Quaternary Geochronology最新文献

{"title":"A detailed quartz and feldspar luminescence chronology for the Khonako II loess section (Southern Tajikistan)","authors":"Amélie Challier ,&nbsp;Kristina J. Thomsen ,&nbsp;Redzhep Kurbanov ,&nbsp;Piotr Sosin ,&nbsp;Andrew Murray ,&nbsp;Guillaume Guérin ,&nbsp;Olga Meshcheryakova ,&nbsp;Asliddin Karayev ,&nbsp;Farhad Khormali ,&nbsp;Natalia Taratunina ,&nbsp;Anna Utkina ,&nbsp;Jan-Pieter Buylaert","doi":"10.1016/j.quageo.2024.101571","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101571","url":null,"abstract":"<div><p>Parts of Central Asia have been dominated by high dust flux since the start of the Quaternary. The resulting loess-palaeosol deposits are important archives for landscape and climate changes, but there is a lack of chronological data for the subaerial deposits of Southern Tajikistan. Our study presents a high-resolution luminescence chronology for the Khonako II section in the Khovaling region. Thirty-seven samples were collected from the first ∼8 m of the section, corresponding to the Holocene soil and the upper part of the Loess 1 (L1) unit. We applied quartz OSL dating to the coarse-silt fraction (40–63 μm) and polymineral pIRIR_200,290 dating to the very fine sand fraction (63–90 μm). The polymineral pIRIR_200,290 signal has satisfactory characteristics. The quartz dose response curve displays a non-single exponential growth above ∼100 Gy, thus, the D_e values were estimated by fitting a single exponential function plus linear component to the dose response data. To assess the pIRIR_200,290 residual dose at deposition, we used the offset between our quartz and polymineral chronologies from Khonako II and equivalent doses measured on modern dust samples from Tajikistan and Uzbekistan. The resulting 9.2 ± 0.4 Gy dose was then subtracted from the pIRIR_200,290 doses for final age calculation. The quartz OSL and pIRIR ages are then generally consistent. The obtained high-resolution luminescence chronology shows that the upper part of the L1 unit accumulated during the end of marine isotope stage (MIS) 3 and through MIS 2 (39–20 ka). The average dust accumulation rates (DAR) increased from ∼31 cm ka⁻¹ to 41 cm ka⁻¹ between MIS 3 and MIS 2. The DAR reached a peak of ∼71 cm ka⁻¹ at 21 ka. A hiatus of ∼7–9 ka was then identified between the end of the last glacial maximum (LGM) and the beginning of the Holocene, and the average DAR decreased during the Holocene. Our results indicate a continuous high dust flux in the Khovaling plateau over the last 39 ka, but reworking processes and potential deflation events mark the LGM-Holocene transition. High-resolution luminescence dating studies in Tajikistan are therefore important to detect potential discontinuities in the sequences and provide an independent timescale for interpreting the climate proxies and calculating dust accumulation rates.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101571"},"PeriodicalIF":1.7,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S187110142400075X/pdfft?md5=006d86a782a50d956820c39aaab11be2&pid=1-s2.0-S187110142400075X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141483732","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":"Dating the setting of a late prehistoric statue-menhir at Cruz de Cepos, NE Portugal","authors":"I.K. Bailiff ,&nbsp;E. Andrieux ,&nbsp;M. Díaz-Guardamino ,&nbsp;L.B. Alves ,&nbsp;B. Comendador Rey ,&nbsp;L. García Sanjuán ,&nbsp;Maria Martín Seijo","doi":"10.1016/j.quageo.2024.101569","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101569","url":null,"abstract":"<div><p>The emergence of ‘standing stone’ monuments within the European Late Prehistoric landscape is considered to be associated with a pivotal human cultural transition from hunting and gathering to agriculture and permanent settlement, being the earliest monuments currently dated by radiocarbon to the 5th millennium BCE. However, many standing stones were first erected, subsequently collapsed, and then re-erected during the following three millennia. The excavation of the site of an apparently in situ statue-menhir at Cruz de Cepos in NE Portugal provided the rare opportunity in Iberian prehistory to apply radiocarbon and luminescence techniques to establish the date of construction. On the basis of the iconography, the standing stone was assigned to a sculptural tradition of north-western and western Iberia, loosely dated to the Early/Middle Bronze Age (ca. 2000/1900–1250 BCE). The optically stimulated luminescence (OSL) and dosimetry characteristics of quartz extracted from sediment samples taken from locations associated with the socket pit and surrounding backfilling deposits were examined, producing OSL single grain ages at eight locations. Comparison of the OSL and calibrated radiocarbon ages shows very good agreement, with the mid-3rd millennium BCE dates confirming original erection during the Copper Age and not a much later transformation of the monument. These encouraging results indicate that OSL has the potential to provide reliable dating of depositional processes related to the construction process and is suitable for wider application to megalithic monuments of this type.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101569"},"PeriodicalIF":1.7,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000736/pdfft?md5=b1708279c507b6fba6b9708182125331&pid=1-s2.0-S1871101424000736-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141483730","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":"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 ,&nbsp;Chun-Ru Liu ,&nbsp;Wen-Peng Li ,&nbsp;Chuan-Yi Wei ,&nbsp;Bhupati Neupane ,&nbsp;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_E 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":"83 ","pages":"Article 101568"},"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}

{"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,&nbsp;Xilin Cao,&nbsp;Zhigang Zhang,&nbsp;Mengying He,&nbsp;Xinggong Kong,&nbsp;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_e). In contrast, the K-feldspar exhibited much greater luminescence intensity and narrower D_e 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.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101570"},"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}

{"title":"Coupled ESR and U-series dating of the northernmost evidence of Gigantopithecus from Jianshi Longgudong site, China","authors":"Fei Han ,&nbsp;Jean-Jacques Bahain ,&nbsp;Qingfeng Shao ,&nbsp;Pierre Voinchet ,&nbsp;Fangfang Tang ,&nbsp;Mi Zhou ,&nbsp;Manchen Huang ,&nbsp;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":"83 ","pages":"Article 101573"},"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}

{"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 ,&nbsp;Samuel Niedermann ,&nbsp;Tibor Dunai","doi":"10.1016/j.quageo.2024.101560","DOIUrl":"10.1016/j.quageo.2024.101560","url":null,"abstract":"&lt;div&gt;&lt;p&gt;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 &lt;sup&gt;40&lt;/sup&gt;Ar/&lt;sup&gt;39&lt;/sup&gt;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 &lt;sup&gt;3&lt;/sup&gt;He (&lt;sup&gt;3&lt;/sup&gt;He&lt;sub&gt;c&lt;/sub&gt;) and &lt;sup&gt;21&lt;/sup&gt;Ne (&lt;sup&gt;21&lt;/sup&gt;Ne&lt;sub&gt;c&lt;/sub&gt;) 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 &lt;sup&gt;3&lt;/sup&gt;He in olivine and pyroxene have identical values of 135 ± 8 at/g/yr (2&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mover&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;‾&lt;/mo&gt;&lt;/mover&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;; standard error) using time-independent Lal (1991)/Stone (2000) (&lt;em&gt;St&lt;/em&gt;) scaling factors. These production rates decrease to identical values of 130 ± 8 at/g/yr (2&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mover&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;‾&lt;/mo&gt;&lt;/mover&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;; standard error) when &lt;sup&gt;3&lt;/sup&gt;He measurements are standardized to the CRONUS-P pyroxene standard. The &lt;em&gt;St-&lt;/em&gt;scaled, error-weighted mean, total reference production rates of &lt;sup&gt;21&lt;/sup&gt;Ne in olivine and pyroxene are 48.4 ± 2.9 at/g/yr and 26.5 ± 1.7 at/g/yr (2&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mover&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;‾&lt;/mo&gt;&lt;/mover&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;; standard error), respectively, increasing to 49.3 ± 3.0 at/g/yr and 27.0 ± 1.7 at/g/yr (2&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mover&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;‾&lt;/mo&gt;&lt;/mover&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;; standard error), respectively, when standardized to the CREU-1 quartz standard. &lt;sup&gt;3&lt;/sup&gt;He and &lt;sup&gt;21&lt;/sup&gt;Ne production rates (&lt;em&gt;St&lt;/em&gt;) overlap within 2σ uncertainty with other &lt;em&gt;St&lt;/em&gt;-scaled production rates in the literature. SLHL &lt;sup&gt;3&lt;/sup&gt;He and &lt;sup&gt;21&lt;/sup&gt;Ne production rates in SP flow olivine and pyroxene are nominally lower if time-&lt;u&gt;dependent&lt;/u&gt; &lt;em&gt;Lm&lt;/em&gt; and &lt;em&gt;Sa&lt;/em&gt; scaling factors are used. Olivine and pyroxene both have identical, error-weighted mean SLHL production rates of 127 ± 8 at/g/yr (2&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mover&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;‾&lt;/mo&gt;&lt;/mover&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;; standard error) using &lt;em&gt;Lm&lt;/em&gt; scaling factors and CRONUS-P standardized &lt;sup&gt;3&lt;/sup&gt;He measurements. These production rates decrease to identical values of 110 ± 7 at/g/yr (2&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mover&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;‾&lt;/mo&gt;&lt;/mover&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;; standard error) for olivine and pyroxene when using &lt;em&gt;Sa&lt;/em&gt; scaling factors. The &lt;em&gt;Lm&lt;/em&gt;-scaled, error-weighted mean, total reference production rates of &lt;sup&gt;21&lt;/sup&gt;Ne in olivine and pyroxene are 48.1 ± 2.8 at/g/yr and 26.4 ± 1.7 at/g/yr (2&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mover&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;mo&gt;‾&lt;/mo&gt;&lt;/mover&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;; standard error), respectively, when standardized to the CREU-1 quar","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101560"},"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}

{"title":"Geochemical analysis of extremely fine-grained cryptotephra: New developments and recommended practices","authors":"Helen M. Innes,&nbsp;William Hutchison,&nbsp;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 (&lt;10 μm). Geochemical characterisation of these shards is challenging because conventional preparation and analytical techniques require highly polished glass areas &gt;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 &lt;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 &lt;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":"83 ","pages":"Article 101553"},"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}

{"title":"Multi-method geochronological approach to reconstruct post-1800 floodplain sedimentation in the upper Rhine plain, France","authors":"Cassandra Euzen ,&nbsp;François Chabaux ,&nbsp;Gilles Rixhon ,&nbsp;Frank Preusser ,&nbsp;Frédérique Eyrolle ,&nbsp;Valentin Chardon ,&nbsp;Anja M. Zander ,&nbsp;Dominique Badariotti ,&nbsp;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 (¹³⁷Cs, ²¹⁰Pb_xs) 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.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101561"},"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}

{"title":"U-series in situ dating of secondary carbonates associated with rock paintings using LA-MC-ICPMS","authors":"Yanuo Jiao ,&nbsp;Yue Liu ,&nbsp;Zeji Lu ,&nbsp;Rainer Grün ,&nbsp;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 (&lt;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 (&lt;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 <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 (&gt;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":"82 ","pages":"Article 101552"},"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}

{"title":"Luminescence dating of glacially sourced deposits from northern Switzerland: Comparing multigrain aliquots and single grains of quartz and feldspar","authors":"Daniela Mueller ,&nbsp;Lukas Gegg ,&nbsp;Alexander Fülling ,&nbsp;Marius W. Buechi ,&nbsp;Gaudenz Deplazes ,&nbsp;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_e 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_e 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":"82 ","pages":"Article 101551"},"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}