Pub Date : 2024-10-10DOI: 10.1016/j.quageo.2024.101633
Luke A. Gliganic , Jo McDonald , Caroline Mather , Lloyd T. White
Rock engravings are globally ubiquitous, provide evidence for symbolic behaviours, and demonstrate connections to country and the desire to communicate with other humans. However, rock engravings have proven difficult to date. The development of luminescence rock surface dating approaches has the potential to address this deficiency in applicable dating techniques. Specifically, luminescence rock surface exposure dating methods can be used to tell how long a rock surface has been exposed to sunlight, thus providing a potential avenue to date rock engravings. Here, we present results from laboratory and field bleaching experiments from the Murujuga rock art complex in Western Australia. Four major art-bearing lithologies are petrographically characterised and tested for useable luminescence signals. Three bleaching experiments are conducted: two in the laboratory and one at the study area. The gabbro and microgranite lithologies are shown to be bleachable and show potential for rock surface burial dating. The microgranite can be used to accurately estimate exposure duration over the timescales tested in all experiments, demonstrating promising potential to date rock engravings.
{"title":"A method to date rock engravings using luminescence – tested at Murujuga, Western Australia","authors":"Luke A. Gliganic , Jo McDonald , Caroline Mather , Lloyd T. White","doi":"10.1016/j.quageo.2024.101633","DOIUrl":"10.1016/j.quageo.2024.101633","url":null,"abstract":"<div><div>Rock engravings are globally ubiquitous, provide evidence for symbolic behaviours, and demonstrate connections to country and the desire to communicate with other humans. However, rock engravings have proven difficult to date. The development of luminescence rock surface dating approaches has the potential to address this deficiency in applicable dating techniques. Specifically, luminescence rock surface exposure dating methods can be used to tell how long a rock surface has been exposed to sunlight, thus providing a potential avenue to date rock engravings. Here, we present results from laboratory and field bleaching experiments from the Murujuga rock art complex in Western Australia. Four major art-bearing lithologies are petrographically characterised and tested for useable luminescence signals. Three bleaching experiments are conducted: two in the laboratory and one at the study area. The gabbro and microgranite lithologies are shown to be bleachable and show potential for rock surface burial dating. The microgranite can be used to accurately estimate exposure duration over the timescales tested in all experiments, demonstrating promising potential to date rock engravings.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101633"},"PeriodicalIF":1.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441910","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 : 2024-09-30DOI: 10.1016/j.quageo.2024.101627
Gustav Firla , Christopher Lüthgens , Stephanie Neuhuber , Clemens Schmalfuss , Ernst Kroemer , Frank Preusser , Markus Fiebig
Overdeepened valleys are structures scoured into the underlying substrate by glaciers that have been subsequently filled with sediment, which recorded the environmental history of the adjacent landscape. Investigated here is an overdeepened structure that was formed beneath the Salzach Paleoglacier west of Freilassing, Bavaria (southern Germany). In a previous study, infinite infrared stimulated luminescence (IRSL) ages have been determined for the lower part of the core using a multi-grain approach. Applying single-grain feldspar luminescence dating allows to identify the unsaturated signals, previously masked by multi-grain signal averaging. Identification of the normally distributed leading edge in equivalent dose (De) distributions allows for the dismissal of low value De (LOVED) grains that appear to reflect underestimating outliers. Measurement of eleven samples distributed along the entire length of the core yielded two distinct age clusters, for which fading corrected IRSL50 and uncorrected pIRIR225 ages agree within uncertainties. Whereas the younger age cluster at the top of the sequence is attributed to Marine Isotope Stage (MIS) 3, the older age cluster is assigned to MIS 6. It is shown that single grain pIRIR measurements will allow to resolve the infill chronology of overdeepened structures in the Alps, at least for the last ca. 200 ka. Overall, the present study represents a further step towards understanding and handling complex De distributions often encountered in single grain feldspar luminescence dating. This contributes to better understand the frequently observed age offset between single grain and single-aliquot measurements.
过深谷是冰川冲刷到下层基底的结构，随后被沉积物填满，记录了附近地貌的环境历史。本文研究的是德国南部巴伐利亚州弗赖拉辛（Freilassing）以西萨尔扎赫古冰川下形成的过深结构。在之前的研究中，采用多晶粒方法测定了岩心下部的无限红外激发发光（IRSL）年龄。采用单粒度长石发光测年法可以识别出之前被多粒度信号平均法掩盖的不饱和信号。通过识别等效剂量（De）分布中的正态分布前缘，可以剔除那些似乎反映了低估离群值的低值 De（LOVED）晶粒。对沿岩心全长分布的 11 个样本进行测量，得出了两个不同的年龄群，其衰减校正 IRSL50 年龄和未校正 pIRIR225 年龄在不确定范围内一致。研究结果表明，单颗粒 pIRIR 测量结果可用于解析阿尔卑斯山超深构造的填充年代学，至少可用于最近约 200 ka 的年代学研究。总之，本研究在理解和处理单颗粒长石发光测年中经常遇到的复杂 De 分布方面又迈进了一步。这有助于更好地理解经常观察到的单颗粒和单等值测量之间的年龄偏移。
{"title":"Analyzing complex single grain feldspar equivalent dose distributions for luminescence dating of glacially derived sediments","authors":"Gustav Firla , Christopher Lüthgens , Stephanie Neuhuber , Clemens Schmalfuss , Ernst Kroemer , Frank Preusser , Markus Fiebig","doi":"10.1016/j.quageo.2024.101627","DOIUrl":"10.1016/j.quageo.2024.101627","url":null,"abstract":"<div><div>Overdeepened valleys are structures scoured into the underlying substrate by glaciers that have been subsequently filled with sediment, which recorded the environmental history of the adjacent landscape. Investigated here is an overdeepened structure that was formed beneath the Salzach Paleoglacier west of Freilassing, Bavaria (southern Germany). In a previous study, infinite infrared stimulated luminescence (IRSL) ages have been determined for the lower part of the core using a multi-grain approach. Applying single-grain feldspar luminescence dating allows to identify the unsaturated signals, previously masked by multi-grain signal averaging. Identification of the normally distributed leading edge in equivalent dose (D<sub>e</sub>) distributions allows for the dismissal of low value D<sub>e</sub> (LOVED) grains that appear to reflect underestimating outliers. Measurement of eleven samples distributed along the entire length of the core yielded two distinct age clusters, for which fading corrected IRSL<sub>50</sub> and uncorrected pIRIR<sub>225</sub> ages agree within uncertainties. Whereas the younger age cluster at the top of the sequence is attributed to Marine Isotope Stage (MIS) 3, the older age cluster is assigned to MIS 6. It is shown that single grain pIRIR measurements will allow to resolve the infill chronology of overdeepened structures in the Alps, at least for the last ca. 200 ka. Overall, the present study represents a further step towards understanding and handling complex D<sub>e</sub> distributions often encountered in single grain feldspar luminescence dating. This contributes to better understand the frequently observed age offset between single grain and single-aliquot measurements.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101627"},"PeriodicalIF":1.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428163","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 : 2024-09-29DOI: 10.1016/j.quageo.2024.101634
Arbaz N. Pathan , Rabiul H. Biswas , Benjamin Lehmann , Georgina E. King , Frédéric Herman
Depth-dependent luminescence in the top few millimetres of rock surface emerges as a potential tool to estimate rock surface exposure age and post-exposure erosion rate. It relies on the principle that the luminescence depth profile (LDP) propagates deeper with the time of sunlight exposure and moves to shallower depth with the erosion rate. The propagation of LDP is generally assumed to follow the first-order kinetic (FOK) model, except for a few recent studies. The FOK model predicts an exponential decay of infrared stimulated luminescence (IRSL) signal with light exposure time, which rarely corroborates experimental observation; IRSL signal decay is much slower than exponential decay. The faster decay of IRSL, predicted by the FOK model, results in faster propagation of LDP and thus always underestimates the exposure age and translates into a higher erosion rate. Interestingly, the slower-than-exponential decay of the IRSL signal can be better explained by general order kinetics (GOK). Thus, recent studies on rock surface luminescence dating have employed the GOK model. However, the GOK model is yet to be explored to predict post-exposure erosion rates. Here, we apply the GOK model and theoretically demonstrate the impact of the order of kinetics on the calibration and propagation of LDP in the presence of erosion and how the LDP's transient to steady state transition depends on the order of kinetics. We have performed a series of synthetic tests to assess the impact of selecting an incorrect model on the prediction of erosion rate. Finally, using the revised rate equation, the erosion rates are recalculated for natural samples (data available in the literature: Lehmann et al. (2019b)) and the impact of GOK on the predicted erosion rate is discussed.
{"title":"Towards accurate modelling of rock surface exposure dating using luminescence to estimate post-exposure erosion rate","authors":"Arbaz N. Pathan , Rabiul H. Biswas , Benjamin Lehmann , Georgina E. King , Frédéric Herman","doi":"10.1016/j.quageo.2024.101634","DOIUrl":"10.1016/j.quageo.2024.101634","url":null,"abstract":"<div><div>Depth-dependent luminescence in the top few millimetres of rock surface emerges as a potential tool to estimate rock surface exposure age and post-exposure erosion rate. It relies on the principle that the luminescence depth profile (LDP) propagates deeper with the time of sunlight exposure and moves to shallower depth with the erosion rate. The propagation of LDP is generally assumed to follow the first-order kinetic (FOK) model, except for a few recent studies. The FOK model predicts an exponential decay of infrared stimulated luminescence (IRSL) signal with light exposure time, which rarely corroborates experimental observation; IRSL signal decay is much slower than exponential decay. The faster decay of IRSL, predicted by the FOK model, results in faster propagation of LDP and thus always underestimates the exposure age and translates into a higher erosion rate. Interestingly, the slower-than-exponential decay of the IRSL signal can be better explained by general order kinetics (GOK). Thus, recent studies on rock surface luminescence dating have employed the GOK model. However, the GOK model is yet to be explored to predict post-exposure erosion rates. Here, we apply the GOK model and theoretically demonstrate the impact of the order of kinetics on the calibration and propagation of LDP in the presence of erosion and how the LDP's transient to steady state transition depends on the order of kinetics. We have performed a series of synthetic tests to assess the impact of selecting an incorrect model on the prediction of erosion rate. Finally, using the revised rate equation, the erosion rates are recalculated for natural samples (data available in the literature: Lehmann et al. (2019b)) and the impact of GOK on the predicted erosion rate is discussed.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101634"},"PeriodicalIF":1.7,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428164","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 : 2024-09-29DOI: 10.1016/j.quageo.2024.101632
Kate M. Swanger , Jennifer L. Lamp , Joerg M. Schaefer , Gisela Winckler , Irene Schimmelpfennig
In three cirques in the western Olympus Range of the McMurdo Dry Valleys, Antarctica, previous advances of cirque glaciers are recorded by a sequence of three drifts in each of the cirques. We dated drift limits and the deposits on modern glaciers in two of these cirques, Dean and Dipboye, via cosmogenic 3He in pyroxene from 41 dolerite boulders, 36Cl in pyroxene from 12 of those dolerites, and 10Be in quartz from 11 sandstone boulders. Exposure age scatter is high on all deposits. The 3He exposure ages across all deposits range from ∼35 to ∼2300 ka and 10Be exposure ages range from ∼7 to ∼435 ka. Coupled 36Cl/3He from dolerites support constant exposure with erosion for nine of the 12 samples, while the other three might have experienced complex exposure-burial histories. Due to the mesa-butte topography and slow bedrock erosion rates, nuclide inheritance is the primary cause of age scatter in dolerites, accounting for >1 Myr of exposure age error. Mean exposure ages from sandstones are 2–7 times younger than those from dolerites for the same deposits, indicating that inheritance is less common in sandstones in this region. Weathering analyses of sandstone boulders show an increase in average siliceous crust thickness and rock strength with deposit age, an example of case hardening. Based on both relative and exposure age dating, drift age increases with distance from the modern glaciers in both Dean and Dipboye cirques, with three advances during the past <700 ka. However, due to high exposure age scatter, it cannot be determined if the three drifts are temporally correlated across the two cirques and therefore the drifts might record different glacial advances in Dean Cirque vs. Dipboye Cirque despite the apparent stratigraphic correlation of the drifts. This study has implications for drift depositional processes of cold-based glaciers and the importance of source-bedrock lithology and geomorphology on nuclide inheritance in Antarctica.
在南极洲麦克默多干谷奥林帕斯山脉西部的三个峡谷中，每个峡谷中的三个漂移序列都记录了峡谷冰川之前的前进过程。我们通过从 41 块辉绿岩巨石中提取辉石中的宇宙成因 3He，从其中 12 块辉绿岩中提取辉石中的 36Cl，以及从 11 块砂岩巨石中提取石英中的 10Be，对其中两个山圈（迪安山圈和迪波耶山圈）的漂移界限和现代冰川上的沉积物进行了年代测定。所有矿床的暴露年龄散布很广。所有矿床的 3He 暴露年龄在 ∼35 ∼2300 ka 之间，10Be 暴露年龄在 ∼7 ∼435 ka 之间。来自辉绿岩的36Cl/3He耦合数据支持12个样品中的9个样品在侵蚀作用下不断暴露，而另外3个样品可能经历了复杂的暴露-埋藏历史。由于中山-山顶地形和缓慢的基岩侵蚀速度，核素继承是造成辉绿岩年龄分散的主要原因，占暴露年龄误差的>1 Myr。砂岩的平均出露年龄比同一矿床的辉绿岩年轻2-7倍，这表明该地区砂岩中的继承现象并不常见。对砂岩巨石的风化分析表明，随着沉积年龄的增长，平均硅质结壳厚度和岩石强度都在增加，这是外壳硬化的一个例子。根据相对年代测定法和暴露年代测定法，漂移年代随迪安和迪波伊海圈与现代冰川距离的增加而增加，在过去的 <700 ka 期间有三次漂移。然而，由于暴露年龄的高度分散性，无法确定这三个漂移在时间上是否与两个海湾相关，因此，尽管漂移在地层上有明显的相关性，但在迪恩海湾和迪波耶海湾，漂移可能记录了不同的冰川期。这项研究对冷基冰川的漂移沉积过程以及源基岩岩性和地貌对南极洲核素继承的重要性具有重要意义。
{"title":"Pleistocene glacial advances and exposure age scatter in the Olympus Range, Antarctica: A study of cosmogenic 36Cl/3He in dolerites and 10Be in sandstones","authors":"Kate M. Swanger , Jennifer L. Lamp , Joerg M. Schaefer , Gisela Winckler , Irene Schimmelpfennig","doi":"10.1016/j.quageo.2024.101632","DOIUrl":"10.1016/j.quageo.2024.101632","url":null,"abstract":"<div><div>In three cirques in the western Olympus Range of the McMurdo Dry Valleys, Antarctica, previous advances of cirque glaciers are recorded by a sequence of three drifts in each of the cirques. We dated drift limits and the deposits on modern glaciers in two of these cirques, Dean and Dipboye, via cosmogenic <sup>3</sup>He in pyroxene from 41 dolerite boulders, <sup>36</sup>Cl in pyroxene from 12 of those dolerites, and <sup>10</sup>Be in quartz from 11 sandstone boulders. Exposure age scatter is high on all deposits. The <sup>3</sup>He exposure ages across all deposits range from ∼35 to ∼2300 ka and <sup>10</sup>Be exposure ages range from ∼7 to ∼435 ka. Coupled <sup>36</sup>Cl/<sup>3</sup>He from dolerites support constant exposure with erosion for nine of the 12 samples, while the other three might have experienced complex exposure-burial histories. Due to the mesa-butte topography and slow bedrock erosion rates, nuclide inheritance is the primary cause of age scatter in dolerites, accounting for >1 Myr of exposure age error. Mean exposure ages from sandstones are 2–7 times younger than those from dolerites for the same deposits, indicating that inheritance is less common in sandstones in this region. Weathering analyses of sandstone boulders show an increase in average siliceous crust thickness and rock strength with deposit age, an example of case hardening. Based on both relative and exposure age dating, drift age increases with distance from the modern glaciers in both Dean and Dipboye cirques, with three advances during the past <700 ka. However, due to high exposure age scatter, it cannot be determined if the three drifts are temporally correlated across the two cirques and therefore the drifts might record different glacial advances in Dean Cirque vs. Dipboye Cirque despite the apparent stratigraphic correlation of the drifts. This study has implications for drift depositional processes of cold-based glaciers and the importance of source-bedrock lithology and geomorphology on nuclide inheritance in Antarctica.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101632"},"PeriodicalIF":1.7,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441911","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 : 2024-09-26DOI: 10.1016/j.quageo.2024.101631
Robin B. Trayler , Lauren E. Lopes , Patricia A. Holroyd , Sora L. Kim , John R. Southon
Tar seeps trap and preserve diverse fossil assemblages that reflect unique environmental histories. While the macro preservation of the fossils is usually good, preservation of organic bone collagen is often variable. Radiocarbon dating and stable isotope analysis of tar seep taxa can reveal distinct paleoecological insights but are complicated by the contamination from tar infiltration. Additionally, the removal of tar is complex and time-consuming. Therefore identifying fossils with preserved collagen prior to further investigation minimizes unnecessary damage to fossil collections and improves success rates for analyses that require organic preservation.
We used tar pit fossils where the collagen preservation state was independently known to test non-destructive (visual inspection) and minimally-destructive (infrared spectroscopy; FTIR) methods to determine the most reliable methods to identify bones with well preserved collagen. We found that while collagen is less often preserved in heavily weathered bones, visual cues alone are not a reliable indicator. Instead, the Water-Amide-on-Phosphate FTIR index is highly sensitive and specific at identifying fossils suitable for radiocarbon dating and stable isotope analysis. While our protocol and analysis code were developed using fossils from two California tar seep localities (McKittrick and Rancho La Brea), they are likely to be broadly applicable to other tar seep localities that have yielded fewer fossils, thus requiring even greater care when selecting specimens for further analysis.
焦油渗漏会捕获并保存反映独特环境历史的各种化石群。虽然化石的宏观保存情况通常很好，但有机骨胶原的保存情况往往各不相同。对沥青渗漏分类群进行放射性碳年代测定和稳定同位素分析，可以揭示独特的古生态见解，但由于焦油渗入造成的污染而变得复杂。此外，清除焦油的工作既复杂又耗时。因此，在进一步调查之前识别保存有胶原蛋白的化石可最大限度地减少对化石收藏的不必要损害，并提高需要有机物保存的分析的成功率。我们使用胶原蛋白保存状态独立已知的焦油坑化石来测试非破坏性（目测）和微破坏性（红外光谱；傅立叶变换红外光谱）方法，以确定识别胶原蛋白保存完好的骨骼的最可靠方法。我们发现，虽然胶原蛋白在风化严重的骨骼中保存较少，但仅靠视觉线索并不是可靠的指标。相反，磷酸盐水酰胺傅立叶变换红外指数在识别适合进行放射性碳年代测定和稳定同位素分析的化石方面具有高度灵敏性和特异性。虽然我们的方案和分析代码是利用加利福尼亚两个焦油渗漏区（McKittrick 和 Rancho La Brea）的化石制定的，但它们很可能广泛适用于其他焦油渗漏区，因为这些地方出产的化石较少，因此在选择标本进行进一步分析时需要更加谨慎。
{"title":"Rapid, effective screening of tar seep fossils for radiocarbon and stable isotope analysis","authors":"Robin B. Trayler , Lauren E. Lopes , Patricia A. Holroyd , Sora L. Kim , John R. Southon","doi":"10.1016/j.quageo.2024.101631","DOIUrl":"10.1016/j.quageo.2024.101631","url":null,"abstract":"<div><div>Tar seeps trap and preserve diverse fossil assemblages that reflect unique environmental histories. While the macro preservation of the fossils is usually good, preservation of organic bone collagen is often variable. Radiocarbon dating and stable isotope analysis of tar seep taxa can reveal distinct paleoecological insights but are complicated by the contamination from tar infiltration. Additionally, the removal of tar is complex and time-consuming. Therefore identifying fossils with preserved collagen prior to further investigation minimizes unnecessary damage to fossil collections and improves success rates for analyses that require organic preservation.</div><div>We used tar pit fossils where the collagen preservation state was independently known to test non-destructive (visual inspection) and minimally-destructive (infrared spectroscopy; FTIR) methods to determine the most reliable methods to identify bones with well preserved collagen. We found that while collagen is less often preserved in heavily weathered bones, visual cues alone are not a reliable indicator. Instead, the Water-Amide-on-Phosphate FTIR index is highly sensitive and specific at identifying fossils suitable for radiocarbon dating and stable isotope analysis. While our protocol and analysis code were developed using fossils from two California tar seep localities (McKittrick and Rancho La Brea), they are likely to be broadly applicable to other tar seep localities that have yielded fewer fossils, thus requiring even greater care when selecting specimens for further analysis.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101631"},"PeriodicalIF":1.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428162","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}
Determining the age of precise sea level markers such as marine terraces is often difficult because of the inherent limitation of traditional dating methods. A novel method based on Optical Stimulated Luminescence applicable to rock surfaces has been showing great promise in dating boulder and cobble surfaces from various environments. We performed Optically Stimulated Luminescence Rock Surface Dating (OSL RSD) on five cobbles from a basal transgressive lag deposit sealing a marine terrace referred to as the Last Interglacial (Marine Isotopic Stage 5e). We applied a consistent and highly selective 3-step acceptance criteria on five cobbles and obtained that only one was sufficiently well-bleached prior to burial. The resulting ages of 131 ± 8 ka and 127 ± 8 ka (obtained on 22 analyzed aliquots, n = 22) derived from the post-infrared infrared stimulated signal at 225oC (pIRIR225) and the preceding infrared stimulated signal at 50oC (pIR50/225), respectively, are consistent with each other as well as with the conventional luminescence age of ∼135 ka from the same sequence and with the U/Th age of ∼130 ka obtained from coral fragments. This work demonstrates that the RSD is a promising method for dating gravel veneer deposits overlaying marine terraces, enabling new chronologies for similar Quaternary deposits.
由于传统测年方法的固有局限性，确定诸如海洋阶地等精确海平面标志物的年龄往往十分困难。一种适用于岩石表面的基于光学激发发光的新方法在对各种环境中的巨石和卵石表面进行年代测定方面显示出了巨大的前景。我们对五块鹅卵石进行了光学刺激发光岩石表面定年（OSL RSD），这些鹅卵石来自封存最后一个间冰期（海洋同位素阶段 5e）海洋阶地的基底横切滞积层。我们对五块鹅卵石采用了一致的、高度选择性的三步验收标准，结果发现只有一块鹅卵石在埋藏前经过了充分漂白。从 225 摄氏度的后红外刺激信号（pIRIR225）和 50 摄氏度的前红外刺激信号（pIR50/225）得出的年龄分别为 131 ± 8 ka 和 127 ± 8 ka（根据 22 个分析等分样品得出，n = 22）、分别与同一序列的常规发光年龄 ∼135 ka 相一致，也与从珊瑚碎片中获得的 U/Th 年龄 ∼130 ka 相一致。这项工作表明，RSD 是对覆盖在海洋阶地上的砾石表层沉积物进行年代测定的一种很有前途的方法，可以为类似的第四纪沉积物提供新的年代学依据。
{"title":"Luminescence dating of rock surfaces in challenging environments: The case of MIS5e gravelly transgressive lag deposit (Southern Sardinia, West Mediterranean Sea)","authors":"Giulia Cossu , Daniele Sechi , Reza Sohbati , Andrew Murray , Vincenzo Pascucci , Stefano Andreucci","doi":"10.1016/j.quageo.2024.101630","DOIUrl":"10.1016/j.quageo.2024.101630","url":null,"abstract":"<div><div>Determining the age of precise sea level markers such as marine terraces is often difficult because of the inherent limitation of traditional dating methods. A novel method based on Optical Stimulated Luminescence applicable to rock surfaces has been showing great promise in dating boulder and cobble surfaces from various environments. We performed Optically Stimulated Luminescence Rock Surface Dating (OSL RSD) on five cobbles from a basal transgressive lag deposit sealing a marine terrace referred to as the Last Interglacial (Marine Isotopic Stage 5e). We applied a consistent and highly selective 3-step acceptance criteria on five cobbles and obtained that only one was sufficiently well-bleached prior to burial. The resulting ages of 131 ± 8 ka and 127 ± 8 ka (obtained on 22 analyzed aliquots, n = 22) derived from the post-infrared infrared stimulated signal at 225<sup>o</sup>C (pIRIR<sub>225</sub>) and the preceding infrared stimulated signal at 50<sup>o</sup>C (pIR<sub>50/225</sub>), respectively, are consistent with each other as well as with the conventional luminescence age of ∼135 ka from the same sequence and with the U/Th age of ∼130 ka obtained from coral fragments. This work demonstrates that the RSD is a promising method for dating gravel veneer deposits overlaying marine terraces, enabling new chronologies for similar Quaternary deposits.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101630"},"PeriodicalIF":1.7,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318620","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 : 2024-09-21DOI: 10.1016/j.quageo.2024.101628
Junjie Zhang , Jennifer Klose , Denis Scholz , Norbert Marwan , Sebastian F.M. Breitenbach , Lutz Katzschmann , Dennis Kraemer , Sumiko Tsukamoto
Speleothems are a key archive of past climatic and environmental changes. 230Th/U dating is the most commonly used method to determine speleothem ages. However, incorporation of non-radiogenic thorium may hamper 230Th/U dating, and samples older than 600 ka also remain out-of-reach. Calcite exhibits a thermoluminescence (TL) signal at 280 °C with a high characteristic saturation dose, and provides significant potential to date carbonate samples over several million years. Hitherto, the application of TL dating for calcite has mainly been hindered by two factors: 1) a spurious TL signal occurring in the high temperature range, and 2) non-uniform dose rate due to U-series disequilibrium. Here we test an isothermal TL (ITL) dating method on a speleothem sample from Bleßberg cave 2, Germany. We show that the ITL signal measured at 240 °C can completely remove the 280 °C TL peak with a negligible TL contribution from the higher temperature range, thus reducing the influence from the spurious signal. The time-dependent dose rate variation can be simulated using the initial radioactivity of 238U, 234U, 230Th and their decay constants. We use the 230Th/U dating method to provide precise and accurate radiometric ages documenting that the speleothem grew between 425.5 ± 5.4 and 320.5 ± 9.7 ka. The ITL ages (421 ± 23 to 311 ± 23 ka) of four subsamples from the speleothem are consistent with the 230Th/U ages at isochronous sampling positions, showing the general reliability of the ITL dating method. ITL dating provides a pathway to construct chronologies for palaeoclimate reconstructions for speleothems beyond the range of the 230Th/U-method and for samples that are unsuitable for U-series dating methods.
{"title":"Isothermal thermoluminescence dating of speleothem growth – A case study from Bleßberg cave 2, Germany","authors":"Junjie Zhang , Jennifer Klose , Denis Scholz , Norbert Marwan , Sebastian F.M. Breitenbach , Lutz Katzschmann , Dennis Kraemer , Sumiko Tsukamoto","doi":"10.1016/j.quageo.2024.101628","DOIUrl":"10.1016/j.quageo.2024.101628","url":null,"abstract":"<div><div>Speleothems are a key archive of past climatic and environmental changes. <sup>230</sup>Th/U dating is the most commonly used method to determine speleothem ages. However, incorporation of non-radiogenic thorium may hamper <sup>230</sup>Th/U dating, and samples older than 600 ka also remain out-of-reach. Calcite exhibits a thermoluminescence (TL) signal at 280 °C with a high characteristic saturation dose, and provides significant potential to date carbonate samples over several million years. Hitherto, the application of TL dating for calcite has mainly been hindered by two factors: 1) a spurious TL signal occurring in the high temperature range, and 2) non-uniform dose rate due to U-series disequilibrium. Here we test an isothermal TL (ITL) dating method on a speleothem sample from Bleßberg cave 2, Germany. We show that the ITL signal measured at 240 °C can completely remove the 280 °C TL peak with a negligible TL contribution from the higher temperature range, thus reducing the influence from the spurious signal. The time-dependent dose rate variation can be simulated using the initial radioactivity of <sup>238</sup>U, <sup>234</sup>U, <sup>230</sup>Th and their decay constants. We use the <sup>230</sup>Th/U dating method to provide precise and accurate radiometric ages documenting that the speleothem grew between 425.5 ± 5.4 and 320.5 ± 9.7 ka. The ITL ages (421 ± 23 to 311 ± 23 ka) of four subsamples from the speleothem are consistent with the <sup>230</sup>Th/U ages at isochronous sampling positions, showing the general reliability of the ITL dating method. ITL dating provides a pathway to construct chronologies for palaeoclimate reconstructions for speleothems beyond the range of the <sup>230</sup>Th/U-method and for samples that are unsuitable for U-series dating methods.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101628"},"PeriodicalIF":1.7,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358951","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 : 2024-09-19DOI: 10.1016/j.quageo.2024.101626
Edward J. Rhodes , Tessa M.C. Spano , Rebecca A. Hodge , André O. Sawakuchi , Dailson J. Bertassoli Jr.
This paper describes ways that Infra-Red Stimulated Luminescence (IRSL) signals from K-feldspar grains can be used to determine patterns and rates of sediment transport. In particular, it focusses on the potential provided by single grains to reveal their individual exposure and burial histories by the application of multiple elevated temperature (MET) IRSL measurements. We examine similarities and differences in bleaching behaviour with different light sources and introduce the concept of an equilibrium bleach. We present data on the variability of bleaching parameters for grains from single sediment samples, and discuss different analysis approaches to best determine individual grain histories. We describe a single grain “bleach recovery” experiment, and the application of a combined growth-bleach protocol designed to allow optimal data collection of both aspects of grain behaviour. We discuss the development of a burial-bleach model using numerical simulations based on direct observations of sample characteristics.
{"title":"Single grain K-feldspar MET-IRSL sediment transport determination: Bleaching patterns and rates","authors":"Edward J. Rhodes , Tessa M.C. Spano , Rebecca A. Hodge , André O. Sawakuchi , Dailson J. Bertassoli Jr.","doi":"10.1016/j.quageo.2024.101626","DOIUrl":"10.1016/j.quageo.2024.101626","url":null,"abstract":"<div><div>This paper describes ways that Infra-Red Stimulated Luminescence (IRSL) signals from K-feldspar grains can be used to determine patterns and rates of sediment transport. In particular, it focusses on the potential provided by single grains to reveal their individual exposure and burial histories by the application of multiple elevated temperature (MET) IRSL measurements. We examine similarities and differences in bleaching behaviour with different light sources and introduce the concept of an equilibrium bleach. We present data on the variability of bleaching parameters for grains from single sediment samples, and discuss different analysis approaches to best determine individual grain histories. We describe a single grain “bleach recovery” experiment, and the application of a combined growth-bleach protocol designed to allow optimal data collection of both aspects of grain behaviour. We discuss the development of a burial-bleach model using numerical simulations based on direct observations of sample characteristics.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101626"},"PeriodicalIF":1.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318618","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 : 2024-09-18DOI: 10.1016/j.quageo.2024.101629
Gergő Magyar , Tamás Bartyik , Rastko S. Marković , Dávid Filyó , Tímea Kiss , Slobodan B. Marković , Viktor Homolya , Alexia Balla , Gábor Bozsó , Sándor Baranya , Helena Alexanderson , Tin Lukić , György Sipos
Recently, it has been proposed that the luminescence sensitivity of quartz grains, i.e. their luminescence response to unit dose, might be used for sediment fingerprinting. Sensitivity is determined both by the origin of quartz grains and the sedimentary processes they underwent. However, a more detailed understanding of the factors influencing sensitivity is essential in order to expand and specify the applicability of the parameter in sediment sourcing and geomorphological studies alike. In the present research, we examined the spatial changes of sensitivity parameters of coarse grain quartz in modern sediments of the largest rivers of the Carpathian Basin, Central Europe, to determine the role of source areas and transportation distance.
Based on the luminescence analysis of 39 samples, quartz extracts with a Carpathian origin (catchment of the Tisza River) have a significantly higher sensitivity, except the LM-OSL medium component, than those originating from the Alpine domain (catchment of the Danube River). No clear relationship could be identified between natural sensitisation and transportation distance. In terms of the Tisza the observed downstream increase of quartz sensitivity is due to high sensitivity quartz grains supplied by its tributaries. In the meantime, a recurring change was observed along the Danube, which can be attributed mostly to local erosional processes. Consequently, tributaries and erosion can overprint the potential downstream sensitisation of quartz grains in large rivers.
Meanwhile, in terms of the Danube on sections where a significant downstream increase was detected in LM-OSL fast component sensitivity, LM-OSL medium component sensitivity systematically decreased. Additionally, during laboratory sensitisation, the CW-OSL sensitivity of Danube samples increased considerably, whereas changes were more moderate in the case of Tisza samples. Moreover, in the case of Tisza-related quartz extracts, the 110 °C TL sensitivity and the LM-OSL fast and medium components showed a strong correlation, indicating the stability of luminescence processes (trapping and recombination). Whereas, in the case of the Danube both LM-OSL components show a weak correlation with the 110 °C TL intensity. All these indicate that Alpine-origin quartz grains are more susceptible to the rearrangement of electron traps and/or recombination centres, which can also be an indicator of sediment sources in Quaternary studies in the region.
最近有人提出，石英颗粒的发光灵敏度（即其对单位剂量的发光响应）可用于沉积物指纹识别。灵敏度由石英颗粒的来源及其经历的沉积过程决定。然而，为了扩大和明确该参数在沉积物来源和地貌研究中的适用性，必须更详细地了解影响灵敏度的因素。在本研究中，我们考察了中欧喀尔巴阡山盆地最大河流现代沉积物中粗粒石英灵敏度参数的空间变化，以确定来源地区和运输距离的作用。根据对 39 个样本的发光分析，除 LM-OSL 中分量外，喀尔巴阡山（蒂萨河流域）来源的石英提取物的灵敏度明显高于阿尔卑斯山（多瑙河流域）来源的石英提取物。自然敏感度与运输距离之间没有明确的关系。就蒂萨河而言，观察到的下游石英敏感性增加是由于其支流提供了高敏感性石英颗粒。与此同时，多瑙河沿岸出现了反复变化，这主要归因于当地的侵蚀过程。因此，支流和侵蚀可能会对大河中石英颗粒的潜在下游敏感性产生影响。同时，在多瑙河上检测到 LM-OSL 快速组分敏感性显著增加的下游河段，LM-OSL 中等组分敏感性则系统性地降低。此外，在实验室敏化过程中，多瑙河样本的 CW-OSL 灵敏度大幅提高，而蒂萨河样本的变化则较为温和。此外，在与 Tisza 相关的石英提取物中，110 °C TL 灵敏度与 LM-OSL 快速和中等成分显示出很强的相关性，表明发光过程（捕获和重组）的稳定性。而多瑙河的两个 LM-OSL 分量与 110 °C TL 强度的相关性较弱。所有这些都表明，源自阿尔卑斯山的石英颗粒更容易受到电子捕获器和/或重组中心重新排列的影响，这也可以作为该地区第四纪研究中沉积物来源的一个指标。
{"title":"Downstream change of luminescence sensitivity in sedimentary quartz and the rearrangement of optically stimulated luminescence (OSL) components along two large rivers","authors":"Gergő Magyar , Tamás Bartyik , Rastko S. Marković , Dávid Filyó , Tímea Kiss , Slobodan B. Marković , Viktor Homolya , Alexia Balla , Gábor Bozsó , Sándor Baranya , Helena Alexanderson , Tin Lukić , György Sipos","doi":"10.1016/j.quageo.2024.101629","DOIUrl":"10.1016/j.quageo.2024.101629","url":null,"abstract":"<div><div>Recently, it has been proposed that the luminescence sensitivity of quartz grains, i.e. their luminescence response to unit dose, might be used for sediment fingerprinting. Sensitivity is determined both by the origin of quartz grains and the sedimentary processes they underwent. However, a more detailed understanding of the factors influencing sensitivity is essential in order to expand and specify the applicability of the parameter in sediment sourcing and geomorphological studies alike. In the present research, we examined the spatial changes of sensitivity parameters of coarse grain quartz in modern sediments of the largest rivers of the Carpathian Basin, Central Europe, to determine the role of source areas and transportation distance.</div><div>Based on the luminescence analysis of 39 samples, quartz extracts with a Carpathian origin (catchment of the Tisza River) have a significantly higher sensitivity, except the LM-OSL medium component, than those originating from the Alpine domain (catchment of the Danube River). No clear relationship could be identified between natural sensitisation and transportation distance. In terms of the Tisza the observed downstream increase of quartz sensitivity is due to high sensitivity quartz grains supplied by its tributaries. In the meantime, a recurring change was observed along the Danube, which can be attributed mostly to local erosional processes. Consequently, tributaries and erosion can overprint the potential downstream sensitisation of quartz grains in large rivers.</div><div>Meanwhile, in terms of the Danube on sections where a significant downstream increase was detected in LM-OSL fast component sensitivity, LM-OSL medium component sensitivity systematically decreased. Additionally, during laboratory sensitisation, the CW-OSL sensitivity of Danube samples increased considerably, whereas changes were more moderate in the case of Tisza samples. Moreover, in the case of Tisza-related quartz extracts, the 110 °C TL sensitivity and the LM-OSL fast and medium components showed a strong correlation, indicating the stability of luminescence processes (trapping and recombination). Whereas, in the case of the Danube both LM-OSL components show a weak correlation with the 110 °C TL intensity. All these indicate that Alpine-origin quartz grains are more susceptible to the rearrangement of electron traps and/or recombination centres, which can also be an indicator of sediment sources in Quaternary studies in the region.</div></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101629"},"PeriodicalIF":1.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S187110142400133X/pdfft?md5=3fcb6cb7f96d41c8107832afd6502199&pid=1-s2.0-S187110142400133X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314524","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 : 2024-09-04DOI: 10.1016/j.quageo.2024.101618
Aske L. Sørensen , Thomas M. Hansen , Jesper Nørgaard , Jan-Pieter Buylaert , Andrew S. Murray , Ekaterina Kulakova , Redzhep Kurbanov , Mads F. Knudsen
We introduce a novel age-depth modeling approach called CosmoChron that integrates both cosmogenic nuclide concentrations and other age constraints, such as radiocarbon and OSL ages, from different depths in a sedimentary sequence. Based on probabilistic inverse modeling, CosmoChron constrains the age-depth relationship of a sedimentary sequence along with associated uncertainties. Knowledge about the sample origins and the accumulation process is incorporated in the prior model. The 26Al/10Be ratio is computed at different depths in the forward model by accounting for different pre-burial scenarios, radioactive decay and post-burial production of 26Al-10Be, which is directly tied to the age-depth relation itself. Synthetic test cases demonstrate the method's ability to construct accurate age-depth relationships given by the posterior distribution, even for complex scenarios that include slow and varying accumulation rates, complex pre-burial histories, hiatuses, and unconformities. Based on observed unconformities, users have the option to manually input hiatuses into the model at specific depths, which allows estimation of their durations. Application of CosmoChron to real 26Al/10Be data from the Laujunmiao section in China yields ages that are similar to those obtained with conventional burial dating methods for specific stratigraphic layers. However, the associated uncertainties are significantly reduced with CosmoChron (by ∼47 % on average) because it exploits the vertical coupling of data combined with knowledge of the relative age of the samples, which must become younger towards the top of the profile. Additionally, the age-depth model reflets the duration of three hiatuses inferred from unconformities observed in the field. When CosmoChron is applied to OSL-derived ages from Jingbian section A on the Chinese Loess Plateau, covering the last ∼140 ka, the method produces results that are almost identical to those obtained with the well-established Bacon age-depth modeling approach. CosmoChron consequently offers a new, versatile and reliable tool to construct age-depth models for Quaternary sediment sequences.
{"title":"CosmoChron: A versatile age-depth modeling approach using cosmogenic nuclides and direct age constraints","authors":"Aske L. Sørensen , Thomas M. Hansen , Jesper Nørgaard , Jan-Pieter Buylaert , Andrew S. Murray , Ekaterina Kulakova , Redzhep Kurbanov , Mads F. Knudsen","doi":"10.1016/j.quageo.2024.101618","DOIUrl":"10.1016/j.quageo.2024.101618","url":null,"abstract":"<div><p>We introduce a novel age-depth modeling approach called CosmoChron that integrates both cosmogenic nuclide concentrations and other age constraints, such as radiocarbon and OSL ages, from different depths in a sedimentary sequence. Based on probabilistic inverse modeling, CosmoChron constrains the age-depth relationship of a sedimentary sequence along with associated uncertainties. Knowledge about the sample origins and the accumulation process is incorporated in the prior model. The <sup>26</sup>Al/<sup>10</sup>Be ratio is computed at different depths in the forward model by accounting for different pre-burial scenarios, radioactive decay and post-burial production of <sup>26</sup>Al-<sup>10</sup>Be, which is directly tied to the age-depth relation itself. Synthetic test cases demonstrate the method's ability to construct accurate age-depth relationships given by the posterior distribution, even for complex scenarios that include slow and varying accumulation rates, complex pre-burial histories, hiatuses, and unconformities. Based on observed unconformities, users have the option to manually input hiatuses into the model at specific depths, which allows estimation of their durations. Application of CosmoChron to real <sup>26</sup>Al/<sup>10</sup>Be data from the Laujunmiao section in China yields ages that are similar to those obtained with conventional burial dating methods for specific stratigraphic layers. However, the associated uncertainties are significantly reduced with CosmoChron (by ∼47 % on average) because it exploits the vertical coupling of data combined with knowledge of the relative age of the samples, which must become younger towards the top of the profile. Additionally, the age-depth model reflets the duration of three hiatuses inferred from unconformities observed in the field. When CosmoChron is applied to OSL-derived ages from Jingbian section A on the Chinese Loess Plateau, covering the last ∼140 ka, the method produces results that are almost identical to those obtained with the well-established Bacon age-depth modeling approach. CosmoChron consequently offers a new, versatile and reliable tool to construct age-depth models for Quaternary sediment sequences.</p></div>","PeriodicalId":54516,"journal":{"name":"Quaternary Geochronology","volume":"85 ","pages":"Article 101618"},"PeriodicalIF":1.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149795","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}
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