Quaternary Science Reviews最新文献

{"title":"Pollen-based reconstruction of Holocene vegetation dynamics and climate variability in northern Northeast China: Divergent hydroclimatic trends and possible westerly forcing","authors":"Sihan Sun ,&nbsp;Yukun Zheng ,&nbsp;Yong Luo ,&nbsp;Yue Yao ,&nbsp;Yue Wang ,&nbsp;Ying Cheng ,&nbsp;Yiyin Li ,&nbsp;Hongyan Liu","doi":"10.1016/j.quascirev.2026.109798","DOIUrl":"10.1016/j.quascirev.2026.109798","url":null,"abstract":"<div><div>Holocene vegetation and climate variability in Northeast China have attracted increasing attention in recent years. However, precise quantitative reconstructions remain limited, constraining a comprehensive understanding of regional environmental evolution and the underlying climatic mechanisms. In this study, we present a well-dated Holocene pollen record from Lake Daerbinluo, northern Northeast China. Vegetation dynamics were inferred using the biomization method, while mean annual temperature (<em>Tann</em>) and annual precipitation (<em>Pann</em>) were quantitatively reconstructed using a random forest approach. Our results reveal that a mosaic of forest and steppe dominated the region between 12,600 and 6200 Cal yr BP, transitioning to a temperate deciduous broadleaf forest as the dominant vegetation type after 6200 Cal yr BP. Climatic reconstructions show distinct trajectories for <em>Tann</em> and <em>Pann</em>. <em>Tann</em> exhibited a warming trend during the early Holocene, remained relatively high throughout the mid-Holocene, and experienced a slight decline during the late Holocene, broadly consistent with trends observed across the Northern Hemisphere. In contrast, <em>Pann</em> remained low but gradually increased prior to 5500 Cal yr BP, followed by an abrupt rise and sustained high levels during the mid to late Holocene, despite a minor decreasing tendency. These findings provide new insights into the climatic evolution and potential forcing mechanisms in Northeast China. The increased humidity during the mid-to late Holocene in our study area was likely driven by a strengthened westerly influence, despite the EASM remaining the principal moisture source, possibly via more frequent frontal cyclones and enhanced westerly moisture transport.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109798"},"PeriodicalIF":3.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940354","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":"Variable erosion depth in the Chinese Loess Plateau driven by human activities: Evidence from lacustrine uranium comminution ages","authors":"Run Zhang ,&nbsp;Laifeng Li ,&nbsp;David William Hedding ,&nbsp;Dejun Wan","doi":"10.1016/j.quascirev.2025.109783","DOIUrl":"10.1016/j.quascirev.2025.109783","url":null,"abstract":"<div><div>Human activities have substantially altered the transfer of surface material and sedimentary source-to-sink processes, particularly since the 1950s, thereby influencing global sediment flux. Surface erosion has profound effects on the Earth Critical Zone, wherein human activities significantly change erosion processes by intensifying both erosion flux and depth. While previous research has predominantly focused on erosion flux dynamics, variations in erosion depth remain poorly constrained due to the inherent limitations of conventional proxies (e.g., Sr-Nd isotopes, sedimentation rates), which typically fail to detect depth-related changes. The ²³⁴U/²³⁸U activity ratio, conventionally denoted as (²³⁴U/²³⁸U), can quantify sediment comminution age, which provides a qualitative indicator of changes in sediment sourcing or residence time. In this study, we utilize (²³⁴U/²³⁸U) derived from fine silicate fractions (&lt;50 μm) of Gonghai Lake sediments, located in the northeastern Chinese Loess Plateau, to reconstruct historical variations in erosion depth and assess anthropogenic impacts. Sr-Nd isotopic data confirm the local and upwind loess deposits as the primary sedimentary source, while uranium isotope records reveal multiple-stage comminution age shifts since the 1900s, reflecting human-driven erosion depth changes. Notably, mass sedimentation rates (sediment flux, indicative of erosion flux) exhibit relatively little variation in the last century, demonstrating an inconsistency between erosion flux and depth. This work establishes lacustrine sedimentary records of uranium isotopes as a novel proxy for quantifying source-area erosion depth and demonstrates that beyond affecting erosion flux, human activities profoundly influence erosion depth—an essential factor for designing effective soil system conservation strategies.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109783"},"PeriodicalIF":3.3,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940358","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":"The Cistercians as forerunners of the Anthropocene: a multi-proxy paleoecological study from western Poland","authors":"Sambor Czerwiński ,&nbsp;Piotr Kołaczek ,&nbsp;Piotr Guzowski ,&nbsp;Mariusz Gałka ,&nbsp;Monika Karpińska-Kołaczek ,&nbsp;Katarzyna Marcisz ,&nbsp;Adam Izdebski ,&nbsp;Malo Pilloix ,&nbsp;Mariusz Lamentowicz","doi":"10.1016/j.quascirev.2025.109779","DOIUrl":"10.1016/j.quascirev.2025.109779","url":null,"abstract":"<div><div>This study presents a high-resolution, multi-proxy paleoenvironmental reconstruction documenting nearly 1000 years of socio-ecological change under monastic and post-monastic land use based on the Święte peatland in western Poland. By integrating paleoecological proxies (pollen, micro- and macrocharcoal, testate amoebae, and plant macrofossils) with dense radiocarbon dating and historical records, we identified three major phases of landscape transformation: pre-Cistercian (ca. 1100–1270 CE), Cistercian (ca. 1270–1800 CE), and modern (ca. 1800–2017 CE). We show that after an initial capacity buildup, Cistercian economic activity significantly altered the local environment, initiating large-scale deforestation, peatland acidification, and hydrological shifts starting in the 14th century CE. Peat accumulation accelerated, enabling high-resolution insight into forest decline, agricultural expansion, and fine-grained socio-ecological dynamics, such as the temporary decline in human activity during the 17th-century CE military-epidemiological crisis, followed by a robust recovery. In the post-Cistercian phase, Prussian modernization efforts—such as wetland drainage and monoculture forestry—led to further ecological degradation. Our findings highlight the long-term impact of monastic and modern land use on wetland ecosystems, demonstrating how socio-political and economic dynamics shaped ecological resilience and induced degradation over centuries.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109779"},"PeriodicalIF":3.3,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940295","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":"Hydroclimate changes on the Chinese loess plateau during Marine isotope stage 3 revealed by multi-proxy speleothem records","authors":"Yijia Liang ,&nbsp;Bin Zhao ,&nbsp;Jinguo Dong ,&nbsp;Jiaqi Cong ,&nbsp;Peng Zhang ,&nbsp;Yongjin Wang ,&nbsp;R. Lawrence Edwards","doi":"10.1016/j.quascirev.2026.109802","DOIUrl":"10.1016/j.quascirev.2026.109802","url":null,"abstract":"<div><div>The East Asian summer monsoon (EASM) is crucial to hydroclimatic anomalies on the Chinese Loess Plateau, although the relationship between them is ambiguous during the last glacial period. Based on ²³⁰Th/U dating, stable isotope and trace metal data from one stalagmite (No. L30), we reconstruct the evolution of EASM and palaeohydroclimate on the Chinese Loess Plateau from 53 to 38 ka BP during Marine Isotope Stage 3. On the millennial timescale, the δ¹⁸O record (a proxy of EASM intensity) captures Dansgaard-Oeschger (DO) 8–14 and Heinrich (H) 4–5 events, which are imprinted in δ¹³C and trace metal records. By applying principal component analysis to δ¹³C and trace metal data, we derived a local precipitation record that changes consistently with rapid monsoon shifts at the onset of DO and H events. However, disparities exist, manifested as an anomalously high-precipitation period from 44 to 38 ka BP, which is not observed in the trendless EASM record but is supported by records from northern and northwestern China. Orbital-scale climatic background of the global ice volume and precession could have caused the sub-orbital decoupling between the EASM circulation and regional rainfall in northern and northwestern China. Ice sheet advance during glaciation cools the northern high latitudes and forces the strengthening and southward movement of the westerly jet, while low precession causes the westward expansion of the Western Pacific Subtropical High. A strong westerly jet carries moisture from the Atlantic Ocean, encountering the moist water vapor from the Pacific Ocean, leading to the development of the frontal rain, and thus the high-precipitation period since 44 ka BP in northern and northwestern China. Therefore, local rainfall on the Chinese Loess Plateau generally couples with the EASM circulation on the millennial timescale, but decoupling could also occur due to the influence of other climatic subsystems, including the westerly jet and the Western Pacific Subtropical High, which are modulated by orbital-scale background conditions.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109802"},"PeriodicalIF":3.3,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940297","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":"Bipolar volcanic ice-core synchronization of the entire last glacial period","authors":"Anders Svensson ,&nbsp;Guido Vettoretti ,&nbsp;Jia-mei Lin ,&nbsp;Giulia Sinnl ,&nbsp;Dorthe Dahl-Jensen ,&nbsp;Jørgen Peder Steffensen ,&nbsp;Sune Olander Rasmussen ,&nbsp;Bo Vinther ,&nbsp;Christine Hvidberg ,&nbsp;Helle Astrid Kjær ,&nbsp;Vasileios Gkinis ,&nbsp;Eliza Cook ,&nbsp;Johannes Lohmann ,&nbsp;Jonathan Ortved Melcher ,&nbsp;Sune Halkjær ,&nbsp;Sepp Kipfstuhl ,&nbsp;Frank Wilhelms ,&nbsp;Florian Adolphi ,&nbsp;Hubertus Fischer ,&nbsp;Matthias Bigler ,&nbsp;Raimund Muscheler","doi":"10.1016/j.quascirev.2025.109755","DOIUrl":"10.1016/j.quascirev.2025.109755","url":null,"abstract":"<div><div>Precise synchronization of paleoclimate records is essential for inferring the dynamics and past evolution of the climate system. For the last glacial period, the time scales of ice cores from the Greenland and Antarctic ice sheets have been synchronized by the use of cosmogenic radionuclides, atmospheric gas concentrations, and traces of large volcanic eruptions. Here we identify the sulfate deposition signatures of the same 300 volcanic eruptions in different Greenland and Antarctic ice cores to obtain an inter-hemispheric volcanic ice-core synchronization of the entire last glacial period and the early Holocene (10–110 ka). Compared to earlier bipolar volcanic synchronizations, we close a gap in the period 16.5–24.5 ka and extend the synchronization to cover the 10–12 ka and 60–110 ka intervals. Furthermore, we increase the density of bipolar match points and make updates and corrections of the existing bipolar and unipolar synchronizations. The volcanic synchronization is in agreement with existing bipolar synchronizations from independent ¹⁰Be and methane matching. The bipolar volcanic synchronization allows us to determine the precise phasing of interhemispheric abrupt climate events throughout the last glacial period, particularly those associated with Dansgaard-Oeschger (D-O) events. Our improved synchronization and extended time period allow us to show that at the time of the D-O warming transitions, the average Antarctic temperature reaches a maximum within decades after the Greenland temperature maximum. This rapid Antarctic warming is superimposed on the well-known millennial-scale thermal bipolar-seesaw warming in Antarctica commonly attributed to oceanic heat transport and confirms earlier work that the abrupt change observed in Greenland is associated with a direct atmospheric circulation change at a global scale. The exception to this pattern occurs for the EDML ice-coring site located in the Atlantic sector of Antarctica, potentially related to sea-ice conditions in the Weddell Sea. Comparison to state-of-the-art climate model simulations shows excellent agreement in the overall bipolar climate phasing at the warming transitions and allows for analysis of the climate-system behavior at those transitions. The model simulations suggest that the abrupt Antarctic warming response observed is connected with an interhemispheric atmospheric response involving a global scale reorganization of the zonal mean atmospheric circulation. The abrupt D-O surface warming signal in the Northern Hemisphere is teleconnected into an abrupt Antarctic surface warming through changes in the Southern Hemisphere eddy-driven jet and anomalous circulation changes in the associated Ferrel and Polar cells.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109755"},"PeriodicalIF":3.3,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940356","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":"Paleoseismic evidence for the 1730 Mw ≥9 Chile earthquake in a former coastal lagoon: an infrequent, shallow, tsunamigenic rupture with plausible near-term recurrence","authors":"Marco Cisternas ,&nbsp;Bladimir Saldaña ,&nbsp;Lisa L. Ely ,&nbsp;Robert L. Wesson ,&nbsp;Mario Guerra ,&nbsp;Dominik Brill ,&nbsp;Daniel Melnick ,&nbsp;Allison Espinoza ,&nbsp;Tina Dura ,&nbsp;Jessica Pilarczyk","doi":"10.1016/j.quascirev.2025.109789","DOIUrl":"10.1016/j.quascirev.2025.109789","url":null,"abstract":"<div><div>We report the first paleoseismic evidence jointly documenting coseismic subsidence and tsunami inundation from the 1730 Chile earthquake (Mw ≥ 9) and its trans-Pacific tsunami. At Campiche, a former coastal lagoon in Chile's Metropolitan Region, multiproxy stratigraphic, sedimentological, and microfossil data reveal a laterally continuous tsunami sand sheet that extends ∼2 km inland, sharply disrupts lagoonal mud, and shows an erosional lower contact, rip-up clasts, and mud drapes from waning flow. Accompanying shifts from freshwater to brackish–marine diatom assemblages and the sudden appearance of salt-tolerant plant remains record a persistent increase in tidal influence, indicating coseismic subsidence. Radiocarbon and luminescence ages constrain its deposition to 1698–1782 CE, consistent with historical accounts of the 1730 tsunami and the absence of any other comparable event in the written record. Campiche thus complements previously reported uplift-dominated mid-Holocene records by showing that infrequent, subsidence-generating shallow ruptures—not just deeper, uplift-producing earthquakes—are an integral component of central Chile's megathrust behavior. Remarkably, this paleoseismic archive, formed during a brief window within a ∼4000-year marine-to-terrestrial transition and preserved in an emergent, semiarid, preservation-limited margin, suggests that similar evidence may exist in other unfavorable settings. Integration of the Campiche record with historical, geophysical, and geodetic data indicates that a shallow slip deficit of ∼20 m may have accumulated since 1730, consistent with highly coupled shallow asperities, the recent shift from coastal stability to gradual subsidence, and proposed 200–650 yr recurrence intervals for large tsunamis. Taken together, these lines of evidence suggest that Chile's Metropolitan Region now lies within a plausible near-term window for another large tsunamigenic rupture. These findings underscore the need to integrate paleoseismic records and deep–shallow rupture interplay—including infrequent shallow Mw ≥ 9 events superimposed on more frequent Mw ∼8 deeper earthquakes—into tsunami-hazard models for Chile and the wider Pacific.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109789"},"PeriodicalIF":3.3,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940357","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":"Pleistocene geochemical signatures of the transgressive, overflow, and regressive phases of Lake Bonneville","authors":"B. Lee Drake ,&nbsp;Jennifer DeGraffenried ,&nbsp;Andrea Brunelle ,&nbsp;Isaac Hart ,&nbsp;Kaylee Barket Jones ,&nbsp;Bruce Kaiser ,&nbsp;Rachel Quist","doi":"10.1016/j.quascirev.2025.109775","DOIUrl":"10.1016/j.quascirev.2025.109775","url":null,"abstract":"<div><div>The rise and fall of Lake Bonneville at the end of the Pleistocene was driven by complex changes in North American hydrography. Using multiple sediment cores from Dugway Proving Grounds (DPG), we evaluate changes in composition from 30.0 to 13.0 cal ka BP ago using loss-on-ignition (LOI) and x-ray fluorescence (XRF) data. We find that the Stansbury Oscillation is associated with an increase in detrital inputs into the basin as evidenced by Ti/Ca, Rb/Sr, and Si/Ca ratios and coincided with Heinrich Event (HE) 2 around 24.0 cal ka BP. High lake level from 21.0 to 17.8 cal ka BP are associated with continued high influxes of sediment into the basin. However, an apparent punctuated drop in detrital proxy records was observed beginning at 17.8 cal ka BP with HE 1, lasting 500 years. This change was likely not due to changes in detrital inputs, but rather due to the overflow event at Red Rock Pass, which changed the Bonneville Basin from a closed to an open system. Detrital inputs remain high throughout the Provo stand from 17.0 to 16.0 cal ka BP, after which detrital inputs decline. From 16.0 to 15.0 cal ka BP, an increase in Mn abundance paired with a drop in organic content suggests a hypoxia episode. This was followed by a rapid evaporative event evidenced by higher aragonite and elevated Sr/Ca ratios at 14.5 cal ka BP which closely corresponds to the Bølling-Allerød interstadial period.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109775"},"PeriodicalIF":3.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940372","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":"Linear and nonlinear responses of annual mean sea surface temperature to orbital forcing","authors":"Xinwei Kong ,&nbsp;Zhengyu Liu ,&nbsp;Mi Yan ,&nbsp;Fuxian Xie ,&nbsp;Qin Wen ,&nbsp;Samantha Bova ,&nbsp;Yair Rosenthal ,&nbsp;Liang Ning ,&nbsp;Jian Liu","doi":"10.1016/j.quascirev.2025.109790","DOIUrl":"10.1016/j.quascirev.2025.109790","url":null,"abstract":"<div><div>The response of sea surface temperature (SST) to orbital-induced insolation is not well understood. Here, using transient climate simulation of the last 200,000 years, we investigate whether mean annual SST (MASST) responds linearly or nonlinearly to orbital forcing. Our results show that the response of SST to insolation is regionally variable. It is nearly linear across most of the tropics and high latitudes, with the MASST dominated by obliquity variability. In the mid-latitude and eastern equatorial Pacific, the response of SST is, however, nonlinear with MASST dominated by precession variability. The nonlinear MASST response can be biased towards winter or summer SST, caused by the rectification of the seasonal insolation forcing by cloud albedo or mixed layer depth depending on the region. Specifically, the MASST in the northwest Pacific is biased towards its winter season SST, which could mainly be attributed to the seasonal cycle of cloud cover. The summer season biased MASST in the mid-latitude south Pacific might be related to the seasonal variation of the oceanic mixed layer. The summer season biased MASST in the northeast Pacific might be a combined effect of atmospheric cloud and oceanic mixed layer. The peculiar seasonal bias of MASST in the eastern equatorial Pacific, however, could be related to the remote transmission signal from the mid-latitude south Pacific. Our study has implications for better interpreting proxy SST records through gaining further insights on the physical mechanisms controlling SST responses to orbital forcing.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109790"},"PeriodicalIF":3.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940296","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":"Ages of different shell species associated to vermetid bioconstructions remains and their implications on Mid-to Late-Holocene Brazilian sea-level curves","authors":"Rodolfo José Angulo ,&nbsp;Paulo César Fonseca Giannini ,&nbsp;Maria Cristina de Souza ,&nbsp;Augusto Luiz Ferreira Junior ,&nbsp;Thiago de Freitas Toniolo ,&nbsp;Jesús Alberto Salas Rangel ,&nbsp;Ed Garrett","doi":"10.1016/j.quascirev.2025.109788","DOIUrl":"10.1016/j.quascirev.2025.109788","url":null,"abstract":"<div><div>Vermetid bioconstructions have been widely used as Holocene paleo-sea level indicators along the Brazilian coast, due to their abundance and accuracy, especially in the case of <em>Petaloconchus varians</em> (d’Orbigny, 1841). Most age determinations for this species have been performed using conventional ¹⁴C dating of bulk bioconstruction samples. However, this type of sample may contain several types of carbonate or carbonaceous impurities, including remains of other organisms such as mollusks and barnacles, which can affect the reliability of the age. This work compares previous conventional ¹⁴C ages of vermetid bioconstruction bulk samples with ¹⁴C AMS ages of shells from different species dated individually. The objectives are: i. To establish the relationship among the ages of different species in order to reveal the direction or tendency of past sea-level changes; ii. To evaluate the error in dating bulk samples; iii. To analyze the reliability of the ages obtained from each species, based on aspects such as purity, alteration and neomorphism. The dating results obtained for fossil shells of different species were in agreement with the relative ages expected based on the observed spatial relationship between them. <em>Tetraclita stalactifera</em> parietal plates were older than overgrowing vermetids shells, and shells of the bivalve <em>Leiosolenus</em> aff. <em>bisulcatus</em> in life position, which perforate the bioconstruction, were younger. The ages of individual shells were older than those obtained by dating bulk vermetid bioconstructions, and this difference increased with the age. Taking the paleolevels previously determined for the studied samples and using the revised ages reported here, we infer that relative sea level in southern Brazil was more than 2 m above present between 6000 and 7000 cal aBP. The differences in ages between bulk and individual shell samples highlight that paleo-sea levels inferred from bulk vermetid remains and respective Holocene sea-level curves need revision. More data for separate species are therefore necessary to improve the accuracy of Holocene sea-level curves from Brazil. Furthermore, methodological care must be taken to avoid the influence of micritic envelopes, bioturbation, biofouling, and cement infill on the age.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109788"},"PeriodicalIF":3.3,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940298","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":"Seabird-mediated changes in sedimentary sterols and stanols","authors":"Matthew P. Duda ,&nbsp;David C. Eickmeyer ,&nbsp;John P. Smol ,&nbsp;Jules M. Blais","doi":"10.1016/j.quascirev.2025.109784","DOIUrl":"10.1016/j.quascirev.2025.109784","url":null,"abstract":"<div><div>Effective conservation strategies for at-risk animal species greatly benefit from long-term trend data. Yet, most populations lack continuous monitoring beyond 30 years, with many often lacking monitoring altogether. Paleolimnology provides a retrospective method for reconstructing animal populations over thousands of years. Here we critically evaluated the efficacy of sterols and stanols as a supporting proxy to reconstruct seabird colony dynamics of a well-studied colony with distinct peaks in population size over ∼1700 years on Baccalieu Island, Newfoundland and Labrador (Canada). We analyzed sediment from a waterbody adjacent to the world's largest colony of Leach's Storm-Petrel (<em>Hydrobates leucorhous</em>), a nearby reference pond with no colonial seabird influences, and storm-petrel feces to determine the pathway of introduction of sterols and stanols to sediment to better understand their preservation and potential transformation over time. Cholesterol represented over 95 % of sterols/stanols in storm-petrel feces, reflecting the piscivorous and planktivorous invertebrate diet of the bird. In sediment, cholesterol increased over the last ∼200 years, coinciding with the increase in seabird colony size, but did not track the population decline ca. 1980 CE. The diagenetic products of cholesterol, such as cholestanol, 5α-cholestanone, and epi-coprostanol, however, closely tracked both increases and decreases in two known peaks in seabird population size (ca. 500 CE and ca. 1980 CE). Other sterols, such as campesterol, desmosterol, fucosterol, β-sitosterol, and 5α-stigmastanol, may track the indirect environmental impacts of the seabird colony, such as nest formation and fecal-derived nutrient enrichment of the terrestrial environment. Our findings support the use of sterols and stanols as effective and informative proxies for reconstructing long-term animal populations, especially when considered in a multi-proxy framework.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"375 ","pages":"Article 109784"},"PeriodicalIF":3.3,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940355","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}