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Little is known about the ecological implications of high-magnitude, low frequency jokulhlaup events in proglacial systems. This study highlights how kettle lakes produced by jokulhlaups in proglac...

Loess was first studied in Michigan on the Buckley Flats, where outwash, overlain by ≈70 cm of loamy sediment, was originally interpreted as loess mixed with underlying sands. This paper re-evaluates this landscape through a spatial analysis of data from auger samples and soil pits. To better estimate the loamy sediment’s initial textures, we utilized “filtered” laser diffraction data, which remove much of the coarser sand data. Textures of filtered silt data for the loamy sediment are similar to loess. The siltiest soils are found in the low-relief, central part of the Flats. Spatial analyses revealed that many silt fractions are nearly uniformly distributed, suggesting that the loess was not derived from a single source. The previous depositional model for the loamy mantle relied on loessfall followed by pedoturbation, but does not explain (1) the variation in sand contents across the Flats, or (2) the abrupt contact below the loamy mantle. This contact suggests that the outwash was frozen when the sediments above were deposited. Deep gullies at the western margins of the Flats were likely cut as permafrost facilitated runoff. Our new model for the origin of the loamy mantle suggests that the sands on the uplands were generated from eroding gullies and saltated onto the uplands along with loess that fell more widely. Sands saltating to the west of the Flats may have entrained some silts, facilitating loessfall downwind. At most sites, the loamy mantle gets increasingly silty near the surface, suggesting that saltation ended before loess deposition.

The Rospuda subglacial channel hosts not only deep ribbon lakes and the Rospuda River itself, but also an outwash plain. The paper deals with a lithofacies analysis of deposits from exposures within the Rospuda outwash plain. With the support of geomorphological and geological analyses, it has been found that the outwash plain formed along the Rospuda subglacial channel that was being exposed from under the ice cover. The lithological record of the Rospuda outwash plain shows a distinct division into a proximal and a distal zone. The deposits under study reveal a record of a break in basial sedimentation, when ice-wedge casts developed under conditions of periglacial climate. The development of the Rospuda outwash plain is linked with the ice-marginal zone of the Pomeranian phase, similarly to the Olecko-Rajgród outwash plain that is located to the west.

Estimation of groundwater recharge is one of the most challenging subjects in hydrogeology. It is a critical factor influencing the pollution migration, assessment of aquifer vulnerability to contamination, small-scale groundwater budget calculation, modeling of nutrient cycling and detailed flow path calculations. In Poland an infiltration rate method is widely used, which depends on a system of rate coefficients referring to the type of soil in the vadose zone and shows which part of the precipitation actually reaches the water table. The paper presents results of numerical simulations of vertical flow in unsaturated zone of an experimental site located on Brda outwash plain. Two simulations for varying vegetative cover (pine forest and grass) were performed. The results were compared with five infiltration rates classifications.

Anhand von zwei Dünenprofilen wird die Art, Dauer und Intensität von spätglazialen und holozänen Flugsand- und Bodenbildungen innerhalb des Pommerschen Sandergebietes dargestellt. Hierfür wurde ein interdisziplinärer Ansatz aus Sedimentologie, Pedologie, Palynologie und Geochronologie verwendet. Während des Spätglazials kommen auf den Sanderhochflächen flache Flugsanddecken zur Ablagerung, unterbrochen durch die Bildung des Finowbodens. Durch die Ausbreitung einer geschlossenen Vegetationsdecke im Frühholozän, erfolgt eine Stabilisierung der Reliefoberfläche mit anschließender Bodenbildung. Nach intensiven mittelalterlichen Rodungen werden die Oberflächen erneut destabilisiert. Es kommt zur partiellen Aufarbeitung der Flugsande resultierend in Dünenbildungen und einem kuppigen Relief. Eine der untersuchten Dünen wurde dabei komplett im späten Subatlantikum gebildet. Diese Studie unterstreicht die zeitlich-räumliche Variabilität äolischer Aktivität, wobei Umlagerungen entsprechender Korngrößen während verschiedener Phasen nach der Deglaziation ermöglicht wurden., research

Throughout much of eastern North America, quantitative records of historical fire regimes and interactions with humans are absent. Annual resolution fire scar histories provide data on fire frequency, extent, and severity, but also can be used to understand fire-climate-human interactions. This study used tree-ring dated fire scars from red pines (Pinus resinosa) at four sites in the Northern Sands Ecological Landscapes of Wisconsin to quantify the interactions among fire occurrence and seasonality, drought, and humans. New methods for assessing the influence of human ignitions on fire regimes were developed. A temporal and spatial index of wildland fire was significantly correlated (r = 0.48) with drought indices (Palmer Drought Severity Index, PDSI). Fire intervals varied through time with human activities that included early French Jesuit missions, European trade (fur), diseases, war, and land use. Comparisons of historical fire records suggest that annual climate in this region has a broad influence on the occurrence of fire years in the Great Lakes region.

Successional changes of pine forests were studied in outwash areas characterised by topography with ridges and depressions. The spatial series of pine forests of different stand ages and those that have not experienced the impact of human activities were analyzed. Pine forests in outwash areas form two successional series depending on the different ecotopes. The following successional series occurs at the tops of ridges: boreal green moss pine forest à boreal green moss – dwarf shrub forests à boreo-nemoral pine forest with admixture of birch, oak, spruce à nemoral polydominant spruce broad-leaved forest. Another successional series is formed on gentle ridge slopes: boreal polytric pine forest à boreal bilberry-polytric pine forest à boreo-nemoral pine forest with admixture of birch, oak, spruce à nemoral polydominant spruce broad-leaved forest. We show that ecotope has the leading role in the organisation of cenoses at the early stages of succession: green moss pine forests are formed at high and relatively dry relief sites (ridges) and polytric pine forests are formed on relatively wet ridge slopes. The ecotopic mosaic is complicated by the vegetation pattern created by animals (e.g., seed hawkers) at the intermediate stages of succession. Zoochoric species appear in the community: Vaccinium vitis-idaea, Convallaria majalis, Sorbus aucuparia and Quercus robur more often take root at the top of ridges; Vaccinium myrtillus, Frangula alnus and Picea abies grow on the slopes. The mosaic created by trees is imposed on a mosaic caused by ecotopes and animals at the final stages of succession: tree-fall gaps appear in the place of old dead trees with tree undergrowth. As a result, a heterogeneous community with a number of asynchronously developing gaps is formed in place of homogeneous pine forest

The study area near Chelm in Western Pomerania, NW Poland, is located between the end moraine and outwash plain of the glaciomarginal zone of the Pomeranian Phase (Weichselian glaciation) Four assemblages of deposits are exposed in the Chem pits: gravelly diamictons derived from debrisflows, sandy diamictons derived from hyperconcentrated flows, alternating sand and gravel deposited by sheetflows and sandy deposits filling shallow, braided-stream channels. The first facies association predominates in the proximal part of the transition zone and the last one in the distal part. This spectrum of facies associations, some resembling those of the end moraines and others those of the adjacent outwash plain, is considered to be unique, and is attributed to the formation of an array of coalescent ice-contact fans (‘transition’ fans). Architectural element analysis highlights the southwards change from debrisflow processes accompanied by sheetflows to hyperconcentrated flows and further to channelized streamflow. This transition zone in the present case is c. 1–km wide. It is suggested that analogous transitional zones, with similar or different widths, may have been developed in other glaciomarginal belts and remain to be recognized.

We report on a silt-rich mantle, generally 35-45 cm thick, on a section of the Outer Port Huron outwash plain in northwest Lower Michigan, known locally as the Buckley Flats. Below the mantle (cap) are coarse, sandy outwash sediments. The study examines various hypotheses on the origin of the silt-rich sediment. The silty cap was sampled at 67 sites across the Buckley Flats; data derived from these sites were kriged to create smoothed surfaces of cap thickness and various textural attributes. The silty cap thins progressively from south to north, away from the Manistee River valley. The cap also becomes progressively siltier and finer-textured, and contents of medium and coarser sands diminish, toward the north, away from the presumed source. We suggest that, during the latter phases of the Port Huron advance, while the Manistee River was carrying glacial meltwater, the Buckley Flats would have been a high, dry, stable landscape, relatively near to the river. Silty sediment probably was transported by win...

Outwash plains, sometimes known as sandar or valley trains, are broad, gently sloping, sheets of outwash sediment deposited by meltwater streams fed by glacier ablation (e.g. Church 1972; Church & Gilbert 1975; Benn & Evans 2010). They may be formed by coalescing outwash fans fed by streams emerging directly from a former ice margin or from proglacial braided rivers; such glacial meltwater streams usually have highly variable discharge and, especially when flow is high, transport large quantities of glacier-derived suspended sediment and bedload (Church & Gilbert 1975). An example of a drowned outwash plain exists off northern British Columbia in Hecate Strait (Fig. 1a), where rapid glacial retreat left an extensive plain that formerly stretched 150 km across the strait linking the British Columbia mainland to the islands of Haida Gwaii. Fig. 1. Multibeam bathymetry and cross-profile of an outwash plain that abruptly ends at a …

The Tinglev outwash plain is situated in the southemmost part of Jutland, Denmark, and continues southwards across the Danish-German border. Traditionally the melt water deposits between ground surface and the uppermost till are referred to the Weichselian. This paper shows that the melt water sediments can be separated into two outwash plains. The upper one being deposited in the Weichselian, the lower one in the Saalian. To the west the outwash plains are separated by marine Eemian sediments. Further eastwards the units may be distinguished by lirnnic Eemian deposits as well as Eemian weathering horizons. The paper presents contour maps showing the surface of the uppermost till, a map showing the extension of the marine Eemian in situ, isopach maps of the two outwash plains and a map showing the extension of the Saalian outwash plain.

Outwash plains, such as Skeiaararsandur, serve as prototypes for braided river facies and analogs for the Mars Pathfinder and Viking 1 landing sites on the margins of the Chryse Basin. Glacier outburst floods (jokulhlaups) have generated some of the largest known terrestrial freshwater flows and recent studies suggest that the stratigraphy of outwash plains (sandur) is dominated by sedimentary sequences laid down during jokulhlaups, rather than by braided river facies produced by an ablation-related flow regime. The modern point-source drainage configuration on Skeiaararsandur evolved from a diffuse, multipoint distributary system during glacier retreat, when meltwater began to be routed parallel to the ice front. The contemporary pattern of water and sediment dispersal across Skeiaararsandur differs from the conditions that prevailed when the ice front was coupled to the sandur, and the November 5–6 1996 outburst flood from Skeiaararjokull had little impact on the proximal surface of Skeiaararsandur beyond the confines of the entrenched channels that traverse it. Thus, the point-source dispersal system on Skeiaararsandur may not provide an exact analogue for the pattern of meltwater dispersal responsible for the sediment assemblage laid down during past jokulhlaups, and caution may be required when comparing conditions on Skeiaararsandur to those presumed to have been experienced during massive outburst floods elsewhere.

Sand and pebbles of the beaches of outer Cape Cod are derived from eroding coastal cliffs of lacustrine-fluvial outwash plains of Wisconsin age. The beach sands and the sands of the older and younger Wellfleet, Highland and Truro plains have similar mineralogically mature, quartzose compositions. These sands are quartz-arenites to subarkoses with small amounts of glauconite pellets. The complete samples of the combined outwash and beach groups average 89% quartz and 4% feldspar; the medium-sand fractions average 91% quartz and 5% feldspar. The non-opaque, non-micaceous heavy minerals in the medium-sand fraction of the beaches average 42% tourmaline, 16% staurolite, 14% garnet, 13% sillimanite, 5% amphibole, 5% andalusite, and 5% others. Although the proportions of heavy minerals in the outwash sands vary among samples, the average composition is similar to the beach sands: 40% tourmaline, 16% staurolite, 16% sillimanite, 12% garnet, 6% andalusite, 4% amphibole, and 6% others. A common provenance for outwash and beach sands is also reflected in the nearly uniform ratios of color varieties of tourmaline in all samples. Most of the quartzose sand of the beaches and outwash has a long history of recycling from Atlantic coastal-plain strata of Cretaceous to Tertiary age. These sands were entrained by Illinoian (?) glacial ice, which deposited gravel and sand in till and outwash over the Gulf of Maine. Sangamon marine reworking of the surface of these deposits mantled them with glauconitic, quartzose sand and gravel. Wisconsin ice moved southeastward, stripping the floor of the Gulf of Maine down to crystalline rocks and remnants of Cretaceous to Tertiary strata. Melt-water streams flowed southwestward from the South Channel Lobe into lakes, building the outwash plains with quartzose sand and lithic pebbles. The shapes and surfaces of many round, subspherical quartz grains were modified by grinding during transport in the ice, producing conchoidal fractures, flat-edged plate-like fragments, sharp edges, sliver-like chips, and grooves. Subsequent longshore transport of the quartzose sand and lithic pebbles north and south from a nodal zone has somewhat rounded the grains, but has not made the medium-sand fraction more quartzose. The nodal zone is northeast of Wellfleet, as evidenced by an increase in hydraulic equivalent ratios for tourmaline, sillimanite, staurolite, garnet and hornblende north and south along the coast from this location.

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On 30 September 1996, seismological evidence indicated that a volcanic eruption was starting north of the Grimsvotn caldera in the glacier Vatnajokull, Iceland. As the eruption developed during the first half of October, meltwater was collected in the subglacial lake2 Grimsvotn at a tremendous rate. It was obvious that a catastrophic jokulhlaup could be expected on the outwash plain Skeiðararsandur south of the glacier Skeiðararjokull, endangering travellers, as well as bridges and roads in the area. This paper describes the events, hydrograph and suspended sediment transport for the catastrophic flood on Skeiðararsandur, following the subglacial eruption.

Initial studies of the seismoelectric effect in an outwash plain have been conducted near Yellow Springs, Ohio. The purpose was to make seismoelectric measurements in a simple, well-understood test site where the seismoelectric signals could be clearly recorded and theoretical predictions could be calculated with as few assumptions as possible. Suppression of electrical noise was a major concern because 60 Hz electromagnetic fields from the power grid system are unavoidable in most parts of the United States. The site was characterized by seismic refraction surveys, DC resistivity surveys, and two drill holes. The site has a fairly uniform, 3 m thick unsaturated layer over a thick saturated sandy layer. The water table was near the top of the outwash layer. For the seismoelectric studies a sledgehammer source was used. Seismic signals and electrical signals were recorded separately and jointly with a variety of electrode combinations. An engineering seismograph was used to record both the seismic and electrical signals. The built-in 60 Hz and 180 Hz notch filters were effective in suppressing much of the power grid pickup. Electrical signals were observed which were consistent in time and frequency with the expectation of seismoelectric response due to the electrokinetic effect. Themore » peak-to-peak electric field amplitude was about 6 mV/m and the time delay corresponded with one-way seismic travel times to the water table.« less

During the 1950s a glacial outwash plain in southeastern Iceland, the Hoffellssandur, was studied by researchers from Uppsala University, Sweden. Several articles appeared in Geogr. Ann., but some data collected during the studies still remain to be published. This article contains results from the analysis of a core of 25 m length, drilled in the distal part of the sandur. The stratigraphy of the core is described in general terms Y r with information on bedding, grain size distributions, etc. The content of diatoms in different parts of the core has been analy/ '' sed, showing that the sediments of the lower part of the core were 64-JREYKAJA a / deposited in a marine environment. The petrographic composition of the core sediments has also been investigated, revealing 0 50km for instance a rather high content of ore minerals. The sediments are rich in volcanic glass, the origin and transport processes of which are discussed. Post-depositional in situ formation of A/ , i aragonite is proposed as an explanation of the occurrence ofi z ~ELLSJm! "aragonite needles". Introduction , During the early 1950s a glacial outwash plain in southeastern Iceland, the Hoffellssandur, was investigated by a study group from the Department of Physical Geography, Uppsala University, ))) % inal// under the leadership of the late Professor Filip ' Hjulstrom. The project included morphological, hydrological and sedimentological studies of the outwash plain (Figs. 1 and 2). A preliminary plan was set up for publishing the results of the investigations. A series of papers appeared in Geografiska Annaler during the period 1954-57 (Hoffells\ sandur I, II and III, written by Hjulstrom, Arnborg, J6nsson and Sundborg). Due to diffei rent reasons the original plan for publishing could ? not be fulfilled. However, some of the unpublished results may ! r still be of general interest, more than 30 years ,( liing later. The stratigraphy of sandur deposits has not been documented from many other outwash plains. During the Hjulstr6m project a 25 m long I ' . """.. drilling core from the distal part of the sandur was drilling core from the distal part of theFig. 1. Map of Hoffellssandur with surroundings in southeastern brought up. The results from those drillings may Iceland. Location of drilling operations indicated by circle. ..nr..fi A.nn....r .. 71 A .1QQo\ . -A 199 I %UGeyrtillbKd ZIIIIdlt::l * I I :70:WOf) 0--t This content downloaded from 157.55.39.35 on Fri, 02 Sep 2016 04:26:05 UTC All use subject to http://about.jstor.org/terms

A homoclinal sequence of Middle Triassic rocks crops out in the southern flanks of Mt Potts between Tank and Rocky Gullies, Canterbury. The basal conglomerates and sandstones of this sequence were deposited by braided streams filling an early Triassic valley, cut into deformed older sandstones. The basal conglomerates and sandstones are conformably overlain by coal measures containing diverse megafossil plant assemblages typical of Late Anisian to Ladinian rocks of Gondwanaland. These coal measures are in turn conformably overlain by beach sandstones and shallow-marine siltstones containing Ladinian (Kaihikuan local stage) marine fossils. Two new formations are described, namely Bench Sandstone and Tank Gully Coal Measures, and a new fault, the Rocky Peak Fault, is located. The whole Triassic sequence was deposited on a narrow coastal outwash plain and shallow marine shelf adjacent to alpine fold mountains in a cool temperate to subantarctic climate and latitude. This interpretation of the Triass...

Sediments and bed forms from three braided outwash plains and one steep non-braided mountain stream in the Rocky Mountains of Alberta are compared to sediments and structures exposed in a paleo-outwash sequence.Channel sediments are subdivided into (a) pool facies: ripple- and parallel-laminated silty sand, with current crescents around isolated stones; and (b) riffle facies: parallel-stratified gravel and silt or silty sand.'Transverse ribs' constitute a bed form typical of riffle portions of channels. This bed form occurs as a train of regularly spaced pebble, cobble, or boulder ridges oriented transversely to the flow. Locally, the pebbly ribs are separated by, and rest on, a stone-free silty substratum. It is suggested that transverse ribs constitute a common equilibrium bed form in higher gradient riffle portions of gravelly alluvium.Longitudinal bars dominate interchannel areas of the modern outwash plains. They consist of coarse, poorly sorted gravel, either massive or exhibiting crude horizontal stratification. The paleo-outwash, composed of finer-grained and better sorted gravel, is characterized by sets 5 to 30 cm thick of cross-stratified sand and by sets 75 to 82 cm thick of cross-bedded pebble gravel. These may be related to progradation of dunes and bars, respectively.Standard deviations of channel azimuths in modern outwash plains are appreciably less than that recorded by cross-stratification measurements in the time-transgressive sequence of paleo-outwash. This is partly due to the braided system of channels having swept from side to side across the plain through time.

In this study, a glacial lake-outburst flood was documented in the immediate foreland of the maximum phase of the Wartanian (Warthian, Late Saalian, MIS 6) Glaciation at Adamow in south central Poland. The structural and textural analyses of the sediments, as well as palaeohydraulic analysis, were carried out in the proximal part of the outwash plain where a fragment of the floodwater drainage system comprising buried erosional channels have been documented. Their fill reached a thickness of up to 11 m and was composed of poorly sorted, massive gravels with boulders, as well as horizontally, sub-horizontally, low-angle, and cross-stratified gravels. The coarse sediments were found to be inversely and normally graded. These sediments constituted the records of two subsequent flooding episodes. In the channel fill, the lenticular accumulations of gravel were identified and interpreted as buried large gravel dunes, while exhibiting a thickness of up to 2.5 m. Traces of sediment diapirism at the contact of channel fill and underlying sediments were also documented. Deformation was observed to originate from liquefaction caused by the rapid depositional loading of flood deposits. The example used in this study exhibited that the impact of glacial lake-outburst floods in shaping the marginal zones and foreland of ice sheets in the North European Plain was higher than that considered earlier. This example also showed a different case of glacial outburst flood in the foreland of the Middle Pleistocene ice sheets of Europe than that already known, which includes the discharge of sub- or englacial meltwater reservoirs emanated from a large proglacial ice-dammed lake.

Knowledge of the spatial distribution of lithofacies, obtained through detailed modelling of the movement of water and solutes, may improve precise predictions of an area’s vulnerability towards contaminants. This calls for information on lithofacies variability on several scales. The possibilities for upscaling lithofacies distribution from excavation scale to field scale or to an even larger scale with the use of ground-penetrating radar (GPR) is tested on one of the largest outwash plainsin Denmark: the Karup Outwash plain in the western part of Jutland. The testing involves GPR surveys at 16 locations along a 30 km long profile following the ancient mean flow direction of the braided-river system, as well as combined detailed sedimentological investigations at selected locations. The GPR testing is divided into several phases of which this paper reports on the first two. In the first phase, GPR surveys and sedimentary investigations at gravel-pits and excavation sites are carried out at the same location with the aim of determining whether lithofacies can be related to GPR reflection sequences either directly or through facies architecture models. Studies of outcropping glaciofluvial deposits at a gravel-pit and a shallow excavation in the proximal and intermediate parts of the outwash plain, respectively, show that the sand-dominated outwash plain typically contains lithofacies types with bed thicknesses of up to 0.5 m and successions of beds of thicknesses upto 1 m. GPR surveys carried out at the same locations show that the observed lithofacies types typically have dimensions that, in a vertical direction, are the same as or less than the resolution obtained by a 200 MHz GPR system. In such sand-dominated outwash deposits, the GPR reflections may more often be caused by the bedding structures in successions of beds and of larger erosion surfaces separating different lithofacies, rather than by the lithofacies boundaries themselves. In the second phase, tests are conducted to determine whether facies architecture changes along the ancient mean flow direction in the outwash plain can be recognized using radar stratigraphic analysis. Radar stratigraphic analysis, so far limited to two GPR sections orientated parallel and perpendicular to the ancient mean flow direction at 15 locations, reveals a systematic change in the pattern of radar sequence boundaries and the occurrence of radar facies. The changes in radar sequences seem to reflect changes in lithology and sedimentary structures related to the overall fall in the depositional energy from the proximal to the distal part of the outwash plain. The results clearly indicate that radar stratigraphic analysis reveals realistic facies architecture models for the outwash plain, provided densely spaced GPR data are acquired and locally calibrated against excavations and coreholes. It is concluded that GPR can be used for upscaling lithofacies distributions in sedimentological settings like the present Karup Outwash Plain.

Deeply dissected tundra polygons are described from the continuous permafrost environment of northernmost Ungava. They are developed on a glacial outwash plain, formed subsequent to déglaciation of the site about 7,500 BP. The exposed surfaces of the polygons are sparsely vegetated and aeolian deflation has removed their sandy matrix material. The furrows between the polygons attain depths of 0.5-2 m. From the base of one. a 0.25 m wide wedge of peat and sandy material penetrates to a minimum depth of 0.7 m (the frost table depth). Radiocarbon dates of 1650 ± 60 BP and 740 ± 80 BP indicate that progressive filling of this fissure accompanied decay of a preexisting ice-wedge. The present low mean annual air temperature at the site ( - 70C) suggests that thawing of the ice-wedges may be related more to local dynamic factors, such as deflation and improved local drainage associated with fluvial dissection, than to regional climatic amelioration. Wedge ice is believed to still underlie the polygon furrows., On décrit ici les polygones de toundra profondément disséqués de la zone de pergélisol continu de l'extrémité nord de l'Ungava. Ils se sont développés sur une plaine d'êpandage fluvio-glaciaire qui s'est formée à la suite de la déglaciation vers 7500 BP. Une végétation rare occupe la surface exposée des polygones et la déflation a emporté la matrice sablonneuse. La profondeur des sillons entre les polygones atteint de 0,5 à 2 m. À la base d'un d'entre eux, on observe une fente large de 0,25 m à remplissage composé de lentilles de tourbe et de sable, jusqu'à au moins 0,7 m de profondeur (front de dégel). Deux datations au 14C de 1650 ± 60 BP et de 740 ± 80 BP montrent que le remplissage progressif de la fissure s'est fait au fur et à mesure de la désintégration d'une fente de gel préexistante. La basse température moyenne annuelle de - 7°C indique que la fonte des fentes de gel dépend davantage de facteurs dynamiques locaux, comme la déflation et un meilleur drainage, qu'à une amélioration du climat. On croit que des fentes de gel occupent encore la partie inférieure des sillons de polygone.

The 75-km reach of the Skeidararsandur coast of southern Iceland is a mesotidal area (spring tidal range 2 m) dominated by an accreting series of barrier spits oriented east-west and backed by wide wind-tidal flats and active braided streams. The spits average 5-10 km in length and increase from 200 m to 750 m in width in a westerly (downdrift) direction. Eolian beach ridges are absent, but the uppermost spit surfaces are covered with transverse dunes migrating in response to strong easterly and westerly winds. Sediment is provided by two major glacial-outwash stream systems that exit through a series of narrow river distributaries cut through the barriers. Major flow occurs during the summer melt season when up to 5.1 g/l of sediment is carried in suspension by currents that attain surface velocities of 3.3 m/sec. Sand carried seaward by upper-regime flow (particularly at low tide) builds river distributary deltas. Maximum recorded longshore current velocities in the surf zone of 130 cm/sec are generated both by storm waves from the SE and longer period swell from the SW. The net sediment transport direction is to the west. The beach and nearshore zones feature well developed rhythmic topography and large offshore bars. Offshore bottom profiles (PDR) indicate a large subtidal sediment bulge downdrift of the major river systems and seaward of the widest barriers. Beach profiles at 40 localities, detailed morphological mapping, together with natural cuts through the spits, show beach accretion by multiple berm growth. A generalized model based upon sedimentary structures shows that these berms, consisting of ridge (swash bar), berm-ridge, berm-top, and beach-face stratification compose a thin veneer (1-2 m) on top of fluvial sediment derived from river distributary migration and from glacier-burst floods (Jokulhlaups). These floods fragment and inundate certain portions of the coast, thereby significantly affecting the coastal geomorphology. Where floods have not occurred recently, inactive outwash plains (sandurs) and wind-tidal flats exist behind the spits and are covered by mound-like vegetated eolian dunes.

The study analyses a 7.5-m-thick sedimentary succession deposited in the largest sandur (the Gwda sandur, a glacial outwash plain) in NW Poland, during the late Weichselian (MIS 2). Although the study site is located in the distal zone of the sandur, its sedimentological features and palaeohydrological parameters reflect the presence of an energetic, powerful environment typical of the proximal zone. Three sedimentary units were recognized in the studied sedimentary succession: (1) lower unit — fine-grained sands with ripple cross-lamination and horizontal lamination; (2) middle unit — gravelly coarse-grained sands and sandy gravels with planar cross-stratification; and, (3) upper unit — sands and gravelly sands with trough cross-stratification. Although the age of deposition of the sandur is accepted to be convergent with that of end-moraines of the same phase, the sediments in the distal zone of the Gwda sandur correlate with an earlier glaciation phase/subphase. Our findings hint at a complex problem: large sandurs such as the Gwda sandur were probably deposited over a long time, and their successions might record the textural and structural features of the proximal subenvironment, even in their distal parts due to deglaciation-related shifting of the proximal zone of a sandur. This paper presents a new approach to analysing the depositional processes in large sandurs, shows a new light on glaciofluvial water supply dynamics of distal parts of sandurs, and may solve several fundamental problems related to the sandur deposition.

Glacial landforms are a significant element of landscape in many regions of Earth. The increasing availability of high-resolution digital elevation models (DEMs) provides an opportunity to develop automated methods of glacial landscape exploration and classification. In this study, we aimed to: 1) identify glacial landforms based on high-resolution DEM datasets; 2) determine relevant geomorphometric and spectral parameters and object-based features for the mapping of glacial landforms; and 3) develop an accurate workflow for glacial landform classification based on DEM. The developed methodology included the extraction of secondary features from DEM, feature selection with the Boruta algorithm, object-based image analysis, and random forest supervised classification. We applied the workflow for three study sites: one in Svalbard and two in Poland. It allowed the identification of six categories of glacial landforms: till plains, end moraines, hummocky moraines, outwash/glaciolacustrine plains, valleys, and kettle holes. The majority of relevant secondary features represented DEM spectral parameters calculated from 2-D Fourier analysis. The supervised classification models with the highest performance exhibited up to 96% overall accuracy with regard to a groundtruth dataset. This study showed that glacial landforms can be identified using novel image-processing methodology and spectral parameters of high-resolution DEM. The complete classification workflow developed herein provides a solution for the transparent generation of thematic maps of glacial landforms that may be reproducible and transferrable to various glacial regions worldwide.

The spatial and temporal controls on variability of the relative contributions of groundwater within and between flow systems to shallow lakes in the low-relief glaciated Boreal Plains of Canada were evaluated. Eleven lakes located in a coarse glacial outwash, of varying topographic positions and potential groundwater contributing areas, were sampled annually for stable O and H isotope ratios over the course of 8 years. It was demonstrated that landscape position is the dominant control over relative groundwater contributions to these lakes and the spatial pattern of the long-term isotopic compositions attributed to groundwater overrides interannual variability due to evaporative effects. Lakes at low landscape positions with large potential groundwater capture areas have relatively higher and more consistent groundwater contributions and low interannual variability of isotopic composition. Isolated lakes high in the landscape experience high interannual variability as they have little to no groundwater input to buffer the volumetric or isotopic changes caused by evaporation and precipitation. An alternative explanation that lake morphometry (area and volume) control long-term isotopic compositions is tested and subsequently refuted. Landscape position within coarse outwash is a strong predictor for relative groundwater input; however, surface-water connections can short circuit groundwater pathways and confound the signal. A hydrogeological case study for three of the study lakes is used to contextualize and further demonstrate these results.

Final Palaeolithic (Terminal Palaeolithic) — the last, final phase of the Upper Palaeolithic of Europe, dating from 13.5—10 kyr and has numerous paleogeographic equivalents — Dryas period, Late glacier, Late or Final glacial, Tardiglacial period, reindeer age. In Zhytomyr Polissia there are two main groups of different Final Palaeolithic monuments with different cultural and chronological characteristics. At the beginning of the epoch, Еpigravettian mammoth hunters lived in the region. In particular, on the Ovruch ridge at the beginning of the Final Paleolithic a separate variant of the Еpigravettian developed. The extinction of mammoths about 13 kyr and the onset of the reindeer era caused a change in population. During the Allerod warming about 12 kyr reindeer hunters of the Lyngby culture advanced from the South-Western Baltic region to Polissia. The spread of Lyngbian cultural traditions at the end of Allerod in the outwash plains from Jutland to the Neman, Prypiat, Upper Dnipro and Upper Volga laid the groundwork for the emergence 11 000 years ago areas of related cultures with arrowheads on blades. In addition to Lyngby, it includes the following cultures: Ahrensburg in Northern Germany, Swiderian in the Vistula, Prypiat and Neman basins, and Krasnosillia in the Prypiat, Neman and Upper Dnipro basins. The specificity of their flint inventory is the leading role of various tanged arrowheads on blades, while the cultural marker of Epigravettian complexes are a variety of micro-inserts with a backed edge. Genetically descended from the Lyngby culture population, Krasnosillian and Swiderian hunter groupes lived in the cold forest-tundra, hunting for herds of seasonally migrating reindeers. The sharp warming 10 kyr led to the migration of Krasnosillian and Swidrian groupes following the reindeer to the north of Eastern Europe, which they settled during the VIII millennium BC. On the Swiderian basis, the post-Swiderian Mesolithic was formed. It is Butovo and similar Mesolithic cultures of the forest belt of Eastern Europe from the Baltics to the Northern Ural. The Mesolithic Pisochnyi Riv culture of the Middle Desna, the Grensk culture of the Upper Dnipro, and the Ienevo culture of the Upper Volga were formed on the Krasnosillian basis. These Mesolithic communities of northern Eastern Europe in ethno-cultural terms were probably distant ancestors of the Finnish peoples.