Boreas最新文献

{"title":"Subtle relict channels associated with large dolines in an area formerly beneath the Laurentide Ice Sheet, northern Ohio, USA","authors":"Timothy G. Fisher,&nbsp;Douglas J. Aden,&nbsp;Brittany D. Parrick,&nbsp;Kennedy O. Doro,&nbsp;Ira D. Sasowsky,&nbsp;Tyler A. Norris,&nbsp;Giorgi Chartolani","doi":"10.1111/bor.70016","DOIUrl":"https://doi.org/10.1111/bor.70016","url":null,"abstract":"<p>Low-relief dry channels are observed across the Bellevue-Castalia Karst Plain of north-central Ohio, USA. The area was repeatedly glaciated, and the channel forms are of interest because the linear pattern may be related to glacial processes. The 3–5 m deep channels are discontinuous, 0.15–0.4 km wide, and ~2–11 km long. Elongated large dolines of collapse/subsidence origin are parallel with ice flow, bedrock strike, fractures and joints, and are associated with the channels. There is no evidence of continued collapse since deglaciation. Smaller suffosion dolines developed within sediment are active and common across the landscape. Electrical resistivity tomography across uplands, channels, and large dolines indicates two units, a low-resistivity till over a high-resistivity limestone bedrock. Low-relief ridges a few hundred metres long are within, and parallel to, some channels, and are composed of bedrock with till veneer. Where till is exposed, it is tightly packed into dissolutionally enlarged fractures and cavities within bedrock, reducing groundwater connectivity into the subsurface. Channel orientations are offset and overlap with bedrock fractures, joints and elongated doline orientations. Three hypotheses are proposed to explain the channels. A subglacial meltwater channel hypothesis is supported by the channels incised into bedrock, covered in till and cross-cut by deglacial shorelines. A linear arrangement of collapse dolines hypothesis is supported by many channels orientated parallel to fractures within the bedrock and a crenulated channel margin. A fluviokarst origin for some channels relies upon preglacial subaerial streams progressively captured within Columbus Limestone bedrock, and subsequent non-selective glacial erosion. Erosion during the last glaciation may have been limited to ~1 m of bedrock, which would support preservation of karst features through successive glaciations. The second and third hypotheses are related, and with all three hypotheses these various previously unrecognized channels can be explained.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 4","pages":"567-589"},"PeriodicalIF":2.9,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145341566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Drastic peatland regime shift and landscape disturbances connected to warm and cold climate events over the past centuries in subarctic Finland","authors":"Sanna R. Piilo,&nbsp;Mari Kuoppamaa,&nbsp;Teemu Tahvanainen,&nbsp;Timo Kumpula,&nbsp;Niina Kuosmanen,&nbsp;Marc Macias-Fauria,&nbsp;Minna Väliranta","doi":"10.1111/bor.70017","DOIUrl":"https://doi.org/10.1111/bor.70017","url":null,"abstract":"<p>Palaeoecological studies reporting long-term development histories of subarctic fens—explicitly, orohemiarctic peatlands—are scarce, and overall, permafrost-free peatlands located in the immediate vicinity of permafrost zones have received little attention in Fennoscandia. Here, we use a multiproxy approach to study the millennial-scale dynamics of two neighbouring peatlands located in Finnish Lapland (Katsapuli and Maader). In addition to studying autogenic succession and external forcing, we aimed to resolve the impact of surrounding landscape changes, potentially related to reindeer herding. The pollen data did not indicate major changes in regional vegetation, except for an increase in the proportion of sedges towards modern times and a decrease in the proportion of tree pollen. This, together with an increase in regional fire (microcharcoal) and erosion rates (measured as the mineral component in the sediments) in the area, coincided with both colder temperatures (Little Ice Age) and the emergence of reindeer-based pastoralism. The macrofossil peat plant data of the two profiles suggested a clear and relatively simultaneous local regime shift from sedge-dominated local habitat conditions to a <i>Sphagnum</i> community, where <i>S. lindbergii</i> became increasingly dominant towards the present day, suggesting a prevalence of relatively moist conditions. In both sites, the regime shift was coeval with the onset of Medieval Climate Anomaly climate conditions and is sustained thereafter. Vegetation changes in <i>Sphagnum</i> mosses induced high peat growth rates, and most of the peat stock is relatively young. Based on these data, we suggest that <i>Sphagnum</i> moss communities are resilient to climate fluctuations and might continue to act as effective carbon accumulation systems under warmer climates.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 1","pages":"85-97"},"PeriodicalIF":2.9,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146154561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Persistence and dynamic of forest snails in the Western Carpathians over the last 40 thousand years","authors":"Lucie Juřičková,&nbsp;Jitka Horáčková,&nbsp;Veronika Horsáková,&nbsp;Petra Hájková,&nbsp;Jan Hošek,&nbsp;Michal Horsák","doi":"10.1111/bor.70019","DOIUrl":"10.1111/bor.70019","url":null,"abstract":"<p>The glacial/interglacial cycles have shaped the landscape of temperate Europe for the past 2.5 million years, with open landscapes prevailing during the glacial and forested landscapes during the interglacial periods. However, the survival and recolonization strategies of temperate forest species during glacial phases remain poorly understood and hotly debated. This study investigates the persistence and postglacial dispersal of forest molluscs in the Western Carpathians by analysing molluscs from 126 Last Glacial and Early Holocene sites. Radiocarbon dating was applied to directly date shells of the target forest species, minimizing the risk of contamination from colluvial sediments. Our results confirm the presence of 15 forest snails in 33 sites in the region for the last 44 ka, with evidence of five species surviving the MIS 2. These findings support the hypothesis of localized microrefugia in the Western Carpathians, which allowed forest species to persist during unfavourable climatic conditions and facilitated their recolonization in the Holocene. In addition, our study highlights considerable temporal variation in mollusc successional patterns, with a sharp increase in forest species during the post-Last Glacial Maximum period. Despite these advances, the exact location of glacial (micro)refugia remains unclear for many species, highlighting the need for further research. This study provides new insights into the complex biogeographical history of forest molluscs in temperate Europe, emphasizing the need for high-resolution dating techniques and extensive sampling to accurately reconstruct past environmental changes.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 1","pages":"98-109"},"PeriodicalIF":2.9,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146136288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Luminescence analysis of a postglacial landscape in northeastern Norway and northern Finland","authors":"Alastair Goodship,&nbsp;Helena Alexanderson,&nbsp;Joanna Anjar","doi":"10.1111/bor.70015","DOIUrl":"https://doi.org/10.1111/bor.70015","url":null,"abstract":"<p>Portable optically stimulated luminescence (pOSL) analysis allows rapid relative dating of sediments that potentially can be calibrated against known OSL ages to provide an age estimate for landforms across a large area. This study uses 186 pOSL measurements and 20 OSL ages to investigate the postglacial landscape evolution inside the Younger Dryas moraines in NE Finnmark and Finnish Lapland. Aeolian sediments are widespread in the study area, with activity initiating in Finnmark around 10.2 ka. Increases in aeolian activity and dune formation occur from 6.5 ka across the study area, with a peak in the last 1500 years. Glacial sediments and landforms provided more challenging targets for both OSL and pOSL analyses and dating, but properties determined from pOSL proxy data show potential for determining sediment history of mobilization and deposition. Calibration of pOSL data against OSL age estimates, a developing method of luminescence dating, lets us build a chronology of activity from a larger data set, and in a much less time- and cost-consuming way than using only OSL would allow.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 1","pages":"164-181"},"PeriodicalIF":2.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146136109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"The role of shallow banks and marine ice domes in marine-based ice-sheet deglaciation","authors":"Bartosz Kurjanski,&nbsp;Brice R. Rea,&nbsp;Matteo Spagnolo","doi":"10.1111/bor.70012","DOIUrl":"https://doi.org/10.1111/bor.70012","url":null,"abstract":"<p>Marine-based ice sheets are susceptible to collapse and faster retreat than their land-terminating counterparts. One of the key factors contributing to the relative stability of marine-terminating ice sheets is the presence of shallow bathymetric banks and islands acting as pinning points for the ice sheet. This study examines the seabed geomorphology of Storbanken, a shallow bank in the central Barents Sea. The preserved geomorphology/bedforms visible in the bathymetry provide new insights into the dynamics of the palaeo-Svalbard Barents Sea Ice Sheet (SBSIS). Contrary to previous assumptions that ice rises are transient features within ice shelves, the findings suggest that the Storbakken marine ice dome was a persistent ice accumulation centre that probably detached from the SBSIS after the collapse of its divide at ∼14–15 ka and before the ice cap was confined mainly to Svalbard area ∼12 ka. The geomorphic imprint left on the seabed reveals evidence for active deglaciation and the reorganization of multiple small ice streams, responding to shifts in driving stress within the marine ice dome. This challenges traditional models of gradual ice margin retreat and suggests that smaller marine ice domes and rises may have been more common during the deglaciation than previously recognized. Additionally, the study highlights discrepancies between empirical observations and existing ice-sheet reconstructions, which typically depict a stepwise ice-margin retreat without considering the formation of independent ice rises. The findings underscore the need to reevaluate the role of shallow bathymetric banks in influencing the stability and decay of marine-based ice sheets, with concomitant implications for understanding ice-sheet behaviour under future climate scenarios, which is particularly relevant for the chiefly marine-based West Antarctic Ice Sheet.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 4","pages":"649-671"},"PeriodicalIF":2.9,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145341702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"A 3200-year weathering record of the Mekong River basin by sediments from the South China Sea","authors":"Yujie Cheng,&nbsp;Haiou Gu,&nbsp;Sang Chen,&nbsp;Liqiang Xu","doi":"10.1111/bor.70013","DOIUrl":"https://doi.org/10.1111/bor.70013","url":null,"abstract":"<p>The Mekong River is a mega-river in East and Southeast Asia, and precipitation in its watershed influences more than 300 million people. However, the controlling factor in precipitation and weathering in the basin remains controversial. Here we present a high-resolution record of weathering of the Mekong River basin over the past 3200 years by magnesium isotopes (δ²⁶Mg) of silicate components in a sediment core from an area off the Vietnam coast in the western South China Sea. The results show that the δ²⁶Mg values of silicates in marine sediments range from −0.40 to 0.036‰, and display evident change patterns. Our data support a theory that weathering in the Mekong River basin is controlled by three monsoon systems including the East Asian summer monsoon (EASM), the Indian summer monsoon (ISM), and the Western North Pacific summer monsoon (WNPSM), but the ISM may have played a more important role in the past century.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 1","pages":"73-84"},"PeriodicalIF":2.9,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146139894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Palaeoenvironmental changes recorded at the Velika Vrbica loess-palaeosol sequence, Wallachian Basin, during MIS 3–MIS 1","authors":"Zoran M. Perić,&nbsp;Cathal S. Ryan,&nbsp;Warren Thompson,&nbsp;Milica G. Radaković,&nbsp;Petar Krsmanović,&nbsp;Helena Alexanderson,&nbsp;Slobodan B. Marković","doi":"10.1111/bor.70009","DOIUrl":"https://doi.org/10.1111/bor.70009","url":null,"abstract":"<p>This study presents a detailed investigation of the Velika Vrbica loess-palaeosol sequence, situated in the Wallachian Basin of northeastern Serbia, with the aim to reconstruct palaeoenvironmental changes spanning Marine Isotope Stages (MIS) 3 to 1. Using optically stimulated luminescence (OSL) dating, low field magnetic susceptibility (χ_lf), and mass accumulation rates (MARs), we have developed a robust geochronological framework and analysed sedimentary and environmental processes over the last glacial–interglacial cycle. The OSL chronology reveals consistent loess deposition from ~41 to 3 ka, with peak accumulation rates recorded during MIS 3 and late MIS 2. The MAR data challenge conventional models of loess formation, as higher deposition rates are observed during the interstadial MIS 3 compared to the Last Glacial Maximum. This finding suggests regional variations in aeolian activity and climate dynamics that differ from the widely accepted pattern of intensified dust deposition during colder glacial periods. The environmental magnetic record of the Velika Vrbica loess sequence presented here shows more similarities with equivalent sections in the Wallachian Basin than in the Vojvodina region. These findings contribute to the broader understanding of loess formation processes and palaeoenvironmental variability on a continental scale, reinforcing the importance of high-resolution chronological and sedimentological studies in disentangling global vs. regional influences on past dust deposition.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 1","pages":"134-149"},"PeriodicalIF":2.9,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146139765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Comments on ‘Late Middle Pleistocene Wolstonian Stage (MIS 6) glaciation in lowland Britain and its North Sea regional equivalents – a review’","authors":"Harry E. Langford","doi":"10.1111/bor.70011","DOIUrl":"https://doi.org/10.1111/bor.70011","url":null,"abstract":"<p>Divergent views debated over the past 20 years on the Wolstonian depositional record of Fenland and the Peterborough area have centred on whether there is evidence of a single (middle or late) glaciation or of both a middle and a late glaciation. A recent review promoted a single late Wolstonian glaciation, despite there being incontrovertible evidence of extensive cold-stage gravels associated with glacially related drainage diversion both pre-dating and post-dating late Wolstonian interglacial deposits.\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 1","pages":"258-271"},"PeriodicalIF":2.9,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146148230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Multiple indicators record human adaptations to climatic change during the Middle Holocene at the Wanbei site in the middle and lower Huai River valley, China","authors":"Weixin Tian,&nbsp;Wuhong Luo,&nbsp;Huiyuan Gan,&nbsp;Liugen Lin,&nbsp;Tianci Sun,&nbsp;Yajie Sun,&nbsp;Hanlin Xu,&nbsp;Caiwei Zhang,&nbsp;Xin Wang,&nbsp;Juzhong Zhang","doi":"10.1111/bor.70010","DOIUrl":"https://doi.org/10.1111/bor.70010","url":null,"abstract":"<p>The archaeological sediment successions from the Wanbei site provide an ideal case for reconstructing both natural and human-induced environmental changes in the middle and lower reaches of the Huai River valley located in the transitional zone of eastern China during the Middle Holocene. The findings of this work, in terms of phytoliths, pollen and spores, and chemical elemental analyses suggest that the climatic conditions that were recorded in the Wanbei profile responded well to broader climatic changes, with an overall warm and humid climate during 5700–5300 a BP, albeit with a cooling trend between 5600 and 5400 a BP. Rice (<i>Oryza sativa</i>) was always the main cereal crop in mixed rice-millet farming owing to warm and humid conditions, although the proportions of broomcorn millet (<i>Panicum miliaceum</i>) and foxtail millet (<i>Setaria italica</i>) significantly increased during the cooling period. The structural characteristics and adjustments of mixed farming over time show an adaptation strategy in response to the climatic changes at Wanbei. Furthermore, multiple indicators reveal that human activities at the Wanbei site would increase rather than decrease during the cooling period between 5600 and 5400 a BP. This study not only highlights the dynamic nature of early agricultural societies, but also enhances our understanding of their adaptation strategies in response to climatic changes in the middle and lower Huai River valley during the Middle Holocene.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"55 1","pages":"150-163"},"PeriodicalIF":2.9,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146139800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Complex past ice flow from Norway to the North Sea Plateau during the Quaternary: evidence from Marstein Trough and earlier reconstructions using 3D seismic data sets","authors":"Dag Ottesen,&nbsp;James D. Kirkham,&nbsp;Julian A. Dowdeswell,&nbsp;Harald Brunstad,&nbsp;Morten Halvorsen","doi":"10.1111/bor.70007","DOIUrl":"https://doi.org/10.1111/bor.70007","url":null,"abstract":"<p>Based on a regional 3D seismic data set and a small high-resolution 3D seismic data set (~40 km²) we have mapped a buried glacially eroded trough on the North Sea Plateau, west of the Norwegian Channel (latitude 59°N, longitude 3°E). The trough, which we informally name Marstein Trough, is 60 km long, 30 km wide, 120 m deep, and trends NE–SW. Marstein Trough contains an extensive pattern of glacial lineations at its base, which follow the trough axis, and is infilled by two seismic units interpreted as tills. From its stratigraphical position, we infer that the trough was eroded by an ice stream that flowed from western Norway and crossed the Norwegian Channel in a southwesterly direction, probably during the penultimate, Saalian glaciation. Marstein Trough, and its diagnostic landforms, provide detailed evidence of complex, switching ice flow across the North Sea during the Quaternary. Westward ice flow from Norway took place during early Scandinavian Ice-Sheet build-up prior to the activation of the Norwegian Channel Ice Stream. In contrast, ice-flow patterns during full-glacial conditions caused ice flow to reorientate to a S–N direction when the Norwegian Channel Ice Stream with a huge catchment that included the Baltic was established. Our results highlight the complex patterns of ice flow experienced over this region of the North Sea, with implications for reconstructions of Quaternary history, modern renewable energy infrastructure installation, and glacial processes during the build-up phase of ice sheets.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"54 3","pages":"351-369"},"PeriodicalIF":2.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.70007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}