Quaternary Geochronology最新文献

{"title":"Single-grain K-feldspar post-IR IRSL dating of glaciofluvial sediments of Guxiang Glaciation in SE Tibetan Plateau","authors":"Yantian Xu ,&nbsp;Xianjiao Ou ,&nbsp;Xiaojun Zou ,&nbsp;Cai Yang ,&nbsp;Geoff A.T. Duller ,&nbsp;Yang Li ,&nbsp;Helen M. Roberts ,&nbsp;Kunmei Yang ,&nbsp;Lanhua Zeng","doi":"10.1016/j.quageo.2024.101612","DOIUrl":"10.1016/j.quageo.2024.101612","url":null,"abstract":"<div><p>The Guxiang Glaciation, a key reference for classifying late Quaternary glaciations on the Tibetan Plateau, has been dated to MIS 6 using cosmogenic ¹⁰Be exposure dating of two boulders. However, additional dating methods are needed to evaluate and improve its chronology. In this study, we used the post-infrared infrared stimulated luminescence (post-IR IRSL) signal at 225 °C from single K-feldspar grains to date a lateral moraine corresponding to the Guxiang Glaciation in the Bodui Zangbo Valley, southeastern Tibetan Plateau. Six samples from glaciofluvial sand lenses interbedded within the moraine were analyzed. The L_nT_n method was utilized for D_e determination to avoid truncation in D_e distribution and age underestimation. A common standardized growth curve (SGC) was established for all samples, and the least-squares (LS)-normalized L_n/T_n values of the brightest grains were selected for L_n/T_n and D_e estimation using the central age model (CAM). Using one fading-correction model, the post-IR IRSL ages (159 ± 9 ka to 181 ± 11 ka, average value of 173 ± 4 ka) fall within the expected MIS 6 interval and align with previous ¹⁰Be exposure ages. However, the ages are close to the limit of the method, and a different model for correcting fading suggests a much older age (average 308 ± 27 ka). This study reveals both the potential and challenges of single-grain K-feldspar luminescence dating as a means to establish chronological control for glaciations beyond the last glacial period on the Tibetan Plateau.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"84 ","pages":"Article 101612"},"PeriodicalIF":1.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937880","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 the MIS 6 glaciation of the Pamir mountains (Central Asia)","authors":"M.O. Efimova ,&nbsp;E.V. Deev ,&nbsp;N.A. Taratunina ,&nbsp;J.-P. Buylaert ,&nbsp;P.M. Sosin ,&nbsp;A.V. Panin ,&nbsp;A.S. Murray ,&nbsp;R. Schneider ,&nbsp;M.S. Lukyanycheva ,&nbsp;O.A. Tokareva ,&nbsp;O.A. Meshcheryakova ,&nbsp;R.N. Kurbanov","doi":"10.1016/j.quageo.2024.101596","DOIUrl":"10.1016/j.quageo.2024.101596","url":null,"abstract":"<div><p>The Pamir Mountains are one of the highest mountain systems in the world; they act as sources of fresh water for the main rivers of Central Asia: the Amudaria and Syrdaria. Throughout the Quaternary, the Pamirs played a major role in controlling atmospheric circulation and land-surface processes, and provided great volumes of terrigenous sediments for transport by large rivers to the depressions in the Aral and Caspian regions. These ultimately provided broad aeolian cover in the sandy deserts, and finer dust for the widely distributed loess-palaeosol sequences. The glaciation history of this highly dynamic region provides an important basis for understanding climate change, sediment source and landscape evolution in Central Asia during the Quaternary. The question of the number, distribution, extent and timing of Pleistocene glaciations in the Pamir is debated. One of the main obstacles to research, together with difficulties of access and severity of current climate, is the varying degree of preservation of traces of previous glaciations in the western and eastern Pamir. As a result of a geological survey, we for the first time identified a thick lacustrine deposit at high altitudes in a tributary of the Panj – the valley of the Sary-Shitharv River – this records the damming of the Panj River valley by a large glacier. Luminescence measurements were undertaken to obtain the age of the Sary-Shitharv glacially-dammed lake. As often in mountain catchments the quartz OSL signal was unsuitable for dose estimation, and so the chronology of the Sary-Shitharv section is based entirely on post-IR IRSL signals from K-rich feldspar. We used pIRIR_50,290 and pIRIR_200,290 protocols and obtained indistinguishable ages from both protocols. Given the high sedimentation rates deduced from the structure of lacustrine deposits, the entire sequence must have been accumulated rather quickly, over a period of no more than a few thousand years. The average age over the whole series of dates is 165 ± 11 ka. This places the existence of the glacially-dammed lake at Sary-Shitharv in late MIS 6, a result that fits well with the general course of the glacial history of the Pamirs.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101596"},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141706379","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":"Multi-method luminescence dating of young aeolian dunes in the central Tibetan plateau","authors":"Shengli Yang ,&nbsp;Xiaojing Liu ,&nbsp;Jinbo Zan ,&nbsp;Pushuang Li ,&nbsp;Xuechao Xu ,&nbsp;Dongxue Li ,&nbsp;Qiong Li ,&nbsp;Li Liu ,&nbsp;Chen Wen ,&nbsp;Xiaomin Fang","doi":"10.1016/j.quageo.2024.101595","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101595","url":null,"abstract":"<div><p>The environment of the Tibetan Plateau (TP) is extremely sensitive to global climate change, and the frequent aeolian activity on the central TP generates large amounts of dust with the result that the region has a major impact on regional and global environmental change. The extensive aeolian dunes on the central TP provide a direct and valuable archive of aeolian activity; however, the age and sediment deposition processes of these dunes are still poorly understood. Optically stimulated luminescence (OSL) dating, an effective method for dating aeolian sediments, has been used sparingly in the region. In this study, we applied quartz single-aliquot regenerative-dose (SAR) OSL, K-feldspar post-infrared infrared-stimulated luminescence (pIRIR), and single-grain K-feldspar pIRIR methods to determine the ages of two well-preserved sand dunes in the Lunpola (LD) and Tuotuohe (TTH) river basins in the central TP. Our results showed that the quartz OSL signal of the TTH dune was dim, while the LD dune quartz exhibited a higher OSL sensitivity than that of the TTH dune. The high recuperation observed could be attributed to the low signal-to-noise ratio of the OSL signals. The K-feldspar signal was bright and the pIR₅₀IR₁₇₀ signal could be used to date young dune samples in the central TP, whereas it could be affected by the residual dose, or incomplete bleaching in the TTH profile, resulting in age overestimation. The single-grain K-feldspar protocol had a good potential for dating the young TP dunes. Multi-method luminescence dating is recommended for the cross-checking of young dune samples with low OSL sensitivity in the TP. Our luminescence dating reveals that aeolian dunes in the central TP formed approximately 385 to 330 a and persisted to the present, possibly in response to climate change since the late stage of Little Ice Age (1400−1850 CE).</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101595"},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583209","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":"Absolute dating of sediments forming the Lena river terraces (Northeastern Siberia)","authors":"Anzhela N. Vasilieva ,&nbsp;Andrew S. Murray ,&nbsp;Natalia A. Taratunina ,&nbsp;Jan-Pieter Buylaert ,&nbsp;Vasiliy M. Lytkin ,&nbsp;Grigoriy I. Shaposhnikov ,&nbsp;Thomas Stevens ,&nbsp;Gábor Ujvari ,&nbsp;Titanilla G. Kertész ,&nbsp;Redzhep N. Kurbanov","doi":"10.1016/j.quageo.2024.101592","DOIUrl":"10.1016/j.quageo.2024.101592","url":null,"abstract":"<div><p>Sediments of the Lena River represent an important environmental archive for understanding the Quaternary history of North-Eastern Siberia. However, at present, the structure, origin and age of the Lena River terraces are poorly known. This article presents results of lithofacies analysis and absolute dating of the Ust’-Buotama section exposing the fourth (Bestyakh) terrace of the Lena River. We report the first quartz and K-feldspar luminescence ages, the reliability of which was argued by age relations and standard tests. Three stratigraphic units have been recognized in the section (depths from the top): lacustrine-alluvial deposits (85–120 m) of the Mavrinka Formation; aeolian sand deposits of the Dolkuma Formation (23–85 m), and Holocene aeolian dune sediments (0–23 m). The resulting chronology suggests that the sediments of the Mavrinka Formation were deposited no later than 300 ka (MIS 9 or later). Deposition of the Dolkuma Formation occurred from ∼30 ka to ∼15 ka (late MIS 3 - late MIS 2). Holocene aeolian dune formed during initial Neoglacial cooling post climatic optimum (c. 5.5 cal ka BP). More extensive Late Holocene dune sediments which formed ∼400 years ago are coeval with Little Ice Age (11th-19th centuries).</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101592"},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141630478","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":"Multi-step post-IR IRSL dating and palaeoclimate implications from 270 to 90 ka in the Central Shandong Mountains, eastern China","authors":"Qiuyue Zhao ,&nbsp;Shuzhen Peng ,&nbsp;Xiuying Liu ,&nbsp;Min Ding ,&nbsp;Luo Wang ,&nbsp;Qingzhen Hao ,&nbsp;Shugang Kang ,&nbsp;Wei Zhang ,&nbsp;Renwei Xiong ,&nbsp;Junsheng Yue ,&nbsp;Ting Fan","doi":"10.1016/j.quageo.2024.101590","DOIUrl":"10.1016/j.quageo.2024.101590","url":null,"abstract":"<div><p>The aeolian sediments in the Central Shandong Mountains (CSM) in eastern China provide a faithful carrier of climate and sea-level variations outside of the Chinese Loess Plateau. However, due to the lack of or limited application of absolute dating protocols, previous studies of Shandong loess have focused mainly on loess deposited since the last interglacial period, with fewer studies on provenances and climate changes recorded in older penultimate interglacial period characterized by a long duration and significant climate fluctuations, which is not helpful to understand the spatiotemporal pattern changes of East Asian monsoon. In this study, multi-elevated-temperature post-infrared infrared-stimulated luminescence (MET-pIRIR) dating method was utilized to obtain the absolute ages from the Dongheishan (DHS) section in CSM region. Preheat plateau and dose recovery tests indicate that the MET-pIRIR signals of 250 °C and 300 °C have negligible anomalous fading and they can give reliable ages for the loess since ∼270 ka. Luminescence dating results suggest that the DHS loess mainly accumulated from 265 ± 12 ka to 93 ± 4 ka. The loess sedimentation rates during ∼195 ± 18–108 ± 4 ka were much lower than expected in the DHS section, which occurred approximately correlates with the Qingshui erosion period (∼136 ka), as indicated by the planation surface outside the CSM. Both the grain-size characteristics and sedimentation rate variations suggest that the dust sources of the DHS loess were primarily proximal sediments, which is possibly due to frequent variations in dust provenances caused by plentiful precipitation during the interglacial periods and diversions of the Yellow River. This study implies that the CSM loess with a good chronology could be utilized to decipher regional sedimentation and climatic changes processes.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101590"},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141630647","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":"Constraining the age of the Pleistocene sedimentary infill of Cueva Mayor (Atapuerca, N Spain) through a multi-technique dating approach","authors":"V. Martínez-Pillado ,&nbsp;M. Demuro ,&nbsp;J.E. Ortiz ,&nbsp;Q. Shao ,&nbsp;L.J. Arnold ,&nbsp;M. Duval ,&nbsp;H. Cheng ,&nbsp;T. Torres ,&nbsp;E. Santos ,&nbsp;C. Falguères ,&nbsp;O. Tombret ,&nbsp;N. García ,&nbsp;A. Aranburu ,&nbsp;A. Gómez-Olivencia ,&nbsp;J.L. Arsuaga","doi":"10.1016/j.quageo.2024.101576","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101576","url":null,"abstract":"&lt;div&gt;&lt;p&gt;Establishing chronologies of archaeological sites by using a single dating method may not always reliably constrain the age of a deposit or a fossil, as potential biases may naturally arise, particularly in complex sedimentary settings such as caves. In this study, we performed a multi-technique dating approach that targets different materials in two caves from the Cueva Mayor-Cueva del Silo karst system, Sierra de Atapuerca, Spain. Two new fossil teeth from lithostratigraphic unit LU4 (GE-I pit) at Galería de las Estatuas have been dated by combined U-series/ESR and Amino Acid Racemisation (AAR) methods. The former provides ages of 117 ± 13 and 87 ± 9 ka that agree with previous dating studies of this Neandertal site, confirming the assignment of level LU4 to Marine Isotope Stage (MIS) 5. In contrast, AAR analyses produce very scattered ages, pointing to significant post-burial chemical modifications in dentine. A first set of ages is presented for the Cata Litario pit at Sala de los Cíclopes, a palaeontological site formed exclusively of cave bear fossils belonging to the Middle Pleistocene species &lt;em&gt;Ursus deningeri&lt;/em&gt;. We provide U-series/ESR and AAR ages for two bear teeth from lithostratigraphic unit LU5, and extended-range luminescence ages for the sediment deposits that host, and immediately underlie and overlie, the bear accumulation. Depositional ages of the sediment were obtained using single-grain thermally-transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains and post-infrared-infrared stimulated luminescence (pIR-IR) dating of K-feldspars. Several speleothems, both &lt;em&gt;in situ&lt;/em&gt; and reworked fragments embedded in the different lithostratigraphic units, have additionally been dated by U-series to constrain the timing of the sequence formation. The results indicate that the sediment originally entered the cave between MIS-12 and MIS-10 (444 ± 28 ka to 367 ± 32 ka). Nevertheless, the AAR and U-series/ESR fossil ages, as well as some of the speleothem fragment ages from LUs 5 and 6 are significantly younger. Leaving aside methodologically questionable results for one of the bear tooth samples, the most reliable AAR and U-Series/ESR ages range from 287 ± 23 ka to 256 ± 24, while the speleothem fragments indicate several formation episodes between 444 ± 19 and 284 ± 8 ka. The apparent difference between the U-Series/ESR ages on the fossils and the luminescence ages on the host sediment are not likely to be wholly explained by uncertainties on uranium uptake modelling or gamma dose rate evaluation, and thus is most likely related to taphonomic processes or a complex site formation history.&lt;/p&gt;&lt;p&gt;The presence of fossils and eroded speleothem clasts of younger age within these levels is consistent with either an event of prior erosion, transport and resedimentation of LUs 4, 5 and 6, and/or a complex post-depositional mixing history for the stratigraphic sequence at Cata Litario. This study h","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101576"},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141606324","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":"Extending the ESR and OSL dating comparison on coastal dune deposits from the Wilderness-Knysna area (South Africa)","authors":"E. Ben Arous ,&nbsp;M.D. Bateman ,&nbsp;M. Duval","doi":"10.1016/j.quageo.2024.101580","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101580","url":null,"abstract":"<div><p>Our work follows up on the initial methodological ESR dating study by Ben Arous et al. (2022) on several quartz samples from the Plio-Pleistocene to Holocene aeolian coastal dune deposits of the Wilderness-Knysna area (South Africa) that were previously dated by optically stimulated luminescence (OSL). Here, we extend this first ESR-OSL comparison with five additional optically-bleached quartz samples. We used the Multiple Aliquot Additive Dose (MAAD) method to specifically (i) evaluate the influence of the irradiation dose steps on the determination of low D_e values (&lt;100 Gy) and (ii) obtain finite ESR ages for older samples that sometimes show saturated OSL signals. Following the Multiple Centre ESR dating approach, the Aluminium (Al) and Titanium (Ti) signals (Ti–H and Ti–Li–H, the latter resulting from a mixture of Ti centres) were systematically measured in all samples, and resulting D_e values and age estimates were compared with the corresponding OSL data. Our results show that for young samples (&lt;50 ka) showing D_e values of a few tens of Grays (Gy), the use of smaller irradiation steps spaced by &lt; 100 Gy has a noticeable impact on the MAAD dose evaluation from the Ti centres, usually leading to D_e results closer to the expected values (for 2/3 samples). However, this also makes the ESR measurements somewhat more challenging, with higher experimental uncertainties, lower measurement repeatability and lower goodness-of-fit resulting from the relatively weak Ti ESR intensities, ultimately impacting the robustness of the ESR data collected. In this sense, our study illustrates the limitations of the ESR method to detect very low dose irradiation values &lt; 30 Gy with our experimental conditions (i.e., using MAAD procedure, a standard resonator and a measurement temperature of ∼90 K). On the contrary, it also highlights the greater potential of the Ti–H signal to date Late Pleistocene samples, confirming previous studies. Moreover, our results suggest that the transport and bleaching conditions of these aeolianite deposits may not be ideal for the reset of the radiation-induced Al and Ti ESR signals, which is consistent with the very few existing studies specifically focused on this type of samples, but contrasts with other previous dating applications centered on fluvial environments. Finally, we also provide additional chronological constraints to the Landward barrier complex and Coversands deposits, two of the oldest Plio-Quaternary formations in the Wilderness-Knysna area.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101580"},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583211","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":"Observing impacts on luminescence depth profile evolutions from surface altered quartzite using OSL laser scanning and controlled light exposed rock sampling techniques","authors":"Tristan Bench ,&nbsp;David Sanderson ,&nbsp;James Feathers","doi":"10.1016/j.quageo.2024.101600","DOIUrl":"10.1016/j.quageo.2024.101600","url":null,"abstract":"<div><p>A technique for parameterizing rock surfaces for luminescence surface exposure dating involves the use of known age rock surfaces which may host no surficial alterations or weathering rinds. However, exposure dated rock surfaces often host subsurface weathering rinds or foreign surficial components, which may impact the development of luminescence depth profiles in the rock material. To observe any effects of depth profile development and parameterizations of naturally altered rock surfaces, controlled exposure experiments were conducted on surface altered and surface non-altered luminescence saturated quartzite samples from the top and bottom portions of rock surface cores, collected from two erratic members of the Foothills Erratics Train, Alberta. Spatially resolved OSL laser scanning techniques were used to acquire two-dimensional OSL maps of the surface core samples for depth profile generation. Results produced varied intensities of depth profile data scatter and depth profile parameterizations between surface altered and non-altered samples. Several cores which exhibited surface alterations produced lower attenuation coefficients than comparable cores with no surface alterations, possibly from the effects of surface features and weathering rinds attenuating light intensity for OSL stimulation. These trends indicate samples hosting surface alterations such as weathering rinds, lichen cover, and staining may offer parameterizations which are inequivalent to rock surfaces with no surface altered components, and that depth dependent, multi-order parameterizations may be needed to adequately parameterize rock surfaces hosting surface altered features for exposure dating.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101600"},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141703144","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":"Single-grain luminescence dating of Manas Lake paleoshorelines reveals late quaternary glacial meltwater forced lake level highstand in arid Central Asia","authors":"Xiaoyan Wang ,&nbsp;Guoqiang Li ,&nbsp;He Yang ,&nbsp;Yixuan Wang ,&nbsp;Ming Jin ,&nbsp;Zhongfeng Yan ,&nbsp;Caixin Qin ,&nbsp;Siyi Gou ,&nbsp;Long Pan ,&nbsp;Jin Yang","doi":"10.1016/j.quageo.2024.101601","DOIUrl":"10.1016/j.quageo.2024.101601","url":null,"abstract":"<div><p>The spatiotemporal patterns of late Quaternary lake evolution, along with their responses to climatic changes and glacial meltwater in the westerlies-dominated Central Asia, remain unclear primarily due to the lack of well-dated records spanning across glacial and interglacial cycles. In this study, we investigated five well-preserved paleolake shoreline sequences, 15–27 m above the modern lake basin of the now-dry Manas Lake, a representative terminal lake in the Junggar Basin of arid Central Asia. Both single aliquot and single-grain K-feldspar post-infrared infrared stimulated luminescence (pIRIR) dating protocols were applied to 26 shoreline samples to reconstruct a lake level variation for Manas Lake over the past 90 kyr. The reliability of the K-feldspar pIRIR dating was tested through assessment of luminescence characteristics and comparison of single-grain and single-aliquot K-feldspar pIRIR D_es. The results indicate that the highest water levels (∼25 m deep) occurred during late Marine Isotope Stage (MIS) 5 (∼80 ka) and MIS 3 (31–27 ka). A lake level 20 m above modern lake basin (a.m.l.b.) occurred from the last deglaciation to the early Holocene (14–10 ka) and again in the late Holocene (3.4–0.3 ka). The lake level changes of Manas Lake are decoupled from observed Westerlies precipitation changes over the past 90 kyr. This decoupling suggests enhanced glacial meltwater sourced from the high Tianshan Mountains, triggered by higher mean summer temperatures, worked together with Westerlies precipitation drove periods of lake level highstand in Manas Lake during late MIS 5, late MIS 3, and early Holocene periods.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"83 ","pages":"Article 101601"},"PeriodicalIF":1.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141697150","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 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":"2024-08-01","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}