impact of bedrock surface topography on spatial distribution of quaternary sediments and on the flow pattern of late weichselian glaciers on the east european craton russian plain this paper presents the first high quality maps of the bedrock surface topography and the quaternary sediment distribution for the late weichselian glaciation area on the east european craton eec and the reasoning behind the estimated sediment distribution geographic information system gis based three dimensional model of the bedrock surface topography the current digital terrain model dtm and the ice flow pattern of the last glaciation provided the main source data for the analyses and interpretations in the current continental area of the western eec which was covered by the last scandinavian ice sheet sis the bedrock lies overwhelmingly 85 above the contemporary sea level with an average altitude of 54 m above sea level the topography of the bedrock surface is very well reflected in the current topography and an 80 m difference in the ice bed surface altitudes results in the topographic focusing of the ice flow and thus all late weichselian ice streams were accommodated to the depressions in the subglacial surface such depressions are characterised by a thin 10 m layer of sediment with one till bed just 50 m upslope from the bottom of the depressions the thickness of the sediment increases two to threefold and comprises five or more till layers indicating relief enhancement through subsequent glaciations the average calculated thickness of the quaternary deposits in the study area was 49 m and the total volume of sediments was 20 280 km3

the last glaciation of earth size and volume of ice sheets abstract the volume and size of the late glacial ice sheets in the northern hemisphere has been estimated based on geomorphic and chronostratigraphic data limited glacial extents during the late glacial maximum characterized both arctic canada and northern eurasia in contrast to the presence of the large laurentide scandinavian and devensian ice sheets to the south glacial maxima were not synchronous throughout the northern hemisphere for example the novaya zemlya ice sheet reached its maximum extent ca 39 000 bp approximately 20 000 years earlier than the maximum extent of the contiguous scandinavian ice sheet western and central siberia and the chukhui peninsula were marked by limited glaciation during the last glacial maximum although pre sartanian events were more extensive mountain glaciation in northeast asia was similarly restricted during the last glacial maximum spatial and dynamic characteristics of the last glaciation developed in response to climatic factors the establishment and strength of high pressure systems over siberia limited precipitation and glacier formation throughout northeastern eurasia

hydrocarbons and inorganic gases in the gravberg 1 well siljan ring sweden abstract hydrocarbons and inorganic gases have been analyzed in the drilling fluid of the gravberg 1 well siljan ring sweden which represents the first commercial exploration for mantle derived methane hydrocarbons detected to a depth of 6 6 km have been in trace amounts dissolved in the drilling fluid low concentrations of hydrocarbons from granite intervals are rich in unsaturated hydrocarbons and may result from abiogenic synthesis from inorganic carbon species in the granite or may be synthesized during drilling operations from organic precursors in the drilling fluid below 5 km higher hydrocarbon concentrations in granite intervals are correlated with two different lubricants added to the drilling fluid these gases are characterized by distinctive suites of hydrocarbons especially in the c4 c6 range the effects of hydrocarbon production from these and other additives are particularly pronounced in this well due to the low concentration of indigenous hydrocarbons the highest concentrations of methane were enriched in 13c 13 c 26 and were associated with several dolerite intrusions in the granite rocks this methane was present in both a core and cuttings and is similar to methane isolated from dolerite in a well recently drilled in massachusetts u s a the methane may have a deep upper mantle origin or may be a product of abiogenic synthesis in crustal rocks significant quantities of h2 and he occurring deeper than 6 km appear to have a low temperature crustal origin there is no evidence of significant amounts of upper mantle he in the gravberg 1 gases

southwest scandinavia 40 15 kyr bp palaeogeography and environmental change twelve palaeogeographical reconstructions illustrate environmental changes at the southwest rim of the scandinavian ice sheet 40 15 kyr bp synchronised land sea and glacier configurations are based on the lithostratigraphy of tills and intertill sediments dating is provided by optically stimulated luminescence and calibrated accelerator mass spectrometry radiocarbon an interstadial sequence ca 40 30 kyr bp with boreo arctic proglacial fjords and subarctic flora and occasional glaciation in the baltic was succeeded by a last glacial maximum sequence ca 3020 kyr bp with the closure of fjords and subsequent ice streams in glacial lake basins in kattegat and the baltic steadily flowing ice from sweden bordered the norwegian channel ice stream a deglaciation sequence ca 20 15 kyr bp indicates the transgression of arctic waters retreat of the swedish ice and advance of baltic ice streams succeeded by a return to interstadial conditions when ameliorated ice free conditions prevailed in maritime regions glaciers advanced through the baltic and when interstadial regimes dominated the baltic glaciers expanded off the norwegian coast the largest glacier extent was reached in the north sea around 29 kyr bp about 22 kyr bp in denmark and ca 18 kyr bp in the baltic our model provides new data for future numerical and qualitative landform based models copyright c 2003 john wiley sons ltd less

implications for the late pleistocene climate in finland and adjacent areas from the isotopic composition of mammoth skeletal remains nine samples of subfossil bone and teeth remains from woolly mammoth mammuthus primigenius discovered in finland russian karelia and western russia were analyzed for the oxygen isotope composition of the phosphate fraction and the carbon and oxygen isotope composition of the carbonate fraction in skeletal apatite the samples have been radiocarbon dated in previous studies and are of late middle weichselian to late weichselian age the preservation of the samples was tested analyzing the chemical composition and checking the isotopic equilibrium between the phosphate and carbonate components in skeletal apatite according to these tests five out of the nine samples were determined to have retained their original isotopic composition these samples were used to estimate late pleistocene climatic conditions in finland and neighboring areas based on the best preserved enamel samples the isotopic composition of oxygen in late pleistocene precipitation was 1 3x lower than that in the mean annual precipitation in southern and central finland today using the relationship between the isotopic composition of precipitation and the ambient temperature it can be estimated that the mean temperatures during the middle weichselian ice free period were 2 6 8c lower compared to the present day values d 2005 elsevier b v all rights reserved

early mis 3 glacial lake evolution ice marginal retreat pattern and climate at sokli northeastern fennoscandia lake development at sokli northern finland is traced through the analysis of diatoms and other siliceous micro fossils in a 2 meter thick minerogenic laminated clay silt deposit dated to the early part of marine isotope stage mis 3 fluctuating water levels and changes in lake extent depicted by the siliceous micro fossil record together with lithology suggest that an important part of the sediment sequence was deposited in a glacial lake the proxy based glacial lake evolution is tested using a digital elevation model and geomorphologic evidence including eskers dated to the early mis 3 tulppio interstadial at sokli despite the apparent ice dammed nature of the lake the sediment is relatively rich in fossils and there are limited signs of re deposition of older fossil material the siliceous micro fossil record together with data from other proxies previously analysed in the same sediment samples provides a coherent picture of past environmental changes around the sokli site this is most probably due to the sheltered position of the coring site in a lake embayment quantitative climate reconstructions based on the diatom record show mean july air temperatures as high as present day values at sokli and the temperature ranges indicated by the diatom record are in agreement with temperature reconstructions based on chironomids the position of sokli in the northeastern portion of the central area of the scandinavian glaciations and the northern retreat pattern implies that an important part of eastern fennoscandia was deglaciated during the early mis 3 warming event

luminescence chronology of late pleistocene loess paleosol and tephra sequences near fairbanks alaska abstract thermoluminescence tl and infrared stimulated luminescence irsl sediment dating methods have been applied to paleosol and tephra bearing loess sequences younger than marine oxygen isotope stage mis 7 at three important sites tl ages indicate the development of significant paleosols 75 000 and 30 000 yr ago in the loess sequence at the gold hill site relatively minor soil development occurred 70 000 and 48 000 yr ago like the 75 000 yr old soil the 30 000 yr old soil is apparently of global extent and consistent in timing with inferred warm intervals elsewhere e g greenland europe western and central china at birch hill replicate tl dating of primary loess combined with two earlier tl results from the same site and with an earlier mean fission track glass shard age of 140 000 10 000 yr for the associated old crow tephra yield a more precise numeric age of 142 300 6600 yr for this alaska yukon chronostratigraphic marker ash bed three of the tl ages at the halfway house site are difficult to interpret but combined with other evidence they indicate 1 the upper 5 6 m of loess from halfway house is not part of the gold hill loess equivalent to pre mis 5 age as long thought by t l pewe but rather is much younger 2 the regionally significant variegated tephra found in the fairbanks and klondike areas and previously thought to be older than mis 5 has an age of 77 800 4100 yr late mis 5

middle wisconsinan marine shells near repulse bay nunavut canada implications for marine isotope stage 3 ice free conditions and laurentide ice sheet dynamics in north west hudson bay

mis 3 mammoth remains from sweden implications for faunal history palaeoclimate and glaciation chronology the distribution of low arctic megafaunal remains in time and space from the area previously covered by the scandinavian ice sheet sis suggests the presence of breeding mammoth populations in the circum baltic region during the time interval from 44 to 26 ka ago the transport history of 30 mammoth teeth and bones from southern and north central sweden was estimated and the remains were subjected to osteological analyses and 14c dating oxygen isotope analyses of tooth enamel indicate a palaeoclimate considerably more homogenous than that experienced in sweden today showing moderate north south gradients in the d18o value of precipitation and temperature in general the results support the model of restricted ice sheet distribution during the second half of the middle weichselian the clear discrepancy in the inferred absence of glaciation in the central swedish uplands and the baltic basin as evidenced by the swedish mammoth data versus the danish osl based glaciation chronology in the period from 40 to 30 ka ago is discussed in the light of radiocarbon calibration and glacial dynamics r 2007 published by elsevier ltd less

extent and dynamics of the scandinavian ice sheet during oxygen isotope stage 3 65 000 25 000 yr b p the climate of the middle weichselian glaciation marine oxygen isotope stage 3 ois 3 a relatively mild period compared to the glacial maxima of ois 4 and ois 2 consisted of long warm interstades punctuated by brief cold excursions that grew colder and more frequent with time the ois 4 ice sheet is generally thought to have persisted throughout ois 3 but evidence from dated ois 3 interstadial deposits suggests that it was swiftly reduced to small remnants which only briefly expanded and retreated only 30 000 years ago the deteriorating climate initiated a sustained ice advance leading toward the final glacial maximum of ois 2 dynamic ice sheet models support the existence of a prolonged ice free interval during ois 3 induced perhaps by low precipitation due to extensive sea ice cover offshore

carbon isotope systematics of the cambrian vendian aquifer system in the northern baltic basin implications to the age and evolution of groundwater groundwater in the cambrian vendian aquifer system has a strongly depleted stable isotope composition 18o values of about 22 and a low radiocarbon concentration which suggests that the water is of glacial origin from the last ice age the aim of this paper was to elucidate the timing of infiltration of glacial waters and to understand the geochemical evolution of this groundwater the composition of the dissolved inorganic c dic in cambrian vendian groundwater is influenced by complex reactions and isotope exchange processes between water organic materials and rock matrix the 13c composition of dissolved inorganic c in cambrian vendian water also indicates a bacterial modification of the isotope system the corrected radiocarbon ages of groundwater are between 14 000 and 27 000 radiocarbon years which is coeval with the advance of the weichselian glacier in the area

modelling of the bedrock response to glacial loading at the olkiluoto site finland the olkiluoto island is situated in baltic sea near the southwestern coast of finland the most abundant rock type is migmatic mica gneiss intruded by tonalites granodiorites and granites response of bedrock at olkiluoto site was modelled with 3dec program considering four future ice age scenarios each scenario produces shear displacements of fractures with different time of occurrence and varying recovery rate generally the larger the maximum ice load the larger the permanent shear displacements will be for basic case the maximum shear displacements were few centimeters at suggested nuclear waste repository level the sensitivity study performed showed that shear stiffness and joint friction angle of bedrock structures are the most critical parameters for bedrock displacements

reflection of scandinavian ice sheet fluctuations in norwegian sea sediments during the past 150 000 years the record of glacier fluctuations in western scandinavia as reconstructed from continental data has been correlated with records of ice rafted detritus ird from well dated sediment cores from the norwegian sea covering the past 150 000 yr b p the input of ird into the ocean is used as a proxy for ice sheet advances onto the shelf and thus for the calibration of a glaciation curve the marine results generally support land based reconstructions of glacier fluctuations and improve the time control on glacial advances the saalian ice sheet decayed very rapidly approximately 125 000 yr b p in the early weichselian a minor but significant ird maximum indicates the presence of icebergs in isotope substage 5b especially between 95 000 and 83 000 yr b p reduced amounts of calcareous nannofossils indicate that surface waters were influenced by meltwater discharges during isotope substages 5d and 5b an extensive build up of inland ice began again during isotope stage 4 but maximum glaciation was reached only in early stage 3 58 000 53 000 yr b p marine sediments have minimum carbonate content indicating strong dilution by lithogenic ice rafted material generally the ird accumulation rate was considerably higher in stages 4 2 than in stage 5 a marked peak in ird accumulation rates from 47 000 to 43 000 yr b p correlates well with a second middle weichselian ice sheet advance dated by the laschamp olby paleomagnetic event minimum ice extent during the alesund interstade 38 500 32 500 yr b p and several glacial oscillations during the late weichselian are also seen in the ird record of several late weichselian glacial oscillations on the shelf at least four correspond to the north atlantic heinrich events ice sheet behavior was either coupled or linked by external forcing during these events whereas internal ice sheet mechanisms may account for the noncoherent fluctuations

the last interglacial glacial cycle in fennoscandia abstract the climate and glacier fluctuations during the last interglacial glacial cycle in fennoscandia seem to correspond roughly in time with the climate fluctuations recorded in france germany holland however the climate in fennoscandia was considerably colder and the coldest phases are recorded as periods with glacier fluctuations admittedly the exact age and amplitudes of some fluctuations are still much debated

the last interglacial glacial cycle mis 5 2 re examined based on long proxy records from central and northern europe abstract current multi proxy studies on a long sediment sequence preserved at sokli n finland i e in the central area of fennoscandian glaciations are drastically changing classic ideas of glaciations vegetation and climate in northern europe during the late pleistocene the sediments in the sokli basin have escaped major glacial erosion due to non typical bedrock conditions in this review the sokli record is compared in great detail with other long proxy records from central temperate and northern boreal europe these comprise the classic records of la grande pile e france and oerel n germany and more recently obtained records from horoszki duze e poland and lake yamozero nw russia the focus of the review is on pollen lithology and macrofossil and insect based temperature inferences the long records are further compared with recent proxy data from nearby terrestrial sites as well as with the rapidly accumulating high resolution proxy data from the ocean realm the comparison allows a re examination of the environmental history and climate evolution of the last interglacial glacial li g cycle mis 5 2 it shows that environmental and climate conditions during mis 5 ca 130 70 ka bp were distinctly different from those during mis 4 2 ca 70 15 ka bp mis 5 is characterized by three long forested intervals broadly corresponding to mis 5e 5c 5a both in temperate and northern boreal europe these mild periods were interrupted by two short relatively cold and dry intervals mis 5d and 5b with mountain centered glaciation in fennoscandia millennial scale climate events were superimposed upon these longer lasting climate fluctuations the time interval encompassing mis 4 2 shows open vegetation it is characterized by two glacial maxima mis 4 and 2 with sub continental scale glaciation over northern europe and dry conditions in strongly continental eastern european settings high amplitude climate oscillations of millennial duration characterized the climate variability of mis 3 mild climate conditions in early mis 3 caused large scale deglaciation of the fennoscandian ice sheet and ice free conditions with betula dominated vegetation including tree birch persisted over large parts of fennoscandia possibly interrupted by glaciation during major part of mis 3 till ca 35 ka bp overall mis 5 was mostly mild with warmest or peak interglacial conditions at the very start during mis 5e mis 4 2 was mostly cold with most extreme or peak glacial conditions in the closing phase during mis 2 this points to a subdivision of the last climate cycle into an early overall mild interglacial half and a late overall cold glacial half each with duration of ca 50 ka this review also shows that the climate variability in central and northern europe during the li g cycle was mostly in degrees of continentality with major shifts in winter temperature and precipitation values summer temperatures on the other hand remained largely unchanged it points to the waxing and waning of sea ice over the north atlantic ocean as a possible characteristic feature of the late pleistocene the present compilation based on long terrestrial sequences high resolution multi proxy data from the oceans and quantified paleo climate data strongly favors a definition of entire marine oxygen isotope stage 5 as the last interglacial similar as in the original marine stratigraphy and the stratigraphy at la grande pile in france the proxy based climate data places the start of the last glacial at the base of mis 4 and the northwest european pleniglacial it shows that the division between the eemian mis 5e and the early weichselian mis 5d a is not useful as not relevant from a climate point of view

the latest woolly mammoths mammuthus primigenius blumenbach in europe and asia a review of the current evidence abstract during the last cold stage woolly mammoths ranged very widely across northern eurasia into north america but then disappeared as part of the global phenomenon of late quaternary megafaunal extinction the timing and causes of this highly significant event have generated conflicting opinions and much debate however the overriding need is for more data and recent years have seen the accumulation of significant new finds and radiocarbon dating evidence in particular research is currently focussing on the geographical pattern of extirpation leading to final extinction rather than seeking a single last appearance datum this viewpoint article was commissioned by the editor in chief and is published following the paper by lougas et al dating the extinction of european mammoths new evidence from estonia quat sci rev 21 2002 1347 to place their finding in a wider context we give a brief review of the youngest directly dated mammoth remains from different regions of eurasia based both on published sources and on our own current research this includes a very important new record from cherepovets north russian plain which together with the new date from puurmani estonia indicates the persistence of mammoth in this region close to the pleistocene holocene boundary these and other records suggest that the previous picture of mammoths widespread before 12 000 ka bp uncalibrated radiocarbon years ago then restricted to limited areas of northern siberia although correct in outline has important exceptions which modify our understanding of mammoth extinction despite the many available radiocarbon dates for eurasian mammoth relative to other extinct megafauna it is apparent that much more work is needed only then can we adequately tackle the important question of the cause or causes of extinction whether by climatic environmental change or overkill by human hunters

origin and formation of methane in groundwater of glacial origin from the cambrian vendian aquifer system in estonia abstract groundwater in the cambrian vendian aquifer system in estonia is characterised by the most depleted isotopic composition known in europe 18o down to 23 the water most likely originates from glacial meltwater recharge from the fennoscandian ice sheet in the pleistocene the aquifer system is characterised by relative high methane concentrations up to 50 of dissolved gases estimated absolute concentration up to 1600 mol l 1 the origin of which has so far remained unclear in this paper we focus on the origin of methane the factors controlling its spatial distribution and its isotope geochemistry in the aquifer system the data reveal a large spatial variability in methane concentration 13cch4 and 2hch4 values from 6 to 105 and from 220 to 420 respectively we show that local oxidation processes rather than different pathways of methane formation have affected the initial isotopic composition of methane using the least modified 13cch4 values from 85 to 105 we conclude that methane most likely originates from the organic material overridden by the fennoscandian ice shield during the late weichselian glaciation that was carried into the aquifer system with infiltrating glacial meltwater the estimated 18o values of the water where the methane was formed are 17 1 5 supporting the inference that the methane was formed during the middle weichselian interstadial the study shows that groundwater of glacial origin in the cambrian vendian aquifer system can serve as an alternative palaeoenvironmental archive to be used for studying the variations in climatic and environmental conditions in northern europe during glacial interglacial cycles of the pleistocene

woolly mammoth mammuthus primigenius blum and its environment in northern europe during the last glaciation abstract woolly mammoths were large herbivorous cold adapted mammals of the late pleistocene the diet and habitat requirements of the species set certain constraints on the palaeoenvironments it could occupy the relationship between the mammoth s shifting range and changing environments can be explored using independent data on ice sheet configuration temperature and vegetation provided the locality and age of the fossil remains can be validated here we present a comprehensive record of occurrence of the woolly mammoth in the circum baltic region of northern europe during the last glaciation based on a compilation of radiocarbon dated remains the record shows that the mammoth was widespread in northern and north eastern europe during marine isotope stage 3 mis 3 at 50 000 30 000 calibrated years ago 50 30 ka the presence of the species up to 65 n latitude supports the restriction of the scandinavian ice sheet sis during mis 3 the widest distribution range round 30 ka was followed by a decline that led to the disappearance of mammoths from the area during the maximum extent of the sis from 22 to 18 ka the woolly mammoth re colonized the baltic region and southern scandinavia after the onset of the late glacial deglaciation at 17 ka the late glacial record suggests a markedly fluctuating population changing its range in tune with the rapid environmental changes the last appearance of mammoth in our study region was in estonia during the younger dryas greenland stadial 1 gs1 at about 12 ka the two major periods of occurrence during mis 3 and the late glacial stadial suggest that mammoth had a wide tolerance of open to semi open tundra and steppe tundra habitats with intermediately cold climate whereas the 22 18 ka disappearance suggests a major southward and or eastward retreat in response to extremely cold glacial conditions near the sis margin the final regional extinction correlates with the re forestation during the rapid warming at the younger dryas holocene boundary

fennoscandian palaeoglaciology reconstructed using a glacial geological inversion model the evolution of ice sheet configuration and flow pattern in fennoscandia through the last glacial cycle was reconstructed using a glacial geological inversion model i e a theoretical model that formalises the procedure of using the landform record to reconstruct ice sheets the model uses mapped flow traces and deglacial melt water landforms as well as relative chronologies derived from cross cutting striae and till lineations as input data flow trace systems were classified into four types i time transgressive wet bed deglacial fans ii time transgressive frozen bed deglacial fans iii surge fans and iv synchronous non deglacial event fans using relative chronologies and aggregation of fans into glaciologically plausible patterns a series of ice sheet configurations at different time slices was erected a chronology was constructed through correlation with dated stratigraphical records and proxy data reflecting global ice volume geological evidence exists for several discrete ice sheet configurations centred over the scandinavian mountain range during the early weichselian the build up of the main weichselian fennoscandian ice sheet started at approximately 70 ka and our results indicate that it was characterised by an ice sheet with a centre of mass located over southern norway this configuration had a flow pattern which is poorly reproduced by current numerical models of the fennoscandian ice sheet at the last glacial maximum the main ice divide was located overthe gulf of bothnia a major bend in the ice divide was caused by outflow of ice to the northwest over the lowest part of the scandinavian mountain chain widespread areas of preserved pre late weichselian landscapes indicate that the ice sheet had a frozen bed core area which was only partly diminished in size by inward transgressive wet bed zones during the decay phase

new radiocarbon dates from finnish mammoths indicating large ice free areas in fennoscandia during the middle weichselian 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

study of directivity effect on electromagnetic emissions in the hf band as earthquake precursors preliminary results on field observations abstract this work focuses on the use of electromagnetic emissions em in the hf band as a warning event for earthquakes em at hf components 41 mhz and 46 mhz were monitored and recorded from eight field stations in greece and correlated with seismological events directivity effect raised since em emissions at specific station locations were correlated to earthquake events from prescribed regions em recordings during 1999 were used and by visual inspection were associated to most of the earthquake events greater than 5r using these observations a novel algorithm based on the ratio of short term to long term signal average together with a prediction rules set derived from 1999 s em emissions study were developed to combine results from several field stations performance of the system was promising but was dependent on the geographic area of interest overall performance for earthquakes events of magnitude greater than 5 7 r was 75 of seismic events were correctly predicted by em activity while 25 were not predicted

age dating and the orbital theory of the ice ages development of a high resolution 0 to 300 000 year chronostratigraphy using the concept of orbital tuning a continuous high resolution deep sea chronostratigraphy has been developed spanning the last 300 000 yr the chronology is developed using a stacked oxygen isotope stratigraphy and four different orbital tuning approaches each of which is based upon a different assumption concerning the response of the orbital signal recorded in the data each approach yields a separate chronology the error measured by the standard deviation about the average of these four results which represents the best chronology has an average magnitude of only 2500 yr this small value indicates that the chronology produced is insensitive to the specific orbital tuning technique used excellent convergence between chronologies developed using each of five different paleoclimatological indicators from a single core is also obtained the resultant chronology is also insensitive to the specific indicator used the error associated with each tuning approach is estimated independently and propagated through to the average result the resulting error estimate is independent of that associated with the degree of convergence and has an average magnitude of 3500 yr in excellent agreement with the 2500 yr estimate transfer of the final chronology to the stacked record leads to an estimated error of 1500 yr thus the final chronology has an average error of 5000 yr