Quaternary Science Reviews最新文献

{"title":"The sensitivity of tectonic uplift corrections to the penultimate deglacial ice volume and configuration","authors":"Schmitty B. Thompson ,&nbsp;Jessica R. Creveling ,&nbsp;Jerry X. Mitrovica","doi":"10.1016/j.quascirev.2025.109210","DOIUrl":"10.1016/j.quascirev.2025.109210","url":null,"abstract":"<div><div>Reconstructions of peak global mean sea-level (GMSL) change during the interglacials and interstadials between Quaternary glacial cycles provide insight into the past behavior of the cryosphere and climate system and may inform projections of future change. Erosional and constructional terraces and other relative indicators of past sea-level high stands are a key component of GMSL reconstructions as these indicators provide a geographically widespread dataset that is readily comparable to geophysical model predictions. However, along tectonically active margins, the present-day elevation of a relative sea level (RSL) indicator reflects vertical motion due to active tectonics (and other processes) such that any inference of GMSL involves a correction for the latter (and vice versa). The most robust method to estimate tectonic uplift for field localities with a Last Interglacial (Marine Isotope Stage (MIS) 5e) RSL indicator is to compute the difference between the observed elevation of the MIS 5e indicator and a site-specific peak LIG relative sea level computed from a glacial isostatic adjustment model. Dividing the difference between the observed indicator elevation and computed sea level value by the age of the MIS 5e high stand provides an uplift rate. If the resulting tectonic uplift rate is presumed to be constant throughout the recent glacial–interglacial cycle, then this rate can be applied to other RSL indicators at the same site, such as those formed during the MIS 5a and 5c interstadials, to compute the uplift-corrected local RSL elevation. Here we explore the sensitivity of the tectonic uplift-correction applied to MIS 5a RSL indicator elevations to the volume and configuration of continental ice sheets during the MIS 6 penultimate glacial maximum and deglaciation (Termination II), as this ice history impacts the local modeled MIS 5e high stand elevation input into the tectonic uplift correction calculation. We explored 5 models of ice volume and configuration that vary the total ice volume and the relative ratio of continental ice in North America and Eurasia. We find that these ice models produce ∼5–10 m shifts in the elevation of uplift-corrected MIS 5a relative sea level indicators (or, equivalently, ∼6–12 cm/kyr variation in tectonic uplift rates) for sites along the Pacific coasts of the U.S. and Mexico, U.S. Atlantic coast, and Caribbean. Future assessments of GMSL during MIS 5a, MIS 5c, or other interglacials/interstadials that rely upon relative sea level indicators subject to a tectonic uplift correction should account for the sensitivity of the local modeled MIS 5e elevation to the MIS 6 glacial maximum ice volume and configuration.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"353 ","pages":"Article 109210"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduced magnitude of Early Pleistocene intensification of Northern Hemisphere Glaciation","authors":"G.R. Grant ,&nbsp;T.R. Naish ,&nbsp;B.A. Keisling ,&nbsp;M.O. Patterson ,&nbsp;P.J.J. Kamp ,&nbsp;S.R. Meyers ,&nbsp;D.P. Strogen ,&nbsp;P. Stocchi ,&nbsp;R.M. McKay","doi":"10.1016/j.quascirev.2024.109096","DOIUrl":"10.1016/j.quascirev.2024.109096","url":null,"abstract":"<div><div>Increased magnitude and expanding geographic distribution of ice-berg rafted debris in deep ocean sediment cores and increasing amplitude of variability in the benthic oxygen isotope (δ¹⁸O) proxy-global ice volume from ∼2.7 Ma marks the intensification of the Northern Hemisphere glaciation (iNHG). However, the location, extent and volume of Northern Hemisphere Ice Sheets (NHISs) is poorly constrained by proximal geologic evidence, and global sea-level records cannot determine individual polar ice sheet contributions alone.</div><div>Quantitative relationships between sediment transport, water depth and grain size on a wave-graded continental shelf were previously applied to Pliocene shallow-marine sedimentary deposits in Whanganui Basin, New Zealand to provide an independent relative sea level record (<em>PlioSeaNZ;</em> 3.3–2.5 Ma). Here, we extend the duration of the sea-level record from 3.3 to 1.7 Ma (<em>X</em>-<em>PlioSeaNZ</em>) using a well-documented, shallow-marine sedimentary succession, that outcrops in the Rangitikei River Valley of the Whanganui Basin.</div><div>The resulting glacial-interglacial, relative sea-level fluctuations are up to 45 ± 12.5 m paced by 41 kyr-obliquity frequency during the Early Pleistocene, but also contain modulation of 100 kyr-eccentricity cycle. These maximum sea-level amplitudes are more comparable to the mean of those previously reconstructed from calibrated benthic δ¹⁸O (e.g. Miller et al., 2020), and are significantly lower than estimates provided by albeit limited geological evidence proximal to the NHIS (Batchelor et al., 2019). Here we suggest that while NHISs acquired continental extent by 2.6 Ma, their collective volume may be overestimated in benthic δ¹⁸O calibrations and area-volume reconstructions, by as much as 50%.</div><div>We propose that a reduced aspect ratio of ice sheets during iNHG was driven by 41-kyr changes in integrated summer insolation and enhanced by a subglacial regolith feedback reducing resistance to basal sliding. Regardless, the lower ice volume through the iNHG implies a lower ice sheet sensitivity (ice equivalent sea-level per degree Celsius change in temperature) under higher atmospheric CO₂ of 4–6 m/°C compared to ∼20 m/°C for the period since the Last Glacial Maximum. This ice sheet sensitivity still has significant implications for society and sea-level will continue to rise under current emissions.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109096"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring branching corals as high-resolution paleo-SST archives","authors":"Tianran Chen ,&nbsp;Xiaolan Tan ,&nbsp;Ting Zhang ,&nbsp;Sheng Liu ,&nbsp;Jianxin Zhao","doi":"10.1016/j.quascirev.2024.109137","DOIUrl":"10.1016/j.quascirev.2024.109137","url":null,"abstract":"<div><div>Branching coral reconstructions have the potential to significantly enrich paleoclimate records derived from fossil reef cores. This study explores the utility of <em>Acropora</em> and <em>Pocillopora</em> corals as high-resolution archives for paleo-sea surface temperatures (paleo-SSTs) in the western tropical Pacific. Analyses of biweekly-to weekly-resolution Sr/Ca ratios in modern corals revealed distinct seasonal variations consistent with local SSTs, particularly during the 2016 El Niño event. Given the evident interspecies variabilities in Sr/Ca, separate calibration equations from combined Sr/Ca-SST records were established for each genus. These equations were applied to derive paleo-SSTs from subfossil core records, which were subsequently integrated into a ∼1000-year paleo-SST reconstruction. Our paleo-SST records showed comparability with reconstructed SSTs from other archives in adjacent regions. These findings highlight the potential of branching corals as novel and abundant sources of paleo-SST data. Additionally, this study emphasizes the need to address uncertainties arising from sample size limitations and inter-colony offsets. Incorporating data from both branching genera and massive corals, such as <em>Porites</em>, could further expand and enhance subfossil archives for robust paleoclimate reconstructions.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109137"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Under what climate conditions were the New Zealand subantarctic islands glaciated?","authors":"Shaun Eaves ,&nbsp;Brian Anderson ,&nbsp;Rebecca Gray","doi":"10.1016/j.quascirev.2024.109124","DOIUrl":"10.1016/j.quascirev.2024.109124","url":null,"abstract":"<div><div>Mountain glaciers are highly sensitive to climatic changes, making them key indicators for reconstructing past climate conditions. This study focuses on the New Zealand subantarctic Auckland and Campbell archipelagos, where geomorphological evidence of past glaciation provides rare insights into past terrestrial climate in the Southern Ocean. Using a 2D glacier model, we explored the temperature, precipitation, and seasonality conditions necessary for different glaciation extents on these islands. Our findings suggest that the Auckland Islands, with higher topography and greater precipitation, are more prone to glaciation than Campbell Island. We find that the most recent period of glaciation occurred in a climate that was 6–7 °C below mid-20th century levels, while the islands were covered by ice caps at temperatures more than 8 °C lower (assuming present day precipitation). Increased temperature seasonality relative to present requires further temperature reductions to achieve equivalent ice volumes, underscoring the sensitivity of glacier mass balance to summer temperatures. Our results provide a refined understanding of glaciation in the southwest Pacific sector of the Southern Ocean and offer a framework for assessing global climate model simulations of past climates. However, the climatic implications of the glacial record in these islands remain uncertain without precise dating of past glaciation events.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109124"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Provenance of fine-grained Quaternary sediments in the Tengger Sandy Desert recorded by Sr-Nd isotopes and its linkage with Quaternary aeolian silts on the Chinese Loess Plateau","authors":"Yuxin Fan ,&nbsp;Minmin Gao ,&nbsp;Fei Wang ,&nbsp;Qingsong Cai ,&nbsp;Guangliang Yang ,&nbsp;Chunlei Zong ,&nbsp;Ke Bi ,&nbsp;Xueyu Yan ,&nbsp;Qiang Shu ,&nbsp;Bowen Kong","doi":"10.1016/j.quascirev.2024.109117","DOIUrl":"10.1016/j.quascirev.2024.109117","url":null,"abstract":"<div><div>Aeolian dust, a product of aridification, can directly affect the climate system by reflecting and absorbing solar radiation, or indirectly by altering cloud properties. It also plays a role in regulating carbon uptake in marine ecosystems through the iron fertilization effect. The Gobi Deserts in southern Mongolia have traditionally been considered major sources of sandstorms and dust emissions in Asia's interior. However, a recent sediment tracing study using U-Pb age spectra of coarse detrital zircon grains challenges the role of these sandy deserts as sources of aeolian dust for the downwind Chinese Loess Plateau (CLP). This study aimed to identify the provenance area of Quaternary fine-grained sediments in the proximal sandy Desert Tengger and to explore their potential link with aeolian dust in the downwind CLP during the Quaternary. (1) ⁸⁷Sr/⁸⁶Sr values ranging from 0.715124 to 0.728164 and ¹⁴³Nd/¹⁴⁴Nd values from 0.511987 to 0.512192 were measured in the acetic acid-insoluble &lt;75 μm fraction of 30 Quaternary sediment samples from the core BJ14, drilled in the Tengger Sandy Desert hinterland. (2) These ¹⁴³Nd/¹⁴⁴Nd values resemble those of riverine sediments eroded from rocks in the Northern Qinghai-Tibet Plateau (NTP) but differ from those eroded from the Gobi Altai Mountains (GAMs). This indicates that the NTP is the primary source of the &lt;75 μm component of the Tengger Sandy Desert sediments during the Quaternary. Alongside previous studies on U-Pb age spectra of detrital zircons, our results suggest that after 0.8 Ma, the contribution of fine-grained detritus from the NTP decreased, although it continued to dominate the provenance of fine-grained sediments. However, the contribution of coarse detritus from the NTP increased significantly, becoming predominant in coarse grains, especially after 0.36 Ma. These changes record enhanced physical weathering and wind transporting capacity driven by temperature differences in the context of global aridification following the Kunlun-Huanghe Movement and the Mid-Pleistocene Transition. (3) After 0.9 Ma, a deviation on ¹⁴³Nd/¹⁴⁴Nd values of the &lt;75 μm Quaternary sediments within the hinterland of Tengger from that of the 28–45 μm fraction in the loess/paleosol sequence in Lingtai in the central CLP suggests that the source-sink linkage between the hinterland Tengger and Chinese Loess Plateau was weak after 0.9 Ma. But high shoreline areas of the paleolake Tengger might be a persistent source area emitting fine-grained detritus to the CLP throughout the Quaternary period. This study indicates further research is needed to enhance our understanding of dust fluxes in northern China.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109117"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of the REVEALS model to reconstruct present mountain vegetation cover in the North-Western Alps: A model evaluation for past land cover reconstruction","authors":"Andréa Julien ,&nbsp;Charline Giguet-Covex ,&nbsp;Erwan Messager ,&nbsp;Florence Mazier ,&nbsp;Laurent Marquer","doi":"10.1016/j.quascirev.2024.109089","DOIUrl":"10.1016/j.quascirev.2024.109089","url":null,"abstract":"<div><div>Mountain ecosystems have been significantly shaped by both climate and land use changes. In order to better understand the present status of mountain ecosystems, it is necessary to explore changes over a long-term period, i.e. centuries to millennia. While pollen analyses have provided a strong understanding of Holocene vegetation dynamics in the French Alps, quantitative and spatially detailed pollen-based estimates of vegetation change are still needed. Obtaining such estimates is challenging due to the complexity of mountain landscapes resulting from altitudinal gradients, topography, geology, exposure and anthropogenic activities. Pollen-based land cover models, such as the Landscape Reconstruction Algorithm (LRA), which corrects for inter-taxonomic differences in pollen production, dispersal and deposition mechanisms, have been developed for quantitative land cover reconstructions, mainly in lowlands. Applying these models in mountainous areas requires careful evaluation of input parameters (e.g. wind speed…) and consideration of the sampling design (i.e. number of sites…).</div><div>This study evaluates the performance of the REVEALS model in the North-Western Alps, i.e. the first module of the LRA scheme which aims to reconstruct vegetation at a regional scale. For this purpose, we are comparing raw pollen data (untransformed data), REVEALS estimates, and a contemporary vegetation map.</div><div>Our results demonstrate that REVEALS greatly improves estimations of the regional plant abundances (compared to untransformed pollen data), thus providing reliable reconstructions of regional vegetation for the study region. The study further underlines the need to understand the environmental context, in terms of altitudinal gradients of vegetation, atmospheric conditions and transfer processes (e.g. wind, insects, gravity, runoff), to set up model experiments. Furthermore, variability in site-specific topography and environmental conditions should be taken into account when applying REVEALS. The main limitations for the use of REVEALS in mountain regions concerned the integration of insect pollination and topography conditions. However, the results are very promising, especially when considering land cover types, which are very close to the vegetation map (closer than raw pollen data). The present study demonstrates the potential of REVEALS for long-term reconstructions of vegetation dynamics in mountain regions.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109089"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testate amoebae in an ombrotrophic bog reconcile equivocal palaeoclimate reconstructions for the Western Carpathians","authors":"Anna Šímová ,&nbsp;Petra Hájková ,&nbsp;Libor Petr ,&nbsp;Jan Divíšek ,&nbsp;Kateřina Kintrová ,&nbsp;Michal Hájek","doi":"10.1016/j.quascirev.2024.109062","DOIUrl":"10.1016/j.quascirev.2024.109062","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Knowledge about climate changes is crucial for understanding past and current anthropogenic ecosystem changes, but individual palaeoclimate proxies involve different habitat-dependent confounding factors. Continuously ombrotrophic bogs are an excellent system for palaeoclimate reconstructions because their functioning depends tightly on water table depth (WTD), which varies exclusively with the balance between precipitation and temperature. Here, we investigate a 7000-year-long record from the Puścizna Wielka bog (Poland). We focused on developing the first palaeoclimatological reconstruction for the Western Carpathians, which together includes testate amoebae (TA), the isotopic signal in &lt;em&gt;Sphagnum&lt;/em&gt; stems (δ&lt;sup&gt;13&lt;/sup&gt;C and δ&lt;sup&gt;18&lt;/sup&gt;O), and plant macrofossils (PM), the latter enabling to trace micro-topographical changes and assess if the consistent ombrotrophic conditions needed for unbiased reconstruction were met. Both the regional (TA&lt;sub&gt;REG&lt;/sub&gt;, PM) and continental (TA&lt;sub&gt;EU&lt;/sub&gt;) calibration training sets were used for quantitative WTD reconstructions. Our WTD reconstructions were compared with the downscaled CCSM3 simulations. Pollen data provided information on the surrounding vegetation. Reconstructed pH and species composition of PM confirmed continual ombrotrophy. At the Middle-Late Holocene boundary (ca 4300–4200 cal yr BP), the TA-rich lawn phase with &lt;em&gt;Sphagnum magellanicum&lt;/em&gt; and &lt;em&gt;Eriophorum vaginatum&lt;/em&gt; replaced the initial hollow-like phase with &lt;em&gt;Scheuchzeria, Sphagnum&lt;/em&gt; sec. &lt;em&gt;Cuspidata&lt;/em&gt; and &lt;em&gt;Archerella flavum&lt;/em&gt;. The climate driver of this change (decreased humidity) is also suggested by a 100–200 years delayed increase in fir pollen at the expense of spruce. For the last ca 230 years, δ&lt;sup&gt;13&lt;/sup&gt;C and TA suggest that the bog had experienced unprecedented drought. The bog was dominated by &lt;em&gt;Sphagnum rubellum-&lt;/em&gt;dwarf shrub hummocks with &lt;em&gt;Alabasta militaris&lt;/em&gt;, &lt;em&gt;Assulina muscorum&lt;/em&gt; and &lt;em&gt;Hyalosphenia elegans&lt;/em&gt; at this time. Apart from these major changes, we identified several other events that are otherwise documented only by individual studies across Europe for the Late Holocene, especially for the Little Ice Age. Six distinctly wet and five distinctly dry periods were consistent among at least two proxies, with a conspicuously warm and dry climate at the beginning of the Bronze Age, allowing human colonisation of previously harsh mountain areas. The consistency with CCSM3 was the highest for TA&lt;sub&gt;REG&lt;/sub&gt;-inferred WTD and lowest for δ&lt;sup&gt;18&lt;/sup&gt;O. The temperature and precipitation of the warmest quarter were the most influential explanatory variables in multiple regression. Additively to CCSM3, isotopes in &lt;em&gt;Sphagnum&lt;/em&gt; stems explained some WTD variation reconstructed by TA&lt;sub&gt;EU&lt;/sub&gt; and PM, suggesting a more critical role of the microtopographic position for these proxies. Our results suggest that TA reconcile multiple equivocal reconst","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109062"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence from Mg isotopes indicating reverse weathering as a significant Mg sink in Tibetan Plateau lakes","authors":"Zhongya Hu ,&nbsp;Marc Weynell ,&nbsp;Ni Su ,&nbsp;Simon V. Hohl ,&nbsp;Zhong Han ,&nbsp;Yixiong Wen ,&nbsp;Shouye Yang","doi":"10.1016/j.quascirev.2024.109138","DOIUrl":"10.1016/j.quascirev.2024.109138","url":null,"abstract":"<div><div>The magnesium (Mg) isotopic compositions of Tibetan Plateau rivers have been recently used to quantify silicate weathering fluxes and associated CO₂ consumption. In this work, we present a systematic study on the element and Mg isotope geochemistry of rivers and lakes in the interior of the Tibetan Plateau, to improve our understanding of the magnesium-carbon (C) cycle. δ²⁶Mg values of river waters range from −2.00 ‰ to −0.60 ‰, with an average of −1.12 ± 0.60 ‰. The observed δ²⁶Mg variability of the rivers reflects overall changes in the proportion of silicate over dolostone weathering fluxes, while the effects of geothermal fluid and rainfall are rendered insignificant. The restricted lakes fed by these rivers have low Mg/Na, Al/Na and Si/Na ratios but are considerably enriched in ²⁶Mg, with an average δ²⁶Mg value of −0.61 ± 0.65 ‰, presumably controlled by the in-situ formation of authigenic Mg-bearing minerals. Element and isotope mass balance modeling indicates that nearly 90 % of the riverine Mg²⁺ is consumed by the formation of authigenic Mg-bearing minerals in the lakes, and the Mg isotope fractionation factor between the minerals and water (Δ²⁶Mg_{mineral-water}) is −0.09 ‰ to −0.06 ‰. The best explanation to the contrast between the large Mg sink and a small Δ²⁶Mg_{mineral-water} value is the co-precipitation of Mg-bearing carbonate minerals and phyllosilicates in the lakes. The microscopic observation and EDS analyses of paleo-lake sediments shows that the laminae of carbonate and authigenic Mg-rich clay minerals alternatively overlapped, and elemental and δ²⁶Mg values also suggested that the mixture of Mg-bearing carbonate and authigenic phyllosilicates dominated the sediment geochemistry. An estimation yields that the precipitation of authigenic phyllosilicates due to reverse weathering accounts for nearly 80 % of the total Mg sink in these restricted lakes, from which a considerable amount of CO₂ had been released into the atmosphere. Our results provide new insights into the long-term Mg-C cycle on the Tibetan Plateau.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109138"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global monsoonal systems during the last glacial-interglacial cycle","authors":"Qiuzhen Yin,&nbsp;Haiwei Zhang,&nbsp;Martin H. Trauth","doi":"10.1016/j.quascirev.2024.109144","DOIUrl":"10.1016/j.quascirev.2024.109144","url":null,"abstract":"","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109144"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early Holocene marine incursion and a freshened Tyrrell Sea in Hudson Bay Lowlands, Canada","authors":"Cunhai Gao ,&nbsp;Charles L. Turton","doi":"10.1016/j.quascirev.2024.109134","DOIUrl":"10.1016/j.quascirev.2024.109134","url":null,"abstract":"<div><div>The Tyrrell Sea developed in the Hudson Bay Lowlands after the breakup of the ice saddle of the Laurentide Ice Sheet over Hudson Bay in the early Holocene. Coeval with its incursion was the final drainage of glacial Lake Agassiz-Ojibway which many hypothesize freshened the North Atlantic, causing significant cooling at 8.2 ka. However, little is known about the freshening of this inland sea itself. This paper presents our study of the sedimentology and stable isotope geochemistry on the extensively exposed Tyrrell Sea deposit in the open pit of the former Victor diamond mine near the Attawapiskat River. The sediment succession indicates that the ice saddle covered the study area prior to its breakup and the final drainage of Lake Agassiz-Ojibway, differing from previous interpretations that placed this site in the lake about 135 km south of the ice margin. Oxygen isotope data from benthic foraminifera (<em>Haynesina orbicularis</em>) indicate that the drainage of Lake Agassiz-Ojibway freshened the Tyrrell Sea with low δ¹⁸O (1.18‰ VPDB) for a short period from 8.1 ± 0.3 to 8.07 ± 0.3 cal ka BP. After regaining its original isotope composition with elevated δ¹⁸O (1.7–2.2‰) at 8.07 ± 0.3 to 7.8 ± 0.2 cal ka BP, the sea underwent a major freshening for more than a millennium at 7.8 ± 0.2 to 6.6 ± 0.2 cal ka BP, whereby δ¹⁸O was lowest (0.36–1.15‰). This millennial-scale freshening occurred during the accelerated recession of the ice sheet as previous ¹⁰Be dating work indicates and likely resulted from large meltwater influx from the ice. Subsequent reduction in meltwater influx slowed ocean freshening and raised δ¹⁸O slightly (0.73–0.83‰) until the Tyrrell Sea withdrew from this site around 6.1 ± 0.5 cal ka BP. Although the initial, short-lived freshening agrees in chronology with the 8.2 ka cooling, the later, millennial-scale freshening has no corresponding oxygen isotope and climate anomalies in the Labrador Sea sediment and Greenland ice cores, respectively. This inconsistency casts doubts on the concept that the brief freshening of the North Atlantic by the drainage of Lake Agassiz-Ojibway could have caused the cooling.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"349 ","pages":"Article 109134"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}