breakup of small rivers in the subarctic at the end of the winter the channels of small subarctic rivers in the coastal james bay lowland are filled with snow river ice and icing the major processes associated with the breakup of these rivers include the melting of the snow cover and the resultant generation of meltwater the impoundment of meltwater runoff by snow dams the disintegration and ablation of the river ice cover the formation and dissipation of ice jams and an exchange of overland and channelled flow between the rivers and their adjacent wetlands a generalization of the breakup sequences allows a qualitative prediction of the events for specific segments of the channel findings of this study are applicable to the many small subarctic rivers that fringe the james bay and hudson bay coasts

the physics of wind blown loess implications for grain size proxy interpretations in quaternary paleoclimate studies abstract loess deposits are recorders of aeolian activity during past glaciations since the size distribution of loess deposits depends on distance to the dust source and environmental conditions at the source during transport and at deposition loess particle size distributions and derived statistical measures are widely used proxies in quaternary paleoenvironmental studies however the interpretation of these proxies often only considers dust transport processes to move beyond such overly simplistic proxy interpretations and toward proxy interpretations that consider the range of environmental processes that determine loess particle size distribution variations we provide a comprehensive review on the physics of dust particle mobilization and deposition furthermore using high resolution bulk loess and quartz grain size datasets from a last glacial interglacial sequence we show that because grain size distributions are affected by multiple often stochastic processes changes in these distributions over time allow multiple interpretations for the driving processes consequently simplistic interpretations of proxy variations in terms of only one factor e g wind speed are likely to be inaccurate nonetheless using loess proxies to understand temporal changes in the dust cycle and environmental parameters requires i a careful site selection to minimize the effects of topography and source distance and ii the joint use of bulk and quartz grain size proxies together with high resolution mass accumulation rate calculations if possible

site specific variability of loess and palaeosols ruma vojvodina northern serbia abstract the study of temporal variations in soil intensity has mostly been limited to specific sites however it is important for correctly interpreting the stratigraphy and palaeoclimatic significance of loess and palaeosols series to understand the reasons for the spatial variability more specifically pedogenetic and sedimentological properties should be evaluated separately this is particularly well illustrated at the ruma site serbia in this paper we focus on macroscopic soil characteristics and sediment grain size properties the type succession shows three interglacial pedocomplexes v s1 v s2 and v s3 separated by loess layers that include at least one interstadial pedocomplex in the uppermost loess layer all sediments show a bipartite grain size distribution a coarser grained silt dominated one and a fine grained one

desert loess versus glacial loess quartz silt formation source areas and sediment pathways in the formation of loess deposits abstract pathways are presented which show the proposed sequence of events involved in the formation of loess deposits both hypothetical deposits and those of central china hungary nigeria and tunisia these pathways illustrate the potential role of and inter relationships between a variety of silt generating mechanisms in the formation of loess using these pathways the existence of desert loess is discussed and it is concluded that this depends on how the terms glacial loess and desert loess are applied if desert loess is taken either to signify nonglacial mechanisms of silt production or to characterise the environment from which aeolian entrainment took place then desert loess is a very real and widely distributed deposit however if the term glacial loess is used to refer to the global climatic regime under which the loess deposit has formed rather than the geomorphic mechanisms responsible for silt generation then desert loess would not be an appropriate term for the classification of loess deposits it is suggested that classifying loess deposits with reference to the global climatic regime under which they accumulated would facilitate a greater understanding of the role of environmental conditions at all stages in the formation of loess deposits

rapid and cyclic aeolian deposition during the last glacial in european loess a high resolution record from nussloch germany abstract this paper reports the results of an investigation of the weichselian upper pleniglacial loess sequences of nussloch rhine valley germany based on stratigraphy palaeopedology sedimentology palynology malacology and geochemistry 13 c supported by radiocarbon tl and osl dating grain size and magnetic susceptibility records are taken at 5 cm intervals from the upper pleniglacial upg loess the data indicate cyclic variations in loess deposition between ca 34 and 17 ka when the sedimentation rate is especially high 1 0 1 2 m per ka for more than 10 m the grain size index gsi ratio of coarse silt versus fine silt and clay shows variations which are assumed to be an indirect measurement of wind intensity the sedimentation rate interpreted from the profiles indicates high values in loess loess events le 1 to le 7 and low or negligible values in tundra gley horizons g1 to g8 osl ages from the loess and 14 c dates from organic matter in the loess show that loess deposition was rapid but was interrupted by shorter periods of reduced aeolian sedimentation comparison between the data from nussloch and other european sequences demonstrates a progressive coarsening of the loess deposits between ca 30 and 22 ka this coarsening trend ends with a short but major grain size decrease and is followed by an increase to a new maximum at 20 2 ka w shape correlation between the loess gsi and the greenland ice core dust records suggests a global connection between north atlantic and western european global atmospheric circulation and wind regimes in addition the typical upper pleniglacial loess deposition begins at ca 30 31 ka close to heinrich event he 3 and the main period of loess sedimentation at about 25 2 ka is coeval to he 2 correlation of magnetic susceptibility and grain size records shows that the periods characterised by high gsi coincide with an increase in the amount of ferromagnetic minerals reworked from the rhine alluvial plain they suggest enhancement in the frequency of the storms from n nw these results are integrated within a palaeogeographical model of dust transport and deposition in western europe for the weichselian upper pleniglacial or late pleniglacial

grain size of fine grained windblown sediment a powerful proxy for process identification abstract dust transport by the wind is not a uniform process but may occur in different modes according to source area conditions and transport height and distance subsequently these differences are expressed in terms of grain size and fluxes of the aeolian deposits transport distances may vary from several tens of meters to thousands of kilometers while the height accordingly may vary from meters to more than thousand meters a relation with grain size distributions may be established on the base of type occurrences of different loess facies three main loess populations and several subpopulations of primary windblown origin may be defined according to their grain size dominated by fine sand to very coarse silt silt and very fine silt to clay respectively each of them reflects a specific aeolian process and transport conditions it follows that the grain size distribution of a loess deposit is an excellent proxy for the reconstruction of aeolian processes and wind circulation patterns apart from primary pure wind deposition loess may also be affected by secondary post depositional processes examples are settling of loess particles in a lacustrine setting and reworking by rivers or surface runoff although the primary loess characteristics are maintained reworking processes leave also their imprint in the grain size distribution as a useful tool for secondary process identification

an evaluation of geochemical weathering indices in loess paleosol studies abstract applying geochemical proxies as measure for the weathering intensity of paleosols and sediments such as loess the quaternary scientist is confronted with various element ratios that have been proposed in literature this paper gives an overview on the principle of geochemical weathering indices different types of indices are evaluated with respect to the suitability for loess paleosol sequences regarding the special characteristics of this type of sediments and paleosols case examples in this study are key sections in southeastern and eastern europe the loess paleosol sequences batajnica stari slankamen serbia mircea voda romania and stary kaydaky ukraine which represent archives of the late and mid pleistocene climate change of the region considering element behavior during weathering or diagenesis the chemical proxy of alteration cpa i e the molar ratio al2o3 al2o3 na2o 100 is proposed as the most appropriate index for silicate weathering the cpa was evaluated against commonly used weathering indices including the chemical index of alteration cia the chemical index of weathering ciw the plagioclase index of alteration pia the index b of kronberg and nesbitt and the ba sr and rb sr ratio depth profiles of sr type indices e g ba sr rb sr are likely to be influenced by the dynamics of secondary carbonate on the other hand common na type indices e g cia pia ciw may suffer from uncertainties in separating carbonate ca from silicate ca or from biases due to k fixation illitization the cpa is insensitive against such effects additionally using the cpa as with other na type indices provides the possibility to evaluate the homogeneity of the parent material regarding the relevant host minerals via the a cn k diagram

the loessic palaeolithic in south tadjikistan central asia its industries chronology and correlation abstract this paper starts with an introductory account of the loessic palaeolithic a term used by the author from 1987 to describe those palaeolithic sites which are associated with very thick loess palaeosol successions following a discussion on movius hypothesis on the lower palaeolithic industry of eurasia a brief description of four major palaeolithic sites in south tadjikistan is given the main sites are kuldara 0 8 ma karatau 1 0 2 ma lakhuti 1 0 13 ma and obi mazar 0 09 ma they represent different periods of slowly evolved pebble culture without new influence from other regions the main features of the stone age industry called karatau culture are as follows the clear pebble technique without prepared core bifacial and levallois techniques dispersion of the pebble tools choppers stone slices wedges unifaces and flakes which are not stable for this form and dimensions the blades are practically absent no series of the tools is observed and they are the side scrapers scrapers on occasion borers points carinate tools the karatau culture is similar to the lower palaeolithic industries of china the karatau culture in south tadjikistan has better geological context than other pebble industries of central and south asia

ice core evidence for a very tight link between north atlantic and east asian glacial climate 1 corresponding millennial scale climate changes have been reported from the north atlantic region and from east asia for the last glacial period on independent timescales only to assess their degree of synchrony we suggest interpreting greenland ice core dust parameters as proxies for the east asian monsoon systems this allows comparing north atlantic and east asian climate on the same timescale in high resolution ice core data without relative dating uncertainties we find that during dansgaard oeschger events north atlantic region temperature and east asian storminess were tightly coupled and changed synchronously within 5 10 years with no systematic lead or lag thus providing instantaneous climatic feedback the tight link between north atlantic and east asian glacial climate could have amplified changes in the northern polar cell to larger scales we further find evidence for an early onset of a younger dryas like event in continental asia which gives

towards identifying the origin of metamorphic components in austrian loess insights from detrital rutile chemistry thermometry and u pb geochronology abstract trace element cr nb zr geochemistry and u pb geochronology of detrital rutile grains provide constraints on the nature of potential metamorphic sources of loess in austria cr and nb compositions reveal rutile sources with a predominance of metapelitic lithologies for all three loess samples by contrast zr in rutile geothermometry indicates that formation temperatures for loess rutiles around krems at the bohemian massif bm proved to be ca 100 125 c higher t median 717 and 737 c for two samples from stratzing and krems than those at wels close to the eastern alps ea t median 612 c implying that rutiles in loess at wels were derived from alpine lower amphibolite grade rocks while those in loess around krems from rocks formed under upper amphibolite to granulite grade conditions metamorphic temperatures recorded in rutiles from loess at the bm closely match the two reaction thermobarometry estimates of the last high t overprint 7 11 kbar and 700 800 c of rocks making up the varied series and gfohl units around krems this event dated at 340 to 350 ma is believed to be captured by the detrital rutile u pb data as well e g 349 21 and 352 32 ma all these data demonstrate the significance of proximal bm sources varied series and gfohl unit drained by the danube in loess formation around krems fluvial transport is believed to have played a substantial role in entraining and accumulating rutiles for subsequent aeolian deflation for loess near wels while the ultimate sources of these grains are likely to be in the eastern alps the recycling of these rutiles from the flysch zone of the ea cannot be ruled out despite the uncertainties of cr nb based source discriminations in some cases and the potential decoupling of zr and u pb systematics recognized in rutiles this study demonstrates that rutiles may provide unique details on the nature and metamorphic history of their parent rocks if used with caution and by knowing its limitations under certain conditions it is anticipated that beyond zircon rutile geochemistry will become a powerful provenance tracer in loess studies too this seems to be particularly important to gain a better understanding on the erosion and rutile fertility of different metamorphic terrains and their contributions to loess material issues that have not been adequately addressed thus far

palaeoclimate records 60 8 ka in the austrian and swiss alps and their forelands abstract the european alps and their forelands provide a range of different archives and climate proxies for developing climate records in the time interval 60 8 thousand years ka ago we review quantitative and semi quantitative approaches for reconstructing climatic variables in the austrian and swiss sector of the alpine region within this time interval available quantitative to semi quantitative climate records in this region are mainly based on fossil assemblages of biota such as chironomids cladocerans coleopterans diatoms and pollen preserved in lake sediments and peat the analysis of oxygen isotopes in speleothems and lake sediment records the reconstruction of past variations in treeline altitude the reconstruction of past equilibrium line altitude and extent of glaciers based on geomorphological evidence and the interpretation of past soil formation processes dust deposition and permafrost as apparent in loess palaeosol sequences palaeoclimate reconstructions in the alpine region are affected by dating uncertainties increasing with age the fragmentary nature of most of the available records which typically only incorporate a fraction of the time interval of interest and the limited replication of records within and between regions furthermore there have been few attempts to cross validate different approaches across this time interval to confirm reconstructed patterns of climatic change by several independent lines of evidence based on our review we identify a number of developments that would provide major advances for palaeoclimate reconstruction for the period 60 8 ka in the alps and their forelands these include 1 the compilation of individual fragmentary records to longer and continuous reconstructions 2 replication of climate records and the development of regional reconstructions for different parts of the alps 3 the cross validation of different proxy types and approaches and 4 the reconstruction of past variations in climate gradients across the alps and their forelands furthermore the development of downscaled climate model runs for the alpine region 60 8 ka and of forward modelling approaches for climate proxies would expand the opportunities for quantitative assessments of climatic conditions in europe within this time interval

krems wachtberg excavations 2005 12 main profiles sampling stratigraphy and site formation abstract since 2005 detailed archaeological investigations have been carried out at the upper palaeolithic site of krems wachtberg in eastern austria where a well preserved gravettian find layer is embedded in an 8 m high late pleistocene loess sequence the excavations are accompanied by interdisciplinary sampling strategies applied on the main profiles entire sediment series as well as on selected locations within the archaeological context the latter include both evident anthropogenic structures an in situ occupation surface with hearths and burials and periglacial features that together determine the morphology and explain the formation of the main gravettian find horizon

loess is not just the accumulation of dust most regrettably there is much misuse of terminology in connection with the concept of loess and the interpretation of its origin people often speak and write incorrectly about loess accumulation even loess specialists who are aware of the fact that loess as a concept has to satisfy at least 10 criteria loess is not simply dust carried and deposited by wind dust only becomes loess after the passage of a certain amount of time in a given geographical zone i e only through diagenesis in certain ecological environments to state that loess is of aeolian origin is an oversimplification and an incorrect definition because an aeolian origin applies only to the dust from which the loess has been formed we are aware of the fact that airborne dust cannot be transformed into loess in every geographical environment but only under those conditions typical of semi arid grassland or steppe or forested steppe the process primarily occurs where the rate of dust accumulation exceeds sheet wash or weathering soil formation rates if the rate of dust accumulation is less than that of surface erosion or of soil biogenetic processes the dust then develops into soil or through intensive weathering and increased precipitation into loam or clay only part of the aeolian dust transported and deposited in a zone suitable for loess formation remains there permanently and is transformed in situ into loess dust not affected by diagenesis is usually further transported by snowmelt or rainwash and is only transformed into loess after it has been redeposited the loess itself however is easily erodible and its minerals are readily reworked and reaccumulated and given the appropriate conditions it readily undergoes diagenesis again we do not always have sufficient evidence to determine whether a given loess body is of primary or secondary origin traditionally the minerals making up primary loess have been regarded as originating in dust accumulated by aeolian processes secondary loess by contrast is different from typical loess in many ways and it is not unusual to find various loess series in which superimposed dust fractions have been transformed into loess by different processes recently we have observed that the origin of various types of loess is governed by differences in litho ecological conditions rather than by the way in which the mineral material from which the loess is derived dust has been primarily accumulated loessification is therefore determined by environmental conditions

weathering and global denudation a negative correlation between sediment yield and weathering history as measured by the chemical alteration cia of the suspended sediment is observed for many of the world s major rivers and other regions of denudation the weathering history is a first order control on the sediment yield of such areas termed equilibrium denudation regions for other areas data scatter with either apparent increases or decreases of sediment yield for given cia values these areas are termed nonequilibrium denudation regions low sediment yields can be attributed to moderated erosion either natural or human induced and or the incorporation of unweathered glacial debris accelerated erosion resulting in high sediment yield is primarily human induced and results from cultivation and other land use each of these effects has a profound influence on global sediment discharge from the continents pre human suspended sediment discharge from the continents is estimated to be 12 6 times 10 15 g yr or about 0 6 the

austrian mis 3 2 loess palaeosol records key sites along a west east transect based on a w e transect through the northern loess regions of austria palaeoenvironmental studies were carried out in three loess palaeosol sequences gunderding krems wachtberg and stillfried b locus typicus to complement available results in the context of a multi methodological approach on the base of previously published datings our study concentrates on the mis 3 2 transition the results of detailed micromorphological investigations prove that palaeopedogenesis frost processes and sedimentation rates differ in their spatial occurrence in the loess belt of austria all three sequences are in line with the general trend of a reduced intensity of pedogenic and cryogenic features from western to south eastern europe which can be explained by lower atlantic moisture influence towards the east interstadial cambic horizons are well developed in the mis 3 sequence of western austria whereas the eastern loess profiles only show weak pedogenesis in all studied sequences frost processes were active during the upper mis 3 and mis 2 the studied mis 2 records are characterised by tundra soils with reductaquic horizons which is a clear sign for prolonged phases of permafrost on the spatial scale the sedimentation rate increases in the eastern loess regions and particularly the krems wachtberg sequence in the centre of the transect experienced an exceptionally high sedimentation rate and can thus be seen as one of the most important high resolution records for the mis 3 2 transition in european loess regions

paleoclimate and weathering of the tokaj hungary loess paleosol sequence abstract the tokaj loess paleosol sequence northeast hungary is a well studied site in southeast europe where detailed paleoenvironmental reconstructions of the quaternary have been carried out in this study the geochemical composition of samples from the upper part of the sequence 45 21 ka was analyzed and a variety of commonly used weathering indices and element ratios were applied to estimate weathering intensity a common semi quantitative proxy of paleoclimatic conditions further similarities and differences between these weathering indices and their sensitivity to changes in paleoclimatic conditions were assessed results indicate that all of them accurately track changes in weathering intensity and are with minor exceptions very similar to each other based on different transfer functions for major and trace element concentrations xrf mass specific magnetic susceptibility and stable carbon isotopic 13c data mean annual paleotemperature and mean annual paleoprecipitation for the time intervals of paleosol formation 45 27 ka and dust deposition 27 21 ka were calculated results differ depending on the respective transfer function and method but agree with x 13c based or slightly overestimate xrf based previously published paleoclimate data of the region xrf and 13c based results converge to a mean annual temperature mat range of 8 5 10 c paleosol and 8 9 c loess and a mean annual precipitation map range of 700 900 mm a 1 paleosol and 550 700 mm a 1 loess based results are most consistent with literature data and yield mats of 8 4 c paleosol and 6 6 c loess and maps of 300 500 mm a 1 paleosol and 220 mm a 1 loess

high resolution record of northern hemisphere climate extending into the last interglacial period high resolution record of northern hemisphere climate extending into the last interglacial period

luminescence dating of the stratzing loess profile austria testing the potential of an elevated temperature post ir irsl protocol abstract feldspar infrared stimulated luminescence irsl signals saturate at 2000 gy i e 500 700 ka assuming a dose rate of 3 4 gy ka typical for loess and it is therefore theoretically possible to date middle pleistocene loess however the accuracy of age estimates is hampered by anomalous fading which leads to significant age underestimation fading corrections have been proposed but these corrections are reliant on inherent assumptions and in any case are inapplicable at large doses as the growth curve approaches saturation recent studies have identified a post ir irsl signal that shows less fading and is thus less dependent on accurate fading corrections this study builds upon these investigations and applies a post ir irsl sar dating protocol to polymineral fine grain samples of the loess palaeosol sequence in stratzing lower austria after a preheat at 320 c 60 s and an ir bleach at 50 c 200 s irsl was measured at 290 c for 200 s the same set of conditions were used to measure the response to a test dose recycling ratios recuperation and dose recovery tests show that this protocol is suitable for the loess under investigation although finite residual doses of up to 20 gy are observed for the oldest samples the natural signal is in or close to saturation indicating that fading is negligible in nature this observation is inconsistent with the measured laboratory fading rates of 1 1 5 decade and needs further investigation

the mis 3 2 transition in a new loess profile at krems wachtberg east a multi methodological approach abstract local to regional paleoenvironmental reactions to past climate changes are preserved in loess paleosol sequences lps in order to extract this information we used a multi methodological approach in the upper paleolithic site of krems wachtberg east in lower austria detailed field studies and high resolution geochemical colorimetric and granulometric analyses help to understand the interplay between soil formation loess accumulation and surface processes in comparison to the main profile excavation of krems wachtberg 2005 2015 it can be stated that osl and 14c ages as well as the archeological stratigraphy of both profiles are comparable however pedogenic features are more evident at krems wachtberg east the new investigations show that well established weathering indices do not clearly trace interstadial soil formation in the studied profile apart from this fact single specific elements like fe and mg react more sensitive to initial pedogenic processes weak pedogenesis can further be evidenced by quantitative spectrophotometric results the latter is also capable of refining and supporting the stratigraphy pedology based on field analyses as a general rule next to loess also initial soil horizons of the mis 3 are remarkably rich in primary carbonates indicating that soil formation took place in an alkaline environment due to the fact that hydrolysis of feldspars could not clearly be detected by the application of pedochemical indices soil formation was probably limited to the oxidation of iron bearing minerals and weak carbonate leaching these phases of favorable climatic conditions in terms of pedogenesis were terminated by increasing dust input towards the onset of mis 2 the eolian deposits are overprinted during reducing conditions in soils and or modified by colluvial processes altogether weak pedogenesis can be reliably detected using a multi methodological approach which leads to enhanced paleoenvironmental interpretations the osl ages put the profile in a range of 41 to 30 ka we present a tentative correlation of the studied loess profile to the record of the north greenland ice core project ngrip for the part of the profile where osl and 14c complement each other

hydrologic functions of wetlands in a discontinuous permafrost basin indicated by isotopic and chemical signatures the hydrology of subarctic discontinuous permafrost regions is sensitive to the effects of climatic warming because pronounced changes in water storage and runoff pathways could occur with small additional ground heating the objective of this study is to understand the hydrologic functions of unique land cover types in this region channel fens flat bogs and peat plateaus using isotopic and chemical signatures of surface and subsurface water as well as hydrometric measurements the study was conducted in a 152 km 2 basin of scotty creek located in the central part of the mckenzie river basin in northern canada the headwater of scotty creek goose lake had a strongly enriched isotopic composition due to evaporation the stream water composition changed downstream as the lateral drainage from the active layer of peat plateaus contributed isotopically light and chemically dilute water to channel fens that are part of the drainage network flat bogs received drainage from peat plateau in addition to direct precipitation and were internally drained or drained water to adjacent channel fens average evapotranspiration estimated from the chloride balance method was 280 300 mm yr which was consistent with the hydrometric estimate precipitation minus runoff of 275 mm yr indicating a potential applicability of this method to ungauged basins tracer based hydrograph separation showed that the direct snowmelt contribution to spring runoff was less than half of total discharge suggesting an importance of the water stored over winter in lakes and wetlands the total amount of water stored over winter in the basin was estimated to be 140 240 mm which was comparable to the average annual basin discharge 149 mm q 2004 elsevier b v all rights reserved

the role of permafrost and seasonal frost in the hydrology of northern wetlands in north america abstract wetlands are a common landscape feature in the arctic subarctic and north temperate zones of north america in all three zones the occurrnce of seasonal frost results in similar surface water processes in the early spring for example surface ice and snow generally melt before the soil frost thaws causing melt water to flow into depressions over the land surface and at times across low topographic divides however evapotranspiration and ground water movement differ among the three climatic zones because they are more affected by permafrost than seasonal frost the water source for plants in the arctic is restricted to the small volume of subsurface water lying above the permafrost although this is also true in the subarctic where permafrost exists where it does not plants may receive and possibly reflect more regional ground water sources where permafrost exists the interaction of wetlands with subsurface water is largely restricted to shallow local flow systems but where permafrost is absent in parts of the subarctic and all of the temperature zone wetlands may have a complex interaction with ground water flow systems of all magnitudes

paleoenvironmental fluctuations as recorded in the loess paleosol sequence of the upper paleolithic site krems wachtberg abstract the loess paleosol sequence of krems wachtberg is famous for its archeological findings above all its gravettian infant burials it represents a complex system of paleoclimatic fluctuations which is nearly complete and thus enables the correlation with global paleoclimatic records this sequence comprises activity phases with dominant eolian and partly erosional processes as well as stable short periods of weak pedogenesis periglacial environment with drier climate conditions and high eolian sedimentation rates characterize the upper part of the sequence and in periods with lower sedimentation rates cryosols and permafrost induced structures are developed although the krems wachtberg site is situated at a slope position intensive erosional phases events can be excluded the basal parts of the sequence show signs of decalcification bioturbation organic inclusions as well as changes in element distribution pedogenic horizons are partly overprinted by permafrost related structures and are disturbed by redepositional processes to a minor degree remarkably the archeological horizon is not affected by permafrost in contrast to the layers below and above the focus of this study is deciphering stratigraphy by a combination of paleopedological sedimentological analyses with rock magnetic analyses on the chronological scale the sequence records a timespan from 35 ka to 20 ka altogether there is evidence of five pedogenic units and one archeological layer which are correlated with the greenland interstadials gi 7 to gi 2 however an equivalent of a mis 3 interstadial soil comparable with the lohne soil or stillfried b soil could not be detected

the chronological position of the lohne soil in the nussloch loess section re evaluation for a european loess marker horizon abstract the loess section of nussloch in southwestern germany is a key profile for the reconstruction of the terrestrial palaeo environment of central europe at the time of the last glacial and interglacial recently the significance of the site for palaeo environmental and geoarchaeological research increased additionally with the discovery of unique palaeolithic cultural remains from anatomically and culturally modern humans that invaded southwestern germany during the weichselian wurmian pleniglacial period at nussloch a chrono stratigraphical key position is taken by a middle pleniglacial cambisol remain which under the designation lohne soil serves as an important pedostratigraphic marker horizon for the greater area repeatedly greenland interstadial gis 8 was suggested as a likely period of soil formation for the lohne soil this interpretation is yet not justified on the basis of published chronometric data critical assessment of the data points to a later period of soil formation likely during gis7 to gis5 this conclusion is supported by a new set of radiocarbon ages for the nussloch site which are presented here for the first time consequences of a revised chronology for correlations of pleniglacial cryosols below and above the lohne soil with greenland interstadials are discussed the implications are important for european loess research as the nussloch section serves as a reference base for loess sections throughout europe

upper palaeolithic occupation in the wachtberg area of krems the evidence of surveys sections and core samples abstract the classic upper palaeolithic location of the wachtberg in krems eastern austria features a multitude of exposures in a limited area of about 50 000 m 2 in addition to gravettian sites which have been investigated in detail in the course of recent years using modern methods there are the records of old excavations several documented sections as well as a considerable number of core samples displaying heterogeneous documentation standards this paper provides an overview of these different sources of information and aims at synthesizing the data for a comprehensive understanding of the local loess sedimentation and palaeolithic occupation

loess deposits and the conservation of the archaeological record the krems wachtberg example recent archaeological excavations at the upper palaeolithic open air site of krems wachtberg in eastern austria exposed a late pleistocene loess sequence an interdisciplinary sampling strategy was applied to the 8 m high north profile the extraordinary conservation of a gravettian living floor with several complex features is discussed in this paper

pipe flow in james bay coastal wetlands pipes are common along the banks of streams that drain the wetlands of the james bay coast the primary source of water to the pipes is overland flow which responds very quickly to rainfall events pipe flow therefore becomes insignificant shortly after the termination of surface runoff an assessment of the relative contributions of pipe flow and darcy s groundwater flow to a small coastal creek shows that whereas groundwater flow contributed less than 1 to summer stormflow pipes provided about 10 of stream runoff

geochemical characterization and origin of southeastern and eastern european loesses serbia romania ukraine abstract the loess paleosol sections of batajnica stari slankamen serbia mircea voda romania and stary kaydaky ukraine were geochemically characterized based on discriminant analysis of major and trace elements the ratios of al ti fe ti and al fe the a cn k ternary plot and element enrichment depletion relative to the average composition of the upper continental crust the origin of the loess material in the southern pannonian basin vojvodina the lower danube basin dobrudja and the dnieper area was evaluated by comparison with the representative element composition of possible source areas and by considering the geomorphodynamic setting also the background values of the initial magnetic susceptibility of the loesses were taken into account for the lower danube basin dobrudja and the ukraine paleowind direction was reconstructed based on the geographic distribution of sandy soil texture and dunes related to river systems finally loesses were evaluated as possible samples of the average upper continental crust our results show that danube and dnieper loess areas can be clearly distinguished the former reveal higher al and fe contents the latter higher si zr hf content and indications of effective mineral and grain size sorting we can confirm that vojvodina loess originated from danube alluvial material and loess of the dnieper area from glaciofluvial sediments of the fennoscandinavian ice sheet the dobrudja loess derived also predominantly from danube alluvium but shows significant contribution of a second loess source probably the glaciofluvial sediments of the ukraine this was forced by northerly katabatic winds from the fennoscandinavian ice sheet whereas wnw winds prevailed in the western walachian plain the studied loesses reflect the average composition of the upper continental crust yet biases exist due to selective mineral element enrichment and depletion in the course of previous sedimentary recycling phases respectively material of all studied loess deposits seems to derive originally from sedimentary rocks

comparison of laser grain size analysis with pipette and sieve analysis a solution for the underestimation of the clay fraction classically the grain size of soil and sediment samples is determined by the sieve method for the coarse fractions and by the pipette method based on the stokes sedimentation rates for the fine fractions results from the two methods are compared with results from laser diffraction size analysis which is based on the forward scattering of monochromatic coherent light from a point of view of laboratory efficiency the laser sizing technique is far superior accuracy and reproducibility are shown by measurements on certified materials it appears that laser grain size measurements of certified materials correspond very well with the certificated measurements tests were also done on a set of randomly selected sediments of fluvial aeolian and lacustrine origin except for the 2 m clay fraction there is a coarsening of the mean diameter of one to two size classes 0 25 caused by the non sphericity of the particles the platy form of the clay particles induces considerable differences eight size classes between pipette and laser measurements the 2 m grain size defined by the pipette method corresponds with a grain size of 8 m defined by the laser particle sizer for the studied sediments using a higher grain size level for the clay fraction when laser analysis is applied enables workers in the geological and environmental field to compare classical pipette analysis with a laser sizing technique

high resolution record of the last interglacial glacial cycle in the nussloch loess palaeosol sequences upper rhine area germany the nussloch loess sequences were sampled at close intervals 10 cm and documented in respect of their stratigraphy palaeopedology sedimentology palynology malacology and geochemistry and were dated using radiocarbon and osl methods for each stratigraphic unit the results of both the eld studies and the analytical and geochronological data obtained cast light upon the response of the loessic environment to global climatic variations during the last cycle the basal soil complex underwent a pedosedimentary evolution similar to those of the bordering area complex luvisol greyzem steppe soila which re ects the classic progression towards increased continentality of the environment between the end of the eemian 5d and the beginning of the full glacial stage pleniglacial the lower pleniglacial corresponds to an initially very arid phase dominated by the accumulation of loess followed by the deposition of strati ed niveo eolian sands the middle pleniglacial complex ca 55 30 is clearly characterised by the inhibited loessic sedimentation it is primarily marked by two phases of stabilisation recorded in the form of weathered horizons cambisols which are separated by a rather thin layer corresponding to loessic sedimentation with tundra gleys this intermediate phase brings together organic silt deposits which record an interstadial dated at 32 33 ka c bp the thick loessic accumulations of the upper pleniglacial 10 m which clearly began to accumulate before the oxygen isotope stage ois 3 2 boundary show evidence of vulnerability to considerable uctuations in response to variations in wind dynamics and the intensity of de ation in the rhine valley finally a proposed correlation of loess palaeosol stratigraphies from germany belgium and france spanning the entire last interglacial glacial cycle is presented 2001 elsevier science ltd and inqua all rights reserved

theoretical analysis of snow dam decay snow dams have been observed in many stream channels in the arctic and the sub arctic but there is no theoretical analysis of their decay processes these processes include snowmelt seepage erosion down cutting snow slope failure and flotation of the snow dam snowmelt can be determined by the energy balance seepage of water will cause serious erosion at the point where the stream or pond level in front of the dam intersects the dam face erosion by water overflowing the dam is due to down cutting under cutting and thermal erosion down cutting increases with discharge but decreases with the shear strength of the snow where a hydraulic jump occurs downstream of the dam under cutting can accelerate dam decay thermal erosion depending mainly on water temperature may be less significant than the previous two processes slope failure occurs when the driving forces exceed the resisting forces and these are affected by snow property and snow load when the stream or pond level downstream of the dam rises rapidly the dam is prone to float as peak flow often occurs during the break up period results of the theoretical study of the mechanisms of snow dam decay will improve flood forecasting for arctic streams

luminescence based loess chronostratigraphy of the upper palaeolithic site krems wachtberg austria abstract the loess section krems wachtberg lower austria is well known for its upper palaeolithic find layer which contains a double and a single infant burial the layer containing the grave archaeological horizon ah 4 4 was dated to 26 580 160 14 c bp einwogerer et al 2006 corresponding to ca 31 ka cal bp and is embedded in an 8 m thick loess sequence in order to provide a chronostratigraphy of the entire section 38 samples for luminescence dating were taken at high resolution from below and above the find layer the samples were dated using the quartz coarse grain fraction the quartz fine grain fraction and or the polymineral fine grain fraction the resulting ages are in correct chronostratigraphic order and in case samples were measured with different protocols agree within errors with each other and with the radiocarbon age of the find layer the polymineral fine grain ages are systematically slightly lower than the quartz ages although no fading could be detected in laboratory experiments loess deposition at the site commenced ca 40 ka ago and reaches up to ca 22 ka the ages indicate nearly continuous loess sedimentation throughout this time span short breaks in sedimentation probably exist but cannot be resolved due to the uncertainties of luminescence ages

oxygen 18 16 variability in greenland snow and ice with 10 3 to 105 year time resolution the 3 km long greenland ice sheet project 2 gisp2 ice core presents a 100 000 year detailed oxygen isotope profile covering almost a full glacial interglacial cycle measuranents of isotopic fluctuations in snow frost and atmospheric water vapor samples collected during summer field seasons up to 20 0 are compatible with the large and abrupt 80 160 changes observed in accumulated tim snow pit 15 80 profiles from the gisp2 summit area however show rapid smoothing of the 180 160 signal near the surface beyond about 2 m depth the smoothedi5180 signal is fairly well preserved and can be interpreted in terms of average local weather conditions and climate the longer climate fluctuations also have regional and often global significance in the older part of the record corresponding to marine isotope stages mis 5a to 5d the effect of orbital climate forcing via the 19 and 23 kyr precession cycles and the 41 kyr obliquity cycle is obvious from the end ofmis 5a at about 75 000 years b p till the end of the glacial at the younger dryas preboreal transition at 11 650 years b p the o180 160 record shows frequent rapid switches between intermediate interstadial and low stadial values fourier spectra of the oscillations that are superimposed on the orbitally induced changes contain a strong periodicity at 1 5 kyr a broad peak at 4 0 kyr and additional shorter periods detailed comparison of the gisp2 180 160 record with the vostok antarctica 15d record pacific ocean foraminiferal 180 160 grande pile france tree pollen and insolation indicates that a counterpart to many of the rapid 180 160 fluctuations of gisp2 can be found in the other records and that the gisp2 isotopic changes clearly are the local expression of climate changes of worldwide extent correlation of events on the independent gisp2 and specmap time scales for the interval 10 000 50 000 years b p shows excellent chronometric agreement except possibly for the event labeled 3 1 the glacial to interglacial transition evidently started simultaneously in the arctic and the antarctic but its development and its expression in greenland isotopes was later suppressed by the influence of meltwater especially from the barents sea ice sheet on deep water formation and ocean circulation meltwaters from different ice sheets bordering the north atlantic also influenced ocean circulation during the bolling allerod interstadial complex and the younger dryas and led to a distinct development of european climate and greenland 180 160 values the holocene interval with long term stable mean isotopic values contains several fluauations with periods from years to millennia dominant is a 6 3 year oscillation with amplitude up to 3 to 4 0 periodicities of 11 and 210 years also found in the solar modulated records of the cosmogenic isotopes 1obe and 14c suggest solar processes as the cause of these cycles depression of180 160 values cooling by volcanic eruptions is observed in stacked gisp215 80 records but the effect is small and not likely to trigger major climate changes

a stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized greenland ice core records refining and extending the intimate event stratigraphy due to their outstanding resolution and well constrained chronologies greenland ice core records provide a master record of past climatic changes throughout the last interglacial glacial cycle in the north atlantic region as part of the intimate integration of ice core marine and terrestrial records project protocols have been proposed to ensure consistent and robust correlation between different records of past climate a key element of these protocols has been the formal definition and ordinal numbering of the sequence of greenland stadials gs and greenland interstadials gi within the most recent glacial period the gs and gi periods are the greenland expressions of the characteristic dansgaard oeschger events that represent cold and warm phases of the north atlantic region respectively we present here a more detailed and extended gs gi template for the whole of the last glacial period it is based on a synchronization of the ngrip grip and gisp2 ice core records that allows the parallel analysis of all three records on a common time scale the boundaries of the gs and gi periods are defined based on a combination of stable oxygen isotope ratios of the ice 18o reflecting mainly local temperature and calcium ion concentrations reflecting mainly atmospheric dust loading measured in the ice the data not only resolve the well known sequence of dansgaard oeschger events that were first defined and numbered in the ice core records more than two decades ago but also better resolve a number of short lived climatic oscillations some defined here for the first time using this revised scheme we propose a consistent approach for discriminating and naming all the significant abrupt climatic events of the last glacial period that are represented in the greenland ice records the final product constitutes an extended and better resolved greenland stratotype sequence against which other proxy records can be compared and correlated it also provides a more secure basis for investigating the dynamics and fundamental causes of these climatic perturbations

iron mineralogical proxies and quaternary climate change in se european loess paleosol sequences abstract the loess paleosol sequences batajnica stari slankamen serbia and mircea voda romania represent key archives for the climate and landscape development of the middle and lower danube basin during the last 700 000 years for deciphering the quaternary climate evolution in these regions the batajnica stari slankamen and mircea voda sites are for the first time studied by a multi proxy approach based on iron mineralogical parameters changes in the iron mineralogical composition are identified and characterized by rock magnetic investigations diffuse reflectance spectroscopy drs and munsell color based proxies the results show that environmental conditions during mid and early middle pleistocene interglacials were more favorable for hematite formation suggesting a more oxidizing pedoclimate as in the more recent interglacials this is also reflected in a gradual increase of the anhysteretic remanent magnetization vs saturation isothermal remanent magnetization arm sirm ratio in the studied profiles changes in this ratio can be linked to a preferential hematitization of coarse grained ferrimagnetica and relates to warmer climate conditions and a more extended estival dry period at the same time rock magnetic parameters indicate a preferential destruction of fine grained magnetic particles in older paleosols resulting from seasonal excess moisture a progressive cooling and decrease of rainfall during the middle and late pleistocene is evidenced not only for interglacial pedocomplexes but also for glacial loess layers this finding is in line with previously published proxy records of silicate weathering and clay formation at these sites and similar trends reported from other sites in the european steppe belt relating iron mineralogical proxies to paleopedological characteristics and proxies of silicate weathering additionally a change in the seasonal pattern of the interglacial temperature and precipitation regime from a mediterranean type to a steppe type climate is revealed highlighting the potential of such a multi proxy approach possible triggers for this paleoenvironmental evolution are discussed as well finally highlighting a quaternary uplift hypothesis which best could explain the inferred trend of cooling aridification and increasing continentality accordingly changes in atmospheric circulation and rain shadow effects induced by small scale uplift of european mountain belts alps carpathians dinaric alps would provide a driving mechanism for the westward extension of the eurasian steppe belt into central and se europe during the quaternary

the loess deposits of the bohemian massif silt provenance palaeometeorology and loessification processes abstract the central european loess bodies in hilly regions with their high accumulation rates frequently provide relatively high resolution floating stratigraphies containing both climatic signals common to europe and minor peaks arising from local factors such as slope processes discontinuity events or their palaeometeorological location in the former ice age landscape the loess palaeosol series are often viewed from the point of view of palaeoclimate reconstruction but macroscopic features such as lamination of loess strata corresponding to individual dust storms are better explained by palaeometeorological factors the study of heavy minerals from different loess localities in the czech republic suggests that the north atlantic oscillation wind pattern functioned even during the last glacial cycle the rapid consolidation of dust accumulation by cementation bonds represents the key factor in loessification calcite and allophane impregnations of clay bridges between individual silt grains can be observed the very nature of loessification is associated with rapid evolution of cementation bonds experiments reported here demonstrate that significant quantities of white chalky and powdery loess calcite and si al hydroxides are released during repeated freeze and thaw cycles

the paks loess paleosol sequence a record of chemical weathering and provenance for the last 800 ka in the mid carpathian basin abstract the paks loess paleosol sequence is one of the most important terrestrial records of middle and late pleistocene environmental changes in east central europe spanning the last ca 0 8 ma while geochemical proxies demonstrate a general decreasing chemical weathering trend over the last 0 8 ma in the carpathian basin mineralogy and derived indices reflect intensifying physical erosion in theory the observed chemical weathering trend can be accounted for both by enhanced input of relatively unweathered material and by climate deterioration during the quaternary as the proxies such as cia are not capable of distinguishing between pre and post depositional weathering enhanced physical erosion of the source areas driven by tectonism and resulting increased sedimentation of fresh mineral dust at the depositional site are demonstrated by increasing dolomite illite and chlorite contents and sme ill sme ill chl ratios from older to younger sediments in the profile together with increasing thickness of loess layers towards the youngest part of the sequence at the same time constant smectite contents 30 40 in paleosols appear to disprove progressive aridization of interglacials through time and suggest that the duration of pedogenesis played an important role in determining soil types further the increasing proportion of inherited phyllosilicates illite and chlorite would in theory raise the possibility that the decreasing values of chemical weathering indices are just artifacts of enhanced physical erosion and resulting increased dust deposition by a dilution effect the above findings highlight the fact that the general view on chemical weathering is oversimplistic as its equation includes two basic variables tectonism and time beyond climate and the interplay of these equally important factors will eventually determine its final value to get a better grasp of these processes needs further data more age control in loess profiles data on uplift in and around sedimentary basins and more sophisticated proxies as the mineralogical data presented here can be considered only semiquantitative regarding the provenance of sediments in the paks profile geochemical data demonstrate that felsic rocks dominated the source areas and there have been only very little variations in provenance over the last ca 0 8 ma significant contributions from mafic ultramafic rocks to the sediments can be ruled out as revealed by lower abundances of ferromagnesian trace elements the appearance of amphiboles and high dolomite contents suggest that loess material was at least partly sourced from local rocks and geochemical data reveal a genetic link between floodplain sediments and loess deposits

chronology and paleoenvironment of marine isotope stage 3 from two high elevation speleothems austrian alps abstract a new high resolution stable isotope record from the alpine kleegruben cave 2165 m central alps is presented this record largely duplicates a previously reported speleothem record from this site high precision u series thermal ionization mass spectrometry dates constrain the growth history of this new sample 56 48 ka to the marine isotope stage mis 3 both stalagmites reveal highly similar variations in o isotopes that can be directly compared to o isotope variability associated with dansgaard oeschger interstadials recorded in the greenland ice cores greenland interstadials gis based on the new record we refine our previous age assignments of the gis during this time interval i e gis 15b at 55 7 ka gis 15a at 55 3 ka onset mid point of the prominent gis 14 at 54 5 yr and onset of gis 12 at 48 ka the overall uncertainties associated with these ages are 0 1 0 3 ka the timing of these dansgaard oeschger interstadials is within 0 2 ka of the newly proposed grip sfcp04 timescale the age data for both kleegruben stalagmites demonstrate that liquid water was at least seasonally present in the shallow sub surface allowing calcite precipitation to continue even during stadials of mis 3 given the present day low temperature 2 4 c we propose that these unusual speleothems formed in a karst system overlain by a warm based glacier

high resolution record of the environmental response to climatic variations during the last interglacial glacial cycle in central europe the loess palaeosol sequence of dolni věstonice czech republic abstract high resolution multidisciplinary investigation of key european loess palaeosols profiles have demonstrated that loess sequences result from rapid and cyclic aeolian sedimentation which is reflected in variations of loess grain size indexes and correlated with greenland ice core dust records this correlation suggests a global connection between north atlantic and west european air masses herein we present a revised stratigraphy and a continuous high resolution record of grain size magnetic susceptibility and organic carbon 13c of the famous of dolni vestonice dv loess sequence in the moravian region of the czech republic a new set of quartz osl ages provides a reliable and accurate chronology of the sequence s main pedosedimentary events the grain size record shows strongly contrasting variations with numerous abrupt coarse grained events especially in the upper part of the sequence between ca 20 30 ka this time period is also characterised by a progressive coarsening of the loess deposits as already observed in other western european sequences the base of the dv sequence exhibits an exceptionally well preserved soil complex composed of three chernozem soil horizons and 5 aeolian silt layers marker silts this complex is at present the most complete record of environmental variations and dust deposition in the european loess belt for the weichselian early glacial period spanning about 110 to 70 ka allowing correlations with various global palaeoclimatic records osl ages combined with sedimentological and palaeopedological observations lead to the conclusion that this soil complex recorded all of the main climatic events expressed in the north grip record from greenland interstadials gis 25 to 19