Pub Date : 2024-06-29DOI: 10.1016/j.quageo.2024.101580
E. Ben Arous , M.D. Bateman , M. Duval
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 De values (<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 De values and age estimates were compared with the corresponding OSL data. Our results show that for young samples (<50 ka) showing De values of a few tens of Grays (Gy), the use of smaller irradiation steps spaced by < 100 Gy has a noticeable impact on the MAAD dose evaluation from the Ti centres, usually leading to De 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 < 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.
Ben Arous 等人(2022 年)对来自南非 Wilderness-Knysna 地区上新世至全新世风化海岸沙丘沉积物的几个石英样品进行了初步的 ESR 方法测定研究,并通过光激发发光(OSL)对这些样品进行了测定。在此,我们使用另外五个光漂白石英样品对这一首次 ESR-OSL 比较进行了扩展。我们使用了多等分加成剂量(MAAD)方法,特别是(i)评估了辐照剂量步骤对确定低 De 值(<100 Gy)的影响,以及(ii)为有时显示饱和 OSL 信号的较老样品获得了有限的 ESR 年龄。按照多中心 ESR 测年方法,对所有样品中的铝(Al)和钛(Ti)信号(Ti-H 和 Ti-Li-H,后者由钛中心混合产生)进行了系统测量,并将得出的 De 值和年龄估计值与相应的 OSL 数据进行了比较。我们的结果表明,对于De值为几十格瑞(Gy)的年轻样品(50 ka),使用间距为100 Gy的较小辐照步长会对Ti中心的MAAD剂量评估产生明显影响,通常会导致De结果更接近预期值(对于2/3样品)。然而,这也使得 ESR 测量更具挑战性,由于 Ti ESR 强度相对较弱,导致实验不确定性更高、测量重复性更低和拟合优度更低,最终影响了所收集 ESR 数据的稳健性。从这个意义上说,我们的研究说明了在我们的实验条件下(即使用 MAAD 程序、标准谐振器和 90 K 以上的测量温度),ESR 方法在检测极低剂量辐照值 < 30 Gy 方面的局限性。相反,这也凸显了 Ti-H 信号在确定晚更新世样品年代方面的更大潜力,证实了之前的研究。此外,我们的研究结果表明,这些风化岩沉积物的迁移和漂白条件对于辐射诱导的 Al 和 Ti ESR 信号的重置可能并不理想,这与现有的极少数专门针对这类样品的研究是一致的,但与之前其他以河流环境为中心的年代测定应用形成了鲜明对比。最后,我们还为向陆屏障复合体和覆盖砂沉积提供了更多的年代学约束,它们是 Wilderness-Knysna 地区最古老的两个第四纪地层。
{"title":"Extending the ESR and OSL dating comparison on coastal dune deposits from the Wilderness-Knysna area (South Africa)","authors":"E. Ben Arous , M.D. Bateman , 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<sub>e</sub> values (<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<sub>e</sub> values and age estimates were compared with the corresponding OSL data. Our results show that for young samples (<50 ka) showing D<sub>e</sub> values of a few tens of Grays (Gy), the use of smaller irradiation steps spaced by < 100 Gy has a noticeable impact on the MAAD dose evaluation from the Ti centres, usually leading to D<sub>e</sub> 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 < 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":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-29","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}
Pub Date : 2024-06-28DOI: 10.1016/j.quageo.2024.101582
Nasrin Karimi Moayed , Dimitri Vandenberghe , Koen Deforce , Eva Kaptijn , Karsten Lambers , Wouter Verschoof-van der Vaart , Wim De Clercq , Johan De Grave
The majority of relic charcoal kilns in Europe are more recent than 1650 CE and cannot be precisely dated using radiocarbon dating (14C). Quartz-based optically stimulated luminescence (OSL) dating of the sediments associated with the kiln remains has been suggested as a viable alternative. Owing to the lack of reliable and sufficiently precise independent age information, however, it remains to be established whether OSL dating can yield accurate ages for post-1650 CE features. This is explicitly investigated in this study by applying a commonly adopted quartz OSL methodology to three relic charcoal kilns which are known to have been constructed and operated between December 1941 and March/April 1942 CE.
We first document the quartz luminescence characteristics and show through procedural tests that the adopted single-aliquot regenerative dose procedure should be appropriate for equivalent dose determination. Four samples collected from the uppermost part of the charcoal-rich layers in the three features yield the youngest optical ages and are considered coeval. Their average age is 1928 ± 13 CE (95% probability), which matches the independent age reasonably well. The precision associated with the individual OSL ages ranges between 7 and 14% (1 sigma total uncertainty) and it might ideally be possible to establish relative chronologies with a higher time resolution. Finally, we briefly discuss our entire set of OSL ages in relation to future strategies for sampling charcoal kilns remains. In general, we conclude that OSL dating can be particularly advantageous to help resolving chronometric issues that pertain to post-1650 CE relic charcoal kilns.
{"title":"Optical dating of charcoal kiln remains from WWII: A test of accuracy","authors":"Nasrin Karimi Moayed , Dimitri Vandenberghe , Koen Deforce , Eva Kaptijn , Karsten Lambers , Wouter Verschoof-van der Vaart , Wim De Clercq , Johan De Grave","doi":"10.1016/j.quageo.2024.101582","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101582","url":null,"abstract":"<div><p>The majority of relic charcoal kilns in Europe are more recent than 1650 CE and cannot be precisely dated using radiocarbon dating (<sup>14</sup>C). Quartz-based optically stimulated luminescence (OSL) dating of the sediments associated with the kiln remains has been suggested as a viable alternative. Owing to the lack of reliable and sufficiently precise independent age information, however, it remains to be established whether OSL dating can yield accurate ages for post-1650 CE features. This is explicitly investigated in this study by applying a commonly adopted quartz OSL methodology to three relic charcoal kilns which are known to have been constructed and operated between December 1941 and March/April 1942 CE.</p><p>We first document the quartz luminescence characteristics and show through procedural tests that the adopted single-aliquot regenerative dose procedure should be appropriate for equivalent dose determination. Four samples collected from the uppermost part of the charcoal-rich layers in the three features yield the youngest optical ages and are considered coeval. Their average age is 1928 ± 13 CE (95% probability), which matches the independent age reasonably well. The precision associated with the individual OSL ages ranges between 7 and 14% (1 sigma total uncertainty) and it might ideally be possible to establish relative chronologies with a higher time resolution. Finally, we briefly discuss our entire set of OSL ages in relation to future strategies for sampling charcoal kilns remains. In general, we conclude that OSL dating can be particularly advantageous to help resolving chronometric issues that pertain to post-1650 CE relic charcoal kilns.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141606322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-28DOI: 10.1016/j.quageo.2024.101585
Linda A.E. Maßon , Svenja Riedesel , Anja Zander , Mariana Sontag-González , Tony Reimann
The Atacama Desert is generally considered the driest non-polar desert on Earth and is therefore an ideal study area for exploring the water and biota free endmember of Earth's Critical Zone (ECZ). Single grain (SG) luminescence dating has successfully identified processes in the ECZ. However, SG luminescence dating of Atacama Desert feldspars is challenging and time consuming since only a small fraction of grains emits sufficient luminescence and their potassium (K) contents, needed for internal dose rate calculations, are highly variable. Here we present an adaption of the standardised growth curve (SGC) method adjusted to the conditions of Atacama Desert sediments and a correlation of single-grain geochemistry and luminescence properties.
To evaluate if SGCs are suitable for our study site and to determine the influence of the K-content on our luminescence age calculations, we used a set of five samples from the Atacama Desert and five chemically and structurally different feldspar sediment extracts from various geological origins worldwide. We performed a dose recovery test (DRT) using a post-infrared infrared stimulated luminescence (pIRIR) protocol and measured nine major element concentrations, including K, on a single grain level using a scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDX). The DRT dataset was then used to test the application of SGCs. The accuracy of Atacama feldspar pIRIR measurements fitted onto SGCs frequently suffers from odd values in single measurement cycles, since the SGC approach developed for SG feldspar luminescence (Li et al., 2015b) uses one Lx/Tx measurement to project the Ln/Tn values onto a SGC. We investigate the influence of calculating a synthetic regenerative signal (sR) for SGC fitting, to reduce the effect of those odd values on individual grain measurements. Furthermore, we reduced the regenerative cycles used for our sR approach, to test if shorter protocols would result in equivalent dose (De) estimates in agreement with longer protocols. We then calculated Spearman rank correlations between the results obtained with our modified SGC and the SAR protocol, luminescence signal intensities, and the geochemical dataset.
Finally, we present a new method of fitting data onto a SGC which significantly decreases measurement time, without risking the inclusion of outliers. We furthermore show that the luminescence signal intensities, the De values and their dose recovery ratios obtained with our SGC method and a SAR protocol, are independent of the sample geochemistry.
{"title":"Testing the applicability of standardised growth curves for chemically heterogeneous single-grain feldspars from the Atacama Desert, Chile","authors":"Linda A.E. Maßon , Svenja Riedesel , Anja Zander , Mariana Sontag-González , Tony Reimann","doi":"10.1016/j.quageo.2024.101585","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101585","url":null,"abstract":"<div><p>The Atacama Desert is generally considered the driest non-polar desert on Earth and is therefore an ideal study area for exploring the water and biota free endmember of Earth's Critical Zone (ECZ). Single grain (SG) luminescence dating has successfully identified processes in the ECZ. However, SG luminescence dating of Atacama Desert feldspars is challenging and time consuming since only a small fraction of grains emits sufficient luminescence and their potassium (K) contents, needed for internal dose rate calculations, are highly variable. Here we present an adaption of the standardised growth curve (SGC) method adjusted to the conditions of Atacama Desert sediments and a correlation of single-grain geochemistry and luminescence properties.</p><p>To evaluate if SGCs are suitable for our study site and to determine the influence of the K-content on our luminescence age calculations, we used a set of five samples from the Atacama Desert and five chemically and structurally different feldspar sediment extracts from various geological origins worldwide. We performed a dose recovery test (DRT) using a post-infrared infrared stimulated luminescence (pIRIR) protocol and measured nine major element concentrations, including K, on a single grain level using a scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDX). The DRT dataset was then used to test the application of SGCs. The accuracy of Atacama feldspar pIRIR measurements fitted onto SGCs frequently suffers from odd values in single measurement cycles, since the SGC approach developed for SG feldspar luminescence (Li et al., 2015b) uses one L<sub>x</sub>/T<sub>x</sub> measurement to project the L<sub>n</sub>/T<sub>n</sub> values onto a SGC. We investigate the influence of calculating a synthetic regenerative signal (sR) for SGC fitting, to reduce the effect of those odd values on individual grain measurements. Furthermore, we reduced the regenerative cycles used for our sR approach, to test if shorter protocols would result in equivalent dose (D<sub>e</sub>) estimates in agreement with longer protocols. We then calculated Spearman rank correlations between the results obtained with our modified SGC and the SAR protocol, luminescence signal intensities, and the geochemical dataset.</p><p>Finally, we present a new method of fitting data onto a SGC which significantly decreases measurement time, without risking the inclusion of outliers. We furthermore show that the luminescence signal intensities, the D<sub>e</sub> values and their dose recovery ratios obtained with our SGC method and a SAR protocol, are independent of the sample geochemistry.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S187110142400089X/pdfft?md5=bf9b8612fdb16da46f987dd54510b9ed&pid=1-s2.0-S187110142400089X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-27DOI: 10.1016/j.quageo.2024.101577
Jungyu Choi, Elizabeth Chamberlain, Jakob Wallinga
Evaluating remnant doses is crucial for luminescence dating of late Holocene sedimentary deposits, especially when slow-bleaching feldspar pIRIR signals are employed. Previous research demonstrated that the bleaching capacity varies between individual grains, but only a few attempts have been made to quantify this. In this research, we evaluate variance in bleachability at a single-grain level for a low-temperature pIRIR signal from K-rich feldspar extract. The research is conducted through experimental exposure to natural sunlight of two natural samples. The degree of zeroing is monitored over exposure times up to 100 min and related to the recuperation values obtained on the same grains from the standard pIRIR sequence. We find a positive correlation between recuperation doses of grains and their residual doses, which suggests that recuperation provides a proxy for grain bleachability. In addition, we combine our dataset of bleachability with information on the difference between IRSL50 and pIRIR175 equivalent doses determined on the same grain (De ratio), which allows us to identify grains for which light exposure was too limited to reset both signals. The results demonstrate that prior inheritance, light exposure, and grain bleachability all may impact the residual dose of grains, resulting in overdispersion in equivalent dose distributions. Combining the assessment of bleachability with the information on the De ratio can support the identification of best-bleached grains in a natural sample. Finally, the different bleachability of individual grains demonstrates that it may not be advisable to subtract the mean residual dose from paleodoses obtained with a minimum age model and for Holocene-aged deposits.
评估残余剂量对于全新世晚期沉积物的发光测年至关重要,尤其是在使用慢漂白长石 pIR 信号时。以前的研究表明,漂白能力因颗粒而异,但只有少数研究尝试对其进行量化。在这项研究中,我们评估了富含钾长石提取物的低温长红外信号在单粒水平上的漂白能力差异。研究是通过将两个天然样本暴露在自然阳光下的实验进行的。在长达 100 分钟的暴露时间内对归零程度进行监测,并将其与通过标准 pIR 序列在相同晶粒上获得的恢复值联系起来。我们发现谷物的休养剂量与其残留剂量之间存在正相关,这表明休养提供了谷物漂白性的替代值。此外,我们还将漂白性数据集与在同一谷粒上测定的 IRSL 和 pIRIR 等效剂量之间的差异(D 比值)信息结合起来,这样就可以识别出哪些谷粒由于光照太有限而无法重置这两种信号。结果表明,先前的遗传、光照和谷物的漂白性都可能影响谷物的剩余剂量,导致等效剂量分布过度分散。将漂白性评估与 D 比值信息相结合,可以帮助识别天然样本中漂白性最佳的谷粒。最后,单个谷物的不同漂白性表明,对于全新世年龄的沉积物,从最小年龄模型获得的古剂量中减去平均剩余剂量可能并不可取。
{"title":"Variance in pIRIR signal bleaching for single grains of feldspar","authors":"Jungyu Choi, Elizabeth Chamberlain, Jakob Wallinga","doi":"10.1016/j.quageo.2024.101577","DOIUrl":"10.1016/j.quageo.2024.101577","url":null,"abstract":"<div><p>Evaluating remnant doses is crucial for luminescence dating of late Holocene sedimentary deposits, especially when slow-bleaching feldspar pIRIR signals are employed. Previous research demonstrated that the bleaching capacity varies between individual grains, but only a few attempts have been made to quantify this. In this research, we evaluate variance in bleachability at a single-grain level for a low-temperature pIRIR signal from K-rich feldspar extract. The research is conducted through experimental exposure to natural sunlight of two natural samples. The degree of zeroing is monitored over exposure times up to 100 min and related to the recuperation values obtained on the same grains from the standard pIRIR sequence. We find a positive correlation between recuperation doses of grains and their residual doses, which suggests that recuperation provides a proxy for grain bleachability. In addition, we combine our dataset of bleachability with information on the difference between IRSL<sub>50</sub> and pIRIR<sub>175</sub> equivalent doses determined on the same grain (D<sub>e</sub> ratio), which allows us to identify grains for which light exposure was too limited to reset both signals. The results demonstrate that prior inheritance, light exposure, and grain bleachability all may impact the residual dose of grains, resulting in overdispersion in equivalent dose distributions. Combining the assessment of bleachability with the information on the D<sub>e</sub> ratio can support the identification of best-bleached grains in a natural sample. Finally, the different bleachability of individual grains demonstrates that it may not be advisable to subtract the mean residual dose from paleodoses obtained with a minimum age model and for Holocene-aged deposits.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000815/pdfft?md5=0d72e0cb509be2bd22390f4a7b8dbeee&pid=1-s2.0-S1871101424000815-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-27DOI: 10.1016/j.quageo.2024.101578
Anna Utkina , Jeong-Heon Choi , Andrew Murray , Andrei Panin , Nataliya Zaretskaya , Redzhep Kurbanov , Jan-Pieter Buylaert
In this study we apply optically stimulated luminescence and infra-red stimulated luminescence to the sediments from the interfluve dividing three river basins: the Pechora, the Kama and the Severnaya Dvina, hoping to gather new age data on glaciofluvial sediment. We also studied the valley of the Berezovka, a medium-scale river cutting through this interfluve. We obtained a chronology from 17 quartz and 15 feldspar ages. Sedimentological analyses and luminescence dating show that most of the sediments examined here are water-transported (gully alluvium, slopewash deposits), and their ages mark a period of accumulation during MIS 2. Some of these sediments were reworked by aeolian processes; these took place over a time span consistent with such processes in other parts of the East European Plain (19-12 ka). The Berezovka river experienced incision before ∼22 ka and another erosion event with extremely high floods at 15–16 ka. Its terrace formed in MIS 5, constraining the minimum age of the valley. In the bottom part of the sections, much older, possible MIS 8, glaciofluvial sediments were found; the apparent absence of MIS 6 sediments may argue for moving the MIS 6 ice sheet limit further to the north of the study area.
在这项研究中,我们对划分佩乔拉河、卡马河和塞韦纳亚德维纳河三个流域的交汇处的沉积物进行了光激发发光和红外激发发光研究,希望能收集到冰川沉积物的新年龄数据。我们还研究了别列佐夫卡河谷,这是一条穿过该交汇处的中等规模河流。我们从 17 个石英年龄和 15 个长石年龄中获得了年代学数据。沉积学分析和发光测年显示,这里研究的大部分沉积物都是水运沉积物(沟谷冲积物、斜坡冲积物),它们的年代标志着 MIS 2 期间的堆积时期。别列佐夫卡河在∼22 ka之前经历了侵蚀,在15-16 ka又经历了一次特大洪水的侵蚀。其阶地形成于 MIS 5,从而确定了河谷的最小年龄。在断面的底部,发现了年代更久远的、可能是 MIS 8 的冰川流沉积物;MIS 6 沉积物的明显缺失可能证明了将 MIS 6 冰盖界限进一步移向研究区北部的观点。
{"title":"Luminescence ages of sediments from the margin of the penultimate glaciation in the north-eastern East European plain","authors":"Anna Utkina , Jeong-Heon Choi , Andrew Murray , Andrei Panin , Nataliya Zaretskaya , Redzhep Kurbanov , Jan-Pieter Buylaert","doi":"10.1016/j.quageo.2024.101578","DOIUrl":"10.1016/j.quageo.2024.101578","url":null,"abstract":"<div><p>In this study we apply optically stimulated luminescence and infra-red stimulated luminescence to the sediments from the interfluve dividing three river basins: the Pechora, the Kama and the Severnaya Dvina, hoping to gather new age data on glaciofluvial sediment. We also studied the valley of the Berezovka, a medium-scale river cutting through this interfluve. We obtained a chronology from 17 quartz and 15 feldspar ages. Sedimentological analyses and luminescence dating show that most of the sediments examined here are water-transported (gully alluvium, slopewash deposits), and their ages mark a period of accumulation during MIS 2. Some of these sediments were reworked by aeolian processes; these took place over a time span consistent with such processes in other parts of the East European Plain (19-12 ka). The Berezovka river experienced incision before ∼22 ka and another erosion event with extremely high floods at 15–16 ka. Its terrace formed in MIS 5, constraining the minimum age of the valley. In the bottom part of the sections, much older, possible MIS 8, glaciofluvial sediments were found; the apparent absence of MIS 6 sediments may argue for moving the MIS 6 ice sheet limit further to the north of the study area.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141577414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-27DOI: 10.1016/j.quageo.2024.101566
L. Ageby , S. Jakathamani , A.S. Murray , M. Jain , E.F. Rades
While flint and similar materials are some of the most often preserved finds from the pre-historic archaeological records, trapped charge techniques can currently only be used on heated flint pieces. Here, we investigate if rock surface luminescence dating using the light-sensitive OSL signal is applicable to unheated flint nodules and cobbles by measuring OSL signal-depth profiles in flint samples collected from eastern Zealand and Møn, Denmark. We demonstrate that a detectable, natural OSL signal is present in the centre in eight out of the nine investigated flint samples. Additionally, the OSL signal had been bleached to various depths at the flint surfaces, which were exposed to daylight at the time of sampling. The field-saturated OSL is 50% or lower compared to the laboratory OSL after a 6 kGy dose was administered to field-saturated flint slices; this discrepancy could be related to signal loss occurring over geological time scales, but the exact nature of the mechanism of signal loss remains unclear. The presence of a natural OSL signal that bleaches into the flint when exposed to daylight suggests that rock surface dating of unheated flints is feasible, and the method should be further tested on known-age samples.
{"title":"Feasibility of rock surface luminescence dating technique for measuring the burial ages of unheated flints","authors":"L. Ageby , S. Jakathamani , A.S. Murray , M. Jain , E.F. Rades","doi":"10.1016/j.quageo.2024.101566","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101566","url":null,"abstract":"<div><p>While flint and similar materials are some of the most often preserved finds from the pre-historic archaeological records, trapped charge techniques can currently only be used on heated flint pieces. Here, we investigate if rock surface luminescence dating using the light-sensitive OSL signal is applicable to unheated flint nodules and cobbles by measuring OSL signal-depth profiles in flint samples collected from eastern Zealand and Møn, Denmark. We demonstrate that a detectable, natural OSL signal is present in the centre in eight out of the nine investigated flint samples. Additionally, the OSL signal had been bleached to various depths at the flint surfaces, which were exposed to daylight at the time of sampling. The field-saturated OSL is 50% or lower compared to the laboratory OSL after a 6 kGy dose was administered to field-saturated flint slices; this discrepancy could be related to signal loss occurring over geological time scales, but the exact nature of the mechanism of signal loss remains unclear. The presence of a natural OSL signal that bleaches into the flint when exposed to daylight suggests that rock surface dating of unheated flints is feasible, and the method should be further tested on known-age samples.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1871101424000700/pdfft?md5=6e03f93bc81a34a261f4f27469999736&pid=1-s2.0-S1871101424000700-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-27DOI: 10.1016/j.quageo.2024.101581
Carlos Ortiz , Mauricio Parra , Fernanda C.G. Rodrigues , Thays D. Mineli , André O. Sawakuchi
The optically stimulated luminescence (OSL) sensitivity of the fast component in quartz has been increasingly used in provenance analysis of Quaternary sediments. Quartz OSL natural sensitization is thought to be mainly controlled by the formation conditions of the source bedrock and surface processes occurring mainly in sediment source areas. Thus, quartz OSL sensitivity can be linked to distinct sediment source regions, based on their tectonic setting and erosion conditions. In this way, changes in quartz OSL sensitivity within siliciclastic successions would track variations in sediment provenance. So far, few works evaluated how the OSL sensitivity of quartz sand grains varies in sedimentary successions that experienced long-term cycles of deep burial, exhumation, and erosion. Therefore, this work aims to characterize the sensitivity of the fast OSL component of quartz sand grains retrieved from the Cenozoic sedimentary rocks of the Northern Andes basins and assess its spatiotemporal changes. We found that quartz grains with the lowest OSL sensitivity are sourced by crystalline and volcanic rocks related to the Andean Continental Arc emplaced in the Colombian Central Cordillera, reflecting the onset of denudation in orogenic sources during the Paleocene. Subsequently, increasing trends in OSL sensitivity are related to the sedimentary recycling during the Andean orogeny, reaching maximum values as a result of the progressive unroofing of Cretaceous rocks in the Colombian Eastern Cordillera, originally sourced from the low-relief Amazon Craton. Changes in quartz OSL sensitivity measured in the Cenozoic sedimentary basin-fill sequences of the Northern Andes vary according to the shifts in sediment provenance related to the orogenic construction and sediment recycling of the Andean range.
{"title":"Tracing uplift and erosion in orogenic settings using quartz luminescence sensitivity: Insights from the Northern Andes uplift","authors":"Carlos Ortiz , Mauricio Parra , Fernanda C.G. Rodrigues , Thays D. Mineli , André O. Sawakuchi","doi":"10.1016/j.quageo.2024.101581","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101581","url":null,"abstract":"<div><p>The optically stimulated luminescence (OSL) sensitivity of the fast component in quartz has been increasingly used in provenance analysis of Quaternary sediments. Quartz OSL natural sensitization is thought to be mainly controlled by the formation conditions of the source bedrock and surface processes occurring mainly in sediment source areas. Thus, quartz OSL sensitivity can be linked to distinct sediment source regions, based on their tectonic setting and erosion conditions. In this way, changes in quartz OSL sensitivity within siliciclastic successions would track variations in sediment provenance. So far, few works evaluated how the OSL sensitivity of quartz sand grains varies in sedimentary successions that experienced long-term cycles of deep burial, exhumation, and erosion. Therefore, this work aims to characterize the sensitivity of the fast OSL component of quartz sand grains retrieved from the Cenozoic sedimentary rocks of the Northern Andes basins and assess its spatiotemporal changes. We found that quartz grains with the lowest OSL sensitivity are sourced by crystalline and volcanic rocks related to the Andean Continental Arc emplaced in the Colombian Central Cordillera, reflecting the onset of denudation in orogenic sources during the Paleocene. Subsequently, increasing trends in OSL sensitivity are related to the sedimentary recycling during the Andean orogeny, reaching maximum values as a result of the progressive unroofing of Cretaceous rocks in the Colombian Eastern Cordillera, originally sourced from the low-relief Amazon Craton. Changes in quartz OSL sensitivity measured in the Cenozoic sedimentary basin-fill sequences of the Northern Andes vary according to the shifts in sediment provenance related to the orogenic construction and sediment recycling of the Andean range.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-27DOI: 10.1016/j.quageo.2024.101583
Shuai Zhang , Hui Zhao , Leibin Wang , Fahu Chen
As a vital component of the “Asian water tower”, lakes on the Tibetan Plateau (TP) significantly influence the regional ecosystems and economies and they are also an effective sentinel of climate change. However, the temporal and spatial patterns of lakes and the related hydroclimatic evolution on the northwestern TP (NWTP) remain unclear. We reconstructed the lake level variations of a non-glacier-fed lake, Longjue Co, on the NWTP, using optical dating of paleo-shorelines. The optically stimulated luminescence signals of quartz grains were unsuitable for dating due to high contributions of the medium component, and thus the post-infrared infrared stimulated luminescence signals (pIR50IR170, pIR50IR225) of K-feldspar single grains were used. Internal checks including dose recovery tests, residual dose tests, and anomalous fading tests showed that the pIR50IR170 signal was suitable for paleo-shoreline dating in Longjue Co. However, some of the samples were affected by the incomplete bleaching of pIRIR signals before deposition, and in this case the Minimum Age Model was used to constrain the ages. We also examined the dependence of the K-feldspar equivalent dose (De) on grain brightness and explored the possible mechanisms, and the brightest grains were then used for De calculations. The results show that Longjue Co reached its maximum Holocene level (+34 m) during the early Holocene (10.06 ± 1.39 ka), and then after ∼5 ka it commenced a shrinking trend, punctuated by two rapid lake level decreases. Reference to independent paleoclimate records suggests that the Holocene lake level variations of Longjue Co and the regional hydroclimate were mainly controlled by the Indian summer monsoon.
作为 "亚洲水塔 "的重要组成部分,青藏高原(TP)上的湖泊对区域生态系统和经济有着重要影响,同时也是气候变化的有效哨兵。然而,青藏高原西北部湖泊的时空格局及相关的水文气象演变仍不清楚。我们利用古岸线光学测年重建了西北大裂谷中一个非冰川湖泊龙居湖的湖面变化。石英颗粒的光激发发光信号由于介质成分的高贡献率而不适合测年,因此我们使用了钾长石单颗粒的后红外红外激发发光信号(pIR50IR170、pIR50IR225)。内部检验包括剂量恢复检验、残余剂量检验和异常衰减检验,结果表明 pIR50IR170 信号适用于龙居公司的古海岸线年代测定,但部分样品在沉积前受到 pIRIR 信号不完全漂白的影响,在这种情况下,采用最小年龄模型来限制年龄。我们还研究了钾长石当量剂量(De)与晶粒亮度的关系,并探讨了可能的机制,然后采用最亮的晶粒进行 De 计算。结果表明,龙居湖在全新世早期(10.06 ± 1.39 ka)达到了全新世的最高水位(+34 m),然后在 ∼5 ka 之后开始呈萎缩趋势,并出现了两次湖面快速下降。参考独立的古气候记录表明,龙居湖全新世的湖面变化和区域水文气候主要受印度夏季季风的控制。
{"title":"Holocene lake shrinkage on the northwestern Tibetan Plateau revealed by K-feldspar single-grain pIRIR dating of paleo-shorelines","authors":"Shuai Zhang , Hui Zhao , Leibin Wang , Fahu Chen","doi":"10.1016/j.quageo.2024.101583","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101583","url":null,"abstract":"<div><p>As a vital component of the “Asian water tower”, lakes on the Tibetan Plateau (TP) significantly influence the regional ecosystems and economies and they are also an effective sentinel of climate change. However, the temporal and spatial patterns of lakes and the related hydroclimatic evolution on the northwestern TP (NWTP) remain unclear. We reconstructed the lake level variations of a non-glacier-fed lake, Longjue Co, on the NWTP, using optical dating of paleo-shorelines. The optically stimulated luminescence signals of quartz grains were unsuitable for dating due to high contributions of the medium component, and thus the post-infrared infrared stimulated luminescence signals (pIR<sub>50</sub>IR<sub>170</sub>, pIR<sub>50</sub>IR<sub>225</sub>) of K-feldspar single grains were used. Internal checks including dose recovery tests, residual dose tests, and anomalous fading tests showed that the pIR<sub>50</sub>IR<sub>170</sub> signal was suitable for paleo-shoreline dating in Longjue Co. However, some of the samples were affected by the incomplete bleaching of pIRIR signals before deposition, and in this case the Minimum Age Model was used to constrain the ages. We also examined the dependence of the K-feldspar equivalent dose (D<sub>e</sub>) on grain brightness and explored the possible mechanisms, and the brightest grains were then used for D<sub>e</sub> calculations. The results show that Longjue Co reached its maximum Holocene level (+34 m) during the early Holocene (10.06 ± 1.39 ka), and then after ∼5 ka it commenced a shrinking trend, punctuated by two rapid lake level decreases. Reference to independent paleoclimate records suggests that the Holocene lake level variations of Longjue Co and the regional hydroclimate were mainly controlled by the Indian summer monsoon.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-27DOI: 10.1016/j.quageo.2024.101584
Shugang Kang , Hao Huang , Xulong Wang
Differing from the classic fine silt-dominated loess on the southern and central Chinese Loess Plateau (CLP), sandy loess is extensively distributed along the southern bank of the middle Yellow River and reaches thickness of up to ∼ 200 m. However, its deposition time and formation processes remain unclear. In this study, we dated three representative sandy loess sections along the middle Yellow River using single-aliquot regenerative-dose optically stimulated luminescence (OSL) and multiple-aliquot regenerative-dose recuperated OSL (ReOSL) dating protocols on fine quartz grains (4–11 μm). The reliability of these methods was robustly verified through traditional luminescence dating checks. Our dating results showed that the sandy loess was predominantly deposited during the last glacial period and exhibited an exceptionally high dust accumulation rate surpassing that of the classic loess on the southern and central CLP. By considering atmospheric circulation, geomorphology, and proxy data from both the sandy loess and the Yellow River fluvial sediments, we propose that the sandy loess primarily originated from the proximal riverbeds and fluvial plains of the middle Yellow River, transported by northerly East Asian winter monsoon (EAWM) winds. During the last glacial period, weakened East Asian summer monsoon (EASM) in central and northern China resulted in reduced runoff and vegetation cover in the middle Yellow River region. Consequently, the riverbeds and fluvial plains served as main sources of dust material. Subsequently, the strengthened EAWM winds carried and deposited the dust along the southern bank of the middle Yellow River, culminating in the formation of the sandy loess. Our study underscores the importance of aeolian and fluvial processes interactions in contributing to the formation of the sandy loess along the middle Yellow River and suggests that the investigated sandy loess holds potential for high-resolution paleoclimate reconstruction.
{"title":"Luminescence dating of sandy loess along the middle Yellow River and its implications for aeolian–fluvial interactions","authors":"Shugang Kang , Hao Huang , Xulong Wang","doi":"10.1016/j.quageo.2024.101584","DOIUrl":"10.1016/j.quageo.2024.101584","url":null,"abstract":"<div><p>Differing from the classic fine silt-dominated loess on the southern and central Chinese Loess Plateau (CLP), sandy loess is extensively distributed along the southern bank of the middle Yellow River and reaches thickness of up to ∼ 200 m. However, its deposition time and formation processes remain unclear. In this study, we dated three representative sandy loess sections along the middle Yellow River using single-aliquot regenerative-dose optically stimulated luminescence (OSL) and multiple-aliquot regenerative-dose recuperated OSL (ReOSL) dating protocols on fine quartz grains (4–11 μm). The reliability of these methods was robustly verified through traditional luminescence dating checks. Our dating results showed that the sandy loess was predominantly deposited during the last glacial period and exhibited an exceptionally high dust accumulation rate surpassing that of the classic loess on the southern and central CLP. By considering atmospheric circulation, geomorphology, and proxy data from both the sandy loess and the Yellow River fluvial sediments, we propose that the sandy loess primarily originated from the proximal riverbeds and fluvial plains of the middle Yellow River, transported by northerly East Asian winter monsoon (EAWM) winds. During the last glacial period, weakened East Asian summer monsoon (EASM) in central and northern China resulted in reduced runoff and vegetation cover in the middle Yellow River region. Consequently, the riverbeds and fluvial plains served as main sources of dust material. Subsequently, the strengthened EAWM winds carried and deposited the dust along the southern bank of the middle Yellow River, culminating in the formation of the sandy loess. Our study underscores the importance of aeolian and fluvial processes interactions in contributing to the formation of the sandy loess along the middle Yellow River and suggests that the investigated sandy loess holds potential for high-resolution paleoclimate reconstruction.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141566612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-26DOI: 10.1016/j.quageo.2024.101576
V. Martínez-Pillado , M. Demuro , J.E. Ortiz , Q. Shao , L.J. Arnold , M. Duval , H. Cheng , T. Torres , E. Santos , C. Falguères , O. Tombret , N. García , A. Aranburu , A. Gómez-Olivencia , J.L. Arsuaga
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 Ursus deningeri. 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 in situ 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.
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
使用单一的测年方法确定考古遗址的年代不一定能可靠地确定沉积物或化石的年龄,因为可能会自然产生偏差,尤其是在洞穴等复杂的沉积环境中。在这项研究中,我们针对西班牙阿塔普埃尔卡山脉 Cueva Mayor-Cueva del Silo 岩溶系统的两个洞穴中的不同材料,采用了一种多技术测年方法。Galería de las Estatuas 的 LU4 岩石地层单元(GE-I 矿坑)中的两颗新牙齿化石已通过 U 系列/ESR 和氨基酸族化(AAR)方法测定了年代。前者提供的年代为 117 ± 13 ka 和 87 ± 9 ka,与之前对这一新石器时代遗址的年代研究结果一致,证实了 LU4 层被归入海洋同位素阶段(MIS)5。相比之下,AAR 分析得出的年龄非常分散,表明牙质在埋葬后发生了重大的化学变化。我们提供了 Sala de los Cíclopes 的 Cata Litario 洞穴的第一组年龄,这是一个完全由属于中更新世物种 Ursus deningeri 的穴熊化石组成的古生物遗址。我们提供了岩层单元 LU5 中两颗熊牙齿的 U 系列/ESR 和 AAR 年龄,以及熊堆积物所在沉积物、其下和其上的扩展范围发光年龄。沉积物的沉积年龄是通过对单个石英颗粒进行单颗粒热转移光激发发光(TT-OSL)测年和对 K 长石进行后红外激发发光(pIR-IR)测年获得的。此外,还对嵌入不同岩层单位中的几块原位和再加工碎片进行了 U 系列测年,以确定岩层序列的形成时间。结果表明,沉积物最初进入洞穴的时间介于 MIS-12 与 MIS-10 之间(444 ± 28 ka 至 367 ± 32 ka)。尽管如此,AAR 和 U 系列/ESR 化石年龄,以及 5 号和 6 号地层单元的一些岩浆碎片年龄要年轻得多。撇开其中一个熊齿样本在方法上值得商榷的结果不谈,最可靠的 AAR 和 U 系列/ESR 年龄在 287 ± 23 ka 到 256 ± 24 之间,而岩浆碎片则表明在 444 ± 19 ka 到 284 ± 8 ka 之间有几次形成过程。化石上的铀系列/ESR 年龄与主沉积物上的发光年龄之间的明显差异不可能完全由铀吸收模型或伽马剂量率评估的不确定性所解释,因此很可能与岩石学过程或复杂的遗址形成历史有关。在这些地层中出现的化石和被侵蚀的年龄较小的岩浆岩碎屑,与地层单元 4、5 和 6 先前的侵蚀、搬运和再沉积过程,以及/或者卡塔利塔里奥地层序列复杂的沉积后混合历史相吻合。这项研究强调了使用不同测年方法重建可靠年代框架的重要性,以及了解可能影响测年材料的地质因素的重要性。这些因素包括化石的堆积和移生历史、沉积后的混合过程或在岩溶系统中停留期间影响沉积物的再加工过程。
{"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 , M. Demuro , J.E. Ortiz , Q. Shao , L.J. Arnold , M. Duval , H. Cheng , T. Torres , E. Santos , C. Falguères , O. Tombret , N. García , A. Aranburu , A. Gómez-Olivencia , J.L. Arsuaga","doi":"10.1016/j.quageo.2024.101576","DOIUrl":"https://doi.org/10.1016/j.quageo.2024.101576","url":null,"abstract":"<div><p>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 <em>Ursus deningeri</em>. 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 <em>in situ</em> 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.</p><p>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":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-26","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}