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Over the past tens of years, glacial sandstone erratics variably enriched in Zn, Pb and Cu have been collected from the coast south of Raahe, but their source has remained ambiguous. In these non-metamorphosed and non-deformed boulders, detrital grains of quartz and minor feldspar are cemented by calcium carbonate, which is partly or wholly replaced by ore minerals, including sphalerite, galena, pyrite, marcasite, and chalcopyrite. Analyzed mineralized boulders have yielded total base metals contents between 1 and 19 wt.%. The FeS content in sphalerite is low and variable, ranging commonly between 0.5 and 15 mol.%, which is in harmony with its coexistence with pyrite. Galena shows very radiogenic Pb isotope compositions, with 206Pb/204Pb and 207Pb/204Pb falling in the ranges of 20.55−21.06 and 15.90−15.94, respectively. These compositions are similar to those measured for the Laisvall MVT Pb-Zn deposit in the Swedish Caledonides, being consistent with a similar Ordovician age of ore formation. However, S isotope analyses yielded heterogeneous compositions, with pyrite showing mostly negative δ34S values from −15.6 to −7.6‰, indicating partly a strong bacteriogenic signature, which are distinctly different from the generally heavy sulfur isotope compositions (avg. δ34S +24‰) reported from the Laisvall-type deposits, pointing to a different source of sulfur. These results together with some mineralogical differences (relatively abundant chalcopyrite, scarcity of fluorite and barite) suggest that the boulders were not derived from the eastern front of the Caledonian orogen but their provenance occurs much closer, potentially in a so-far-undiscovered occurrence of stratabound base metal mineralization in Cambrian sediments under the Bothnia Bay. The direction of transportation of the sandstone boulders can be estimated using associated carbonate and mafic metavolcanite boulders whose carbon isotope and major and trace element compositions, respectively, indicate their derivations from the Kalix area, northern Sweden.

Glaciofluvial ice-contact deltas were mapped and altitudes of the highest shorelines defined in the eastern arc of the Salpausselkä zone, southern Finland, using Light Detection and Ranging (LiDAR)-based digital elevation models and GIS tools. Mapping of deltas and the highest shorelines in the Salpausselkä zone were undertaken in order to calculate and define the glacio-isostatic uplift palaeo-isobases, uplift gradients and equidistant diagrams (distance diagrams) for the Salpausselkä zone. The results indicate that the glacio-isostatic uplift palaeo-isobases were orientated NE-SW (50°–230°) and the uplift gradients for both the First and the Second Salpausselkä in the eastern arc, are virtually the same, namely 0.6 mkm-1. This suggests that both Salpausselkä ridge complexes, which were originally laid down in front of the Finnish Lake District Ice Lobe (FLDIL) in relatively shallow water, were deposited within a short time period during the Late Weichselian Younger Dryas Stadial. The results also suggest that the Baltic Ice Lake water level regressed 7.5 metres from Baltic Ice Lake level B I to level B III as the ice retreated in its eastern arc from the First to the Second Salpausselkä.

The SIS (Scandinavian Ice Sheet) became divided into several active, semi-independent ice lobes during the last deglaciation ca 13 000–10 000 years ago. The largest of them, the North Karelian/Oulu Ice Lobe (NKIL/OIL), covered vast areas in central Finland and in northwest Russian Karelia. This paper studies the behaviour and subglacial conditions of the NKIL/OIL with the inversion modelling method. The method is based on the identification and interpretation of mapped glacigenic streamlined lineations, formed during active flow stages of the NKIL/OIL. DEM and LiDAR data on lineations was obtained from seven subsets in different zones of the NKIL/OIL. Results indicate that the NKIL/OIL dynamics were strongly affected by pre-existing Quaternary sediment thickness, bedrock lithology, structures and topography. Due to these factors, the NKIL/ OIL operated through several flow corridors and had several retreat and re-advance cycles throughout its life span.

Mineralogical and geochemical data generated from the well referred shallow core 96/12-1pc on the Lomonosov Ridge, central Arctic Ocean was used to evaluate ice transport from the circum-Arctic sources and variability in sediment drainage and provenance changes. In this study heavy minerals in central Arctic sediments were used to determine those most prominent provenance areas and their changes related to the Late Pleistocene history of glaciations in the Arctic. Provenance changes were then used to infer variations in the paleoceanographic environment of the central Arctic Ocean, such as variations in the distribution of sea ice, icebergs controlled by the Arctic Ocean circulation. Four critical end-members including Victoria and Banks Islands, the Putorana Plateau, the Anabar Shield, and the Verkhoyansk Fold Belt were identified from the Amerasian and Eurasian source areas, and their proportional contributions were estimated in relation to Late Pleistocene ice sheet dynamics and ocean circulation. The results show changes in transport pathways and source areas within two examined transitions MIS6-5 and MIS4-3. The main source for material during MIS6-5 transition was Amerasian margin due to the high dolomite content in the studied section of sediments inferring strong Beaufort Gyre (BG) and Transpolar Drift (TPD) transport for this material. IRD material during late the MIS6 to 5 deglacial event was from terrigenous input through from the MacKenzie route Banks/Victoria Islands then transported as far as the Lomonosov Ridge area. The transition, MIS4-3 in comparison with MIS6-5, shows a clear shift in source areas, reflected in a different mineralogical composition of sediments, supplied from the Eurasian margin, such as the Anabar Shield, the Putorana Plateau and the Verkhoyansk Fold Belt during active decay of the Barents-Kara Ice Sheet presumable associated with an ice-dammed lake outburst then triggered by a strong TPD over the central Arctic. These two studied deglaciations suggest that contributions of different circum-Arctic sediment sources are related to interaction between ice sheet decay, sea ice production and circulation.

The Rautuvaara section in northern Finnish Lapland has been widely considered as the stratotype for the northern Fennoscandian late Middle and Late Pleistocene. It exposes four till units interbedded with sorted sediments resting on Precambrian bedrock. In order to shed light on the Scandinavian Ice Sheet (SIS) history and palaeoenvironmental evolution in northern Fennoscandia through time, a chronostratigraphical study was carried out at the Rautuvaara site. The succession was studied using sedimentological methods and different sand-rich units between till units were dated using the Optical Stimulated Luminescence (OSL) method. The results obtained indicate that the whole sediment succession at Rautuvaara was deposited during the Weichselian Stage and there is no indication of older deposits. The SIS advanced across Finnish Lapland to adjacent areas to the east at least once during the Early Weichselian, twice during the Middle Weichselian (∼MIS 4 and MIS 3) and once during the Late Weichselian substages. Glaciolacustrine sediments interbedded between the till units indicate that a glacial lake repeatedly existed after each deglacial phase. The results also suggest that there were two ice-free intervals in northern Fennoscandia during the Middle Weichselian close to the SIS glaciation centre.

Ice-rafted quartz sand grains of sediment samples representing marine isotope stages (MIS) 3 and 4 from the Lomonosov Ridge, Arctic Ocean, are here analysed with a scanning electron microscope (SEM) to characterise processes in the sediment source area. The microtextural characteristics of the grains were observed and their microtexture frequencies calculated. Specific sets of microtextures were identified and classified (Group I–III) using principal component analysis (PCA) and cluster analysis. The statistically analysed microtextural data were used to identify signals of continental processes that operated during the late Pleistocene (MIS 4 to MIS 3) in the Eurasian Arctic. The microtextures of Group I generally formed as a result of prolonged fluvial/alluvial or aeolian transport. The glacial microtextures of Groups II and III indicate subglacial conditions and transport. Based on the data, two principal components seem to characterise late Pleistocene continental environmental conditions – glacial and non-glacial. There is a signal of non-glacial continental processes in the ice-rafted grains at around 62, 64 and 67 ka ago. A signal of subglacial processes was observed in the grains at around 26, 34, 42 and 45 ka and, concurrent with non-glacial, at around 62 and 64 ka ago. We suggest that these signals in MIS 4 sediments are related to deglaciation with an increased supply of glacial sediment to the Arctic Ocean, whereas during MIS 3 they were probably related more to iceberg calving from the oscillating Barents-Kara ice sheet.

The lithostratigraphy of pre-Late Weichselian sediments and OSL-dating results from four localities in the Suupohja area of western Finland, adjacent to the centre of the former Scandinavian glaciations, are presented. The studied sections expose glacifluvial, quiet-water, littoral and aeolian deposits overlain by Middle and/or Late Weichselian tills. Litho- and biostratigraphical results together with seven OSL age determinations on buried glacifluvial sediment at Ravasen (94±15 ka) and on till-covered littoral and aeolian sediments at Risasen, Ravasen, Jatinmaki and Kiviharju (79±10 to 54±8 ka), accompanied by previous datings and interpretations, suggest that the glacifluvial sediments at Risasen were deposited at the end of the Saalian Stage (MIS 6) and those at Risasen were deposited possibly in the Early Weichselian Substage (MIS 5d?). Palaeosol horizons and ice-wedge casts together with the dated littoral and aeolian sediments between the Harrinkangas Formation (Saalian) and the overlying till(s) indicate that western Finland was ice-free during most of the Weichselian time. Littoral deposits, dated to the Middle Weichselian (MIS 4–3), occur at altitudes of 50–90 m a.s.l., which indicates significant glacio-isostatic depression. The depression resulted from expansion of the ice sheet in the west of Finland at that time.

The last deglaciation of the Scandinavian Ice Sheet (SIS) from ∼ 21 , 000 to 13,000 yr ago is well-constrained by several hundred 10Be and 14C ages. The subsequent retreat history, however, is established primarily from minimum-limiting 14C ages and incomplete Baltic-Sea varve records, leaving a substantial fraction of final SIS retreat history poorly constrained. Here we develop a high-resolution chronology for the final deglaciation of the SIS based on 79 10Be cosmogenic exposure dates sampled along three transects spanning southern to northern Sweden and Finland. Combining this new chronology with existing 10Be ages on deglaciation since the Last Glacial Maximum shows that rates of SIS margin retreat were strongly influenced by deglacial millennial-scale climate variability and its effect on surface mass balance, with regional modulation of retreat associated with dynamical controls. Ice-volume estimates constrained by our new chronology suggest that the SIS contributed ∼ 8 m sea-level equivalent to global sea-level rise between ∼14.5 ka and 10 ka. Final deglaciation was largely complete by ∼10.5 ka, with highest rates of sea-level rise occurring during the Bolling–Allerod, a 50% decrease during the Younger Dryas, and a rapid increase during the early Holocene. Combining our SIS volume estimates with estimated contributions from other remaining Northern Hemisphere ice sheets suggests that the Antarctic Ice Sheet (AIS) contributed 14.4 ± 5.9 m to global sea-level rise since ∼13 ka. This new constraint supports those studies that indicate that an ice volume of 15 m or more of equivalent sea-level rise was lost from the AIS during the last deglaciation.

A total of six small basins were cored to determine the shoreline displacement of the Belomorsk area, NW Russia during the last deglaciation. Conventional shoreline displacement methods were applied where the isolation contacts of the sediment cores from lakes at different altitudes were determined using lithological and diatom taxa changes. The isolation contacts were subsequently dated using the 14C AMS-method. The results show that the area around the cored basins formed part of an extensive ice lake that existed in the White Sea Basin prior to 12,000 cal. yr BP. Dating, together with lithostratigraphical and diatom results, indicate that the isolation of the lakes between 72 and 134 m above the present sea level occurred at 12,000 cal. yr BP and the relative water level in the White Sea Basin dropped at least 62 m within a maximum of 300 years. It is estimated that at least 50–55 m of the relative water-level fall was caused by a sudden drainage of the ice-lake waters into the Barents Sea via the Gorlo Strait and 7–12 m of the water-level decline was caused by glacioisostatic uplift. Preliminary calculations suggest that the total volume of water that burst into the Barents Sea was c. 3000 km3. This, together with that of c. 7000 km3 of water which drained into the North Atlantic as the result of the Baltic Ice Lake drop around 11,600 cal. yr BP, must have affected the behaviour of the eastern flank of the Scandinavian Ice Sheet and had a cooling effect on local climate.

Three lake basins were cored in the Kalevala area, northwestern Russia in order to determine the Weichselian deglaciation history of the eastern flank of the Scandinavian Ice Sheet and to date the Kalevala and Paajarvi end moraines adjacent to these basins. Two of the lake basins, Ala-Kuittijarvi and Keski-Kuittijarvi, are situated on the proximal side of the Kalevala end moraine while the third lake basin, Tuoppajarvi, is located on the distal side of the Paajarvi end moraine. One site from each lake basin was chosen for sedimentological and chronological study. The chronology presented in this paper is based on palaeomagnetic measurements and counting of varved clays and the results are compared to the Finnish palaeomagnetic master curve. The results indicate that the deglaciation sediments in the Ala-Kuittijarvi and Keski-Kuittijarvi lakes were deposited mainly by extra-marginal rivers, while those in Tuoppajarvi were deposited in an ice-contact setting. After the glacial meltwater input ceased, typical large lake gyttja clay/clay gyttja sediment accumulated in all three basins. The palaeomagnetic record obtained from the Ala-Kuittijarvi sediment sequence extends back to 10,900 cal. BP, while that of Keski-Kuittijarvi and Tuoppajarvi dates back to 9800 cal. BP. The palaeomagnetic record, together with 450 counted varves in Ala-Kuittijarvi, indicates that the basin was deglaciated at around 11,350 ± 300 cal. BP. Based on palaeomagnetic results, geomorphological considerations and ice retreat rates, it is estimated that the Kalevala end moraine was formed prior to 11,450 ± 350 cal. BP, while the Paajarvi end moraine, west of Tuoppajarvi, was formed at prior to 11,000 ± 250 cal. BP.

Although the documented history of Dvina Karelia (northern Russian Karelia) does not begin until the second half of the 16th century, individual finds of prehistoric artifacts point to earlier human occupation. The present paleoecological study of the Vuonninen area is the first of its kind concerning prehistoric land use in Dvina Karelia, a large region extending from Finland to the White Sea. It is based on the pollen analysis of sediments from Lake Yla-Kuittijarvi near the old Karelian village of Vuonninen. In its general features, the picture of the early stages of cultivation and human activity in the village of Vuonninen is comparable to results from East Finland, the Karelian Isthmus, and the northern shores of Lake Ladoga. The first, minor indications of human influence appear in the sediments of the 4th–6th centuries A.D. in Lake Kuittijarvi. Distinct and unambiguous signs of human activity appear in the pollen record in the 12th century. This is particularly evident in the decreasing proportion of Picea, caused by the clearance of spruce forest. The beginning of cultivation is dated according to Secale pollen to the beginning of the 15th century. Intensive arable farming emerges in the early 19th century in the form of regular occurrences of Secale and Hordeum pollen. © 2010 Wiley Periodicals, Inc.

Pasanen, A., Lunkka, J. P. & Putkinen, N. 2009: Reconstruction of the White Sea Basin during the late Younger Dryas. Boreas, 10.1111/j.1502-3885.2009.00128.x. ISSN 0300-9483 The Weichselian Scandinavian Ice Sheet (SIS) in the White Sea Basin retreated from its maximum position to the Kalevala end moraine between 17 000 and 11 500 years ago. Even though the deglaciation history is relatively well known, the palaeoenvironments in front of the ice sheet are still poorly understood and partly controversial. In the present paper, we use geomorphological, sedimentological and ground-penetrating radar survey methods to study glaciofluvial plains and shorelines at the Kalevala end moraine. These data are used to define the shoreline gradient for the area and to numerically reconstruct the palaeotopography and the area and volume of the water body in the White Sea Basin during the late Younger Dryas 11 500 years ago. The results indicate that at three sites glaciofluvial plains represent Gilbert deltas deposited to the same water level next to the ice margin. Using the shoreline gradient of 0.42 m/km, it is shown that the water body in the White Sea Basin was extensive and relatively deep, inundating large, currently onshore, areas on the western side of the White Sea and the Arkhangelsk area to the east. The ice margin terminated in the White Sea, which was connected to the Barents Sea via the Gorlo Strait and separated from the Baltic drainage basin to the south.

Investigation of a group of landforms and their underlying deposits on the eastern margin of the Fenland in East Anglia has demonstrated that they represent a series of glaciofluvial delta-fan and related sediments. Section logging, borehole records and previous descriptions combine to indicate that the sediments were deposited in ice-marginal deltaic settings in an ice-marginal lake. The internal structure and form of the fan-like deltas has been demonstrated using extensive ground-penetrating radar investigation. The lake formed by the ice damming westward-aligned river valleys. Together, this evidence confirms historical descriptions of a glaciation of the Fenland, and clarifies the interpretation of gravels of the eastern Fenland margin. Recent reinterpretations of the latter as of fluvial rather than glacial meltwater origin are shown to be incorrect. It is concluded, on the basis of regional correlation, supported by optically stimulated luminescence dating, that the glaciation occurred at c. 160 kyr, i.e. in the Wolstonian (=Saalian) Stage (broadly equivalent to MIS ?11b-6). Comparison with The Netherlands' sequence shows a similarity of glacial marginal morphology, and the dates confirm the time equivalence with that during the late Saalian Drenthe Substage, Amersfoort ice-pushed ridge complex. The implications include that the c. 200 kyr interval, between the Hoxnian (Holsteinian) temperate Stage and the Wolstonian glaciation, was a period during which fluvial and periglacial activity modified the landscape under cold climates, with organic sediments laid down during warmer events. Palaeolithic humans were periodically present during this interval, their artefacts having been reworked by the subsequent glaciation.

Core material obtained from three boreholes was studied from the Ruunaa area, Finnish northern Karelia, in order to reveal the Late Pleistocene environmental history of eastern Finland. Conventional litho- and biostratigraphical methods were used and suitable sediment samples were dated using quartz optically stimulated luminescence. The results indicate that two till units were deposited by two separate Weichselian ice advances into the area. The first advance took place prior to 52 kyr ago, most likely during the early Middle Weichselian, while the second is thought to have taken place during the Late Weichselian after 25 kyr ago. The sediment succession at Ruunaa therefore indicates a Middle Weichselian ice-free period around 50–25 kyr ago in the eastern part of Fennoscandia.

The Nordic countries have experienced multiple glaciations and intervening interglacials during the last ca. 2.5-3 million years. Although evidence from Greenland and Iceland shows that ice sheets started to expand some time before 3 Ma, little is known about the glaciations and intervening interglacials older than the last Glacial Maximum due to repeated phases of glacial erosion and reworking. The extensive Saalian glaciation (c. 140 ka BP) contributed to high sea levels in Greenland and in the Baltic area during the early part of the last interglacial (Eemian). Temperatures were about 5 °C higher during the Eemian than they are today and the Greenland ice sheet was reduced to about half of its present size, causing globally higher sea levels than we have today. Ice extent in Fennoscandia was restricted during early Weichselian stadials, but middle Weichselian ice advances in Scandinavia reached as far as Denmark. During the Last Glacial Maximum, large ice sheets were present in all Nordic countries and coalesced with neighboring ice sheets. Deglaciation commenced around 17-15 ka BP in most areas and was promoted by rapidly rising global sea level and glacial isostasy. The Younger Dryas cold event(c. 12.6-11.5 ka BP) is seen as a short-term re-advance, still-stand or fluctuation of land-based ice sheet margins. Around 7-9 ka BP ice sheets had disappeared or had attained their present size. While uplift is still going on in some regions, others are subject to submergence. The different stages of development of the Baltic Sea are an example of how the intricate interplay between glacial eustasy and isostasy influences sedimentation, basin size and drainage patterns.

The Hitura open pit exposes a sedimentary sequence up to 50 m thick representing Late Saalian to Holocene glacial and non-glacial sediments. The sequence was investigated using sedimentological methods, OSL-dating and pollen and diatom analyses to reconstruct the Middle Weichselian (MWG) glacial event in the central part of the Scandinavian Ice Sheet (SIS). The results indicate that the sediment succession represents two entire glacial advance and retreat cycles. The lowermost deposits are Late Saalian esker and delta sediments overlain by sediments that correlate with the early Eemian lacustrine phase. Remnants of the Eemian soil post-dating the lacustrine phase were also observed. The area was ice-free during the entire Early Weichselian (EWG). The first glacial advance recorded in the sediments is related to the MWG. It started 79 kyr ago, deformed underlying sediments and deposited an immature till, including large detached sediment pods containing remains of organic material, soils and fluvial sediments representing allochthonous material from EWG ice-free stadials and interstadials. The glacial deposits are conformably overlain by glaciolacustrine and littoral accumulations, indicating MWG deglaciation between 62 and 55 kyr ago. Based on the fabric measurements from the till unit overlying the MWG sediments, ice advance during the Late Weichselian (LWG) was initially from the west and later from a north-northwesterly direction. The Hitura strata provide the first dating of the MWG deglaciation (55 to 62 kyr ago) from central parts of the SIS. It can be considered as a key site for studying the growth and decay of SIS during the poorly known early parts of the glaciation.

Glacial landforms of the Lake Kuittijärvi area, Russian Karelia, which covers an area of more than 7000 km^2, were studied in detail using aerial photography and satellite imagery methods and on-site field observations. This was done to reconstruct a detailed historyof Scandinavian ice sheet behaviour in the Lake Kuittijärvi area. The results indicate that the Lake Tuoppajärvi sub-ice stream (TIS) that formed the northern part of the Kuusamo-White Sea ice stream and the Lake Kuittijärvi sub-ice stream (KIS), which was part of theNorthern Karelian ice stream, operated in the area during the last deglaciation. Subglacially formed lineation patterns associated with other indicative landforms such as end moraines and esker ridges indicate a clear age relationship between the ice streams’ activity and that the KIS was active after the linear landforms were created by the TIS. It is estimated that deglaciation of the TIS from the Kalevala end moraine to the Lake Pääjärvi end moraine took place between ca. 11 300 – 10 900 calendar years ago. It seems that the terminus of the KIS marker by the Kalevala end moraine was also formed around 11 300 calendar years ago but the KIS remained active longer than the TIS. Both of these sub-ice streams terminated into a glacial lake that was part of a larger White Sea Basin ice lake.

Stable carbon and oxygen isotope analyses were conducted on pedogenic carbonates collected from a continuous, late Neogene terrestrial sequence located in Lantian, in the Chinese Loess Plateau. The sequence consists of 300 m of fluvial deposits (Bahe Formation) with a basal age of ca. 11 Ma overlain by ca. 50 m thick sequence of aeolian ‘Red Clay’ (Lantian Formation) deposited between 6.8 and 2.6 Ma. Pedogenic carbonates from the fluvial part of the sequence (i.e., the Bahe Formation) show only slight variation in δ 13 C and δ 18 O values suggesting that no marked change in plant photosynthetic pathway or climate took place during ca. 10–6.8 Ma. The carbon isotope compositions imply a pure C 3 vegetation. However, most data are in the upper C 3 plant range suggesting that water stress conditions prevailed in the area. A shift in both carbon and oxygen stable isotope curves occur at the boundary of the two formations where the sedimentation regime changed from fluvial to mainly aeolian. The δ 13 C record shows more depleted values in the Lantian Formation with no indications of C 4 plant contribution in the soil carbonate except for the youngest sample at ca. 2.7 Ma. The formation boundary marks a general rise in δ 18 O values. Moreover, the δ 13 C and δ 18 O values scatter more in the Lantian Formation compared to those measured from the Bahe Formation. As the shift in δ 13 C and δ 18 O values at the formation boundary is concurrent, we hypothesize that the reason for the changes in both values are mostly interrelated. The changes probably reflect increased summer precipitation related to the onset and/or intensification of the Asian monsoon system. Sedimentological and fossil vertebrate analyses suggest that stable environments with relatively dry conditions prevailed during the time when the Bahe Formation was laid down. Slightly below the formation boundary there is a faunal turnover event implying a marked change into more humid and closed habitats. The paleoenvironmental patterns deduced from carbon and oxygen isotopes are in good agreement with the palaeoenvironments inferred from sedimentological and paleontological studies from the Lantian area.

An important key site along the Bahe River in the Lantian area, Shaanxi Province, northern China exposes a conformable sedimentary sequence that records the transition from early Late Miocene fluvial sediments into Late Miocene and Pliocene aeolian Red Clay, and finally into Pleistocene loess. Although the Red Clay and Pleistocene loess in northern China have been intensively studied over the years, the Bahe Formation, beneath the Red Clay in the Lantian area, has been less well studied. Here we present the preliminary results of a detailed lithostratigraphical investigation of the Bahe Formation on the northern slopes of the Bailuyuan Plateau and discuss the style of sedimentation during its deposition. The Bahe Formation in the Lantian area, is composed of fluvial and lacustrine deposits laid down in the Weihe Graben during the Late Miocene. Six main facies assemblages have been distinguished: (1) massive or crudely bedded conglomerates, (2) cross-stratified conglomerate and sandstone deposits, (3) minor sandstone deposits, (4) fine-grained deposits, (5) gritty mudstone and sandstone deposits and (6) marl deposits. These assemblages represent the deposits of active channels, crevasse splays, sheet floods, and floodplains with paleosols and lakes. Thick and laterally pervasive units of fine-grained sediments, formed as suspension fall-out on the floodplain, indicating low-energy conditions and a relatively gentle surface gradient in the area, are by far the most common sedimentary component. Channel-related sandstones and conglomerates indicate that the rivers had a low-sinuosity and were braided, to anastomosing types. The Bahe fluvial system operated for several million years in a tectonically inactive setting in a vegetated area under a relatively arid climate. This environmental interpretation is consistent with that derived from the interpretation of the vertebrate fossil fauna recovered from the sediments.

Lithostratigraphical methods combined with absolute dating (OSL and 14C) were used to establish the Late Pleistocene stratigraphy and the Last Glacial Maximum (LGM) limit of the Scandinavian Ice Sheet south and east of the Lake Onega Basin. An estimate of the ice growth rate for the southeastern sector of the ice sheet, from western Finland to the LGM limit in the northeast Russian Plain is also presented. In addition, an interpretation of palaeoenvironments that existed during the LGM in the Vologda and adjacent areas is also discussed. Evidence from boreholes and exposures indicate that the Scandinavian Ice Sheet entered the Vologda and southern Arkhangelsk area, only once during the last cold stage, during the Late Valdai (Weichsel). It is also concluded that the Scandinavian Ice Sheet reached its maximum at ca. 18 000 calendar years ago in the Vologda area and its extent was more restricted than previously thought. The timing of the LGM at 18 ka presented here, combined with recent ice growth results from Finland, suggest that the southeastern sector of the Scandinavian Ice Sheet expanded across Finland to its maximum position in the northern Russian Plain in 7000 calendar years.

Nine representative sediment sequences and pollen diagrams obtained during the Quaternary mapping programme carried out by the Geological Expedition (St. Petersburg, Russia) between 1960s and 1980s are presented from the Vologda area, NW Russian Plain, covering the time span from the Moscow cold (Saale) stage into the Late Valdai (Weichsel) substage. This work was done in order to shed light on the evolution of palaeoenvironments, vegetation and climate in the area. The results suggest that two major depressions in the Vologda area, namely the Mologa–Sheksnian and Prisukhonian basins, witnessed lake level fluctuations that were most likely closely linked to climatic fluctuations. It is suggested that during the Mikulino (Eem) thermal optimum most of the lowland areas were dry land. However, during the Early and Middle Valdai, the large depressions started to flood as a result of wet and cold climate. This caused the accumulation of lacustrine and also lacustrine–alluvial and lacustrine–bog sediments into the basins. The Valdai forest composition varied between closed spruce–birch forests and treeless tundra. Lakes persisted throughout the Valdai stage including the extremely dry last glacial maximum (LGM)-time when the Scandinavian Ice Sheet dammed the northbound rivers in the Vologda area.

New radiocarbon dates from Finnish subfossil mammoth material (Mammuthus sp.), transported by glacial ice, range in age from ca. 32000 to ca. 22500 yr BP. These results suggest that there was a larger ice-free area in Fennoscandia during the Middle Weichselian than previously assumed. In addition, two dates are also presented for bones found in clay with a different transport history. Copyright © 1999 John Wiley & Sons, Ltd.

Middle Pleistocene Glaciations . In Lapland and western Finland there are sites where till or glaciofluvial deposits underlie Eemian organic sediments. Many of them are correlative to the Saalian glaciation. At Naakenavaara a Holsteinian peat is underlain by the Elsterian till unit. These sites provide the basis for the general Quaternary stratigraphy of Finland. Late Pleistocene Glaciations . After the Eemian Stage interglacial two Early Weichselian stadials and two interstadials (Brorup, MIS 5c and Odderade, MIS 5a) have been found. The extent of the Middle Weichselian ice sheet is still unknown. Finland was ice covered during Late Weichselian Substage and was completely deglaciated by 10 ka ago.

The isostatic adjustment of the solid Earth to the glacial loading (GIA, Glacial Isostatic Adjustment) with its temporal signature offers a great opportunity to retrieve information of Earth’s upper mantle to the changing mass of glaciers and ice sheets, which in turn is driven by variations in Quaternary climate. DynaQlim (Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas) has its focus to study the relations between upper mantle dynamics, its composition and physical properties, temperature, rheology, and Quaternary climate. Its regional focus lies on the cratonic areas of northern Canada and Scandinavia.

The recent mass loss of the Greenland ice sheet (Chen et al. 2006), the observed increases in the velocity of its fast-flowing outlets (Luthcke et al. 2006) and the melting of the permafrost demonstrate the profound changes occurring in the Arctic region as a result of global warming (ACIA 2005). This is corroborated by systematic satellite monitoring that shows there has been a progressive decrease in the extent of sea ice over the last 30 years, with a record low in 2007 (Comiso et al. 2008). Forward modelling predicts accelerated rates of sea-ice disintegration and the almost complete disappearance of Arctic Ocean summer sea-ice cover within this century. It is clear that the environment in the Arctic is changing at a pace not previously monitored by humankind. It is equally clear, however, that to place the current changes in a millennial time perspective, we need to know more about the Pleistocene natural variability and amplitude of, for example, the Greenland ice sheet, Arctic Ocean sea ice and permafrost. Such a longer time perspective can only be established through international collaborative and multidisciplinary studies of nature’s own archives, such as marine and terrestrial stratigraphic records, sediment distribution and landforms.

The marginal configurations and ages of the Valdaian (Weichselian) glacial maxima in northern Russia have hitherto not been well established, thus, numerous versions of the Last Glacial Maximum (LGM) positions of the Scandinavian Ice Sheet are known ( Fig. 1B ). New data on ice sheet growth and decay indicate at least three glacial maxima during the Late Pleistocene each with individual spreading centres and different ages. Results of modern investigations in the Arkhangelsk region, conducted by the authors, are compared with an analysis of previous data on the Late Quaternary geology of Northwest Russia, which comprises a thorough presentation of Russian literature on this subject. This has allowed us to question and revise former models on Valdaian glaciation history and ice-marginal positions in a major part of the Russian North. An Early-Middle Valdaian (c. 70 ka BP) glaciation from the east and southeast, possibly originating on the Timan ridge, crossed the Pyoza River basin and reached the White Sea coast along the Bay of Mezen. The southern terminus of the ice sheet is probably found along parts of the Mezen River ( Fig. 2A,B ). The presence of an Early-Middle Valdaian Scandinavian glaciation, which covered the Arkhangelsk region and in neighbouring areas of Karelia and Vologda is not supported by geological data. In the Middle Valdaian (c. 70 ka BP) an ice sheet from the Barents-Kara Sea flowed from the north, northeast and reached the lower Pyoza River and the south and western shores of Mezen Bay on the White Sea coast. The terminal formations of its maximal stage stretch from west to east just north of Pyoza River and then run marginal to the Timan ridge from the north joining with the Markhida end-moraines on the Pechora Lowland ( Fig. 2A, B ). During the Late Valdaian, the Scandinavian Ice Sheet occupied the northwestern part of the Arkhangelsk region around 19-17 ka BP. The limit of this Late Valdaian glacial maximum runs from the White Sea shore of the Kanin Peninsula in the north, along the Kuloi River south of Mezen to the Middle Pinega River, crossing the rivers Severnaya Dvina and Vaga near the villages of Cherevkovo and Ust-Padenga. The glacial boundary bordered the Melovian and Nyandoma high ground and continued southwestwards to Lake Kubenskoe in the Vologda region. The Pyoza, Mezen and Vashka river basins remained ice-free during the Late Valdaian time, this area being covered by fluvial flood plains, with abundant evidence of permafrost and lakes. The latter have yielded pollen evidence indicating an arctic to subarctic environment between 18-10 ka BP ( Fig. 2A, B ).

During the Quaternary period, ice sheets centred over the Barents and Kara seas expanded several times onto mainland Russia and blocked northflowing rivers, such as the Yenissei, Ob, Pechora and Mezen. Large ice-dammed lakes with reversed outlets, e.g. toward the Caspian Sea, formed south of these ice sheets. Some lakes are reconstructed from shorelines and lacustrine sediments, others mainly from ice-sheet configuration. Ice-dammed lakes, considerably larger than any lake on Earth today, are reconstructed for the periods 90-80 and 60-50 ka. The ages are based on numerous optically stimulated luminescence (OSL) dates. During the global Last Glacial Maximum (LGM, about 20 ka) the Barents-Kara Ice Sheet was too small to block these eastern rivers, although in contrast to the 90-80 and 60-50 ka maxima, the Scandinavian Ice Sheet grew large enough to divert rivers and meltwater across the drainage divide from the Baltic Basin to the River Volga, and that way to the Caspian Sea. Climate modelling shows that the lakes caused lower summer temperatures on the continent and on the lower parts of the ice sheet. The final drainage of the best mapped lake is modelled, and it is concluded that it probably emptied within few months. We predict that this catastrophic outburst had considerable impact on sea-ice formation in the Arctic Ocean and on the climate of a much larger area. (C) 2003 Elsevier Ltd. All rights reserved. (Less)

This paper summarizes the results of studies of the Late Weichselian periglacial environments carried out in key areas of northern Eurasia by several QUEEN teams (European Science Foundation (ESF) programme: “Quaternary Environment of the Eurasian North”). The palaeoglaciological boundary conditions are defined by geological data on timing and extent of the last glaciation obtained in the course of the EU funded project “Eurasian Ice Sheets”. These data prove beyond any doubt, that with the exception of the northwestern fringe of the Taymyr Peninsula, the rest of the Eurasian mainland and Severnaya Zemlya were not affected by the Barents–Kara Sea Ice Sheet during the Last Glacial Maximum (LGM). Inversed modelling based on these results shows that a progressive cooling which started around 30 ka BP, caused ice growth in Scandinavia and the northwestern areas of the Barents–Kara Sea shelf, due to a maritime climate with relatively high precipitation along the western flank of the developing ice sheets. In the rest of the Eurasian Arctic extremely low precipitation rates (less than 50 mm yr−1), did not allow ice sheet growth in spite of the very cold temperatures. Palaeoclimatic and palaeoenvironmental conditions for the time prior to, during, and after the LGM have been reconstructed for the non-glaciated areas around the LGM ice sheet with the use of faunal and vegetation records, permafrost, eolian sediments, alluvial deposits and other evidences. The changing environment, from interstadial conditions around 30 ka BP to a much colder and drier environment at the culmination of the LGM at 20–15 ka BP, and the beginning of warming around 15 ka BP have been elaborated from the field data, which fits well with the modelling results.

This chapter discusses the glaciation history of Finland. According to the Finnish till stratigraphy, there are six stratigraphically significant till beds in Finnish Lapland. The uppermost three represent Weichselian tills. The so-called Till Bed IV was laid down during the Saalian glaciation, and the two lowermost till beds that underlie a Holsteinian peat stratum may represent Elsterian or pre-Elsterian tills. Although Elsterian or pre-Elsterian tills are preserved at scattered localities in northern Finland, there is no conclusive evidence for pre-Saalian tills in Southern Finland. In southern Finland, there are no end-moraines related to the early or middle Weichselian ice advances. Information on the extent of the ice streams is limited and based on the distribution of interstadial organic remnants and till stratigraphy. The stratigraphy of the Early and Middle Weichselian substages in Northern Finland is based on the correlation of interstadial organic deposits, till stratigraphy and till-covered glaciofluvial landforms. Many stratigraphically important areas and key localities are situated in the ice divide zone in Central Lapland. It appears that the processes of glacial erosion and deposition were ex-ceptionally weak in this zone.

The maximum limits of the Eurasian ice sheets during four glaciations have been reconstructed: (1) the Late Saalian (>140 ka), (2) the Early Weichselian (100–80 ka), (3) the Middle Weichselian (60–50 ka) and (4) the Late Weichselian (25–15 ka). The reconstructed ice limits are based on satellite data and aerial photographs combined with geological field investigations in Russia and Siberia, and with marine seismic- and sediment core data. The Barents-Kara Ice Sheet got progressively smaller during each glaciation, whereas the dimensions of the Scandinavian Ice Sheet increased. During the last Ice Age the Barents-Kara Ice Sheet attained its maximum size as early as 90–80,000 years ago when the ice front reached far onto the continent. A regrowth of the ice sheets occurred during the early Middle Weichselian, culminating about 60–50,000 years ago. During the Late Weichselian the Barents-Kara Ice Sheet did not reach the mainland east of the Kanin Peninsula, with the exception of the NW fringe of Taimyr. A numerical ice-sheet model, forced by global sea level and solar changes, was run through the full Weichselian glacial cycle. The modeling results are roughly compatible with the geological record of ice growth, but the model underpredicts the glaciations in the Eurasian Arctic during the Early and Middle Weichselian. One reason for this is that the climate in the Eurasian Arctic was not as dry then as during the Late Weichselian glacial maximum.

Sedimentary sequences in Isoniemi and Hangaskangas in the Oulu area of Finland have been studied using conventional sedimentological techniques including structural and clast-fabric measurements on fold and fault structures and till units. Four different facies were identified from the sequence in the Isoniemi area and three in the Hangaskangas area. In the Isoniemi area, the measurements of glaciotectonic deformation and till clast-fabric analyses can be related to the ice movement from the south-west and the subsequent ice front oscillation from the north-west. These ice movement phases are thought to have taken place during the Late Weichselian. In the Hangaskangas area, the south-western shear-stress direction crosscuts the sediment strata indicating that the latest ice movement came from that direction during the Late Weichselian. However, there is also indication of an earlier shear-stress in the Hangaskangas area indicating the north-western ice movement. The age of this ice movement phase is thought to be older than the Late-Weichselian.