用 pIRIR225 测定法,K 长石的发光强度要大得多,De 分布也更窄。残留、剂量恢复和衰减测试表明,pIRIR225 信号漂白效果好,衰减率相对较低,因此更适合在研究区域应用于年代测定。通过单个等分样品、标准生长曲线(SGC)和单个颗粒测量得出的 pIRIR225 年龄显示,夏鲁湖的主要阶段在 24.1 ± 1.0 ka 到 15.8 ± 1.1 ka 之间,与全球末次冰川极盛时期一致。此外,一个年代为 29.9 ± 2.2 ka 的湖泊样本表明,在末次冰川期,岗来峡有可能发生过多次筑坝事件,不过还需要进一步的证据才能做出全面的解释。
{"title":"The post-IR IRSL dating of an ancient dammed lake upstream of the Ganglai gorge in the upper-middle reaches of Yarlung Tsangpo","authors":"Jingran Zhang, Xilin Cao, Zhigang Zhang, Mengying He, Xinggong Kong, Zhijun Zhao","doi":"10.1016/j.quageo.2024.101570","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101570","url":null,"abstract":"<div><p>The middle reaches of Yarlung Tsangpo, situated on the southern Tibetan Plateau, have experienced extensive river damming events due to glacier advances, resulting in the formation of several ancient dammed lakes. These palaeolakes offer invaluable insights into past hydrological and geomorphological dynamics on the Tibetan Plateau. In this study, we reported a newly identified ancient dammed lake, named the Xiaru palaeolake, located upstream of the Ganglai Gorge in the uppermost segment of the middle reaches of Yarlung Tsangpo, and conducted a pioneer chronological investigation of the lake using K-feldspar post-IR IRSL (pIRIR) dating. Quartz minerals from most lacustrine and fluvial sediments can not provide reliable ages characterized with low intensity and large inter-aliquot scatter in equivalent doses (D<sub>e</sub>). In contrast, the K-feldspar exhibited much greater luminescence intensity and narrower D<sub>e</sub> distribution using the pIRIR<sub>225</sub> dating protocol. Residual, dose recovery, and fading tests demonstrated that the pIRIR<sub>225</sub> signals are well bleached with a relatively low fading rate, making it a more suitable dosimeter for dating applications in the study area. The pIRIR<sub>225</sub> ages, derived through single aliquots, standard growth curve (SGC), and single grain measurements, reveal a major phase of the Xiaru Lake between 24.1 ± 1.0 ka and 15.8 ± 1.1 ka, that commenced aligning with the global Last Glacial Maximum. Furthermore, one lacustrine sample dated to 29.9 ± 2.2 ka suggests the possibility of multiple damming events in Ganglai Gorge during the last glacial period, although further evidence is required for a comprehensive interpretation.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539951","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}
Pub Date : 2024-06-21DOI: 10.1016/j.quageo.2024.101573
Fei Han , Jean-Jacques Bahain , Qingfeng Shao , Pierre Voinchet , Fangfang Tang , Mi Zhou , Manchen Huang , Gongming Yin
Gigantopithecus was a great ape once lived in Southeast Asia and China during the Pleistocene, and the northernmost evidence of its presence is presently known from the Longgupo and Jianshi Longgudong sites located in the West-Hubei and Three Gorges region in Southof China. Here, we report the first radiometric dating by ESR/U-series method on mammalian teeth of Jianshi Longgudong site which was found in 1970s, and renowned by the discovery of both possible hominin and Gigantopithecus fossils in association with undoubted stone artifacts. As the cave site was completely emptied by the successive excavations, the analyzed teeth were selected from museum collections while the dosimetry was established from reworked sediments sampled on the site. The results obtained on two fossil teeth from the lower layer 8 give a weighted mean age of 1512 ± 94 ka, while a mean age of 1044 ± 53 ka was obtained for two other teeth from the upper layer 4. These ESR/U-series dating results, in agreement with the fauna record, are younger than the previous paleomagnetic dating interpretation and suggest that Jianshi Longgudong sequence is younger than the Olduvai subchron and the neighboring Longgupo site dated by the same methods to ca 2.2–2.5 Ma.
{"title":"Coupled ESR and U-series dating of the northernmost evidence of Gigantopithecus from Jianshi Longgudong site, China","authors":"Fei Han , Jean-Jacques Bahain , Qingfeng Shao , Pierre Voinchet , Fangfang Tang , Mi Zhou , Manchen Huang , Gongming Yin","doi":"10.1016/j.quageo.2024.101573","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101573","url":null,"abstract":"<div><p><em>Gigantopithecus</em> was a great ape once lived in Southeast Asia and China during the Pleistocene, and the northernmost evidence of its presence is presently known from the Longgupo and Jianshi Longgudong sites located in the West-Hubei and Three Gorges region in Southof China. Here, we report the first radiometric dating by ESR/U-series method on mammalian teeth of Jianshi Longgudong site which was found in 1970s, and renowned by the discovery of both possible hominin and <em>Gigantopithecus</em> fossils in association with undoubted stone artifacts. As the cave site was completely emptied by the successive excavations, the analyzed teeth were selected from museum collections while the dosimetry was established from reworked sediments sampled on the site. The results obtained on two fossil teeth from the lower layer 8 give a weighted mean age of 1512 ± 94 ka, while a mean age of 1044 ± 53 ka was obtained for two other teeth from the upper layer 4. These ESR/U-series dating results, in agreement with the fauna record, are younger than the previous paleomagnetic dating interpretation and suggest that Jianshi Longgudong sequence is younger than the Olduvai subchron and the neighboring Longgupo site dated by the same methods to ca 2.2–2.5 Ma.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539950","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}
Pub Date : 2024-06-14DOI: 10.1016/j.quageo.2024.101560
Cassandra R. Fenton , Samuel Niedermann , Tibor Dunai
The formally named SP lava flow is a quartz-, olivine- and pyroxene-bearing basalt flow that is preserved in the desert climate of northern Arizona, USA. The flow has an 40Ar/39Ar age of 72 ± 4 ka (2σ) and has undergone negligible erosion and/or burial, making its surface an ideal site for direct calibration of cosmogenic nuclide production rates. Production rates for cosmogenic 3He (3Hec) and 21Ne (21Nec) have been determined from SP flow olivine and pyroxene in this study. The error-weighted mean, sea-level, high latitude (SLHL) total reference production rates of 3He in olivine and pyroxene have identical values of 135 ± 8 at/g/yr (2; standard error) using time-independent Lal (1991)/Stone (2000) (St) scaling factors. These production rates decrease to identical values of 130 ± 8 at/g/yr (2; standard error) when 3He measurements are standardized to the CRONUS-P pyroxene standard. The St-scaled, error-weighted mean, total reference production rates of 21Ne in olivine and pyroxene are 48.4 ± 2.9 at/g/yr and 26.5 ± 1.7 at/g/yr (2; standard error), respectively, increasing to 49.3 ± 3.0 at/g/yr and 27.0 ± 1.7 at/g/yr (2; standard error), respectively, when standardized to the CREU-1 quartz standard. 3He and 21Ne production rates (St) overlap within 2σ uncertainty with other St-scaled production rates in the literature. SLHL 3He and 21Ne production rates in SP flow olivine and pyroxene are nominally lower if time-dependentLm and Sa scaling factors are used. Olivine and pyroxene both have identical, error-weighted mean SLHL production rates of 127 ± 8 at/g/yr (2; standard error) using Lm scaling factors and CRONUS-P standardized 3He measurements. These production rates decrease to identical values of 110 ± 7 at/g/yr (2; standard error) for olivine and pyroxene when using Sa scaling factors. The Lm-scaled, error-weighted mean, total reference production rates of 21Ne in olivine and pyroxene are 48.1 ± 2.8 at/g/yr and 26.4 ± 1.7 at/g/yr (2; standard error), respectively, when standardized to the CREU-1 quar
{"title":"The SPICE Project: Calibrated production rates of cosmogenic 3He and 21Ne in olivine and pyroxene from the 72 ka SP basalt flow, Arizona, USA","authors":"Cassandra R. Fenton , Samuel Niedermann , Tibor Dunai","doi":"10.1016/j.quageo.2024.101560","DOIUrl":"10.1016/j.quageo.2024.101560","url":null,"abstract":"<div><p>The formally named SP lava flow is a quartz-, olivine- and pyroxene-bearing basalt flow that is preserved in the desert climate of northern Arizona, USA. The flow has an <sup>40</sup>Ar/<sup>39</sup>Ar age of 72 ± 4 ka (2σ) and has undergone negligible erosion and/or burial, making its surface an ideal site for direct calibration of cosmogenic nuclide production rates. Production rates for cosmogenic <sup>3</sup>He (<sup>3</sup>He<sub>c</sub>) and <sup>21</sup>Ne (<sup>21</sup>Ne<sub>c</sub>) have been determined from SP flow olivine and pyroxene in this study. The error-weighted mean, sea-level, high latitude (SLHL) total reference production rates of <sup>3</sup>He in olivine and pyroxene have identical values of 135 ± 8 at/g/yr (2<span><math><mrow><msub><mi>σ</mi><mover><mi>x</mi><mo>‾</mo></mover></msub></mrow></math></span>; standard error) using time-independent Lal (1991)/Stone (2000) (<em>St</em>) scaling factors. These production rates decrease to identical values of 130 ± 8 at/g/yr (2<span><math><mrow><msub><mi>σ</mi><mover><mi>x</mi><mo>‾</mo></mover></msub></mrow></math></span>; standard error) when <sup>3</sup>He measurements are standardized to the CRONUS-P pyroxene standard. The <em>St-</em>scaled, error-weighted mean, total reference production rates of <sup>21</sup>Ne in olivine and pyroxene are 48.4 ± 2.9 at/g/yr and 26.5 ± 1.7 at/g/yr (2<span><math><mrow><msub><mi>σ</mi><mover><mi>x</mi><mo>‾</mo></mover></msub></mrow></math></span>; standard error), respectively, increasing to 49.3 ± 3.0 at/g/yr and 27.0 ± 1.7 at/g/yr (2<span><math><mrow><msub><mi>σ</mi><mover><mi>x</mi><mo>‾</mo></mover></msub></mrow></math></span>; standard error), respectively, when standardized to the CREU-1 quartz standard. <sup>3</sup>He and <sup>21</sup>Ne production rates (<em>St</em>) overlap within 2σ uncertainty with other <em>St</em>-scaled production rates in the literature. SLHL <sup>3</sup>He and <sup>21</sup>Ne production rates in SP flow olivine and pyroxene are nominally lower if time-<u>dependent</u> <em>Lm</em> and <em>Sa</em> scaling factors are used. Olivine and pyroxene both have identical, error-weighted mean SLHL production rates of 127 ± 8 at/g/yr (2<span><math><mrow><msub><mi>σ</mi><mover><mi>x</mi><mo>‾</mo></mover></msub></mrow></math></span>; standard error) using <em>Lm</em> scaling factors and CRONUS-P standardized <sup>3</sup>He measurements. These production rates decrease to identical values of 110 ± 7 at/g/yr (2<span><math><mrow><msub><mi>σ</mi><mover><mi>x</mi><mo>‾</mo></mover></msub></mrow></math></span>; standard error) for olivine and pyroxene when using <em>Sa</em> scaling factors. The <em>Lm</em>-scaled, error-weighted mean, total reference production rates of <sup>21</sup>Ne in olivine and pyroxene are 48.1 ± 2.8 at/g/yr and 26.4 ± 1.7 at/g/yr (2<span><math><mrow><msub><mi>σ</mi><mover><mi>x</mi><mo>‾</mo></mover></msub></mrow></math></span>; standard error), respectively, when standardized to the CREU-1 quar","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141416417","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}
Pub Date : 2024-06-14DOI: 10.1016/j.quageo.2024.101553
Helen M. Innes, William Hutchison, Andrea Burke
Tephrochronology is a powerful tool used to synchronise and date stratigraphic records by accurate and precise geochemical analysis of deposited volcanic glass shards. However, in many distal stratigraphic records (e.g., polar ice cores) tephra shards are often extremely fine-grained (<10 μm). Geochemical characterisation of these shards is challenging because conventional preparation and analytical techniques require highly polished glass areas >5 μm for electron probe microanalysis (EPMA) to ensure high analytical totals and minimise alkali element loss. Recent method developments have put forward alternative approaches to accurately measure major oxides of small shards: a smaller 3 μm diameter beam, overlapping large (20 μm) beam areas onto supporting epoxy resin, and using scanning electron microscopy with energy dispersive spectrometry (SEM-EDS). However, there has been no direct intercomparison of these alternative techniques, which to date have only been tested on a limited range of glass compositions and tephras that are much larger than the extremely fine-grained material found in distal archives. These issues complicate decision making about the best analytical approach to take when faced with small shards. Here, we provide a new workflow protocol for the analysis of <10 μm tephra by determining the accuracy and precision of alternative SEM-EPMA methods. By analysing a variety of glass standards including those prepared to replicate fine-grained ice-core cryptotephras, we show that a 3 μm EPMA beam is suitable for use on all glass compositions provided the beam current is reduced to 1 nA. When glass areas are too small for a 3 μm beam we show that overlapping this small beam onto epoxy resin is preferable to SEM-EDS analysis. We also provide evidence confirming that using 3–0.2 μm polishes for <5 min increases analytical precision of the most abundant major oxides by up to three times, whilst, crucially, preserving the smallest shards in a sample. By directly applying these alternative methods to ice-core cryptotephra, we demonstrate the data are of suitable accuracy and precision to make robust geochemical correlations. This workflow can be applied to future tephrochronology studies, significantly increasing the quality and quantity of data that are obtained from cryptotephra horizons in distal records.
{"title":"Geochemical analysis of extremely fine-grained cryptotephra: New developments and recommended practices","authors":"Helen M. Innes, William Hutchison, Andrea Burke","doi":"10.1016/j.quageo.2024.101553","DOIUrl":"10.1016/j.quageo.2024.101553","url":null,"abstract":"<div><p>Tephrochronology is a powerful tool used to synchronise and date stratigraphic records by accurate and precise geochemical analysis of deposited volcanic glass shards. However, in many distal stratigraphic records (e.g., polar ice cores) tephra shards are often extremely fine-grained (<10 μm). Geochemical characterisation of these shards is challenging because conventional preparation and analytical techniques require highly polished glass areas >5 μm for electron probe microanalysis (EPMA) to ensure high analytical totals and minimise alkali element loss. Recent method developments have put forward alternative approaches to accurately measure major oxides of small shards: a smaller 3 μm diameter beam, overlapping large (20 μm) beam areas onto supporting epoxy resin, and using scanning electron microscopy with energy dispersive spectrometry (SEM-EDS). However, there has been no direct intercomparison of these alternative techniques, which to date have only been tested on a limited range of glass compositions and tephras that are much larger than the extremely fine-grained material found in distal archives. These issues complicate decision making about the best analytical approach to take when faced with small shards. Here, we provide a new workflow protocol for the analysis of <10 μm tephra by determining the accuracy and precision of alternative SEM-EPMA methods. By analysing a variety of glass standards including those prepared to replicate fine-grained ice-core cryptotephras, we show that a 3 μm EPMA beam is suitable for use on all glass compositions provided the beam current is reduced to 1 nA. When glass areas are too small for a 3 μm beam we show that overlapping this small beam onto epoxy resin is preferable to SEM-EDS analysis. We also provide evidence confirming that using 3–0.2 μm polishes for <5 min increases analytical precision of the most abundant major oxides by up to three times, whilst, crucially, preserving the smallest shards in a sample. By directly applying these alternative methods to ice-core cryptotephra, we demonstrate the data are of suitable accuracy and precision to make robust geochemical correlations. This workflow can be applied to future tephrochronology studies, significantly increasing the quality and quantity of data that are obtained from cryptotephra horizons in distal records.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000578/pdfft?md5=3e6536ad8c7a07eb566dae6a3bee163b&pid=1-s2.0-S1871101424000578-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141391912","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}
Pub Date : 2024-06-13DOI: 10.1016/j.quageo.2024.101561
Cassandra Euzen , François Chabaux , Gilles Rixhon , Frank Preusser , Frédérique Eyrolle , Valentin Chardon , Anja M. Zander , Dominique Badariotti , Laurent Schmitt
The precise dating of sedimentary archives covering the last 200 years in floodplains massively impacted by human activities is a major challenge. A combination of geochronological approaches is necessary to accurately date post-1800 sedimentary deposits. Here, we use a combination of a wide range of methods to unravel floodplain sedimentary dynamics, through the example of the Upper Rhine which is a highly regulated river. This comprises short--lived radionuclides (137Cs, 210Pbxs) and Infrared Stimulated Luminescence (IRSL) single-grain dating. Luminescence profiling methods (IRSL screening, portable luminescence reader) were also used to further characterise sedimentation dynamics. These were combined with a hydrogeomorphological approach based on historical planimetric and hydrological data, the knowledge of engineering works as well as the morpho-sedimentary adjustments they induced. Our study demonstrates the value of historic maps as well as historical hydrological data, which provide precise time markers for dating the sedimentary archive under study. We illustrate different assumptions, validity domains and limitations inherent to each method, especially the complexity of 137Cs to date floodplain sediments and the potential of luminescence methods for dating and estimating sedimentation continuity. We finally show the advantage of combining geochronological approaches in the construction of robust age models for young floodplain sedimentary archives in highly anthropized fluvial environments.
{"title":"Multi-method geochronological approach to reconstruct post-1800 floodplain sedimentation in the upper Rhine plain, France","authors":"Cassandra Euzen , François Chabaux , Gilles Rixhon , Frank Preusser , Frédérique Eyrolle , Valentin Chardon , Anja M. Zander , Dominique Badariotti , Laurent Schmitt","doi":"10.1016/j.quageo.2024.101561","DOIUrl":"10.1016/j.quageo.2024.101561","url":null,"abstract":"<div><p>The precise dating of sedimentary archives covering the last 200 years in floodplains massively impacted by human activities is a major challenge. A combination of geochronological approaches is necessary to accurately date post-1800 sedimentary deposits. Here, we use a combination of a wide range of methods to unravel floodplain sedimentary dynamics, through the example of the Upper Rhine which is a highly regulated river. This comprises short--lived radionuclides (<sup>137</sup>Cs, <sup>210</sup>Pb<sub>xs</sub>) and Infrared Stimulated Luminescence (IRSL) single-grain dating. Luminescence profiling methods (IRSL screening, portable luminescence reader) were also used to further characterise sedimentation dynamics. These were combined with a hydrogeomorphological approach based on historical planimetric and hydrological data, the knowledge of engineering works as well as the morpho-sedimentary adjustments they induced. Our study demonstrates the value of historic maps as well as historical hydrological data, which provide precise time markers for dating the sedimentary archive under study. We illustrate different assumptions, validity domains and limitations inherent to each method, especially the complexity of <sup>137</sup>Cs to date floodplain sediments and the potential of luminescence methods for dating and estimating sedimentation continuity. We finally show the advantage of combining geochronological approaches in the construction of robust age models for young floodplain sedimentary archives in highly anthropized fluvial environments.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141415482","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}
Pub Date : 2024-06-01DOI: 10.1016/j.quageo.2024.101552
Yanuo Jiao , Yue Liu , Zeji Lu , Rainer Grün , Qingfeng Shao
Rock art is found in many different regions of the world, with ages dated from late Palaeolithic period to the present. However, determining the precise ages for such artworks with direct chronological methods is challenging. U-series dating of secondary carbonates can constrain the age of rock art if these carbonates stratigraphically connected to the art. Hitherto, U-series isotope-dilution analyses with multi-collector inductively-coupled plasma mass spectrometry (ID-MC-ICPMS) has been increasingly used for rock art dating. This approach can achieve U–Th isotope-ratio quantification at the per-mille or submille level, but requires chemical pretreatment using isotope spikes and results in a relatively low sampling resolution. While in situ U-series dating using laser ablation-MC-ICPMS (LA-MC-ICPMS) is significantly less precise than ID-MC-ICPMS analysis, it allows to collect spatially resolved data sequences on very thin samples (<1 mm). This is important for identification of open systems and the chronological integrity of the analyses. Therefore, we developed a new method for high spatial resolution U-series in situ analysis. A piece of homogeneous stalagmite was selected as an in-house standard (RM-C1) for U-series in situ dating analysis. RM-C1 contains high U (17.3 ± 1.0 μg/g) and low Th concentrations (<5 ng/g). The 234U/238U and 230Th/238U activity ratios of 1.0116 ± 0.0006 and 0.9525 ± 0.0013, respectively, corresponding to a U-series age of 303.5 ± 1.5 ka, were determined by the ID-MC-ICPMS analyses (n = 10). Using the RM-C1 standard, we were able to date the Dansgaard–Oeschger (D/O) 19 event (with an expected age of 68.9 to 70.3 ka) in a stalagmite to a range from 68.0 ± 2.0 to 71.2 ± 2.5 ka, with an average age of 69.6 ± 1.5 ka (n = 15). This demonstrates the accuracy and reproducibility of our dating protocol. Subsequently, we conducted U-series in situ dating of secondary carbonates associated with rock paintings with two samples from the Cangyuan shelter (CY2-4 and CY2-7) and two samples from the Wanrendong Cave (SL3-A and SL5-A) in Yunnan Province, southwestern China. These samples had high U-concentration (>4 μg/g) and negligible environmental Th. The carbonate layers immediately overlying the pigments of CY2-4 and CY2-7 were dated to 3.7 ± 0.3 and 3.2 ± 0.2 ka, respectively, suggesting that the Canyuan rock paintings belongs to a late Neolithic culture of this area. The pigment layer sandwiched in the sample SL3-A was bracketed to between 8.7 ± 0.3 and 10.1 ± 0.3 ka and in SL5-A to between 10.4 ± 0.3 and 10.8 ± 0.4 ka, implying that the Wanrendong rock paintings probably were created by a hunting-gathering population during the early Holocene.
{"title":"U-series in situ dating of secondary carbonates associated with rock paintings using LA-MC-ICPMS","authors":"Yanuo Jiao , Yue Liu , Zeji Lu , Rainer Grün , Qingfeng Shao","doi":"10.1016/j.quageo.2024.101552","DOIUrl":"10.1016/j.quageo.2024.101552","url":null,"abstract":"<div><p>Rock art is found in many different regions of the world, with ages dated from late Palaeolithic period to the present. However, determining the precise ages for such artworks with direct chronological methods is challenging. U-series dating of secondary carbonates can constrain the age of rock art if these carbonates stratigraphically connected to the art. Hitherto, U-series isotope-dilution analyses with multi-collector inductively-coupled plasma mass spectrometry (ID-MC-ICPMS) has been increasingly used for rock art dating. This approach can achieve U–Th isotope-ratio quantification at the per-mille or submille level, but requires chemical pretreatment using isotope spikes and results in a relatively low sampling resolution. While <em>in situ</em> U-series dating using laser ablation-MC-ICPMS (LA-MC-ICPMS) is significantly less precise than ID-MC-ICPMS analysis, it allows to collect spatially resolved data sequences on very thin samples (<1 mm). This is important for identification of open systems and the chronological integrity of the analyses. Therefore, we developed a new method for high spatial resolution U-series <em>in situ</em> analysis. A piece of homogeneous stalagmite was selected as an in-house standard (RM-C1) for U-series <em>in situ</em> dating analysis. RM-C1 contains high U (17.3 ± 1.0 μg/g) and low Th concentrations (<5 ng/g). The <sup>234</sup>U/<sup>238</sup>U and <sup>230</sup>Th/<sup>238</sup>U activity ratios of 1.0116 ± 0.0006 and 0.9525 ± 0.0013, respectively, corresponding to a U-series age of 303.5 ± 1.5 ka, were determined by the ID-MC-ICPMS analyses (n = 10). Using the RM-C1 standard, we were able to date the Dansgaard–Oeschger (D/O) 19 event (with an expected age of 68.9 to 70.3 ka) in a stalagmite to a range from 68.0 ± 2.0 to 71.2 ± 2.5 ka, with an average age of 69.6 ± 1.5 ka (n = 15). This demonstrates the accuracy and reproducibility of our dating protocol. Subsequently, we conducted U-series <em>in situ</em> dating of secondary carbonates associated with rock paintings with two samples from the Cangyuan shelter (CY2-4 and CY2-7) and two samples from the Wanrendong Cave (SL3-A and SL5-A) in Yunnan Province, southwestern China. These samples had high U-concentration (>4 μg/g) and negligible environmental Th. The carbonate layers immediately overlying the pigments of CY2-4 and CY2-7 were dated to 3.7 ± 0.3 and 3.2 ± 0.2 ka, respectively, suggesting that the Canyuan rock paintings belongs to a late Neolithic culture of this area. The pigment layer sandwiched in the sample SL3-A was bracketed to between 8.7 ± 0.3 and 10.1 ± 0.3 ka and in SL5-A to between 10.4 ± 0.3 and 10.8 ± 0.4 ka, implying that the Wanrendong rock paintings probably were created by a hunting-gathering population during the early Holocene.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141190716","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}
Pub Date : 2024-06-01DOI: 10.1016/j.quageo.2024.101551
Daniela Mueller , Lukas Gegg , Alexander Fülling , Marius W. Buechi , Gaudenz Deplazes , Frank Preusser
A complex picture of the Pleistocene glaciation history of northern Switzerland has been identified over the last three decades. To gain further insights into the long-term landscape evolution, numerical dating is required. In the absence of alternative dating techniques, luminescence dating is the key method for establishing chronological constraints of past glaciations. However, this is presented with complex challenges, especially in regard to the resetting of the luminescence signal prior to deposition, the components contributing to the signal as well as the signal intensity and stability. In this study, the luminescence properties of glacially sourced deposits from northern Switzerland are assessed using single aliquot (SA) and single grain (SG) measurements of feldspar (F) and quartz (Q). While no obvious connection between bleaching and distal or proximal deposition in relation to the proposed ice margin is observed, most samples seem to reveal a partially bleached signature in F SG De measurements. This appears to be masked in the respective F SA measurements even though only few grains emit luminescence signals. In addition, comparisons between fading corrected infrared stimulated luminescence (IR) and post-infrared infrared stimulated luminescence (pIR) De values appear to be unreliable indicators of bleaching, even though these signals bleach at different rates. Hence, it is recommended to conduct both IR and pIR investigations in combination with Q measurements on a SG level. The dating potential of the investigated deposits remains rather limited, yet, in the sedimentologic context the presented results reveal that several glacial advances occurred prior to the Last Interglacial in the study area.
在过去的三十年中,瑞士北部更新世冰川历史的复杂图景已被确定。为了进一步了解地貌的长期演变,需要进行数字测年。在没有其他测年技术的情况下,发光测年是确定过去冰川年代的关键方法。然而,这也面临着复杂的挑战,尤其是在沉积前的发光信号重置、信号成分以及信号强度和稳定性方面。本研究使用长石(F)和石英(Q)的单等分(SA)和单晶粒(SG)测量方法评估了瑞士北部冰川沉积物的发光特性。虽然没有观察到漂白与拟议冰缘的远端或近端沉积之间的明显联系,但大多数样本似乎在长石 SG De 测量中显示出部分漂白特征。尽管只有极少数晶粒发出发光信号,但在相应的 F SA 测量中这一特征似乎被掩盖了。此外,褪色校正红外激发发光(IR)和后红外激发发光(pIR)De 值之间的比较似乎是不可靠的漂白指标,尽管这些信号的漂白速度不同。因此,建议在进行红外和 pIR 调查的同时,对 SG 进行 Q 值测量。所调查沉积物的测年潜力仍然相当有限,但是,从沉积学的角度来看,所提供的结果表明,在研究区域的末次间冰期之前,曾发生过几次冰川运动。
{"title":"Luminescence dating of glacially sourced deposits from northern Switzerland: Comparing multigrain aliquots and single grains of quartz and feldspar","authors":"Daniela Mueller , Lukas Gegg , Alexander Fülling , Marius W. Buechi , Gaudenz Deplazes , Frank Preusser","doi":"10.1016/j.quageo.2024.101551","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101551","url":null,"abstract":"<div><p>A complex picture of the Pleistocene glaciation history of northern Switzerland has been identified over the last three decades. To gain further insights into the long-term landscape evolution, numerical dating is required. In the absence of alternative dating techniques, luminescence dating is the key method for establishing chronological constraints of past glaciations. However, this is presented with complex challenges, especially in regard to the resetting of the luminescence signal prior to deposition, the components contributing to the signal as well as the signal intensity and stability. In this study, the luminescence properties of glacially sourced deposits from northern Switzerland are assessed using single aliquot (SA) and single grain (SG) measurements of feldspar (F) and quartz (Q). While no obvious connection between bleaching and distal or proximal deposition in relation to the proposed ice margin is observed, most samples seem to reveal a partially bleached signature in F SG D<sub>e</sub> measurements. This appears to be masked in the respective F SA measurements even though only few grains emit luminescence signals. In addition, comparisons between fading corrected infrared stimulated luminescence (IR) and post-infrared infrared stimulated luminescence (pIR) D<sub>e</sub> values appear to be unreliable indicators of bleaching, even though these signals bleach at different rates. Hence, it is recommended to conduct both IR and pIR investigations in combination with Q measurements on a SG level. The dating potential of the investigated deposits remains rather limited, yet, in the sedimentologic context the presented results reveal that several glacial advances occurred prior to the Last Interglacial in the study area.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000554/pdfft?md5=1325ffe6c4a497ef07a91b38ebeed8a0&pid=1-s2.0-S1871101424000554-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141239653","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}
Pub Date : 2024-05-22DOI: 10.1016/j.quageo.2024.101549
W.K. Thompson , J. Christensen , A.S. Murray , M. Autzen
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 De 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.
{"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 , J. Christensen , A.S. Murray , 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 IRSL<sub>180</sub> 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<sub>e</sub> on one rock. After subtracting a residual, the dose recovery ratio results for the unheated rocks post-IR IRSL<sub>180</sub> and IR<sub>50</sub> 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 IR<sub>50</sub> 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 IR<sub>50</sub> signals significantly over-estimated the quartz age. However, the sedimentary quartz ages, the heated cobble quartz ages and the fading corrected IR<sub>50</sub> 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":null,"pages":null},"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}
Pub Date : 2024-05-22DOI: 10.1016/j.quageo.2024.101547
Kunmei Yang , Xianjiao Ou , Yang Li , Geraint Jenkins , Pan Yao , Daobin Tang , Yantian Xu , Jinming Xie , Lanhua Zeng , Xiangjun Liu
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 Ln/Tn-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.
{"title":"Luminescence dating of cobbles buried in moraines from the source area of the Litang River (Konglongluo Valley), eastern Tibetan Plateau","authors":"Kunmei Yang , Xianjiao Ou , Yang Li , Geraint Jenkins , Pan Yao , Daobin Tang , Yantian Xu , Jinming Xie , Lanhua Zeng , 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 <sup>10</sup>Be exposure ages were generated from eight boulders obtained from the ridges of two moraines, to provide an external age control. A post-IR<sub>50</sub> IRSL<sub>225</sub> single aliquot regenerative dose (SAR) protocol was applied to measure the luminescence signal from rock slices. The IRSL<sub>50</sub> L<sub>n</sub>/T<sub>n</sub>-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 <sup>10</sup>Be exposure ages. Particularly, the age of cobbles from one of the moraines (20.0 ± 1.6 ka) is consistent with independent <sup>10</sup>Be 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":null,"pages":null},"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}