bluuebunny/crossref_metadata_2025_split huggingface dataset:
The objectives of the North Atlantic Seaboard Programme (NASP), a constituent subproject of IGCP‐253
Authors: Lowe J. John , Lowe J. John 
Published: February 2007

AbstractThe North Atlantic Seaboard Programme (NASP) is one of the main sub‐projects of IGCP‐253 (‘Termination of the Pleistocene’) and is concerned with the history of environmental changes in areas adjacent to the North Atlantic during the last glacial‐interglacial transition. The organisation and aims of IGCP‐253 are briefly outlined, to provide the wider context of the NASP. The specific aims of the NASP are introduced, with reference to the importance of the North Atlantic region in late Quaternary research. Some methodological problems are outlined as is the strategy adopted in regional summaries and an overall North Atlantic synthesis, which are presented separately in the issue of Journal of Quaternary Science of which this introductory paper forms a part.
The Devensian/Weichselian Late‐glacial in northwest Europe (Ireland, Britain, north Belgium, The Netherlands, northwest Germany)
Authors: Walker M. J. C. , Bohncke S. J. P. , Coope G. R. , O'Connell M. , Usinger H. , Verbruggen C. 
Published: February 2007

AbstractA synthesis of environmental changes during the Devensian (Weichselian) Lateglacial period (14‐9 ka BP) is presented for an area extending from Ireland in the west to northwest Germany in the east. Following a brief reference to the problems of chronology, the principal changes in geomorphology and soils, vegetation history and climate experienced in the region during the Late‐glacial are described. Reconstructions of thermal variations during the Late‐glacial period are attempted independently for Ireland, England and Wales, Scotland (Highlands and Islanads), north Belgium, The Netherlands and northwest Germany. The collective palaeotemperature data, based mainly uppoln pollen data but also in Britain and The Netherlands on coleopteran data using the ‘mutual climatic range’ approach, provide an overview of regional differences along an east‐west transect in northwest Europe.
Late Weichselian environmental change in southern Sweden and Denmark
Authors: Berglund Björn E. , Björck Svante , Lemdahl Geoffrey , Bergsten Helene , Nordberg Kjell , Kolstrup Else 
Published: February 2007

AbstractA synthesis is presented of the envronmental and climatic variations that are inferred to have occurred in southern Sweden (up to latitude 59°N) and Denmark during the Weichselian Late‐glacial (14‐9 ka BP). The chronology and characteristics of the main phases of deglaciation, sea‐level change, periglacial activity, soil development, vegetation cover and climate change are summarised. A curve representing the main changes in temperature, including quantitative estimates based upon beetle data and using the ‘mutual climatic range’ method, is presented.
Late Weichselian environmental change in Norway, including Svalbard
Authors: Birks Hilary H. , Paus Aage , Svenndse J. I. , Alm Torbjørn , Mangerud J. , Landvik J. Y. 
Published: February 2007

AbstractA synthesis of the principal environmental changes that are inferred to have occurred in Norway and Svalbard (Fig. 1) during the Late‐glacial period (14‐9 ka BP) is presented. The paper has three sections dealing separately with (I) western Norway, (II) northern Norway and (III) Spitsbergen, Svalbard. The main conditions described include glacial events, sea‐level changes, vegetation history and climatic variations. A summary chart of environmental reconstructions is presented for each of the three areas, each including a curve of temperature reconstructions for the Late‐glacial period. These indicate some significant regional variations in contemporaneous thermal conditions during the Late‐glacial.
A review of the environmental history of Iceland, 13 000‐9000 yr BP
Authors: Ingólfsson Ólafur , Norddahl Hreggvidur 
Published: February 2007

AbstractA synthesis of the main environmental changes that are interpreted to have occurred in Iceland during the period 13‐9 ka BP is presented. Most of the evidence available relates to variations in the position of ice margins, although some limited information on vegetation history and soil stability is also referred to. Only qualitative and limited climatic inferences can be made for this period because of the lack of detailed evidence. A summary curve of the relative extent of ice cover is presented.
Wisconsinan Late‐glacial environmental chage in New Brunswick: A regional synthesis
Authors: Cwynar Les C. , Levesque André J. , Mayle Francis E. , Walker Ian 
Published: February 2007

AbstractA synthesis is presented of the history of deglaciation, vegetation cover and climate in New Brunswick, Canada, during that part of the Wisconsinan Late‐glacial period (12‐9 ka BP) for which detailed records exist. Curves of inferred temperature variations in the region during this period are presented based upon qualitative interpretations of plant records and quantitative estimates based upon fossil chironomid assemblages.
Wisconsinan Late‐glacial environmental chage in Québec: A regional synthesis
Authors: Richard P. J. H. 
Published: February 2007

AbstractA synthesis is presented of the evidence for regional deglaciation, lake sediment stratigraphy, vegetation history and climatic variations in Québec during that part of the Wisconsinan Late‐glacial (12.5‐9 ka BP) for which detailed records exist. Lake sediment data for all or part of this period are available from more than 125 lakes or bogs in the region. The information available indicates strong regional differentiation in climatic conditions, probably due to local effects close to the edge of the retreating Late Wisconsinan ice sheet. The Younger Dryas cooling is not evident in the data from Québec, but there appears to have been a strong climatic reversal during the early Holocene. Summary charts are presented of deglaciation and vegetation patterns in the region, but only qualitative assessments can be made of temperature variations.
Wisconsinan Late‐glacial environmental change on the southeast Baffin shelf, southeast Baffin Island and northern Labrador
Authors: Andrews J. T. 
Published: February 2007

AbstractThe importance of the Baffin‐Labrador region is explained in terms of the channelling through this area of the mass flux of meltwater from the Laurentide Ice Sheet and the probable effects of this on the thermohaline circulation of the North Atlantic. The chronology of glaciation and deglaciation in the region is summarised. Reference is made to recent marine records from the Baffin Shelf. Isotopic changes recorded in foraminiferal assemblages obtained from marine sediments in the Baffin Shelf‐Labrador Sea area indicate the timing and possible magnitude of meltwater fluxes during the period 14.0‐11.0 ka BP.
Climatic changes in areas adjacent to the North Atlantic during the last glacial‐interglacial transition (14‐9 ka BP): A contribution to IGCP‐253
Authors: Lowe J. John , Ammann B. , Birks H. H. , Björck S. , Coope G. R. , Cwynar L. , de Beaulieu J.‐L. , Mott R. J. , Peteet D. M. , Walker M. J. C. 
Published: February 2007

AbstractThis paper presents a summary of the evidence for climatic changes during the last glacial‐interglacial transition (14‐9 ka BP) in land areas adjacent to the North Atlantic. It is a synthesis of the results of the 12 regional summaries compiled by contributors to the North Atlantic Seaboard Programme of IGCP‐253 that are published separately in this issue of Journal of Quaternary Science. Eighteen palaeotemperature curves are compared and arranged in three transects, one from southern Europe to Spitsbergen, a second from Ireland to Poland, and the third from southern New England to the Labrador‐Baffin Shelf area. Ten maps are presented that summarise the synoptic climatic conditions of the region in 500‐year time periods. The purpose of the exercise is to examine the extent to which any emerging patterns support the Ruddiman and Mclntyre model of large‐scale shifts in the position of the oceanice Polar Front during the last glacial‐interglacial transition. Some broad agreement emerges, although the influence of oceanic changes is diminished in areas that lay in close proximity to the Laurentide and Fennoscandian ice sheets. Attention is drawn to limitations in the compilations and to the potential for improved models in the future.
Plio‐Pleistocene palaeoceanography of the tropical Indian Ocean (ODP Hole 709C): Radiolarian and CaCO3 evidence
Authors: Haslett Simon K. , Funnell Brian M. , Dunn Claire L. , Bloxham Kathryn S. 
Published: February 2007

AbstractSediments spanning the Olduvai subchron (1.79–1.95 Ma) of ODP Hole 709C in the tropical Indian Ocean were sampled at 5‐cm intervals. High‐resolution quantitative radiolarian and CaCO3% data have been used as proxies in interpreting palaeoceanographical conditions, an a comparison made with previously obtained oxygen isotope data. Radiolarian data were subjected to principal components analysis, resulting in four varimax factors. Factor 1 accounted for the greatest variation and comprised well‐know warm‐water and cold‐water taxa, with high +ve and ‐ ve scores respectively, which were used in the construction of a temperature index. Results indicate a tripartite temporal division of Olduvai palaeoceanography. In the early Olduvai, prior to 1.895 Ma, and the late Olduvai, approximating the Plio‐Pleistocene boundary at 1.81 Ma, divergence‐driven equatorial upwelling and high‐productivity coincide with isotope‐defined ‘interglacials’, and with generally low CaCO3%. However, during the mid‐Olduvai, upwelling, productivity and sedimentation rates were all reduced. These changes in palaeoceanography are thought to be linked directly to eccentricity modulated variations in the precession of the Earth's orbit. The early and late Olduvai coincide with periods of minimum eccentricity, when precessional reinforcemnet of the southwest monsoon is weakest, coastal upwelling along the Oman margin is reduced, and zonal wind‐driven equatorial divergence upwelling is increased. The mid‐Olduvai, however, corresponds with an eccentricity maximum, during which monsoonal activity is stronger and equatorial divergence upwelling weak.
Sedimentation and Iithostratigraphy of the North Sea Drift and Lowestoft Till Formations in the Coastal cliffs of northeast Norfolk, England
Authors: Lunkka Juha Pekka 
Published: February 2007

AbstractThe most complete terrestrial sequence of Anglian (Elsterian) glacial sediments in western Europe was investigated in northeast Norfolk, England in order to reconstruct the evolution of the contemporary palaeoenvironments. Lithostratigraphically the glacial sediments in the northeast Norfolk coastal cliffs can be divided into the Northn Sea Drift and Lowestoft Till Formations. Three of the diamicton members of the North Sea Drift Formation (Happisburgh, Walcott and Cromer Diamictons) were deposited as lodgement and/or subglacial deformation till by grounded ice, but one, the Mundesley Diamicton, is waterlain and was deposited in an extensive glacial lake. Sands and fine sediments interbedded between the diamictons represent deltaic sands and glaciolacustrine sediments derived not solely from the melting ice in the north but also from extra‐marginal rivers in the south. The Lowestoft Till Formation is not well preserved in the cliffs but includes lodgement till (Marly Drift till) and, most probably, associated meltwater deposits. Extensive glaciotectonism in the northern part of the area is shown to relate to oscillating ice that deposited the Cromer Diamicton and also partially to the ice sheet that deposited the Marly Drift till. It is suggested that during the Anglian Stage the present day northeast Norfolk coast was situated on the northwestern margin of an extensive glaciolacustrine basin. This basin was dammed by the Scandinavian ice sheet in the north and northeast. Because the grounding line of this ice sheet oscillated in space and time, part of the North Sea Drift diamictons were deposited directly by this ice. However, during ice retreat phases glaciolacustrine deposition comprised waterlain diamicton, sands and fines. When the Scandinavian ice sheet was situated in northernmost Norfolk, the British ice sheet (responsible for depositing the Marly Drift facies) entered the area from the west. This ice sheet partially deformed the North Sea Drift Formation sediments in the northern part of the area but not in the south, where the British ice sheet apparently terminated in water. The interplay of these two ice sheets on the northern and western margins of the glacial lake is thought to be the major determining factor for the accumulation of thick glacial deposits in this area during the Anglian glaciation.
Glacial dynamics and transport of debris during the final phases of the Weichselian Glaciation, southwest Skåne, Sweden
Authors: Persson Kärstin Malmberg , Lagerlund Erik 
Published: February 2007

AbstractLate Weichselian glacial sediments were studied in three sections west of Lund, southwest Sweden. The lowermost sedimentary unit is a lodgement till containing rock fragments derived from the northeast‐east. Fabric analyses indicate successive ice flow directions: from the northeast, east‐northeast, south‐southeast and then east. The last active ice movement in the area was from the east. Above the lodgement till are deglaciation sediments consisting of meltout till, flow till and glaciofluvial sand and gravel deposited in a subaerial stagnant‐ice environment. The uppermost unit consists of glaciolacustrine clay and silt, containing abundant ice‐rafted debris, deposited during a short‐lived transgression phase when stagnant ice was still present in the area. At the westernmost site investigated, the petrographical composition of the deglaciation deposits displays a gradual change, with upwards increasing components of Cretaceous chalky limestone. The presence of this rock type requires a period of glacial transport from the south. This stratigraphy cannot be explained with traditional glaciodynamic models. A possible scenario can, however, be constructed using a previously published model (Lagerlund, 1987) where marginal ice domes in the southwestern Baltic area interact with the main Scandinavian Ice Sheet.
Amino acid diagenesis in the marine bivalve Arctica islandica Linné from northwest European sites: Only time and temperature?
Authors: Sejrup Hans Petter , Haugen John‐Erik 
Published: February 2007

AbstractCollections of the molluscan species Arctica islandica from seven sites in Norway, Scotland and the North Sea, ranging in age from recent to Early Pleistocene, have been sampled for amino acid analyses. The shells were sampled in profiles through the valves at different distances from the umbo. In the fossil material a general trend of increasing degree of isoleucine (lle) epimerisation and decreasing amino acid concentrations were found going from the inner part of the valve to the outer. Although less pronounced, there is a similar trend from the central part of the valve to the margin. As the concentration of alloisoleucine (alle) remains nearly constant, the observed changes in alle/lle ratios are a result of variations in the amount of isoleucine. The amino acid composition is fairly uniform in recent shells and the observed gradients are established in mid‐Holocene samples. Therefore, it is suggested that the gradients are established during rapid early degradation of the protein, possibly due to microbiological activity. Differences in alle/lle ratios observed in molluscs from sites of the same age and same thermal history could be explained by differences in the exposure to amino‐acid‐consuming microorganisms during the very early stage of diagenesis.
Palaeontology and taphonomy of Late Quaternary fossil assemblages at Somersham, Cambridgeshire, England, and the problem of reworking
Authors: West Richard G. , Knudsen Karen L. , Penney David N. , Preece Richard. C. , Robinson J. Eric 
Published: February 2007

AbstractAssemblages of foraminifers, ostracods and molluscs from temperate Ipswichian Stage (last temperate stage) sediments and overlying cold Devensian Stage (last cold stage) sediments at Somersham in the southern Fenland of Cambridgeshire have been analysed. The Ipswichian sediments contain faunas consistent with temperate brackish water conditions under tidal influence. The Devensian assemblages were recovered from a series of sands and gravels laterally accreting in a channel cutting into Ipswichian sediments. In contrast to the Ipswichian faunas, the faunas of particular Devensian samples show a complex mixture of temperate freshwater, brackish and marine taxa. The molluscs are mainly freshwater, with few land snails; they occur together with foraminifers and ostracods. Freshwater, brackish water and marine ostracods are present with foraminifers. A sample of Devensian fine laminated sediment in the channel was analysed for pollen; only abundant pre‐Quaternary spores were present, with abundant foraminifers in the same sample. The taphonomy of the assemblages and the difficulties of their interpretation in environmental terms are discussed. The importance of taphonomy in assessing environments, climate, range of taxa and dating is stressed.
Late Quaternary environmental change and human impact around Lake Bolac, western Victoria, Australia
Authors: Crowley Gabriel M. , Kershaw A. Peter 
Published: February 2007

AbstractThe late Quaternary history of the Lake Bolac region is reconstructed from sedimentary and pollen analysis of lake and swamp sequences and is supported by archaeological remains from lunette sediments. Freshwater deposits recovered from lake Turangmoroke appear to date from the last glacial period, when the vegetation was composed of herbfield and grassland. Subsequent dry conditions at the end of the Pleistocene caused the deflation of some accumulated sediments. On refilling, the lake had become saline. As moisture availability increased, casuarina woodland, dominated by Allocasuarina verticillata, became the regional vegetation cover. Domination by casuarina ended ca. 8000–7000 yr BP, probably as a result of rising saline ground‐water tables. Casuarinas were replaced to some degree by eucalypts, augmented by the development of a riverine Eucalyptus camaldulensis woodland. Swamp deposition commenced in the channel of neighbouring Fiery Creek at ca. 4000 yr BP, most likely as the result of a reduction in stream flow with decreased precipitation. Despite suggestions of significant impact on the vegetation by Aboriginal people from other sites in southeastern Australia, there is no evidence of any alteration here from periods of occupation dated to around 13000 yr BP and after 3500 yr BP. The period of European occupation, though, is marked by significant changes in fire patterns, reduced tree cover, loss of floristic diversity, increased erosion rates and salinity levels, and decreased water levels.
Drumlin formation in Southern Anglesey and Arvon, Northwest Wales
Authors: Hart Jane K. 
Published: February 2007

AbstractThis is a study of Late Devensian drumlins formed in southern Anglesey and Arvon, northwest Wales. This area was affected by ice sheet coalescence when the Welsh ice sheet met with the lrish Sea ice sheet, and drumlins were formed once the two had coalesced. It is suggested that the drumlins were the result of net subglacial soft‐bed erosion, and that they represent more resistant cores within the subglacial deforming layer. The drumlins have either gravel or till cores, and where the core was deformable, large‐scale compressive glaciotectonic structures were seen (e.g. Dinas Dinlle) with local subglacial compression of –59%. Where the cores were more resistant (e.g. Lleiniog) these were not deformed but remained as more competent masses within the deforming layer. It is suggested that the less competent material flowed around the cores, some remaining as a thin carapace, but most of the material being removed down glacier, leaving the drumlins as erosional remnants.In northwest Wales there is a multi‐till sequence that traditionally has been interpreted as having been deposited as the result of separate ice‐sheet advances and retreats. However, in this study, it is suggested that the different tills were deposited as the result of ice‐sheet coalescence, and that sites such as Dinas Dinlle do not show evidence of a major readvance in the retreat of the Devensian ice, but are indicative of continuously changing conditions within the subglacial deforming bed.
Holocene landscape change at Carn Dubh, near Pitlochry, Perthshire, Scotland
Authors: Tipping Richard 
Published: February 2007

AbstractDetailed palynological analyses, including pollen preservation and charcoal counts, and sedimentological analyses (loss‐on‐ignition, percentage dry weight, dry bulk density and humification), supported by 15 14C dates, were applied to a small upland (350 m OD) peat basin near Pitlochry, east‐central Grampians, Scotland. Stratigraphical analyses and radiocarbon dating were also undertaken on the valley peat surrounding the basin.Organic sediment began to accumulate in the basin and on the valley floor at ca. 9800 yr BP. ‘Recurrence surfaces’ within the valley floor peat correlate with the end of a trend to increased aridity in the deep basin, from 8900 to 8500 yr BP. Pine may have colonised the hills, with birch, before the migration of hazel at 9150 yr BP. From around 8000 yr BP elm grew on the base‐rich soils. Alder may have been present by 7000 yr BP but it did not expand until immediately after the first major anthropogenic disturbance, at 4800 yr BP.Above 8000 yr BP silt was commonly deposited in the basin by streams, but several phases of exceptionally intense inwashing are identified, and at least two of these correlate with periods of increased precipitation.Grazing pressure during the elm decline marks the beginning of a long history of generally low intensity pastoralism, interspersed with periods of heightened anthropogenic activity.
Marine evidence for climatic instability during the last interglacial in shelf records from northwest Europe
Authors: Seidenkrantz Marit‐Solveig , Kristensen Peter , Knudsen Karen Luise 
Published: February 2007

AbstractData from the Greenland ice sheet and continental records from Europe have indicated climatic fluctuations during the last interglacial (Eemian: Oxygen Isotope Substage 5e). Similar fluctuations have not, however, been documented previously from marine environments. Here, we show the existence of two cold events during substage 5e in two marine, benthic foraminiferal, shelf records from northwest Europe and suggest that these cooling events are a result of fluctuations in the strength of the North Atlantic surface‐water circulation.
Pollen analyses off Senegal: Evolution of the coastal palaeoenvironment during the last deglaciation
Authors: Lezine Anne‐Marie , Turon Jean‐Louis , Buchet Guillaume 
Published: February 2007

AbstractPollen and dinoflagellate cysts from marine sediments in core A180‐48 (15°19′N, 18°06′W; 2450 m water depth; 530 cm length) are used to reconstruct palaeoenvironmental conditions of nearshore tropical west Africa during the last deglaciation. High concentrations and influxes of pollen and dinoflagellate cysts between 11 000 and 10 000 yr BP are interpreted as reflecting an increase in continental trade‐wind circulation and related coastal upwelling at 15°N latitude. The sea‐surface temperature difference between glacial and interglacial times was not as strong as previously suggested. Together with local (fresh) ground‐water input, this smaller temperature difference may explain the persistence of the Rhizophora mangrove and Guinean gallery forests near the shore until their massive extension during the early Holocene humid maximum around 9500 yr BP. Pollen data from the core are compared with data from Rosilda N110‐Z, from the continental shelf at the same latitude.