bluuebunny/crossref_metadata_2025 huggingface dataset:
Flandrian pollen deposition rates and tree‐line history in northern Fennoscandia
Authors: HYVÄRINEN HANNU
Published: July 2010

Previous absolute polien diagrams from northern Fennoscandia yielded evidence for a retreat of the pine limit from an earlier extended position to a position near the modern one between about 5000 and 3000 B.P. New absolute pollen data from the sediment core of Domsvatnet, a small tundra lake near the eastern coast of Varanger Peninsula, are used to demonstrate a parallel retreat in the birch limit. Areas outside the modern birch limit were colonized by early Flandrian pioneer birch woods between 9500 and 9000 B.P. and remained as birch woodland through middle Flandrian times until a retreat started around 5000 B.P. leading to the present tundra situation.

The Domsvatnet core shows anomalous high pollen deposition rates combined with relatively rapid matrix sedimentation, suggesting that pollen from outside the basin has been washed in with allochthonous material and concentrated in the sediment.
Radiocarbon‐dated mammoth (Mammuthus primigenius Blumenbach) finds in South Sweden
Authors: BERGLUND BJÖRN E. , HAKANSSON SÖREN , LAGERLUND ERIK
Published: July 2010

In connection with the description of a recent find (from Örsjö) of a mammoth tusk in Scania, Sweden, the stratigraphical conditions for two older Scanian (Arrie, Lockarp) finds are discussed. All these have been found in glaciofluvial deposits formed during different phases of the main Weichselian glaciation. These three Scanian finds together with one find from Bohuslän (Dösebacka) have been radiocarbon‐dated. A revised extraction method is described in detail. The radiocarbon ages obtained range between 36,000 and 13,300 B.P. Other finite mammoth dates from Europe and Siberia are compiled for comparison. The distribution of the finds in North Europe in relation to the chronology of the Weichselian Stage is discussed. Comments are made on the extinction of the mammoth.
The Pleistocene/Holocene boundary: a proposed boundary‐stratotype in Gothenburg, Sweden
Authors: MÖRNER NILS‐AXEL
Published: July 2010

The boundary between the last two geological epochs, the Pleistocene and the Holocene, is placed at ‘the date 10,000 B.P., measured in radiocarbon years’. In the European chronostratigraphy, this corresponds to the Younger Dryas/Preboreal boundary, the pollen zone III/IV boundary and the Late Glacial/Postglacial boundary. The stratal sequence in the Botanical Garden of Gothenburg is proposed as a suitable boundary‐stratotype of the Pleistocene/Holocene that fulfils the stratigraphical rules of marine environment and accessibility. A core, labelled B 873, has been analyzed for multiple parameters by various authors. The suggested Pleistocene/Holocene boundary in Core B 873 is indicated by a lithologic boundary, a palynological change tentatively correlated with the pollen zone III/IV boundary, and a distinct palaeomagnetic intensity maximum, the ‘Gålön Magnetic Intensity Maximum’, identified in numerous other cores at the Younger Dryas/Preboreal boundary and at the drainage of the Baltic Ice Lake in varved clay sequences (with the peak dated at the drainage ±4 varves). This boundary is closely radiocarbon dated at 10,000 B.P. (10,000–9950 B.P.) in terrestrial‐lacustrine sequences within the proposed type area in Gothenburg and in Southern Sweden, the established type region for the Pleistocene/Holocene boundary. The corresponding varve date is 9965 varves B.P. (De Geer's varve –1073). The various parameters directly and indirectly connected with the study of Core B 873 make global correlations possible. Because every region has its own local characteristics, however, it will be necessary to establish regional type sections, hypostratotypes.
Palaeoecological significance ofHippophaë rhamnoides, with an example of the protocratic vegetational stage in NE Fennoscandia
Authors: REYNAUD CHRISTIAN
Published: July 2010

A pollen diagram from Säynäjälampi, a small lake in Kuusamo, NE Finland, provides the basis for a description of the protocratic vegetation following the deglaciation of the area. Special attention is paid to the occurrence ofHippophaë rhamnoides.Fossil pollen of this species, which, though decidedly heliophilous in character, shows a broad ecological range in its present‐day habitats, may serve to indicate an open pioneer vegetation. A comparison of pollen diagrams published for Finland in whichHippophaë rhamnoideshas been identified reveals evidence of metachronism in the pioneer vegetation, related to the history of the deglaciation, shore‐line displacement, and forestal advance.
Holocene glacial variations in Sarek National Park, northern Sweden
Authors: KARLÉN WIBJÖRN , DENTON GEORGE H.
Published: July 2010

Detailed mapping of well‐preserved moraine systems fronting 17 small alpine glaciers in Sarek National Park in Swedish Lapland reveals two Holocene intervals of prolonged glacier expansion, each involving a complex of minor fluctuations. The younger interval, which corresponds to the Little Ice Age, experienced advances that culminated about A.D. 1916–1920, 1880–1890, 1850–1860, 1800–1810, 1780, 1700–1720, 1680, 1650, and 1590–1620. The older expansion interval, which probably centered around 2500 14C yr B.P., experienced several minor fluctuations spread through about 600 years.

Lichen data collected on moraine systems in Sarek are internally consistent from glacier to glacier. Lichen measurements on surfaces of known age in Sarek and nearby Kebnekaise match closely, allowing moraine correlations between these areas. Several older expansion intervals are recorded in the Kebnekaise Mountains. Taken together, the two sequences suggest that a series of prolonged expansion intervals, each similar to the Little Ice Age, has characterized the Holocene in Lapland. Fluctuations of the Scandinavian Ice Sheet in Sweden suggest that this series of Little‐Ice‐Age events extends back into the late Weichsel in the form of the Younger Dryas and Oldest Dryas stadials.
Lodgement till and flow till: a discussion
Authors: KRUGER JOHANNES , MARCUSSEN IB
Published: July 2010

A comment by J. Kriiger on I. Marcussen's paper ‘Distinguishing between lodgement till and flow till in Weichselian deposits’(Boreas 4, pp. 113–123) is followed by a reply from I. Marcussen.
The stratigraphy of the Quaternary Clyde Foreland Formation, Baffin Island, illustrated by the distribution of benthic foraminifera
Authors: FEYLING‐HANSSEN ROLF W.
Published: July 2010

The Clyde Foreland Formation is defined as comprising unconsolidated or only slightly consolidated deposits, varying in grain size from very coarse boulder gravel to clay, situated between the outermost part of Clyde Inlet and the coastal mountains west‐northwest of Kogalu River on the northeast coast of Baffin Island, Arctic Canada. They outcrop in an up to 40 m high almost straight‐lined coastal cliff facing Baffin Bay and are composed of mainly marine deposits interbedded with glacigenic layers.

Investigation of assemblages of fossil foraminifera revealed three main stratigraphical units of the marine deposits, viz., the hlandiella zone, being the youngest, the Cibicides rotundatus zone, and the Nonion tallahattensis zone, being the oldest.

The hlandiella zone is supposed to be upper Pleistocene of age, comprising a large Mid‐Wisconsinian (Mid‐Weichselian) interstadial, and an interglacial that can be correlated with the Sangamonian (Eemian) interglacial. The Cibicides rotundatus zone may comprise Illinoian interstadial deposits as well as deposits of Yarmouthian (Holsteinian) interglacial age. The Nonion tallahattensis zone represents an older (Aftonian?) mild interval.
Pollenanalytische und geochronologische Untersuchungen zur Piottino‐Schwankung (Jüngere Dryas)
Authors: KÜTTEL MEINRAD
Published: July 2010

New pollen‐analytical investigations and two14C series indicate that, at the Bedrina on Mount Piottino (Tessin, Switzerland), the post‐Allerød NAP phase (Piottino oscillation) represents the well‐marked Younger Dryas at least for the most part. The late‐glacial part of the profile is re‐classified, and the term Piottino oscillation is rejected, as it is largely identical with the Younger Dryas. Individual14C dates from the transition between the Younger Dryas and the Preboreal should be considered critically. Considerable fluctuations in the14C level are supposed for this period.
Classification and terminology of morainic landforms in Finland
Authors: AARIO RISTO
Published: July 2010

The terms assigned to Finnish morainic landforms were frequently originally established for areas where the glacial environment was different from that in Finland. The terms therefore are not always applicable to the conditions found here and there is a need for some revision. Some new proposals are presented in this paper. The term cover moraine could be adopted to refer to a vencer of till, which has a rather flat surface, devoid of transverse or lineal elements. The term ground moraine would then only he applied when the relief is independent of the underlying bedrock topography. As regards the term hummocky moraine, it would he advantageous to subdivide it into at lcast hummocky disintegration moraine, thehummocky squeezed‐up moraine, and the hummocky active‐ice moraine. Today the term is of little value since it is commonly used to describe forms with varied origins.

Landforms tend to form groups of closely related genetic assenihlagcs or of complexes where the members are areally related, but often genetically different. It is more logical to handle them as an association of forms, rather than to split the group artificially into a number of separate units. A gradational series of assemblages from a fluting assemblage into a drumlin assemblage and further into a hummocky active‐ice assemblage characterizes the Koillisinaa reference area. A bimodal flow system prevailed during the formation of the landforins. Spiral flow predominates in the formation of flutings and linear drumlins, ahercas up and down movement predominates in the formation of the transverse ridges of Kogen moraine. Between these end members coinhinations of these flow patterns occur.
Glacitectonites in till stratigraphy
Authors: BANHAM PETER H.
Published: July 2010

By analogy with hard rock myloniles it is suggested that the base of a glacial, litho‐structural, stratigraphical unit should he taken at the lower limit of penetrative structures in (soft) bedrock. Reference is made to mylonites in the NW Basal Gneiss Complex of South Norway and to the Marly Drift of Norfolk, England.
Subaquatic flow tills: a new interpretation for the genesis of some laminated till deposits
Authors: EVENSON EDWARD B. , DREIMANIS ALEKSIS , NEWSOME JOHAIL W.
Published: July 2010

Detailed field mapping, till fabric, granulometric, and thin section investigations indicate that a 500 m long unit of laminated tills and interstratified glaciofluvial and glaciolacustrine sediments, belonging to the Catfish Creek Formation and exposed along the north shore of Lake Erie, Ontario, were deposited contemporaneously into a proglacial lake by coherent subaqueous mass flows of till (subaquatic flow tills) accompanied by glaciofluvial and glaciolacustrine contribution from supra‐ and/or subglacial and ice marginal sources.

Comparison with descriptions of other stratified tills suggest that several of them may have a similar origin.
Till studies and neotectonics in northwest Skiine, south Sweden
Authors: LAGERLUND ERIK
Published: July 2010

A mosaic distribution of Pre‐Quatcrnary rocks in Skåne constitutes good conditions for using gravel analysis in till‐stratigraphical work. Recently discovered neotcctonic movements and their effect on the composition, distribution, and correlation of tills are discussed. With examples from the Kullen arm, it is shown that compositional variability in a till bed, as cvidenl from gt‐avel analysis, can be deciphered and is of great stratigraphical value.
Glacier and climatic fluctuations inferred from tree‐growth variations over the last 250 years, central southern Norway
Authors: MATTHEWS JOHN A.
Published: July 2010

A Pinus sylvestris (Scots pine) tree‐growth series from near the tree‐line in upper Gud‐ brandsdalen, southern Norway (Slistad 1957) is analysed, and possible relationships to glacier and climatic fluctuations are explored. The series is smoothed by harmonic analysis, and calibrated using a variety of independently derived glaciological, geomorphological, and climatological data from Storbreen (Jotunheimen), the Storbreen gktschervorfeld, and Dombås meteorological station. The curves are then used to make inferences about the number, date, magnitude, and duration of glacier fluctuations and summer temperature fluctuations from 1700 A.D. to 1950 A.D. At least 10 major oscillations in the tree‐growth data, reflecting fluctuations in summer temperatures of amplitude 1.0°C to 3.0°C, are believed to be indicative of glacier fluctuations. Periods of reduced tree‐growth are a response to cool phases and indicate glacier advances after a lag of about 4 years. These short‐term oscillations are superimposed on a general trend of glacier retreat and a long‐term warming of 1.0°C indicated by a glacier equilibrium‐line displacement of 140 m to 145 m since 1750 A.D. Problems and prospects for development of dendroglaciological and dendro‐climatological techniques are discussed.
Subglacial plant remains from the Omnsbreen glacier area, south Norway
Authors: ELVEN REIDAR
Published: July 2010

Plant remains have been found on ground recently deglaciated from the Omnsbreen glacier. They consist of Salix herbacea, Salix spp., Silene acaulis, Polytrichum norvegicum, Kiaeria of. starkei, and some unidentified species. Their age has been determined by the radiocarbon method to approx. 550 years, indicating that the present Omnsbreen glacier emerged as late as the clima deterioration in the late Middle Ages. The past vegetation was similar to the present, but slightly more thermophilous, indicating a rapid clima deterioration in the fourteenth century.
Modern pollen spectra from lake sediments in Finland and Finnmark, north Norway
Authors: PRENTICE LAIN COLIN
Published: July 2010

Absolute (APF) and relative surface pollen spectra from 67 moderate‐sized lakes in Finland and Finnmark are presented as pollen diagrams and isopoll maps and analysed by multidimensional scaling. The results are applicable to problems of regional vegetational history through comparisons of pollen spectra and the use of R‐values. It is shown that relative spectra can discriminate the major vegetational regions. APFs give better resolution among northern forest regions and low APFs characterize tundra. Gradients of tree‐pollen percentages in south and central Finland are related quantitatively to the major forest gradients, which are azonal, mainly related to soils, and affected but not obscured by human influence. Forest clearance is reflected in frequencies of various non‐tree pollen types. Non‐tree pollen and spores also provide vegetational and climatic information in the far north.
Plant colonisation patterns on a gletschervorfeld, southern Norway: a meso‐scale geographical approach to vegetation change and phytometric dating
Authors: MATTHEWS JOHN A.
Published: July 2010

A quantitative geographical approach is made to colonisation by vascular plant species on Storbreen gletschervorfeld, Jotunheimen, southern Norway. The approach adds a second dimension to the study of plant colonisation patterns on recently deglaciated terrain, allows inferences to be made about vegetation change and has implications for phytometric dating. An atlas of computer maps is presented based on the frequency of the most commonly occurring species over a dense pattern of sites. Nonmetric multidimensional scaling is used to compare the maps and to describe their similarities. Species diversity is mapped and described with the aid of trend surface analysis.

Colonisation is interpreted as proceeding by a series of environmentally‐conditioned waves of immigration by species. A ‘pioneer’ species group is replaced by ‘snowbed’ species at high altitudes and by ‘heath’ species at lower altitudes. A peak of diversity is reached after 25–35 years but diversity later declines and may then rise or fall to the climax. The marked spatial discontinuity in species occurrence at the gletschervorfeld boundary indicates that a dynamic equilibrium (the climax state) is still to be reached after 220 years of development. Few species can be regarded as universal indicators of surface age but many species are potentially useful for phytometric dating over a limited environmental range. Species that are characteristic of a particular phase of a succession are most useful for dating purposes.
The subdivision of the Quaternary of Norden: a discussion
Authors: MANGERUD JAN , BERGLUND BJÖRN E.
Published: July 2010

The proposal for Quaternary stratigraphy of Norden published 1974 by Mangerud, Andersen, Berglund & Donner was discussed at a Nordie meeting 1978. On the basis of this discussion some recommendations are proposed here which deviate slightly from the 1974 proposal: (1) the term Flandrian should not be used in Norden until it is properly defined in the type area, (2) the Middle/Late Weichselian boundary should provisionally be defined as 25,000 14C years B. P. In addition it was stated that there is an urgent need for complete subdivision of the Weichselian into a continuous chronozone sequence.
Radiocarbon ages of raised‐beach shells from Oronsay, Inner Hebrides, Scotland: a lesson in interpretation and deduction
Authors: JARDINE W. GRAHAM
Published: July 2010

Comparison of radiocarbon ages of raised‐beach shells from sites in the proximity of Mesolithic shell middens on Oronsay illustrates the importance of correct interpretation of the significance of the stratigraphical, ecological and archaeological contexts of dated shells. A difference of c. 3000 years between the determined ages of shell samples of Patella and Arctica from the same horizon in a raised beach and smaller but significant differences in the ages of shell samples of the same genera and other genera from four horizons within a raised storm beach may have been caused by combinations, in varying degree. of isotopic fractionation, isotopic replacement, depleted initial 14C activity and the hard‐water effect. Comparisons are made with published accounts of similar problems encountered in dated raised‐beach shells from west Greenland, Finnmark (north Norway) and south Wales.
The deglaciation of Scandinavia earlier than 10 000 B.P.: The 1978 Uppsala Symposium
Authors: KÖNIGSSON LARS‐KÖNIG , LUNDQVIST JAN
Published: July 2010

The 1978 Uppsala Symposium was organized as ageste d'honneurto the memory of Otto Torell and his Ice‐Age Theory, published a little more than a hundred years ago. The Symposium opened with a lecture on the development of the Ice‐Age Theory, then four regional surveys of our present knowledge of the deglaciation pattern and chronology yielded new and somewhat controversial ideas about the melting of the Scandinavian Continental Ice, and more than forty individual research reports showed the dynamic scientific situation in Quaternary Geology in Norden. The Symposium and this issue ofBoreasform part of the joint Nordic activity within the IGCP project entitled ‘Quaternary Glaciations in the Northern Hemisphere’.
The deglaciation of southern Sweden 13,500‐10,000 B.P.
Authors: BERGLUND BJÖRN E.
Published: July 2010

Because of its well‐developed ice‐marginal zones, SW Sweden is an important reference area for the study of deglaciation, chronology and palaeoclimate 13,500‐10,000 B.P. The ice‐marginal zones are described and defined. Earlier research and opinions concerning the deglaciation are summarized. Based on radiocarbon dates from shells, vertebrate bones and limnic sediments, a revised deglaciation chronology is presented. This chronology is supported by biostratigraphic transects of time‐space diagrams. The radiocarbon and varve chronologies are compared. Some ice‐marginal zones are supposed to be 400 to 900 years older than expected from the varve chronology. The deglaciation chronology is correlated within the southern margin of the Scandinavian inland ice. Various consequences for the interpretation of glacial dynamics, shoreline displacement, and the biological environment are mentioned.
The deglaciation between Skjerstadfjord and Svartisen, north Norway
Authors: ANDERSEN B. G. , BÖEN F. , RASMUSSEN A. , VALLEVIK P. N.
Published: July 2010

Six successive zones with distinctive marginal moraines are recognized. Based on radiocarbon dates the ages of the three oldest zones are believed to be: older than 11,100 years B.P. (Vasdal event), about 10,900 B.P. (Glomfjord‐Straumöy events), and between 10,400 and 9500 B.P. (Skjerstad event). The three youngest zones are Preboreal. Corresponding marine sediments, shorelines, glaciation limits and other glacial features are described.
The last deglaciation of Svalbard
Authors: SALVIGSEN OTTO
Published: July 2010

Svalbard has been completely covered by an extensive ice sheet at least once, but not in the Late Weichselian (max. 18,000–20,000 years ago). Areas in the western and northwestern parts of Svalbard have been ice‐free for more than 40,000 years. The extension and time of a Barents Shelf glaciation are questions still open for discussion. For most of the Svalbard area we do not know when the last deglaciation started, geographically and in time. The oldest datings for the interval 15,000 to 10,000 years B.P. have an age of about 12,600 years, and datings from between 11,000 and 10,000 years B.P. are rather frequent in the western and northern parts of Spitsbergen. No moraines from Younger Dryas have been found in Svalbard and the glaciers were probably less extensive 10,000 years ago than today. The maximum extension of glaciers in the Holocene took place only a few hundred years ago.
Deglaciation of western Central Norway
Authors: SOLLID JOHAN LUDVIG , SØRBEL LEIF
Published: July 2010

The glacier movements and corresponding ice margins in Central Norway during Younger Dryas and Preboreal are reconstructed. Scattered, older marginal deposits are difficult to correlate. Raised beach features indicate that the deep fjords became ice‐free at an early stage due to calving. In Møre og Romsdal county the glacier front lay at the fjord heads during Younger Dryas, with extensive local glaciation in the intervening mountain areas, and a limit of glaciation 500–600 m lower than the present. In certain places local moraines older than Younger Dryas have been preserved. Autochthonous block fields are widespread in the mountains of Møre og Romsdal. The lower limit of block fields lies at c. 500 m above sea level on the outermost coast and rises to c. 1500 m above sea level in the interior fjord country. No erratics, striation or lateral moraines from the inland ice have been found above this limit. Its gradient, which in outer fjord districts is about 1%, seems to indicate the ice surface at the last maximum of Weichsel glaciation.
Structures and textures in till indicating subglacial deposition
Authors: KRÜGER JOHANNES
Published: July 2010

Five structural and textural features are discussed: (1) small lenses of sorted material, (2) smudges, (3) small‐scale deformations of till matrix and smudges by clasts, (4) clasts consistently striated, and (5) clasts with stoss‐and‐lee sides. Analyses suggest that these features may be produced by subglacial processes acting in the ice‐bed interface. Long axes of small sand lenses and smudges as well as the striation on the upper surface of scattered clasts in lodgement till have a strong preferred orientation in good agreement with the glacier flow direction as indicated by clast fabrics, bedrock striation, and surface fluting of ground moraine. When in traction against the till bed, clasts may plough up till banks. Clasts with stoss‐and‐lee sides development were also very distinctly oriented as their stoss sides faced significantly up‐glacier.

It is concluded (1) that each of the five features discussed is useful as a criterion for subglacial deposition by lodgement, (2) that they indicate important differential movement along the ice‐bed interface and therefore suggest a temperate regime in this part of the glacier during the till deposition, (3) that very few orientation measurements of one or more of these features signify the ice movement direction; i.e. a time‐saving method to find the paleoflow direction of Pleistocene glaciers, and (4) that taken together with till preconsolidation, mechanical composition, and clast fabric, they may support each other and give good indications of the genesis of Pleistocene tills.
A model of Weichselian glacier variation in the North Atlantic region
Authors: BOULTON GEOFFREY S.
Published: July 2010

The evidence for the extent and timing of Weichselian glaciation in Arctic regions shows that: (1) there were no major marine ice domes in the Arctic at 18,000 B.P. but that glaciers were relatively limited in extent; (2) there were no extensive ice shelves at 18,000 B.P. as envisaged by Hughes, Denton & Grosswald(1977); (3) the major periods of glacier expansion were between 125,000 and 80,000 B.P., just prior to 45,000 B.P., and between 11,000 and 8,000 B.P., and thus that glacier fluctuations at the southern margins of the Laurentide and Fennoscandian ice sheets were out of phase with those in the Arctic which advanced during southern interstadials.

Phases of glacier advance in the Atlantic sector of the Arctic can be identified in deep sea cores by the peaks in concentration of iceberg‐dropped detritus and an increase in sedimentation rates, which are highest when sub‐polar water penetrates to the north. The key to the temporal pattern of Arctic glaciation and its association with oceanic changes is given by the intimate association of present‐day Arctic glacierisation with the two major low pressure troughs which penetrate the Arctic in the Atlantic sector and in Baffin Bay. The chronology of glaciation in the Atlantic sector is associated with the activity of these troughs and the related oceanic circulation. Cooling of the Arctic due to reduction in solar radiation at the end of the last interglacial, when the pack ice lay north of 75d̀N in the Atlantic, produced ideal conditions for Arctic glacier growth, with moisture transported by a strong cyclonic flux into a cooling Arctic from a strong North Atlantic Drift current.

A positive feedback loop involving ocean and atmospheric circulation and pack ice, caused movement of the polar front to the south, thus slowly cutting off the supply of moisture to the Arctic. Further cooling at 75,000 B.P. caused a rapid extension of the polar front south of 45d̀N, effectively cut off the northward movement of surface currents on the North Atlantic, and produced a strong zonal oceanic and atmospheric circulation which starved Arctic glaciers of nourishment and caused their retreat, and initiated rapid build up of the Fennoscandian and Laurentide ice sheets. Subsequent extensions of Arctic glaciers were associated with limited northward movement of sub‐polar water and associated Atlantic depressions. The expansion of glaciers within the Arctic between 11,000 and 8,000 B.P. was associated with the first and diachronous penetration of moisture into a still cool Arctic during decay of the two great ice sheets.
The deglaciation of Scandinavia later than 10,000 B.P.: The 1979 Uppsala Symposium
Authors: LUNDQVIST JAN , KÖNIGSSON LARS‐KÖNIG
Published: July 2010

The 1979 Uppsala Symposium was arranged as a continuation of the symposium held in Uppsala in 1978 on the deglaciation of Scandinavia earlier than 10,000 B.P. Papers from the latter symposium were published in Boreas, Vol. 8, No. 2 (1979). In the present issue, eleven contributions from the 1979 Symposium are included, among them three general summaries for Norway, Finland, and Sweden. The Symposium and this issue of Boreas form part of the joint Nordic activity within the IGCP project entitled ‘Quaternary Glaciations in the Northern Hemisphere’
Problems of moraine morphology: Rogen moraine and Blattnick moraine
Authors: MARKGREN MARTIN , LASSILA MAUNO
Published: July 2010

In Västerbotten County, Sweden, both Rogen moraine and Blattnick moraine are common in the inner part of the county. Rogen moraines are found primarily in basins and upslope positions, whereas the Blattnick type (first found in the Blattnicksele area in the county) mostly occurs in broader, more plain‐like areas. Moreover, both types show a great variety of individual forms, due to topography, basal conditions and ice tectonics. Most Rogen moraine ridges are characterized by features due to active ice. The Blattnick moraine type is characterized by broader and more drumlinized ridges. They are often proximally higher and laterally‐distally extended, thus merging into streamlined mounds or hills. The material composition of Rogen and Blattnick moraines is similar. The authors have found the following sequence of transitional forms from the Scandinavian mountains in the west towards the east: (1) Rogen moraines, (2) crescent ridges, (3) Blattnick moraines, (4) drumlins.
The ice lobes of the Scandinavian ice sheet during the deglaciation in Finland.
Authors: PUNKARI MIKKO
Published: July 2010

On the basis of glacial landforms interpreted by means of Landsat satellite imagery and ice‐flow data obtained by other methods, the Scandinavian ice sheet has been observed to have divided at the deglaciation stage into several ice lobes. The ice lobes were more active parts of the uniform ice sheet. They represent parts that had bordered on each other in different directions or on more passive portions of the ice. The reasons for the appearance of separate ice lobes were evidently the Fennoscandian topography, the location of accumulation areas, and regional differences in the amounts of ice generated. In the boundary zones of the different ice lobes, there occur exceptionally large glaciofluvial forms and moraines (interlobate complexes). An area of passive ice was often between ice lobes, and in such areas there occur no noteworthy eskers, marginal formations or streamlined forms. In the part of Finland located on the southern side of the Arctic Circle, six different ice lobes and four major areas of passive ice are interpreted to have existed.
Dating of palaeomagnetic records from Finnish lake sediment cores using pollen analysis
Authors: Huttunen Pertti , Stober Julie
Published: July 2010

Palaeomagnetic and palynological studies have been made of the sediments of two Finnish lakes. Geomagnetic field changes in Finland can be traced since lake sediments record the ambient geomagnetic field at, or close to, the time they are deposited. Pollen analyses provided a useful method of dating these changes since 14C dates proved to be misleading.
An inter‐till organic sediment of Early or Middle Weichselian age from Setesdal, southwestern Norway
Authors: BLYSTAD PER
Published: July 2010

An inter‐till organic sediment, probably a paleosol, was found in a ridge in the Setesdal Valley. A radiocarbon date on the fraction soluble in NaOH gave a finite age of 35,850 B.P., which is probably a minimum age as contamination of younger carbon might have occurred. Pollen analysis indicates that the sediment has originated above the tree‐limit. Compared with different interglacial and interstadial deposits in Scandinavia, the sediment is interpreted as representing an interstadial period, tentatively named the Vatnedal interstadial, of Early or Middle Weichselian age.
The Weichselian glaciation in Svalbard before 15,000 B.P.*
Authors: SALVIGSEN OTTO , NYDAL REIDAR
Published: July 2010

Th/U dating and radiocarbon dating of ‘old’ shells are discussed, and amino acid ratios from shells are used as a method of relative‐age dating. The Svalbard area has been completely covered by an extensive ice sheet at leats once. New data from Sjuøyane indicate that such glaciation took place in the Early Weichselian. The Middle Weichselian was a period of interstadial conditions. Series of beaches of assumed Middle Weichselian age occur in several places in western Spitsbergen while no such beaches are known in the eastern part of the archipelago. The maximum glaciation in the Late Weichselian is assumed to have taken place about 18,000 B.P. In the western part of Spitsbergen, the Late Weichselian glaciation was limited and local, while the eastern part of the archipelago was covered by an ice sheet. Kongsøya has a pattern of Holocene shoreline displacement which indicates that the centre of this ice sheet was east of kong karts Land.
A Middle Weichselain ice‐free period in Western Norway: the Ålesund Interstadial
Authors: MANGERUD JAN , GULLIKSEN STEINAR , LARSEN EILIV , LONGVA ODDVAR , MILLER GIFFORD H. , SEJRUP HANS‐PETTER , SØNSTEGAARD EIVIND
Published: July 2010

Seven localities with fossil‐bearing tills were found in the Ålesund area. Fifteen radiocarbon dates of marine shells in the tills all gave ages between 28,000 and 38,000 years B.P. In spite of a general scepticism to shell dates giving high finite ages, these ages may be accepted mainly because of the quality of the shells, the geological situation in which they were found, and identical results for different fractions. The ice‐free period is named the Ålesund Interstadial. and its Middle Weichselian age is also suggested by amino acid D/L ratios in shells, compared with Late Weichselian and Eemian ratios. Shell and foraminifera faunas suggest arctic conditions with the Atlantic water present during the optimal period. The tills are non‐sorted, compacted and interpreted to be basal tills. Their age is bracketed between c. 28,000 and 12,800 years B.P.
Weichselian sediments containing redeposited interstadialhnterglacial fossils at Slettaelva, North Norway
Authors: VORREN TORE O. , CORNER GEOFFREY D. , NAGY JENÖ
Published: July 2010

The following stratigraphy was found at Slettaelva, near Tromso̊ (from bottom to top): greenish basal till (unit A), laminated c lay (unit B), fossitiferous basal till (Unit C). Unit A probably derives from an early Weichselin local glaciation, Unit B comprises lacustrine sediments which were apparently deposited in an early Weichselian tundra‐like enivironment, Unit C, which contains reworked fossils of moulluscs, palynomorphs and foraminifera, was deposited by a continenntal ice shcet. Amino acid ratios of Mya truncata and plaaeontological evidence indicate that unit Ccontains a mixed fossil assemblage, probably of Eemian and Weichselian interstadial age.
Sedimentology of glacial and glacial marine deposits on the George V‐Adelie continental shelf, East Antarctica
Authors: DOMACK EUGENE W.
Published: July 2010

Mineralogic and textural data suggest that glacial ice derived from the region of the present day Cook Ice Shelf extended to the edge of the d'Urville Sea continental shelf. As part of this glacial maximum, basal tills and glacial marine sediments were deposited over an irregular subglacial surface. Extensive redeposition of eroded material took place in the middle and outer portions of the continental shelf. Retreat of glacial ice was relatively rapid and was associated with widespread deposition of a thin residual glacial marine unit and turbidity current deposits in the far western and eastern parts of the region. Today, sedimentation on the continental shelf of the d'Urville Sea is controlled by biogenic and physical oceanographic processes. Deposition of ice‐rafted detritus from icebergs undoubtedly occurs but is relatively insignificant. Glacial advances along this periphery of East Antarctica appear to the regulated by adjacent outlet glaciers rather than direct advance of the grounded ice sheet.
Norwegian corals: radiocarbon and stable isotopes in Lophelia pertusa
Authors: MIKKELSEN NAJA , ERLENKEUSER HELMUT , KILLINGLEY JOHN S. , BERGER WOLFGANG H.
Published: July 2010

The ahermatypic coral Lophelia pertusa which produces aragonitic skeletons is widely distributed along the Norwegian coast. Specimens from a number of localities have been analyzed for oxygen and stable carbon isotope composition and 14C age. Stable isotope ratios of recent corals provide information on growth rate and seasonality of oceanographic conditions. Lophelia can be useful in paleoenvironmental reconstructions. 14C dates of fossil Lophelia from Drøak in the Oslofjord, collected from 20 m ahove and 40 m below present day sea‐level, indicate regional extinction between 8700 and 7800 years ago. We suggest that the extinction resulted from the cut‐off of deep waters by a rising sill in connection with the postglacial shoreline displacement. Radiocarbon dating of coral bushes suggests a fairly rapid growth rate as older and younger parts of recent corals do not reveal any difference in activity despite the short time scale of the history of bomb‐produced 14C in the oceans.
Late Weichselian and early Flandrian vegetational history of Varanger peninsula, northeast Norway
Authors: PRENTICE HONOR C.
Published: July 2010

Relative a absolute (pollen concentration) diagrams are presented from Bergebyvatnet, Holmfjellvatnet and Stjernevatnet on Varanger peninsula. All three sites are outside the younger Dryas (Main substage) moraines and the pollen assemblage zones are correlated biostratigraphically with chronozones from Allerød to Middle Flandrian. Radiocarbon dates from Bergebyvatnet appear to have been affected by hard water error, but dates from the other two sites agree will with the inferred chronostratigraphy. Pollen diagrams from Varanger peninsula suggest broadly similar vegetational histories, the longest record beign that from Østcrvatnet (H. C. Prentice 1981, Boreas, Vol. 10, pp. 53–70). Open tundra‐like conditions prevailed throughout the Late Weichselian, with Salix dominance interrupted by unstable vegetation with abundant Artemisia during the Older and Younger Dryas zones. Major vegetational and floristic changes began just before 10,000 B.P., the rapid scquence from herb pollen flora was rich and varied, including a mixture of floristic clements similar to that found during the Late Weichselian in southern Scandinavia. Basiphilous herbs were particularly abundant at Østervatnet and Bergebyvtnet. Betula nand and species of Ericales became locallydominant just before the full establishment of B. pubescens, which rapidly spread beyond its present limit. Later immigrants included Alnus incana; Juniperus communis; and Pinus sylvestris, which reached the south western part.
Within‐valley asymmetry and related problems of Neoglacial lateral moraine development at certain Jotunheimen glaciers, southern Norway
Authors: MATTHEWS JOHN A. , PETCH JAMES R.
Published: July 2010

A difference in the size of Neoglacial lateral moraines on either side of a valley axis (within‐valley asymmetry of lateral moraine development) is described. Analysis of clast roundness has revealed subangular material in latero‐terminal and terminal moraines; lateral moraines, however, exhibit a compositional gradient of increasing angularity with distance from the former glacier snout. Comparisons with clasts of known origin suggest that this ‘roundness gradient’ may be explained with reference to either or both of two hypotheses: (1) a variable proportion of supraglacial (or englacial) to subglacial transported material; and (2) the variable composition of regolith incorporated by a push mechanism from the valley sides. Within‐valley asymmetry is inferred to result where the supply of debris to lateral moraines from these sources is unequal either side of a valley axis. Both interpretations are also consistent with the relatively large size of latero‐terminal sections of end moraines. In order to account for the discrepancy between moraine size and apparent debris supply rates, it is suggested that the largest lateral moraines may have been formed over a longer time scale than the ‘Little Ice Age’, and that reworking of deposits may have occurred. The supply of debris to the north‐facing lateral moraine at Nordre Illåbreen has been so great that it has developed into a rock glacier; this suggests the possibility that subglacial material and valley‐side regolith, as well as supraglacial material, contributes to the formation of ice‐cored rock glaciers.
Depositional processes of Pleistocene lowland end Moraines, and their possible relation to climatic conditions
Authors: RUSZCZYŃSKA‐SZENAJCH HANNA
Published: July 2010

Three kinds of end moraines, depending most probably on climatic conditions affecting depositional environments, are characterized: (1) fluvioglacial end moraines ‐ built of gravels and sands froming fans superimposed on one another, and accumulated by abundant melt water during intense melting of an ice front in a comparatively warm environment; (2) ‘Glacial’ end moraines ‐ built of flow tills accumulated during slow melting in a comparatively cold environment; and (3) fluvioglacial‐and‐glacial end moraines, the most widespread ones in Polish lowlands – built of fluvioglacial stratified gravels and sands and of glacial ‘flow’ deposits; zones of considerable prevalence of glacial deposits over fluvioglacial ones may probably point to comparatively cold stages during deposition, and vice versa. The question of deposition of end moraines in distal and proximal direction, and their geological and geomorphological features is also briefly discussed.
Raised coastal landforms as products of modern process variations, and their relevance in eustatic sea‐level studies: examples from eastern Ireland
Authors: CARTER RICHARD W. G.
Published: July 2010

Products of marine processes occupy a considerable vertical range, which varies along the shore. Extreme waves can both cause erosion and form depositional structures up to several metres above the high tide mark. Temporary supra‐elevation of water level by surge or wave set‐up shifts effects upward. The preservation potential of products of extreme storms is relatively high, when compared to those associated with more frequent events. The level to which coastal landforms develop depends upon the conditions under which they form; thus sand beach ridges which are related to fairweathcr periods have a restricted height range when compared to gravel beach ridges building up under extreme storms. The varied coastal scenery of eastern Ireland provides many examples of storm‐related products (barriers. cliffs, platforms, etc.). They have been related to a latc‐Holocene eustatic sea level or even a partly isostatically controlled raised late‐Holoccne sea level, but both elevations and apparent tilts can be explained by longshore variations in waves, tides and surges. Such an explanation is more consistent with other studies of latc‐Holocene coastal evolution around the Irish Sea basin.
Use of an aggregatedRhizocarpon‘species' in lichenometry: an evaluation
Authors: INNES JOHN L.
Published: July 2010

A regular relationship exists between the growth of lichen species within the SectionRhizocarponandRhizocarpon alpicola.This can be quantified and used to adjust lichenometric dates to take into account differences in the growth rates of the two groups.R. alpicolacolonises deposits later than SectionRhizocarponspecies, although subsequent growth byR. alpicolais rapid. If the two groups arc not separated, important dating errors may arise.
Pollen evidence of vegetational change following early European settlement of Monhegan Island, Maine, northeastern U.S.A.
Authors: TOLONEN MIRJAMI
Published: July 2010

Postsettlemcnt vegetation changes beginning in the early 17th century were studied through comparing stratigraphic peat‐pollen data with available historical evidence. The isolation of the site and the relatively long historical record were ideal for the study. Human disturbance of the vegetation was readily identified in the pollen diagram with a contemporaneous increase in sediment mineral matter. The effects were much the same as the changes associated with Neolithic forest clearance in Northern Europe. Settlement resulted in the introduction and expansion of several cultural weeds after grazing and cultivation of Zea mays began on the island in the first decades of the 17th century; Rumex acetosa‐acetosella, Ranunculus acris type, Plantago major‐media and several new Compositae and Umbelliferae species all appeared at that time. The response of the native species to settlement was varied. Because of the limitations of the palynologic method, the area of cultivated land and detailed kind of agriculture can only be estimated. The data suggest that although agriculture was intensive from time to time, it took place on a very limited local scale; fires, grazing, and lumbering were the major factors affecting natural ecosystems.
Fades of subglacial channel sedimentation in late‐Pleistocene drumlins, Northern Ireland
Authors: DARDIS GEORGE F. , McCABE A. MARSHALL
Published: July 2010

The sedimentology of three sand‐cored drumlins in central Ulster. Northern Ireland is described. The sand‐cores of the drumlins consist of complex sequences of cohesive sediment gravity forms, grain‐flow deposits, turbiditic sands and deltaic sands and gravels, showing complex fades relationships. The bulk of the sediments formed in water‐filled cavities associated with a major subglacial meltwater escape route excavated in bedrock. The sand‐cores are overlain by a streamlined carapace of basal melt‐out till. A model is presented to account for spatial variations in faeies arrangement within the sand‐cores. Three specific meltwater depositional subenvironments were recognised: (1) main channel axis, (2) main channel flank, and (3) minor tributary channel. The sand‐cores formed prior to the main phase of basal melt‐out till deposition and before drumlin streamlining.
Pollen diagrams from the Shumagin Islands and adjacent Alaska Peninsula, southwestern Alaska
Authors: HEUSSER CALVIN J.
Published: July 2010

Pollen diagrams of 10 peat sections taken in sedge tundra span as much as 10.730 radiocarbon years and show a varied sequence of pollen assemblages dominated by herbs and shrubs. Taxa, for the most part. belong to the Gramineae. Cyperaceae. Salix, Abuts, Beiula and Empelrum. The assemblages indicate scral changes in the vegetation, resulting from interaction of climate and of successive ashfalls from regional volcanoes, and suggest a patchwork of late Quaternary plant communities. This record from southernmost Beringia enlarges upon previous pollen records from the Aleutian Islands and from the southern part of the Bering land bridge region in western Alaska.
Remnants of an ancient forest on the continental shelf of northwest Japan
Authors: NASU NORIYUKI , FUJII SHOJI , FUJIOKA KANTARO , IGARASHI CHIAKI , KAWAHATA HOTAKA , MAPPA HARUNA , KONISHI KENJI , TANAKA TAKEO , SHIMODA TAKASHI
Published: July 2010

Tree stumps in a standing position have been discovered in 20 to 40 meters of water in Toyama Bay, Japan. Radiocarbon dated samples from two of these stumps yielded ages of 8.480±70 and 9.060±80 years B.P., indicating that the stumps are remnants of a forest that existed during thc early Holocene.
A method for determining total clast roundness in sediments
Authors: OLSEN LARS
Published: July 2010

This method for determining total roundness of clast fractions takes into account both the abrasion and the crushing processes. It is developed from a slightly modified visual estimation method and a newly defined parameter ‐ crushing processes. Based on visual estimation, the method is most useful as a tool for the Quternary field geologist.
Fluctuations glaciaires de la fin du Würm dans les Alpes françaises, établies par des analyses polliniques
Authors: COÛTEAUX MICHEL
Published: July 2010

Sediments from the peat‐bog La Muzelle (Massif des Ecrins, Iserc, France, alt. 2,150 m) were analyzed. The site was reached by a Pinus forest and an Abies forest during the Allerød and the Atlantic, and during the Bølling a shrubland was noted. Forests have been degrading into lawns without intermediary heath long before the appearance of the first signs of human action. The glacier has been receding ever since the Late Würm, except during the Younger Dryas when big frontal moraines were formed close to the peat‐bog. The nature of the sediments allowed a determination of several frontal positions of the glacier. No notable re‐advance could be evidenced during the Older or Oldest Dryas nor during the Holocene; only a minor oscillation may have occurred at the beginning of the Allerød.