Quaternary Geochronology最新文献

{"title":"High-resolution luminescence-dated sediment record for the last two glacial-interglacial cycles from Rodderberg, Germany","authors":"Junjie Zhang ,&nbsp;Bernd Zolitschka ,&nbsp;Ines Hogrefe ,&nbsp;Sumiko Tsukamoto ,&nbsp;Franz Binot ,&nbsp;Manfred Frechen","doi":"10.1016/j.quageo.2024.101535","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101535","url":null,"abstract":"<div><p>The Rodderberg Volcanic Complex (RVC) is well-known for the long climate record archived in its crater basin, which lasts for several glacial-interglacial cycles. However, a detailed chronological framework is still lacking. Here, we perform high-resolution luminescence dating on a 72.8 m-long sediment core with the optically stimulated luminescence (OSL) signal from fine-grained (4–11 μm) quartz and three kinds of post-infrared infrared (pIRIR) stimulated luminescence signals from fine-grained polymineral fractions. Together with magnetic susceptibility, grain size and quartz OSL sensitivity measurements, a numerical age framework is built for the upper half of the sediment core. Quartz OSL ages align well with pIRIR ages for the last 45 ka, but they underestimate in relation to pIRIR ages for ages beyond 45 ka. The three pIRIR signals, including the pIRIR signal at 225 °C (pIRIR₂₂₅), the pulsed pIRIR signal at 150 °C (pulsed pIRIR₁₅₀) and the multi-elevated-temperature pIRIR at 250 °C (MET-pIRIR₂₅₀), yield consistent ages up to ca. 250 ka at a sediment depth of 37.5 m. Below that depth, dating limits of the protocols are reached. Nevertheless, our results indicate that sediments below 37.5 m predate Marine Isotope Stage (MIS) 7. Altogether, obtained ages reveal continuous dust accumulation during MIS 7 and MIS 6. One erosional event happened at the end of the Eemian (MIS 5e), which eroded the Eemian soil. The sedimentation rate during the Weichselian glacial period is tenfold lower compared to the sedimentation rate observed during MIS 7–6. This low sedimentation rate likely arises from the cessation of slope wash effects and the occurrence of various wind erosional events alternating with dust deposition as the basin is filled by dust. A notably high sedimentation rate is observed at the transition from MIS 6 to the Eemian, marked by the deposition of a 7 m-thick loess layer between 135 and 129 (±5) ka. This high sedimentation rate could be attributed to intensified slope wash and solifluction processes resulting from the thawing of permafrost at the time of deglaciation. Alternatively, it might be a signature of Heinrich event 11, during which strong winds brought large amounts of dust into the basin within a short time.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101535"},"PeriodicalIF":2.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000396/pdfft?md5=e6b9674b2023bbfdef0be5d181f5e10f&pid=1-s2.0-S1871101424000396-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140951825","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":"Correlations between quartz OSL dose-response curve and TL glow curve characteristics, and their implications for equivalent dose estimation","authors":"Rosaria B.K. Saktura ,&nbsp;Bo Li ,&nbsp;Richard G. Roberts ,&nbsp;Zenobia Jacobs","doi":"10.1016/j.quageo.2024.101533","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101533","url":null,"abstract":"<div><p>Optically stimulated luminescence (OSL) dating of quartz using the single-aliquot regenerative-dose (SAR) procedure requires construction of dose-response curves (DRCs). The shapes of DRCs and their characteristic saturation doses (D₀ values) are well-known to be highly variable between samples and among individual grains from the same sample, but the factors that control DRC characteristics are imperfectly understood. Here we report correlations between OSL DRC shapes and thermoluminescence (TL) glow curve characteristics for a sample of quartz from northern Australia. Individual grains were measured using the SAR procedure and one of two preheat temperatures (160 °C and 260 °C), and grouped according to similarities in their DRC shapes. Grains from each DRC group were then physically transferred onto a separate disc for TL measurement as a multi-grain aliquot. A strong correlation was observed between DRC group and laboratory-irradiated TL glow curve shapes, along with some differences between the two preheats. Irrespective of the selected preheat, earlier saturating DRC groups are associated with the most intense 110 °C TL signal, and the least intense 325 °C TL signal, which corresponds to the main OSL trap. Later saturating DRC groups generally show the opposite trend. There are also trends within other regions of the glow curve and DRC group, such as prominent TL responses at 140–160 °C, 220–240 °C and 390–410 °C. We assessed the effect on the accuracy of equivalent dose (D_e) estimation using an associated radiocarbon age as an independent cross-check of the OSL ages for the DRC groups. D_e over- and under-estimates were obtained for some DRC groups. Most notably, grains preheated to 160 °C displayed a pattern of D_e values which decreased with an increase in D₀. We relate this to variable concentrations of charge at the ∼230 °C TL trap prior to regenerative dose OSL measurements. OSL ages for most DRC groups preheated to 260 °C are close to the radiocarbon age, as are those of later saturating DRC groups preheated to 160 °C; the latter DRC groups have the smallest TL signals at ∼230 °C relative to the TL peak at 325 °C. The results of this study suggest that correlations between single-grain D_e and D₀ values can occur due to underlying differences in the TL characteristics of grains with different DRC shapes. In the absence of independent age control and prior to measuring multi-grain aliquots of quartz, we recommend that OSL dating practitioners screen their samples for any single-grain patterns of D_e as a function of DRC shape, to determine the optimal SAR measurement conditions and data-analysis procedures for D_e estimation.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101533"},"PeriodicalIF":2.7,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000372/pdfft?md5=73c08acd68c879a0e15f7eafe0a58bf3&pid=1-s2.0-S1871101424000372-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140843262","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":"Post-glacial small delta process uncovered by luminescence and radiocarbon chronology of core sediments from coastal South China Sea","authors":"Yuexin Liu ,&nbsp;Guanjun Xu ,&nbsp;Gui Long ,&nbsp;Yingjin Song ,&nbsp;Ruonan Tian ,&nbsp;Yanwen Li ,&nbsp;Hua Tu ,&nbsp;Hongwei Li ,&nbsp;Zhongping Lai","doi":"10.1016/j.quageo.2024.101530","DOIUrl":"10.1016/j.quageo.2024.101530","url":null,"abstract":"&lt;div&gt;&lt;p&gt;Reliable chronology is crucial for reconstructing delta processes. The past decades witnessed a boost of dating works on the most economically influential large deltas (i.e., subaerial area &gt;1000 km&lt;sup&gt;2&lt;/sup&gt;), but chronology remains lacking on many small deltas (i.e., subaerial area &lt;1000 km&lt;sup&gt;2&lt;/sup&gt;) that are also densely populated and economically active. Luohe River Delta (LRD) in the coastal South China Sea is such a small delta, whose evolution concerns hundreds of thousands of people, and literally no reliable dating results have been reported to support research of its processes. Herein, dating work combining radiocarbon (&lt;sup&gt;14&lt;/sup&gt;C) on mollusk shells and quartz Optically Stimulated Luminescence (OSL) methods were performed on core LFZK06 from LRD, to test applicability of both methods by age comparison and to establish a chronological framework, using Bayesian age-depth models, of LRD for the first time. &lt;sup&gt;14&lt;/sup&gt;C ages are systematically c. 0.5–1 ka younger than OSL ages from the same depths. Such young bias of &lt;sup&gt;14&lt;/sup&gt;C ages in LRD contrasts with previously observed overestimated &lt;sup&gt;14&lt;/sup&gt;C results in the nearby Pearl River Delta (PRD), likely due to the distinction in bedrock types between Luohe River (granites and sandstones only) and Pearl River (limestone prevalence causing hardwater effect) drainages. Ages of core LFZK06 span from 57 ± 7 ka to 3.42 ± 0.05 cal ka BP and contain a hiatus between 57±7–11.9 ± 1.7 ka. Holocene deltaic sequence of the core shows three-stage sedimentary processes: (1) rapid deposition of prodelta/delta front sediments at &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mn&gt;10.2&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;‐&lt;/mo&gt;&lt;mn&gt;0.4&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;0.5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; ka–&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mn&gt;7.7&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;‐&lt;/mo&gt;&lt;mn&gt;0.3&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;0.4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; ka related to rapid sea level rise, (2) hiatus during &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mn&gt;7.7&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;‐&lt;/mo&gt;&lt;mn&gt;0.3&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;0.4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; ka–&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mn&gt;5.7&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;‐&lt;/mo&gt;&lt;mn&gt;0.8&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;0.5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; ka likely due to reduced sediments input or river channel migration, (3) rapid accumulation of delta plain sediments during &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mn&gt;5.7&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;‐&lt;/mo&gt;&lt;mn&gt;0.8&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;0.5&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; ka–&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msubsup&gt;&lt;mn&gt;3.42&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;‐&lt;/mo&gt;&lt;mn&gt;0.85&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;0.42&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; ka reflecting depocenter shift toward core location. Moreover, changes of quartz OSL sensitivity were detected, indicative of sediment provenance transition. A change in sediment source from nearby granite weathering towards fluvial long-transported materials occurred at a depth of 24.7 m, with low quartz OSL sensitivity in the gravell","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101530"},"PeriodicalIF":2.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140769347","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":"Multiple age control of young nebkhas in the Mu Us dune field, north-central China","authors":"Ying Wang,&nbsp;Shihan Li,&nbsp;Shuangwen Yi,&nbsp;Zhiwei Xu","doi":"10.1016/j.quageo.2024.101531","DOIUrl":"10.1016/j.quageo.2024.101531","url":null,"abstract":"<div><p>Nebkhas, a unique type of biogeomorphological aeolian landforms formed by sand accumulation around plants, are widely distributed in arid and semi-arid regions globally. Previous studies have highlighted the potential of nebkha sediments as valuable archives for understanding past climate and environmental changes. However, establishing a reliable chronological framework for nebkha sediments has posed challenges due to the lack of suitable dating methods. In this study, we applied both the quartz OSL and K-feldspar pIRIR₁₅₀ protocols to date nebkha sediments from three different sites within the Mu Us dune field in north-central China. Internal checks indicate that the quartz OSL protocol is suitable for equivalent dose measurements, though age determinations for some quartz samples with weak luminescence signals may be subject to uncertainties. K-feldspar exhibits brighter signal intensity and a higher signal-to-noise ratio, making K-feldspar pIRIR₁₅₀ ages reliable, particularly when residual doses are low, luminescence signals are stable, and dose recovery ratios are satisfactory. The results indicate that the luminescence ages derived from both the quartz OSL and K-feldspar pIRIR₁₅₀ protocols are comparable, and these ages align with stratigraphic sequences and independent ¹³⁷Cs dating results. Based on the established chronologies, our findings suggest that some large nebkhas in the southwestern Mu Us dune field likely originated 100–200 years ago, possibly in response to either climate-driven or human-induced aridification in this region.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101531"},"PeriodicalIF":2.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140771311","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 De underestimation caused by the unstable medium component in the initial OSL signal from lava-baked quartz and correction strategies","authors":"Chun-Xin Wang ,&nbsp;Chang Huang ,&nbsp;Anchuan Fan ,&nbsp;Sheng-Hua Li","doi":"10.1016/j.quageo.2024.101532","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101532","url":null,"abstract":"<div><p>Accurately dating of eruptive events is crucial for understanding the eruptive history of a volcano. The optically stimulated luminescence (OSL) dating technique has been widely used in the geochronological studies of volcanic eruption events. However, its application is challenging due to the complex components of OSL signals in which the unstable medium component often results in age underestimation for quartz related to volcanic activity. In this study, we investigated the quartz OSL properties from a lava-baked sediment layer from the Tengchong volcanic field, southwest China. The results indicated that the initial OSL signal of the lava-baked quartz was primarily dominated by the medium component, which exhibited small Fast Ratio values (&lt;10). The equivalent dose (D_e) values showed a negative correlation with recuperation, and the D_e-t plot concurrently showed a decreasing trend. Pulse-annealing tests confirmed the medium component in the initial OSL signal to be thermally unstable, hence resulting in age underestimation. Consequently, the early background subtraction method and another two correction strategies were employed to derive D_e values from the more stable fast component: Ⅰ) fitting the D_e-t plot, and Ⅱ) fitting the D_e-recuperation plot. The study found that D_e values could only be partially corrected using the early background subtraction method. In contrast, the latter two methods allowed for successful correction. The corrected quartz OSL ages agree well with independent MET-pIRIR ages of potassium feldspar and ¹⁴C ages. The reliable chronological results suggest that the Dayingshan volcano erupted approximately 41–45 thousand years ago.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101532"},"PeriodicalIF":2.7,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140647297","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 statistical method for treating the “negative-age” and “negative-atom-number” conundrums in radioisotope dating","authors":"W.-K. Hu ,&nbsp;W. Jiang ,&nbsp;Z.-T. Lu","doi":"10.1016/j.quageo.2024.101521","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101521","url":null,"abstract":"<div><p>In radioisotope dating, statistical fluctuations of atom counts or decay counts can sometimes lead to unphysical results, such as negative counts after subtracting the background or negative apparent ages near the boundaries of the dating range. How to treat these boundary cases with a unified approach and give proper estimates on age limits and confidence intervals is an important issue in radioisotope dating. In this work, we combine the Feldman-Cousins likelihood-ratio ordering method for interval estimation, a Frequentist approach to make consistent transitions from the choice of one-sided limits to two-sided confidence intervals, and a Bayesian method to treat the background uncertainties. This data treatment method naturally eliminates the unphysical results. We use ⁸¹Kr dating and Atom Trap Trace Analysis as an example to illustrate the advantages. This method can be generalized to other radioisotopes and ultra-sensitive analysis techniques.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"81 ","pages":"Article 101521"},"PeriodicalIF":2.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140344436","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":"Episodic sediment accumulation linked to global change in the endorheic Qaidam Basin of the Tibetan Plateau revealed by feldspar luminescence dating","authors":"Zhaojing Ding ,&nbsp;Songlin Gong ,&nbsp;Guoqiao Xiao ,&nbsp;Yixuan Wang ,&nbsp;Weitao Yuan ,&nbsp;Jianwei Zhang ,&nbsp;Jiang Wang ,&nbsp;Zhongping Lai","doi":"10.1016/j.quageo.2024.101522","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101522","url":null,"abstract":"<div><p>Given its high accumulation rate in sediments, the endorheic basin in arid regions plays a crucial role in reconstructing paleo-environment. However, it would not provide high-resolution climatic records if significant wind-eroded depositional hiatuses were inevitable within a severe wind environment. Unconformable contacts have been found during field survey in the top part of the stratigraphy in the Qaidam Basin, a prototypical endorheic basin in central Asia. To elucidate whether the sediment is continuous, we employed luminescence dating methods of feldspar pIR₂₀₀IR₂₅₀ and quartz OSL to date sediments, including lacustrine sediments and salt crusts, from the Qarhan Playa that is the Quaternary depositional center of the Qaidam Basin. Various experiment tests, including preheat plateau, dose recovery, and residual dose, were conducted. The dating results show that the feldspar pIR₂₀₀IR₂₅₀ can provide dependable ages with negligible residual doses. The pIR₂₀₀IR₂₅₀ dating ages within the last glacial cycle reveal several environmental shifts. A Qarhan paleolake in Marine Isotope Stage (MIS) 5 was demonstrated by the cluster ages of ∼140–80 ka of lacustrine sediments. The salt crust ages of 136 ± 10 ka and 97 ± 6 ka indicate that, before completely disappeared, the paleolake with shallow dish-shape depression had been dried up more than once, illustrating “shallow——dry——shallow” cycles. The playa in the eastern Qaidam Basin evolved mainly in warm periods, such as MIS 5 and MIS 1, supported by the salt crust ages of MIS 5 (136 ± 10 ka and 97 ± 6 ka) and MIS 1 (10 ± 1 ka and 0.6 ± 0.1 ka). Depositional hiatus in the last glacial cycle were identified by unconformable contacts in three sections between the lacustrine strata and their overlying playa strata, with corresponding age gaps of 158 ± 20–97 ± 6 ka, 131 ± 10–10 ± 1 ka, and 84 ± 7–0.6 ± 0.1 ka, respectively. In all the three sections the sediments for the whole of the last glacial period is missing, eroded by wind. This process should have occurred periodically during the glacial-interglacial cycles of the orbital global climatic changes. The results also show that hiatuses are common for endorheic basins on the Earth with age gaps of up to ∼100 ka, suggesting that robust chronology should be established before any climatic correlation due to severe wind erosion leading to episodic sediment accumulation.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"81 ","pages":"Article 101522"},"PeriodicalIF":2.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140339554","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":"New volcanological, 40Ar/39Ar dating and paleomagnetic record from Trindade Island and stratigraphic implications","authors":"N.G. Pasqualon ,&nbsp;J.F. Savian ,&nbsp;E.F. Lima ,&nbsp;W.P. de Oliveira ,&nbsp;G.A. Hartmann ,&nbsp;C.M.S. Scherer ,&nbsp;L.M.M. Rossetti ,&nbsp;F.R. da Luz ,&nbsp;R.I.F. Trindade ,&nbsp;E.B. Cahoon ,&nbsp;D.P. Miggins ,&nbsp;A. Koppers ,&nbsp;A. Di Chiara","doi":"10.1016/j.quageo.2024.101518","DOIUrl":"10.1016/j.quageo.2024.101518","url":null,"abstract":"<div><p>Unrevealing the stratigraphy of volcanic systems is fundamental to understanding their eruptive history and requires a multiproxy approach for the accurate correlation and interpretation of deposits. We present new volcanological, ⁴⁰Ar/³⁹Ar ages and paleomagnetic data from the volcanic rocks of Trindade Island, located at ∼1.260 km from the Brazilian coast in the South Atlantic Ocean. The reconstruction of the volcanic history of Trindade Island is important because it is the youngest volcanic terrain in Brazil and part of a submarine chain that represents the most recent plume-induced alkaline manifestation beneath the South American plate. Our results suggest Trindade Island underwent two main phases of volcanism. The first phase (3.9–1.5 Ma) formed the Trindade Complex and Desejado Formation, with eruptive styles ranging from phreatomagmatic/Surtseyan to Vulcanian and of dominant phonolitic composition. The second phase (1.0–0.06 Ma) formed the nephelinitic monogenetic centers Morro Vermelho, Valado and Paredão Volcano Formations through dominant Hawaiian and Strombolian styles. The new ages imply a revised stratigraphy for the youngest units of Trindade Island, with partial overlap between them. The revised chronology integrated to the paleomagnetic directional data evidence that Trindade Complex formed during Gauss normal chron (D = 355.4°; I = −49.6°), Valado and Paredão Volcano during Brunhes normal chron (D = 14°; I = −42.3° and D = 9.2°; I = −35.2°, respectively), while Morro Vermelho records the late Matuyama-early Brunhes chron (D = 36.5°; I = −19.8°), with site-level mean paleodirections of normal and transitional polarity within the reverse Matuyama interval.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"81 ","pages":"Article 101518"},"PeriodicalIF":2.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140272725","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":"Re-examining the earliest evidence of human presence in western Europe: New dating results from Pirro Nord (Italy)","authors":"Mathieu Duval ,&nbsp;Lee J. Arnold ,&nbsp;Jean-Jacques Bahain ,&nbsp;Josep M. Parés ,&nbsp;Martina Demuro ,&nbsp;Christophe Falguères ,&nbsp;Qingfeng Shao ,&nbsp;Pierre Voinchet ,&nbsp;Julie Arnaud ,&nbsp;Claudio Berto ,&nbsp;Gabriele Luigi Francesco Berruti ,&nbsp;Sara Daffara ,&nbsp;Benedetto Sala ,&nbsp;Marta Arzarello","doi":"10.1016/j.quageo.2024.101519","DOIUrl":"10.1016/j.quageo.2024.101519","url":null,"abstract":"<div><p>We present the results of the first dating study of site P13 at Pirro Nord, Italy, which documents some of the earliest evidence for hominin presence in western Europe. Our multi-technique dating approach is based on a combination of palaeomagnetism, electron spin resonance (ESR), thermally-transferred optically stimulated luminescence (TT-OSL) and combined U-series/ESR applied to both fossil material and host sediment. It provides ages ranging from 627 ± 59 to 1006 ± 126 ka and clustering around 0.8 Ma. One additional fossil tooth collected from the nearby P10 site also returns an age within this range. Ordinarily, this outcome would naturally lend itself to the straightforward conclusion that Pirro Nord has a late Early Pleistocene age of ∼0.8 Ma. However, this interpretation is complicated by the fact that these numerical dating results are in contradiction with the biochronological evidence, which suggests a much older age on the order of 1.3–1.7 Ma. Consequently, we explore the various potential sources of bias that could have influenced the numerical dating methods and the biochronological inferences. In particular, the critical evaluation of the palaeomagnetic data available for various sites belonging to the younger Colle Curti Faunal Unit (FU) indicates that there is non-negligible age uncertainty on the allegedly minimum age of ∼1.1 Ma traditionally assigned to the Pirro FU. Moreover, while the combined U-series/ESR dataset could accommodate an older age for the fossil remains if uranium uptake in the dental tissues occurred relatively rapidly before the closure of the system (CSUS model), the ages obtained from the two semi-independent quartz dating methods (ESR and TT-OSL) both appear to indicate that the sediment was last exposed to sunlight about 0.8 Ma. This disparity opens up the possibility that the sediment and fossil assemblage may not be coeval. In other words, it is possible that the fossil remains may have been reworked into younger deposits that entered the karst about 0.8 Ma. Though feasible from a karst sedimentary dynamics perspective, this hypothesis is not consistent with previous taphonomic studies that indicate an absence of evidence for fossil reworking after entering the karst. At the very least, our dating results indicate that site formation processes at Pirro Nord site P13 are more complex than previously considered.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101519"},"PeriodicalIF":2.7,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140399099","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":"Revisiting a proof of concept in quartz-OSL bleaching processes using sands from a modern-day river (the Séveraisse, French Alps)","authors":"Magali Rizza ,&nbsp;Gilles Rixhon ,&nbsp;Pierre G. Valla ,&nbsp;Stéphanie Gairoard ,&nbsp;Doriane Delanghe ,&nbsp;Jules Fleury ,&nbsp;Michal Tal ,&nbsp;Solveig Groleau","doi":"10.1016/j.quageo.2024.101520","DOIUrl":"10.1016/j.quageo.2024.101520","url":null,"abstract":"<div><p>Conditions of sediment transport and deposition in highly dynamic fluvio-glacial environments enhance incomplete bleaching of luminescence signals during sunlight exposure. Whatever the geomorphic context or application, partial bleaching has been widely reported and remains a methodological limitation for application of Optically Stimulated Luminescence (OSL) dating methods, potentially resulting in sediment-burial age overestimation. This study focuses on the highly dynamic Séveraisse River (SW French Alps) where modern-day alluvial sands of a braided reach were sampled to assess the degree of quartz-OSL partial bleaching associated with superficial pre- and post-deposition geomorphic processes. Our original approach combines (i) a photogrammetry-based survey, (ii) sediment grain-size analysis, and (iii) measurements of both portable OSL luminescence signals and conventional quartz OSL equivalent doses in modern superficial (from 0.1 to 1 cm) and sub-surface (up to 30 cm) alluvial sands exposed to sunlight for at least 19 days. Our results show high but spatially variable residual luminescence signals at the surface, measured in all grain-size fractions with both the portable luminescence reader (≥5 x10⁶ cts/g) and conventional quartz-OSL doses (≥80 Gy), even within the uppermost millimetres of the exposed alluvial surface. Our data thus highlight poor luminescence bleaching in the Séveraisse's modern sands, during both pre-depositional transport and post-depositional exposure. In addition, our study reveals, for the first time, the significant sunlight attenuation over a few millimetres within modern alluvial sediments, perhaps conditioned by dark sand grains, and/or by superficial blanketing by silts (i.e. waning flow stage) that leads to a porosity decrease and very low sunlight penetration. We suggest the occurrence of a critical sediment layer (i.e. only a few mm thick) that could play a key role in bleaching processes for alluvial surfaces, with strong implications for our understanding of residual doses in braided systems' sandy deposits and the dynamics of such alluvial surfaces.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"82 ","pages":"Article 101520"},"PeriodicalIF":2.7,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140281190","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}