Boreas最新文献

{"title":"Sedimentary evidence of the Late Holocene tsunami in the Shetland Islands (UK) at Loch Flugarth, northern Mainland","authors":"Max Engel,&nbsp;Katharina Hess,&nbsp;Sue Dawson,&nbsp;Tasnim Patel,&nbsp;Andreas Koutsodendris,&nbsp;Polina Vakhrameeva,&nbsp;Eckehard Klemt,&nbsp;Philipp Kempf,&nbsp;Isa Schön,&nbsp;Vanessa M. A. Heyvaert","doi":"10.1111/bor.12635","DOIUrl":"10.1111/bor.12635","url":null,"abstract":"<p>Tsunami deposits around the North Sea basin are needed to assess the long-term hazard of tsunamis. Here, we present sedimentary evidence of the youngest tsunami on the Shetland Islands from Loch Flugarth, a coastal lake on northern Mainland. Three gravity cores show organic-rich background sedimentation with many sub-centimetre-scale sand layers, reflecting recurring storm overwash and a sediment source limited to the active beach and uppermost subtidal zone. A basal 13-cm-thick sand layer, dated to 426–787 cal. a CE based on ¹⁴C, ¹³⁷Cs and Bayesian age–depth modelling, was found in all cores. High-resolution grain-size analysis identified four normally graded or massive sublayers with inversely graded traction carpets at the base of two sublayers. A thin organic-rich ‘mud’ drape and a ‘mud’ cap cover the two uppermost sublayers, which also contain small rip-up clasts. Grain-size distributions show a difference between the basal sand layer and the coarser and better sorted storm layers above. Multivariate statistical analysis of X-ray fluorescence core scanning data also distinguishes both sand units: Zr, Fe and Ti dominate the thick basal sand, while the thin storm layers are high in K and Si. Enriched Zr and Ti in the basal sand layer, in combination with increased magnetic susceptibility, may be related to higher heavy mineral content reflecting an additional marine sediment source below the storm-wave base that is activated by a tsunami. Based on reinterpretation of chronological data from two different published sites and the chronostratigraphy of the present study, the tsunami seems to date to <i>c</i>. 1400 cal. a BP. Although the source of the tsunami remains unclear, the lack of evidence for this event outside of the Shetland Islands suggests that it had a local source and was smaller than the older Storegga tsunami (8.15 cal. ka BP), which affected most of the North Sea basin.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"53 1","pages":"27-41"},"PeriodicalIF":2.2,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12635","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134944122","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":"Geomorphological record of the glacial to periglacial transition from the Bølling–Allerød to the Holocene in the Central Pyrenees: the Lòcampo cirque in the regional context","authors":"Marcelo Fernandes,&nbsp;Marc Oliva,&nbsp;José María Fernández-Fernández,&nbsp;Gonçalo Vieira,&nbsp;David  Palacios,&nbsp;Julia Garcia-Oteyza,&nbsp;Josep Ventura,&nbsp;Irene Schimmelpfennig,&nbsp;ASTER Team","doi":"10.1111/bor.12633","DOIUrl":"10.1111/bor.12633","url":null,"abstract":"<p>In the highest tributaries of the Upper Garonne Basin, Central Pyrenees, cirques up to 2600 m a.s.l. were already deglaciated by 15–14 ka. The long-term deglaciation during Termination-1 (T-1) was interrupted by glacial advances within the cirques during the Bølling–Allerød (B-A) interstadial and the Younger Dryas stadial. The cirques preserve a variety of glacial and periglacial landforms whose chronologies are poorly known. This study is focused on the Lòcampo cirque (42°38′06″N and 0°59′10″E), Upper Garonne Basin, where a detailed geomorphological map and ¹⁰Be terrestrial cosmic ray exposure (CRE) dating allowed us to constrain the chrono-sequence between the glacial and periglacial domains. In the small Lòcampo cirque, a glacier formed a cirque moraine between 2200 and 2300 m a.s.l., which surrounds a relict rock glacier encompassing several transversal ridges. Additionally, longitudinal ridges typically observed in debris-covered glaciers are preserved between the moraine and the rock glacier. The eight-sample data set of CRE ages indicates the formation of the cirque moraine during the second half of the B-A, by 13.2±1.1 ka. Exposure ages from the rock glacier boulders show a range between 13.6±0.9 and 11.9±0.7 ka, which did not allow its formation to be chronologically constrained. Therefore, the environmental evolution following the moraine stabilization could follow the formation of a debris-covered glacier at the bottom of the Lòcampo cirque, with the subsequent formation of the rock glacier. After the rock glacier formation, its front rapidly ceased at 13.6±0.9 ka, while the upper ridges gradually stabilized until it became definitively relict at 11.9±0.7 ka or afterwards. These results show evidence of the complex glacial to periglacial transition that needs more robust chronological data sets to better understand the role of climate forcing and local topography during the deglaciation in mid-latitude mountain environments.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"53 1","pages":"71-87"},"PeriodicalIF":2.2,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12633","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49230852","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 resilient ice cover over the southernmost Mendeleev Ridge during the late Quaternary","authors":"Tengfei Song,&nbsp;Claude Hillaire-Marcel,&nbsp;Anne de Vernal,&nbsp;Yanguang Liu","doi":"10.1111/bor.12632","DOIUrl":"10.1111/bor.12632","url":null,"abstract":"<p>The presence of a late Quaternary ice sheet/ice shelf over the East Siberian Sea has been proposed in several papers. Here, we further document its duration/resilience based on the sedimentary, bulk mineralogical, and geochemical (organic matter content and its stable isotopic composition, U-Th series) properties of a core raised from the southernmost Mendeleev Ridge. The chronostratigraphy of the studied core was mainly built from the ²³⁰Th excess (²³⁰Th_xs) distribution and decay downcore. At the core-top, peaking ²³⁰Th_xs values during the early MIS 3 and mid-MIS 1 encompassing an MIS 2 hiatus were observed. As documented in several papers, these peaks suggest seasonally open ice conditions over proximal continental shelves. Below, the interval spanning MIS 4 and possibly MIS 5d records major ice-rafting events illustrated by overall high coarse-fraction contents. Underlying MIS 5e, down to MIS 11, the sediment depicts relatively low sand (1.7±2.5 dw%), high clay (33.5±4.7 dw%), and very low organic carbon (0.10±0.06 dw%) contents, and low δ¹³C_org values (−24.3±0.9‰). This section is interpreted as recording fine sediment transport by deep currents and/or meltwater plumes below a resilient ice cover, only interrupted by a few short-duration events. These events include (i) detrital carbonate pulses assigned to deglacial events along the NW Laurentide Ice Sheet margin (Termination (T) III), and (ii) intervals with some planktonic foraminifer occurrences, likely relating to their advection from open areas of the Arctic Ocean (MIS 5e, 9 and 11). All Terminations, but TII and the early MIS 3, show peaking Mn/Al values linked to the submergence of Arctic shelves under a rising sea level. We conclude that the resilient ice cover, likely an ice shelf, has been present over the southern Mendeleev Ridge during most of the interval after the Mid-Pleistocene Transition and was favoured by the low summer insolation of the MIS 14 to 10 interval.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"53 1","pages":"106-123"},"PeriodicalIF":2.2,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12632","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46404939","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":"British–Irish Ice Sheet and polar front history of the Goban Spur, offshore southwest Ireland over the last 250 000 years","authors":"Stanislaus G. Fabian,&nbsp;Stephen J. Gallagher,&nbsp;David De Vleeschouwer","doi":"10.1111/bor.12631","DOIUrl":"10.1111/bor.12631","url":null,"abstract":"<p>Deep Sea Drilling Program (DSDP) Site 548 was cored in 1984 at a water depth of 1256 m on the Goban Spur, offshore southwest Ireland. Coring retrieved a ~100-m-thick Pleistocene contourite sequence. This study uses planktonic foraminiferal assemblage and benthic foraminiferal oxygen isotope analyses to establish an age model for the upper 40 m of this core. This site's multidisciplinary analyses of planktonic foraminiferal assemblages, lithic grains, facies and calcium carbonate concentration reveal a 250 000-year record of the North Atlantic polar front variability and British–Irish Ice Sheet (BIIS) history. The sequence is characterized by alternations of ice rafted debris (IRD) laden pelagic mud facies with calcium carbonate-rich silty sand contourite facies that track glacial/interglacial cycles. The polar front migrated southward across the area several times during glacial maxima and stadial periods, while warmer Mediterranean Outflow Water (MOW) flowed northward across the region during interglacial and interstadial periods depositing contourites. Lithic analyses reveal a complex history of IRD deposition associated with iceberg calving from the Laurentide Ice Sheet and northwest European ice sheets, mainly the BIIS. Comparison between the Goban Spur (DSDP Site 548) and the Celtic Margin (MD03-2692) and central North Atlantic Integrated Ocean Drilling Program (IODP) Site U1308 suggests differences between the ‘non-Laurentide Ice Sheet’ Heinrich Events (HE) 6 and 3 at the Goban Spur, with IRD from the BIIS being prominent during HE 6 and IRD from other European ice sheets north of the BIIS likely being more dominant during HE 3. The nature of lithics in IRD-rich horizons during Terminations 3, 3A, 2 and 1 suggests significant iceberg calving episodes preceding BIIS retreat during the onset of interstadial intervals.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"52 4","pages":"476-497"},"PeriodicalIF":2.2,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12631","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47703168","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":"From land to sea: provenance, composition, and preservation of organic matter in a marine sediment record from the North-East Greenland shelf spanning the Younger Dryas–Holocene","authors":"Nanna Andreasen,&nbsp;Rebecca Jackson,&nbsp;Arka Rudra,&nbsp;Henrik Nøhr-Hansen,&nbsp;Hamed Sanei,&nbsp;Jørgen Bojesen-Koefoed,&nbsp;Marit-Solveig Seidenkrantz,&nbsp;Christof Pearce,&nbsp;Nicolas Thibault,&nbsp;Sofia Ribeiro","doi":"10.1111/bor.12630","DOIUrl":"10.1111/bor.12630","url":null,"abstract":"<p>The organic matter content of marine sediments is often used to infer past changes in ocean conditions. However, the organic carbon pool preserved in coastal sediments is a complex mixture derived from different sources and may not reflect <i>in situ</i> processes. In this study, we combine taxonomic identification of reworked palynomorphs with pyrolysis organic geochemistry and reflected-light organic petrographic microscopy to investigate the provenance, composition and preservation of organic matter in a marine sediment core retrieved from the NE Greenland shelf. Our study reveals continuous yet variable input of land-derived organic carbon to the marine environment throughout the late Younger Dryas–Holocene, with the highest input of inert carbon in the late Younger Dryas. Although the sediments contain some recent marine palynomorphs, there is no other evidence of fresh marine organic carbon. In contrast, our results indicate that these shelf sediments represent a significant sink of recycled organic carbon. The results of pyrolysis geochemistry revealed that ~90% of the total organic carbon in the sediments is inert. The organic petrography analyses revealed that &gt;70–84% of the organic carbon in the sediment core is terrigenous. Reworked dinoflagellate cysts showed a continuous provenance of Cretaceous land-derived material, most likely from the nearby Clavering Island. Our study points to the importance of constraining the organic matter origin, composition and preservation in marine sediments to achieve more accurate palaeoenvironmental reconstructions based on organic proxies.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"52 4","pages":"459-475"},"PeriodicalIF":2.2,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12630","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47062193","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":"Geometric morphometric assessment of the fossil bears of Namur, Belgium: Allometry and ecomorphology","authors":"Anneke H. van Heteren,&nbsp;Mietje Germonpré","doi":"10.1111/bor.12629","DOIUrl":"10.1111/bor.12629","url":null,"abstract":"<p>The Namur area in Belgium is useful to study brown (<i>Ursus arctos</i>) and cave bears (<i>Ursus spelaeus</i>) as the assemblage contains little temporal and no geographical variation. Here, we aim to assess ontogenetic allometry within cave bears, as well as ecomorphological differences between adult brown bears (n = 9), adult cave bears (n = 5) and juvenile cave bears (n = 3). Landmarks for 3D digitization of the mandible were chosen based on the taphonomical damage of the specimens. Extant brown bears and extinct Pleistocene brown and cave bears were digitized with a Microscribe G2. Generalized Procrustes superimposition was performed on the coordinates. Allometry was studied using regression analysis. Principal component analysis (PCA) was conducted to assess ecomorphological differences between the groups. 61% of the shape variance within juvenile and adult cave bears was predicted by size (n = 8, <i>p</i> &lt; 0.01). The juvenile cave bears have relatively deep horizontal rami. In adult cave bears, the horizontal ramus is much narrower dorsoventrally. Juvenile cave bears have a small masseteric fossa and a short coronoid process, whereas both are larger, relative to mandible size, in adult cave bears. This made juvenile cave bears likely less effective masticators than fully grown cave bears. In the PCA, principal component (PC) 1 accounts for 45.0% of the total variance and PC2 accounts for 27.6%. Fossil <i>U. arctos</i> from Namur fall within the 95% confidence interval of modern North American <i>U. arctos</i> on both PCs, but are more similar to cave bears than the average extant brown bear. From the similarity of fossil and modern brown bears, it can be deduced that the diet of fossil brown bears was probably also within the range of their modern North American conspecifics, although they might have been more efficient at masticating plant matter.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"52 4","pages":"498-506"},"PeriodicalIF":2.2,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12629","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42758249","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":"Holocene relative shore-level changes and development of the Ģipka lagoon in the western Gulf of Riga","authors":"Alar Rosentau,&nbsp;Ieva Grudzinska,&nbsp;Edyta Kalińska,&nbsp;Helena Alexanderson,&nbsp;Valdis Bērziņš,&nbsp;Aija Ceriņa,&nbsp;Laimdota Kalniņa,&nbsp;Jānis Karušs,&nbsp;Kristaps Lamsters,&nbsp;Merle Muru,&nbsp;Māris Nartišs,&nbsp;Līga Paparde,&nbsp;Tiit Hang","doi":"10.1111/bor.12628","DOIUrl":"10.1111/bor.12628","url":null,"abstract":"<p>Holocene relative shore-level changes and development of the Ģipka palaeolagoon in the western Gulf of Riga are reconstructed using multiproxy analyses by combining litho-, biostratigraphical and chronological data with remote sensing and geophysical data. The results show the development of the Ģipka basin from the Ancylus Lake/Initial Litorina Sea coastal zone (before <i>c.</i> 9.1 cal. ka BP) to coastal fen (<i>c.</i> 9.1 to 8.4 cal. ka BP) and gradual development of the Litorina Sea lagoon (<i>c.</i> 8.4 to 4.8 cal. ka BP) and its transition to a freshwater coastal lake (<i>c.</i> 4.8 to 4.6 cal. ka BP), fen (<i>c.</i> 4.6 to 4.2 cal. ka BP), and river floodplain (since <i>c.</i> 4.2 cal. ka BP). The highest shorelines of the Ancylus Lake and Litorina Sea were mapped at an elevation of 12–11 and 9 m a.s.l., respectively. A new relative shore level (RSL) curve for the western Gulf of Riga was constructed based on RSL data from the Ģipka area and from nearby Ruhnu Island studied earlier. The reconstruction shows that the beginning of the last marine transgression in the western Gulf of Riga started at <i>c.</i> 8.4 cal. ka BP, and concurred with the 1.9 m RSL rise event recorded from the North Sea basin. Diatom analysis results indicate the existence of the Ģipka lagoon between <i>c.</i> 7.7 and 4.8 cal. ka BP, with the highest salinity <i>c.</i> 6.1 cal. ka BP. During the existence of the brackish lagoon, settlement sites of the Neolithic hunter–gatherer groups existed on the shores of the lagoon in the period <i>c.</i> 6.0 to 5.0 cal. ka BP.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"52 4","pages":"517-537"},"PeriodicalIF":2.2,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12628","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47165649","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":"Variations in Holocene fire activity and its controls in the Ningshao Plain, eastern China","authors":"Konglan Shao,&nbsp;Jianping Zhang,&nbsp;Hongbo Zheng,&nbsp;Zhaoyan Gu,&nbsp;Bing Xu,&nbsp;Qing Yang,&nbsp;Keyang He,&nbsp;Huayu Lu","doi":"10.1111/bor.12627","DOIUrl":"10.1111/bor.12627","url":null,"abstract":"<p>Extensive fires pose catastrophic threats to both human and natural ecosystems. Understanding the history of fire, particularly Holocene palaeofire activity in densely populated areas, is essential for predicting future fire risks and developing effective fire management policies. The complexity of fire activity is influenced by various factors, including climate and anthropogenic activities. In this study, we analysed microcharcoal from the top 35.36 m of a well-dated sediment core HMD1401 in Ningshao Plain, eastern China. We combined our findings with phytolith and diatom evidence to obtain a comprehensive understanding of variations in Holocene fire activity and its controls. The results showed that there was higher fire activity during the early and late Holocene and less fire activity during the mid-Holocene. More frequent fire occurred from <i>c.</i> 10 000–7000 cal. a BP and was primarily caused by abundant biomass and high seasonal flammability due to increased annual temperature and precipitation and warm but dry winter climate. Fire occurrences between <i>c.</i> 7000–2000 cal. a BP remained at a low level, except for the periods <i>c.</i> 5900–5600 cal. a BP and <i>c.</i> 5300 cal. a BP, which may have been caused by extreme climate events. The impact of fire caused by human activity was significantly enhanced during the last two millennia.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"52 4","pages":"507-516"},"PeriodicalIF":2.2,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12627","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48646873","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 deglaciation of Upernavik trough, West Greenland, and its Holocene sediment infill: processes and provenance","authors":"Jens Weiser,&nbsp;Jürgen Titschack,&nbsp;Dierk Hebbeln","doi":"10.1111/bor.12626","DOIUrl":"10.1111/bor.12626","url":null,"abstract":"<p>Under glacial climates, continental ice sheets such as, e.g., the Greenland Ice Sheet, extended onto the continental shelves and often carved out deep cross-shelf troughs. The sedimentary infill of such troughs commonly is a product of the complex interactions between the ice sheets, largely driving sediment input into the ocean, and the surrounding water masses. Off West Greenland, research has focused on the Disko and Uummannaq troughs, leaving the northerly adjacent Upernavik trough relatively understudied. Hence, neither the chronology of deglaciation nor the details of its postglacial infill are sufficiently well understood. Here, we combine computed tomography image-derived information with geochemical and granulometric data from four sediment cores recovered from the Upernavik trough that point to (i) deglaciation of the mid-shelf probably around 13.4 cal. ka BP that was most likely driven by a northward advection of warmer Atlantic waters during the Bølling–Allerød, (ii) the presence of widespread mass wasting around 8 cal. ka BP on the inner shelf and (iii) the complex interplay between various modes of sediment input, transport and deposition under hemipelagic sedimentation afterwards. While this interplay complicates provenance studies, we identify two major sediment delivery mechanisms that control transport and deposition from four sediment source areas. Through the Early Holocene the relative contributions of sediments from the various sources changed from a predominantly local origin to more southerly sources, mainly driven by decreasing input from the local sources. The integration of relative sediment source contributions with varying sedimentation rates challenges previous studies postulating intensified sediment delivery from the south through a greater influence of the West Greenland Current and highlights the need for the integration of sediment input and transport mechanisms into provenance studies in the area.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"52 3","pages":"314-340"},"PeriodicalIF":2.2,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12626","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49466174","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":"Spatial interpretation of high-resolution environmental proxy data of the Middle Pleistocene Palaeolithic faunal kill site Schöningen 13 II-4, Germany","authors":"Brigitte Urban,&nbsp;Kim J. Krahn,&nbsp;Thomas Kasper,&nbsp;Alejandro García-Moreno,&nbsp;Jarod M. Hutson,&nbsp;Aritza Villaluenga,&nbsp;Elaine Turner,&nbsp;Sabine Gaudzinski-Windheuser,&nbsp;Dalia Farghaly,&nbsp;Mario Tucci,&nbsp;Antje Schwalb","doi":"10.1111/bor.12619","DOIUrl":"10.1111/bor.12619","url":null,"abstract":"<p>To spatially characterize the palaeolakeshore environment at the archaeological kill site Schöningen 13 II-4 of the Middle Pleistocene Reinsdorf sequence, in-depth palynological, geochemical, aquatic microfossil and archaeological analyses were undertaken on sediment sections with an average thickness of about 15 cm, concordantly overlain by faunal remains, dominated by horse, from the unique ‘Spear Horizon’ layers of the 1995 excavation campaign. The data reveal a distinctive lake level drop, documented by the change from a carbonate-rich lake marl to a carbonate-free organic mud with increased carbon content and decreasing C/N, Si/Al, Si/K and Fe/Al ratios, indicating a higher pedogenic supply of organic matter and drier conditions at the site. Compared with older, similar transitional phases of lake level changes occurring within the Reinsdorf sequence, it is important that these youngest sediments are undisturbed, indicating continuous development. Ostracod and diatom analyses indicate a lowering water level with higher salinities and rich aquatic vegetation. Mesorheophilic ostracod species along with tychoplanktic diatom taxa point to flowing waters and turbulence at the lakeshore, presumably related to spring-fed streams originating from nearby highlands. Palynological results reveal a very diverse zonal vegetation pattern around the palaeolakeshore considering an area of investigation of approximately 50 × 75 m and a tessellated type of regional vegetation during the formation of the archaeological horizons. On topographically lower elevated areas, birch groves and taxa favouring wet, marshy conditions such as Cyperaceae, indicative of terrestrialization, were predominating, while other stands of this transitional phase reveal a very dry, grass-dominated steppe woodland favouring a rich wildlife with a striking number of megaherbivores. Our results suggest that the lithological differences of the ‘Spear Horizon’ layers containing the archaeological finds were due to their respective topographical situation and that the layers were deposited almost simultaneously during the beginning of the lake level drop. Human activities seem to have concentrated in sparsely vegetated areas along the palaeolakeshore, rather than in areas of adjacent denser birch swamp forest stands.</p>","PeriodicalId":9184,"journal":{"name":"Boreas","volume":"52 3","pages":"440-458"},"PeriodicalIF":2.2,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/bor.12619","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49536103","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}