onshore and offshore evidences for four abrupt warming episodes during mis 6 at the westernmost tip of continental europe did they control the migrations of neanderthals the total shell production typical of the pupilla association in the onshore site of nantois brittany france evidenced for the first time four brief abrupt warm and humid episodes during the upper saalian mis 6 loess deposition these warming events were also found in the marine deposits of the celtic sea md03 2692 core comparison with the variations of the sea level show that the warming episodes were not only of regional interest but corresponded to global events ruled by precession and insolation cycles other comparisons with biomarker records mollus s charcoal and rodents of the paris basin villiers adam and jersey island la cotte de saint brolade confirm the existence of these warmer events tentative correlations with the discontinuous neanderthal dwelling phases recorded in brittany suggest that these populations were mainly only present in westernmost europe during the warmer episodes

evidence of tephra reworking in loess based on 2d magnetic susceptibility mapping a case study from rocourt belgium abstract in this article a new and original approach to characterize tephra layers based on high resolution magnetic susceptibility ms mapping is applied to the tephra deposits of rocourt belgium a series of ms maps of selected sections show the 3d morphology of tephra horizons including local dip and reworked structures of the rocourt and eltville tephras proven by chemical analyses of phenocrysts at rocourt tephras are observed in loess which is an excellent material for testing the efficiency of the magnetic susceptibility mapping of tephra deposits we also attempted to locate the volcanic source of the eltville tephra based on the spatial analysis of the thickness of deposits in the region our results confirm the previous hypothesis of a volcano source located close to plaidt rheinland pfalz germany

upper pleistocene loess palaeosol records from northern france in the european context environmental background and dating of the middle palaeolithic abstract in northern france the loess cover from the last glacial weichselian is represented by a semi continuous mantle up to 8 m in thickness in the best localities such as leeward slopes e ne exposures in this large area pedostratigraphic sequences from the last interglacial glacial cycle eemian weichselian have been intensively studied especially under the auspices of active rescue archaeological programmes that have provided hundreds of individual sequences from test pits or excavations in spite of variations in the thickness of the different stratigraphic units driven by differences in geomorphological contexts the pedostratigraphic sequences from the last interglacial glacial cycle exhibit a particularly constant pedosedimentary pattern including well identified pedological and periglacial marker horizons that can be followed towards the east in belgium in germany and even in central europe according to the newest data it is shown that northern france loess palaeosol sequences are well suited to record the response of western european environments to rapid climatic changes dansgaard oeschger cycles the main objective of this paper is to present a summary of the pedostratigraphic sequence from northern france supplemented by the data from the new reference sequence of havrincourt and a global correlation scheme with surrounding areas in northern france the synthesis of the observations carried out on ca 100 sequences during the last 20 years allows the establishment of a highly detailed pedostratigraphic and chronostratigraphic scheme that represents a unique database for the discussion of the relations between palaeolithic occupation and environment in this context a strong relationship between the intensity of human occupation and the climatic and environmental context is demonstrated this relationship appears to be conditioned by the relative abundance of large mammal fauna itself linked to vegetation density as indicated by the extremely sparse biomass and the hiatus in human occupation that characterise upper pleniglacial loess

marine origin of savannah river estuary sediments evidence from radioactive and stable isotope tracers to determine the origin of sediments in the savannah river estuary we have measured 137 cs and stable isotope ratios of c n and s in suspended particles and bottom sediments at several sites in the savannah river and estuary and offshore on the continental shelf the 137 cs and stable isotope data were used with a two endmember mixing model to partition the suspended and bottom sediments at sites along a salinity gradient into riverine and marine fractions results from the 137 cs measurements indicated that 65 of inorganic sediments in suspension or in the top 5 cm of bottom deposits in the estuary were of marine origin stable carbon isotope ratios indicated that 74 of the organic sediments in suspension or on the bottom of the estuary were of marine origin except for sediments at the lowest salinity estuarine site

geochemical tracers of sediment sources to san francisco bay river inflow and suspended sediment flux to san francisco bay are dominated by the sacramento and san joaquin river systems suspended sediments collected from rivers within the sacramento and san joaquin drainage basinsshow distinct chemical and sr isotope signatures reflecting their distinct bedrock lithologies concentrations of sm nd k and rb and 8 7 sr 8 6 sr ratios in suspended sediments increase from north to south in sierra nevada rivers and are significantly higher in the san joaquin drainage than in the sacramento drainage we show that variations in the geochemistry of fine grained detrital sediments cored beneath the bay can be used to assess the relative contributions of suspended sediment and inflow from these two major drainages in california for the sampled intervals over the past 1850 yr the proportion of suspended sediment from the sacramento drainage relative to the san joaquin drainage ranged between 5 and 85 average value of 55 compared with a modern value of 91 the current predominance of sediment entering san francisco bay from the sacramento drainage may be the result of greater trapping of sediments by reservoirs within the san joaquin drainage basin changes in the relative proportion of sediment from the sacramento and san joaquin drainages may reflect changes in the position of the storm track over california

a loess paleosol record of climate and glacial history over the past two glacial interglacial cycles 150 ka southern jackson hole wyoming abstract loess accumulated on a bull lake outwash terrace of marine oxygen isotope stage 6 mis 6 age in southern jackson hole wyoming the 9 m section displays eight intervals of loess deposition loess 1 to loess 8 oldest each followed by soil development our age depth model is constrained by thermoluminescence meteoric 10 be accumulation in soils and cosmogenic 10 be surface exposure ages we use particle size geochemical mineral magnetic and clay mineralogical data to interpret loess sources and pedogenesis deposition of mis 6 loess was followed by a tripartite soil thin loess complex soils 8 7 and 6 apparently reflecting the large climatic oscillations of mis 5 soil 8 mis 5e shows the strongest development loess 5 accumulated during a glacial interval 76 69 ka mis 4 followed by soil development under conditions wetter and probably colder than present deposition of thick loess 3 43 51 ka mis 3 was followed by soil development comparable with that observed in soil 1 loess 1 mis 2 accumulated during the pinedale glaciation and was followed by development of soil 1 under a semiarid climate this record of alternating loess deposition and soil development is compatible with the history of yellowstone vegetation and the glacial flour record from the sierra nevada

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

strontium dissolved and particulate loads in fresh and brackish waters the baltic sea and mississippi delta a study was conducted of the isotopic composition and concentration of sr and of major elements in dissolved and suspended loads of fresh and brackish waters the purpose was to establish the contributions of different parent rocks and minerals to sr during weathering and transport and to identify the role of fe mn oxyhydroxides in the redistribution of sr in the water column during the sedimentary cycle studies were conducted on a profile across an oxic anoxic boundary in the baltic and on rivers covering behavior over an annual cycle in general the 87sr 86sr ratios differ between particulate and dissolved loads with more radiogenic sr in the particulate loads these differences are attributed to differential weathering of minerals where high rb sr minerals dominate the particulate load and low rb sr the dissolved load there is broad correlation of 87 sr 86 sr with k al in the suspended load the differences in 87 sr 86 sr between suspended and dissolved load are highly variable and are related to the fe or mn concentration on the particulates in samples with high fe al the difference becomes small a good correlation was found between sr al and fe al or mn al in the particulates both in brackish and fresh waters sr is removed from solution both in rivers and in the baltic sea whenever there is formation of fe mn oxyhydroxide particulates this precipitation greatly diminishes the difference in isotopic composition of the dissolved and suspended loads as the particles containing fe mn oxyhydroxides settle they dissolve in anoxic zones and release sr this provides a mechanism for sr redistribution in the water column sr is thus only quasi conservative in environments where fe mn oxyhydroxides form or dissolve from consideration of the isotopic differences in sr between dissolved and suspended loads it follows that the net sr input depends upon weathering characteristics of the contributing mineral phases changes in weathering mechanisms due to climate change may cause sr isotopic shifts in the marine environment

seismic velocities from the barbados ridge complex indicators of high pore fluid pressures in an accretionary complex three wide aperture 0 5 km offset seismic profiles were shot perpendicular to the strike of the barbados ridge accretionary complex at 16 12 n line 465 14 23 n line 480 and 13 20 n line 484 to image the deep structure of the accretionary complex and obtain seismic velocity data velocity analyses on full fold common depth point cdp gathers were used to provide velocity depth functions at 1 km separation along each line to map the variation in velocity with depth and distance across the accretionary complex the sediments within the complex show consolidation increasing laterally with greater age of the complex as indicated by the increase in seismic velocity and the inferred decrease in porosity the velocity at the base of the wedge along line 480 is 2 4 km s at the toe the velocity at the wedge base at 60 km from the toe where the wedge thickness has increased from 1 8 km to 5 0 km has increased to greater than 3 0 km s however the velocities within the leading margins and within undeithrust sequences in each of the three sections are low as much as 1 0 km s less than velocities found in undeformed sedimentary sequences of equivalent thickness the low velocity regions are interpreted as sediments with high porosity where porosity is inferred to be high pore fluid pressures are also inferred to exceed hydrostatic and pore fluids actually support the increased lithostatic load produced by recent thrusting and thickening of the complex the correlation between the most rapidly thickened regions and the velocity anomalies suggests that a rapid rate of loading relative to the rate of pore fluid expulsion produced these overpressured sediments velocities in the underthrust sequences where the differences between loading histories of wedge sediments and the underthrust sequences are largest are sufficiently low to produce velocity inversions low velocities also occur in regions adjacent to the complex where the pore fluid pressures may be elevated by the pressure produced in the adjacent wedge west of the wedge in the forearc basin along line 480 and near a seismically imaged mud diapir velocities at a depth of 3 5 km below the seafloor are 0 5 km s less than what is expected in a more normal sedimentary section immediately seaward of the complex the deepest undeformed sequences have a velocity anomaly of 0 5 km s velocities remain low for at least 12 km seaward of the complex but they become closer to a more normal sediment section farther from the wedge

loess chronostratigraphy in eastern croatia a luminescence dating approach abstract in eastern croatia impressive loess palaeosol successions up to 30 m thick are exposed along the steep cliffs of the danube river between zmajevac and sarengrad the croatian loess record provides an excellent high resolution archive of climate and environmental change providing evidence for the interaction between accumulation and erosion of aeolian and fluvial sediments during the middle and late pleistocene sedimentological and pedological investigations including granulometry carbonate content and total organic carbon content and infrared optically stimulated luminescence irsl dating were carried out on samples collected from the loess sections at zmajevac erdut and sarengrad the loess successions are intercalated by at least four palaeosols or pedocomplexes which very likely correlate with middle and upper pleistocene interstadials and interglacials in all sediment successions investigated alluvial sediments are intercalated in the loess deposits indicating periods of fluvial activity the stratigraphically youngest alluvial sediments are exposed at the erdut section loess sandwiching these alluvial sediments yielded irsl age estimates of 61 5 6 2 and 53 8 5 4 ka the irsl age estimates give evidence for periods of increased accumulation of dust during the middle and late pleniglacial correlating with oxygen isotope stage ois 3 and ois 2 respectively during the penultimate glaciation and at least the antepenultimate glaciation however it is likely that irsl age estimates 60 ka are underestimated

malacological and sedimentological evidence for warm glacial climate from the irig loess sequence vojvodina serbia four loess units and three paleosol layers are preserved in the irig brickyard vojvodina serbia amino acid geochronology provides stratigraphic correlations between loess units v l1 and v l2 at the irig section with loess of glacial cycles b and c respectively described from other central european localities luminescence dating results for the upper loess layers v l1l1 and v l1s1l1 confirm the geological interpretations although in samples below paleosol v l1s1s2 the age increase with depth is less than in our proposed age model magnetic susceptibility and sedimentological evidence from the irig loess paleosol sequence show general similarities with the mis 6 1 pattern of the specmap oxygen isotope curve malacogical investigations at the irig site reveal the continuous presence of the chondrula tridens and helicopsis striata faunal assemblages throughout the last glacial and final part of the penultimate glacial loess the loess snail fauna which is characterized by the complete absence of cold resistant species suggests a stable dry and relatively warm glacial climate compared with other central european loess localities furthermore these data suggest that the southern slope of fruska gora was a refugium for warm loving and xerophilus mollusc taxa during the otherwise unfavorable glacial climates of the late pleistocene

luminescence dating of loess palaeosol sequences and coversands methodological aspects and palaeoclimatic implications abstract of the terrestrial archives loess palaeosol sequences provide a most complete record of climatic change this may be compared with the marine oxygen isotope stratigraphy and may help in the reconstruction of past atmospheric circulation patterns numerical chronometry of loess palaeosol sequences has generally been based on correlation of variations in climatic proxies such as magnetic susceptibility and particle sizes with marine isotopic data such chronometric assignments involve implicit assumptions about the constancy of sedimentation rates and particle fluxes through time this review presents a brief survey of the present status methodology outstanding problems and interpretational aspects of luminescence techniques and discusses the import of luminescence ages on global land sea correlations statistical analysis of the ages suggests episodicity of loess accumulation with extended periods of quiescence recent luminescence dating studies on closely spaced samples also lead to a similar inference luminescence ages imply high variability in loess sedimentation rates this conflicts with the assumption made in some current attempts to correlate loess records with marine records of almost constant particle fluxes a review of source proximal coversand deposits of northwest europe is also presented evidence of the onset of coversand deposition at 15 ka with a peak in accretion during the younger dryas and subsequent minor reactivation episodes is discussed

reconstruction of late pleistocene paleoenvironments in southern germany using two high resolution loess paleosol records abstract two loess paleosol sequences from the heilbronn basin in southwestern germany frankenbach and talheim have been investigated to gain information about environmental conditions during the last interglacial glacial cycle since paleoenvironmental research on terrestrial archives is crucial for a better understanding of past climatic and environmental conditions the profiles were studied using a multi proxy approach applied methods include the analyses of grain size distribution element contents sediment color rock magnetism micromorphology and black carbon bc via benzene polycarboxylic acids bpca the data reveal that the two profiles show large variations in conservation due to their different geomorphologic positions moreover the results imply a subarctic climate with stable conditions during the middle pleniglacial mis 3 in situ soil formation phase while the lower pleniglacial mis 4 was characterized by erosion and reworking of eemian and early glacial mis 5 material but also by accumulation of aeolian material during the late lower pleniglacial mis 4 in frankenbach the results further suggest that the rhine river floodplain has been a major source for the accumulated material in the two profiles which indicates westerly wind directions during the time of accumulation the low gsi and u ratio of upper pleniglacial mis 2 sediments supported by the overall high content of fine material imply a larger distance to the source area we give an overview of loess in the heilbronn basin and place it in a wider context of loess in western europe

loess in europe mass accumulation rates during the last glacial period abstract upper pleistocene loess palaeosol sequences provide excellent high resolution terrestrial archives of climate forcing due to improvements in numerical age determinations especially in luminescence dating methods a more reliable time based reconstruction of the past climate and environmental change has become available for the loess record in europe chronological information was collected from 43 sites along a northwest to southeast transect in europe thirty three of these sites had sufficient age information to allow estimation of mass accumulation rates and it was possible to isolate the mass accumulation rates of primary loess during the last glacial period 28 13 ka bp at 21 of these locations these sites fall along a coarse climatic gradient from the relatively coastal climate of belgium and france to the drier more continental climate of central europe interpreting mass accumulation rates of loess in terms of this climatic gradient is not straightforward as these deposits are dominated by sources in floodplains and large river systems thus accumulation rates are influenced strongly by regional wind and precipitation patterns but mostly by the availability of glacially derived material from the alps and the periglacial terrains that characterized european fluvial systems during and immediately following glaciation

loess paleosol sequences at the northern european loess belt in germany distribution geomorphology and stratigraphy abstract pleistocene loess and loess derivates are distributed along the mountain front of the central european mountain belt in northern and central germany examples from two regions the lower rhine embayment lre and the northern foreland of the harz mountains fhm show that the distribution of loess and the development of loess paleosol sequences lps are controlled by relief climate tectonics the distance to large river systems the distance to the scandinavian ice sheet and the distance to the shelf of the north sea in the oceanic lre higher humidity enhanced the periglacial processes which increased erosion but also led to preservation in accumulative positions in contrast in the more continental fhm the sediments were affected by less intensive periglacial processes and no solifluction can be detected new loess distribution maps are presented for both key areas and key sections especially for the last glacial cycle are compared and summarized both study regions are located in the west east trending loess belt north of the central european mountain belt in front of the rhenish shield ardennes eifel and harz mountains finally a synthesis of typical sediment sequences for both regions is given as an example of paleoenvironmental landscape development in northern central europe

the loess record from the section at kurtak in middle siberia abstract loess loess like sediments and the intercalated palaeosols along the bluffs of the river yenisei provide a detailed upper pleistocene climate archive for the southern part of middle siberia the section at kurtak is one of the most detailed loess palaeosol sequences in middle siberia two major periods of sediment accumulation were recorded in the sequence the stratigraphically oldest one post dating the last interglacial palaeosol and pre dating the kurtak pedocomplex oxygen isotope stage ois 3 the younger one post dating the kurtak pedocomplex and predating the holocene soil three major phases of soil formation occurred during the upper pleistocene the kameny log pedocomplex ois 5e consists of at least two pedogenetic episodes a lower clayey chernozem forming during a more humid and warmer climate than today and an upper chernozem representing a drier climate than today the latter one including a well pronounced carbonate rich horizon the sukhoy log pedocomplex consists of a chernozem like palaeosol and two kastanozjems ois 5c a and the kurtak pedocomplex ois 3 with two chernozem like palaeosols and up to three humic rich layers additionally weakly developed gleyed horizons are considered to represent palaeohydrological groundwater high levels the results indicate a synchronous evolution of climate and environment change in both the more oceanic driven climate of west and central europe and middle siberia as evidenced by luminescence dating results

accuracy of esr dating of small gastropods from loess and fluvial deposits in the bavarian alpine foreland abstract this study focuses on the accuracy of the electron spin resonance esr dating method applied to small land snail shells from eolian loess deposits and from shell bearing clods of sandy loam and marl in fluvial gravel deposits in the bavarian alpine foreland due to the small size of land snail shells and lack of specimens available for esr analysis it was necessary to reduce individual aliquot sample weights to 0 02 0 07 g while the reduction in sample weight inevitably lowers the signal to noise ratio and thus may also negatively influence the precision on the equivalent dose due to even smallest weight variations between the single aliquots the dating results are in good agreement with independent age control in general the esr ages are mostly within the age interval of previous and new luminescence or radiocarbon dating results we show that esr dating of small terrestrial gastropods in most cases allows differentiating between shells of holocene late or middle wurmian last glacial mis 3 2 penultimate glacial mis 6 or penultimate interglacial mis 7 age with errors between c 10 15

the upper pleistocene loess record at harmignies belgium high resolution terrestrial archive of climate forcing abstract the loess palaeosol sequence in a section at harmignies in belgium is one of the most important upper pleistocene sites in northwest europe an extensive luminescence dating study was carried out to get a reliable chronological framework and to understand the climate forcing in an area where continuous permafrost dominated during most of the last glaciations twenty eight samples were investigated by infrared optically stimulated luminescence irsl and thermoluminescence tl methods resulting in more than 100 luminescence age estimates the dating results on colluvial sediments are in good agreement with landscape destabilisation phases during ois 5 during the last glacial four major periods of loess accumulation were likely to have occurred in europe at the harmignies section the oldest loess was deposited between 67 000 to 60 000 yr the second one from 60 000 to 50 000 yr the third one from 50 000 to 40 000 yr and the youngest loess accumulation period started most likely after the heinrich 3 event and lasted until the heinrich 2 event 25 000 20 000 yr two main periods of permafrost occurred at approximately 60 000 and 28 000 yr bp

late holocene inland dune activity in the uk a case study from breckland east anglia inland dune fields found in breckland east anglia uk have previously been correlated with the widespread late devensian coversands of the region and a seventeenth century sandflood which is known to have inundated the village of santon downham a programme of optically stimulated luminescence and radiocarbon dating undertaken on the dunes at wangford warren and santon downham reveals that episodic aeolian activity has taken place during the last 7000 years five sand depositional phases on breckland dunes are identified c 6500 c 1600 1100 c 500 c 400 335 and from c 200 30 years before present between c 2120 1840 years ago and within the period 1100 300 years ago quiescent periods allowed the development of fen peat and soils local controlling factors on aeolian activity in breckland appear to be related to anthropogenic activities and livestock sheep and rabbits reducing vegetation cover and decreased precipitation and sea levels which led to lowering of water tables breckland aeolian activity when compared to the national and sub continental holocene aeolian activity record shows a high level of concordance the underlying forcing factor for late holocene dune activity in the uk and elsewhere in europe appears to be climatic instability in the north atlantic associated with both the little ice age and previous similar events which led to increased storminess climatic variability and lower temperatures

weathering intensity and pedostratigraphy of the middle to upper pleistocene loess palaeosol sequence of wels aschet upper austria abstract on top of a fluvioglacial terrace near wels aschet a complex loess palaeosol sequence has been investigated to date the terrace is classified as a classical gunz unit older deckenschotter sedimentological and mineralogical analyses were carried out on the basis of palaeopedological field data the results show that in terms of mineralogical composition the palaeosols can clearly be differentiated and are characterised throughout by interglacial weathering intensity bulk mineralogical as well as clay mineralogical data allow a five stage ranking of weathering intensity based on indicator minerals from the bulk mineralogical perspective slightly weathered loess still contains carbonate minerals and primary chlorite whereas the intensely weathered soil horizons are characterised by the total or near absence of carbonate minerals and primary chlorite micas and feldspars in clay mineralogical results chlorite and the relation of 14 a and 18 a vermiculites as well as mixed layer minerals play an important role in determining the weathering stage primary chlorite can be present in slightly weathered loess loams and vermiculite 14 a is dominant there stage 1 and 2 from weathering stage 3 onwards the amount of vermiculite 18 a increases considerably and dominates the following stage 4 most intensive weathering causes the absence of illite stage 5 generally the studied interglacial palaeosols belong to at least stage 3 with the applied methodology four interglacial palaeosols have been demarcated as well as a highly weathered palaeosol within the terrace gravels of the gunz in wels aschet pedostratigrapy points to a classification of the older deckenschotter in mis 14 at minimum however since this glacial period was of low intensity and the weathering intensity of the basal palaeosol was significantly enhanced a correlation of the gunz terrace with mis 16 also seems possible

paleoenvironmental history of the middle dnieper area from the dnieper to weichselian glaciation a case study of the maksymivka loess profile abstract the paper presents the results of interdisciplinary studies on environmental characteristics of the middle and upper pleistocene mis 8 2 of central ukraine based on an example of the new research site at maksymivka the tested profile is situated on the left bank of the dnieper river on the western edge of the dnieper plain it is a representative section of the cliff of the east lakeshore of the kremenchuk reservoir located in the border zone both in longitudinal and latitudinal terms it is located in the southern part of the dnieper terraced plateau on the border of two varieties of forest steppes with an admixture of meadow steppes defined as left bank dnieper and dniester dnieper to the south of the site extends a typical steppe zone the transient position of the research site is a good point to start to trace the history of the volatility of the vegetation cover and the shift of the landscape vegetation boundaries according to the climatic fluctuations to reconstruct environmental changes in the analysed time interval the litho pedo and palaeobotanical methods were used to determine the chronology of changes a number of parallel datings of the loess paleosol sequence were conducted tl gdansk kyiv lublin osl gliwce the profile is comprised of glacial and loess parts the bottom section is built of glacigenic sediments of the marginal zone of the dnieper glaciation the overlying loess soil sequence of the last two glacial interglacial cycles underwent detailed analyses this section is composed of multiple soil levels whose participation in the entire thickness of the layer dominates over primary loess the studies have confirmed that they are lower stratigraphic rank soils of the vytachiv vt unit mis 3 and two complex higher rank units pryluky pl mis 5 and kaydaky kd mis 7 for the distinguished litho and pedostratigraphic units paleoenvironmental characteristics were developed the stratigraphic rank of these units was confirmed by dating the results of the tl and osl dating of the samples show good agreement between the laboratories particularly in relation to the last cycle however the osl dates for the penultimate cycle are significantly underestimated in relation to the tl dates which in turn relate well to the global time framework the reasons of the osl dates underestimation might be connected with the post sedimentation pedogenic changes

175 years of loess research in germany long records and unconformities abstract loess research in germany has a long tradition dating back to the early works of von leonhard von leonhard k c 1823 1824 charakteristik der felsarten 3 bde 772 s heidelberg j engelmann and his contemporary geoscientists ever since that time german researchers and loess research within germany have provided important contributions to the international state of the art to date however perceptual unconformities have existed in both the continuity of loess research in germany and the interpretation of the loess record in both the palaeoecological and the stratigraphic sense this paper briefly highlights some relevant periods of loess research in germany and the approaches adopted from the early days to the present the development of a refined stratigraphy of the last glacial loess in germany during the second half of the 20th century is reviewed in the contribution by a semmel fundamental contributions were first published by schonhals freising and brunnacker in the course of the subsequent work of the loess commission of the international union for quaternary research inqua the stratigraphy of the wurmian loess has since been refined in almost all loess regions of germany and schemes consistent in their fundamental features have been published in recent years contributions have focussed on age determination in particular those based on luminescence dating techniques

geochemistry unravels mis 3 2 paleoenvironmental dynamics at the loess paleosol sequence schwalbenberg ii germany abstract the schwalbenberg ii loess paleosol sequence lps denotes a key site for marine isotope stage mis 3 in western europe owing to eight succeeding cambisols which primarily constitute the ahrgau subformation therefore this lps qualifies as a test candidate for the potential of temporal high resolution geochemical data obtained by x ray fluorescence xrf scanning of discrete samples providing a fast and non destructive tool for determining the element composition the geochemical data is first contextualized to existing proxy data such as magnetic susceptibility ms and organic carbon corg and then aggregated to element log ratios characteristic for weathering intensity log ca sr log rb sr log ba sr log rb k and dust provenance log ti zr log ti al log si al generally an interpretation of rock magnetic particles is challenged in western europe where not only magnetic enhancement but also depletion plays a role our data indicates leaching and top soil erosion induced ms depletion at the schwalbenberg ii lps besides weathering log ca sr is susceptible for secondary calcification thus also log rb sr and log ba sr are shown to be influenced by calcification dynamics consequently log rb k seems to be the most suitable weathering index identifying the sinzig soils s1 and s2 as the most pronounced paleosols for this site sinzig soil s3 is enclosed by gelic gleysols and in contrast to s1 and s2 only initially weathered pointing to colder climate conditions also the remagen soils are characterized by subtle to moderate positive excursions in the weathering indices comparing the schwalbenberg ii lps with the nearby eifel lake sediment archive elsa and other more distant german austrian and czech lps while discussing time and climate as limiting factors for pedogenesis we suggest that the lithologically determined paleosols are in situ soil formations the provenance indices document a zr enrichment at the transition from the ahrgau to the hesbaye subformation this is explained by a conceptual model incorporating multiple sediment recycling and sorting effects in eolian and fluvial domains

high resolution chronologies for loess comparing ams 14c and optical dating results the nuxloch loess section in south west germany is famous in central europe for its thick deposits from the last glacial maximum it has therefore been intensively studied during the past few years and offers an excellent opportunity to compare the performance of different dating techniques covering the period 15 45 ka here we present results fromoptical and ams 14 c dating the silt sized polymineral fraction of the clastic sediments and a multiple aliquot approach was used for ir osl dating 14 c dating was carried out on organic macro remnants and humin fractions extracted fromthe sedim ents with the exception of samples taken from the uppermost 1 5 m of the section ir osl and calibrated 14 c ams ages are consistent over the entire period the inconsistencies in the upper meters are thought to be due to disturbances during soil formation in the holocene the good agreement obtained on the remaining sequence demonstrates the high accuracy of both methods when studying loess sections for the ir osl ages no significant age underestimations are obvious the results clearly document that accurate chronologies can be developed for such continental sedimentary sequences this gives access to archives that can now be studied with a high temporal resolution and allows the establishment of new paleoclimatic proxies for the study of terrestrial responses to past climatic changes r 2003 elsevier science ltd all rights reserved

palaeopedology and magnetic susceptibility of a loess palaeosol sequence in southwest germany abstract a loess palaeosol sequence that formed during the last and the penultimate glacial interglacial cycle was studied by pedological geochemical and rock magnetic methods particular emphasis was placed on magnetic susceptibility in order to derive a climatic signal problems of separating the influence of palaeo relief hydrological influence and climate complicate the interpretation but the results show that minimal levels of soil formation cause a distinct enhancement of the magnetic properties higher magnetic susceptibility signals characterise the more oxidized parts of the palaeosols alternatively hydromorphic processes operating on the ferrimagnetic minerals cause a decrease in magnetic susceptibility reflecting both past climate and changes in the palaeoenvironment extremely low susceptibility values characterise the reduced greyish zones of the interglacial bt horizons additional complications are introduced because magnetic susceptibility may change along the horizons of one soil profile eluvial horizons tend to have lower concentrations of ferrimagnetic minerals than the loess parent material whereas the corresponding illuvial horizons show an increase it is considered that palaeoclimatic interpretation based solely on magnetic susceptibility must be treated with great caution

tracing the distribution of erosion in the brahmaputra watershed from isotopic compositions of stream sediments bank sediments and suspended loads of the brahmaputra river and its important tributaries were collected from the himalayan front to bangladesh along with most of the important tributaries chemical and isotopic compositions of the sediments are used to trace sediment provenance and to understand erosion patterns in the basin overall isotopic compositions range from 0 7053 to 0 8250 for sr and nd from 20 5 to 6 9 this large range derives from the variable proportions of sediments from himalayan formations with high sr isotopic ratios and low nd and transhimalayan plutonic belt with lower sr isotopic ratios and higher nd the latter are exposed to erosion in the tsangpo and in the eastern tributary drainages overall erosion of the himalayan rocks is dominant representing ca 70 of the detrital influx compositions of the brahmaputra main channel are rather stable between 0 7177 and 0 7284 for sr and between 14 4 and 12 5 for nd throughout its course in the plain from the siang tsangpo at the foot of the himalayan range down to the delta this stability despite the input of large himalayan rivers suggests that the siang tsangpo river represents the major source of sediment to the whole brahmaputra geochemical budget implies that erosion of the namche barwa zone represents about 45 of the total flux at its outflow before confluence with the ganga from only 20 of the mountain area higher erosion rates in the eastern syntaxis compared to the other himalayan ranges is related to the rapid exhumation rates of this region possibly triggered by higher precipitation over the far eastern himalaya and the high incision potential of the tsangpo river due to its very high water discharge

paleoclimatic implications of the spatial patterns of modern and lgm european land snail shell δ18o abstract the oxygen isotopic composition of land snail shells may provide insight into the source region and trajectory of precipitation last glacial maximum lgm gastropod shells were sampled from loess from belgium to serbia and modern land snail shells both record 18 o values between 0 and 5 there are significant differences in mean fossil shell 18 o between sites but not among genera at a single location therefore we group 18 o values from different genera together to map the spatial distribution of 18 o in shell carbonate shell 18 o values reflect the spatial variation in the isotopic composition of precipitation and incorporate the snails preferential sampling of precipitation during the warm season modern shell 18 o decreases in europe along a n s gradient from the north sea inland toward the alps modern observed data of isotopes in precipitation gnip demonstrate a similar trend for low altitude sites lgm shell 18 o data show a different gradient with 18 o declining toward the ene implying a mid atlantic source due to increased sea ice and a possible southern displacement of the westerly jet stream balkan lgm samples show the influence of a mediterranean source with 18 o values decreasing northward

the dynamics of a partially mixed estuary measurements of velocity density and pressure gradient in the lower hudson river estuary were used to quantify the dominant terms in the momentum equation and to characterize their variations at tidal and spring neap timescales the vertical momentum flux assumed to be due mainly to turbulent shear stress was estimated indirectly based on the residual from the acceleration and pressure gradient terms the indirect estimates of stress compared favorably to bottom stress estimates using a quadratic drag law supporting the hypothesis that the tidal momentum equation involves a local balance between tidal acceleration pressure gradient and stress divergence estimates of eddy viscosity indicated that there was significant tidal asymmetry with flood tide values exceeding ebb values by a factor of 2 as a consequence of the asymmetry the vertical structure of the tidally averaged stress bore no resemblance to the tidally averaged shear in spite of the asymmetry of vertical mixing the tidally averaged estuarine circulation was found to depend simply on the intensity of bottom turbulence which could be parameterized by a rayleigh drag formulation based on the tidal velocity magnitude and the tidally averaged near bottom flow this seemingly paradoxical result indicates that the estuarine circulation can be modeled without detailed knowledge of the effective eddy viscosity only requiring an estimate of the bottom drag coefficient the tidal forcing conditions and the baroclinic pressure gradient a notable characteristic of this solution is an inverse dependence of the estuarine circulation on the amplitude of the tides

strontium isotope record of seasonal scale variations in sediment sources and accumulation in low energy subtidal areas of the lower hudson river estuary abstract strontium isotope 87sr 86sr profiles in sediment cores collected from two subtidal harbor slips in the lower hudson river estuary in october 2001 exhibit regular patterns of variability with depth using additional evidence from sediment ca sr ratios 137cs activity and al carbonate caco3 and organic carbon ocsed concentration profiles it can be shown that the observed variability reflects differences in the relative input and trapping of fine grained sediment from seaward sources vs landward sources linked to seasonal scale changes in freshwater flow during high flow conditions the geochemical data indicate that most of the fine grained sediments trapped in the estuary are newly eroded basin materials during lower base flow conditions a higher fraction of mature materials from seaward sources with higher carbonate content is trapped in the lower estuary results show that high resolution multi geochemical tracer approaches utilizing strontium isotope ratios 87sr 86sr can distinguish sediment sources and constrain seasonal scale variations in sediment trapping and accumulation in dynamic estuarine environments low energy subtidal areas such as those in this study are important sinks for metastable short to medium time scale sediment accumulation these results also show that these same areas can serve as natural recorders of physical chemical and biological processes that affect particle and particle associated material dynamics over seasonal to yearly time scales

high resolution record of the last climatic cycle in the southern carpathian basin surduk vojvodina serbia abstract high resolution study of the surduk loess palaeosols sequence in serbia vojvodina has been performed within a research project eole focusing on the impact of rapid climatic changes during the last climatic cycle in the european loess belt the methodology used for this multidisciplinary approach is based on a continuous sampling column that allows a very accurate correlation between all studied proxies magnetic susceptibility grain size and organic carbon and the dated samples irsl 14 c according to the stratigraphical and sedimentological data the surduk loess sequence appears as a very complete record of the last climatic cycle 19 m and exhibits a similar pattern than other contemporaneous loess sequences from western central and eastern europe the main difference is the evidence of a drier environment all over the last climatic cycle sedimentological and palaeopedological data the high resolution grain size record 5 cm is well correlated with stratigraphical boundaries and highlights a strong variability within the loess deposition especially during the upper pleniglacial between ca 33 and 15 ka during the upper pleniglacial a succession of millennial timescale events characterised by the deposition of coarser loess are particularly well evidenced by grain size data as in some west european records finally an attempt to correlate the variations of grain size parameters at surduk with the greenland grip dust record is proposed according to this study millennial timescale climatic events that characterise the north atlantic area during the last climatic cycle have thus been recorded in the environments located at the southern border of the european loess belt

the impact of dansgaard oeschger cycles on the loessic environment and malacofauna of nussloch germany during the upper weichselian abstract a loess sequence has been sampled continuously at high resolution in nussloch rhine valley germany for malacological and grain size analyses between ca 34 and 20 ka molluscan abundance and richness percentage in hygrophilous species and grain size index show cyclical variations related to the lithological loess gley alternation major molluscan abundance maxima were triggered by temperature increases through an enhancement of the reproduction cycle whereas cyclical richness fluctuations and percentage in hygrophilous species reflect variations in local humidity and changes in the environmental mosaic malacological parameters allow the distinction of four environmental phases organised in cyclical successions correlated with most of the loess gley doublets the correlation of the grain size index of the nussloch loess sequence with the dust content of the grip ice core demonstrates the synchronicity of major molluscan abundance maxima and 18 o increases characterising temperature increases during dansgaard oeschger interstades a schematic model is proposed to link the north atlantic dansgaard oeschger climatic oscillations with local environmental changes indicated by both malacofauna and pedostratigraphy this malacological study of the nussloch loess sequence thus provides new information about the response of terrestrial loessic palaeoenvironments to millennial timescale climatic fluctuations during the upper weichselian marine isotope stage 2 mis 2 and end of mis 3

pliocene near trench magmatism in southern chile a possible manifestation of ridge collision eight shallow level intrusions and an ophiolite complex have recently been discovered in a remote region along the pacific coast of southern chile known as the taitao peninsula the magmatic rocks are found only 10 to 15 km from the buried extension of the peru chile trench the ophiolite body includes serpentinized ultramaflc rocks gabbro dikes and an interbedded sequence of volcanic and marine sedimentary rocks more regionally distributed granodiorite plutons and porphyritic stocks and sills intrude pre late jurassic basement as well as tertiary marine sequences of the south american forearc k ar ages of 3 5 to 4 0 ma of the ophiolite and other intrusions suggest that these rocks represent a short lived pulse of pliocene magmatism directly seaward of the taitao peninsula a segment of the chile rise bounded by the tres monies and taitao fracture zones collided with the chilean forearc and was subducted about 2 5 to 4 0 ma because of this good spatial and temporal correlation the magmatic activity of the taitao peninsula is likely to be a direct result of ridge subduction

a lightweight extruder for accurate sectioning of soft bottom lake sediment cores in the field a new extrusion device is described for time efficient sectioning of high quality cores of soft bottom lake sediments in particular piston cores and core samples that include the undisturbed sediment water interface the instrument is lightweight versatile and easy to operate in the field while maintaining maximum accuracy in sectioning a sediment profile in predefined increments

comparison between the wintertime and summertime dynamics of the misa river estuary abstract the misa river on the italian adriatic coast is typical of the rivers that drain the apennine mountain range the focus of this study conducted in the late summer of 2013 and mid winter of 2014 was to contrast the general wintertime summertime dynamics in the misa river estuarine system rather than investigate specific dynamical features e g offshore sediment transport channel seiche and flocculation mechanisms summertime conditions of the misa river estuary are characterized by low freshwater discharge and net sediment deposition whereas in the wintertime the misa river and estuary is characterized by high episodic freshwater discharge and net erosion and sediment export major observed differences between wintertime summertime dynamics in the misa river and estuary are a result of seasonal scale differences in regional precipitation and forcing conditions driven largely by the duration and intensity of prevailing wind patterns that frequently change direction in summertime while keep almost constant directions for much longer periods in wintertime thus generating major sea storms sediment deposition was observed in the final reach of the misa river and estuary in the summertime however in the wintertime large flood events led to sediment erosion and export in the final reach of the misa river and estuary that in conjunction with storm wave induced mud transport led to sediment deposition at the river entrance and in the adjacent nearshore region the seasonal cyclic pattern of erosion and deposition was confirmed with bathymetric surveys of the final reach of the estuarine region a critical component for the balance between summertime deposition and wintertime erosion was the presence of an underlying mat of organic deposits that limited the availability of sediments for erosion in winter when massive debris transport occurs further suspended cohesive sediments flocs were subjected to smaller hydrodynamic stresses in the summertime favoring deposition within the estuary conversely during wintertime storms flocs were subjected to larger hydrodynamic stresses favoring breakup into smaller flocs and deposition outside the estuary

correlation between the geologic record and computed plate motions for central california we have attempted to correlate geologic events in part of central california with computed motions of oceanic plates relative to cratonic north america three composite terranes are considered 1 the sierra nevada 2 the coast ranges northeast of the san andreas fault and 3 the salinian block in the sierra nevada jurassic plutonism ending about 147 m y b p and cretaceous plutonism 120 80 m y b p correlate with deduced farallon north america fa na convergence as does the nevadan orogeny 158 153 m y b p however the gap in plutonism 146 121 m y b p outlasted by far an apparent minimum in convergence 145 135 m y b p magmatism ceased in the sierra and uplift slowed during the laramide orogeny 75 45 m y b p when tectonic activity had moved east to the site of the rockies presumably because of a low angle of subduction but volcanisin resumed in the sierra about 33 m y b p indicating that a steeper angle was reestablished apparently east west compression slackened when the pacific north america pa na transform regime developed basalt was erupted in the southern sierra 12 3 m y b p and during this same time the range started its most rapid rise as a normal fault bounded block the coast ranges north east of the san andreas fault are underlain by the franciscan complex the older parts of the complex were probably assembled in a subduction zone far south of their present location but we believe that the same fa na convergence that was cited for sierran plutonism was responsible despite the disparity in latitude as the farallon plate was probably in contact with most of the western margin of north and south america a perceived strong pulse in convergence 100 85 m y b p evidently produced the coast range thrust which on geologic grounds alone most likely originated between 96 and 88 m y b p some of the northwesterly transport of franciscan rocks relative to north america is ascribed to oblique kula north america ku na convergence 85 43 m y b p during which period the coast range thrust was revived about 60 m y b p the farallon plate again influenced the california margin after the kuia plate had moved northward and fa na convergence caused the accretion of the coastal belt and king range terranes of the neo franciscan the advent of pacific north america pa na interaction was marked by local volcanism which advanced from the southeast toward the northwest in consonance with the passage of the mendocino triple junction dickinson and snyder 1978 in the salinian block plutons 107 82 m y old can be ascribed to the same fa na convergence as the contemporary cretaceous plutons of the sierra nevada although the salinian intrusives originated much farther south paleomagnetic results champion et al 1980 from the salinian related pigeon point formation 75 71 m y in age suggest about 2500 km of poleward essentially coastwise movement this postulated large movement during part or all of the last 75 m y poses the greatest dilemma in our study the kuia is the only known plate whose computed obliquely convergent motion is appropriate for the late cretaceous paleogene part of the migration and even this motion is inadequate for the estimated transport within the most likely time window furthermore the farallon plate seems ideally suited for the laramide orogeny 70 45 m y b p both plates could not have been in contact with the same part of the margin at the same time oblique convergence of the kula plate could possibly have caused large coastwise transport and also the laramide orogeny the coast ranges northeast of the san andreas fault and the salinian block both experienced strike slip faulting and en echelon folding correlative with pa na interaction indicating that they were close together by neogene time faulting and folding have been particularly marked since the inception of spreading in the gulf of california and attachment of westernmost california to the pacific plate about 4 m y b p the rise of individual coastal ranges commencing 3 1 m y b p may possibly have been caused by slight convergence which appears in computed pa na relative motions from 5 m y b p to the present

controls over the strontium isotope composition of river water abstract strontium concentrations and isotope ratios have been measured in river and ground waters from the ganges orinoco and amazon river basins when compared with major element concentrations the data set has allowed a detailed examination of the controls over the strontium isotope systematics of riverine input to the oceans in the following environments 1 1 typical drainage basins containing limestones evaporites shales and alumino silicate metamorphic and igneous rocks 2 2 shield terrains containing no chemical or biogenic sediments and 3 3 the floodplains that constitute the largest areas of many large rivers the strontium concentration and isotope composition of river waters are largely defined by mixing of strontium derived from limestones and evaporites with strontium derived from silicate rocks the strontium isotope composition of the limestone endmember generally lies within the phanerozoic seawater range which buffers the 87 sr 86 sr ratios of major rivers a major exception is provided by the rivers draining the himalayas where widescale regional metamorphism appears to have led to an enrichment in limestones of radiogenic strontium derived from coexisting silicate rocks the strontium isotope systematics of rivers draining shield areas are controlled by the intense transportlimited nature of the weathering reactions and thereby limits variations in the strontium flux from these terrains floodplains are only a minor source of dissolved strontium to river waters and precipitation of soil salts in some floodplains can reduce the riverine flux of dissolved strontium to the oceans the most effective mechanisms for altering the isotope ratio and flux of riverine strontium to the oceans are increased glaciation and large scale regional metamorphism of the type produced during continental collision both mechanisms provide a means for increasing the 87 sr 86 sr ratio of the global riverine flux

multiple and single aliquot luminescence dating techniques applied to quartz extracted from middle and upper weichselian loess zemechy czech republic this paper reports the application of optically stimulated luminescence osl dating to relatively coarse grains 100 200 m of quartz extracted from loess two approaches were tested a multiple aliquot technique and a new single aliquot approach which is especially suited to the dating of small quantities of such grains found in some loess the results are compared with infra red stimulated luminescence and thermoluminescence tl measurements on the finer grained 4 11 m polymineral fraction and tl measurements on the relatively coarse grains of quartz the advantages of the new single aliquot osl approach are described and the iterating computer controlled measurement procedure is given the automated iterative single aliquot regeneration aisar method corrects for changes in luminescence sensitivity during the measurement sequence by monitoring the response to a test dose some initial measurements are presented for the loess section at zemechy czech republic and these show that the aisar method gives more precise results than those using a multiple aliquot method copyright 2000 john wiley sons ltd

weichselian upper pleniglacial environmental variability in north western europe reconstructed from terrestrial mollusc faunas and its relationship with the presence absence of human settlements abstract during the weichselian glaciation millennial timescale climatic changes are a major cause of environmental variability which influence the composition of large mammal fauna and the geographical distribution of human prehistoric populations nevertheless precise environmental contexts of archaeological artefacts may remain unknown due to an unclear stratigraphy and or to the bad preservation of paleoenvironmental proxies as pollen is badly preserved in glacial loess deposits a compilation of age constrained high resolution molluscan records is used to initiate the establishment of a canvas of millennial timescale spatial and temporal environmental changes in the european loess belt during the weichselian upper pleniglacial ca 37 20 ka to look for relationships with spatial distribution of human settlements in this study new terrestrial mollusc assemblages have been added to the database previously established for north western europe they strengthen the position of the limit between the two molluscan based biogeographical domains initially highlighted for north western europe a flat and poorly vegetated western domain extending around the channel and in belgium and a hilly domain with more diversified vegetation to the east the analysis of molluscan data shows the persistence of these two domains throughout alternations of loess deposition phases interstadial stadial transitions and stadial phases with phases of development and degradation of tundra gley horizon stadial interstadial transitions and interstadial phases the interpretation of malacofauna from both domains combined with associated pedological and sedimentological features climate modelling and comparisons with present tundra environments reveals a significant effect of both seasonality and snow cover along a longitudinal gradient between both domains but also between phases of loess deposition and phases of tundra gley development during interstadial phases the intense functioning of the active layer and the degradation of permafrost in north western europe led to more homogeneous environments which were less favourable for the diversity of both vegetation and terrestrial mollusc fauna presently uncertainties of numerical ages still preclude precise correlations of loess units and tundra gley horizons between different sites and with nonlocal prehistoric occupations however a first raw comparison of the molluscan data with spatial distributions of aurignacian gravettian and solutrean upper magdalenian lithic cultures reveals that the northern limit of the first two ones fits well with the south eastern border of the poorly vegetated western domain also characterised by well developed ice wedge networks during phases of permafrost installation later an important southward shift of human populations in western europe resulted from the extreme aridity of the last glacial maximum

lower to middle weichselian pedogenesis and palaeoclimate in central europe using combined micromorphology and geochemistry the loess paleosol sequence of alsheim mainz basin germany abstract lower to middle weichselian loess loess derivatives and buried soils of the loess paleosol sequence alsheim central europe were characterised by particle size distribution geochemical and micromorphological data high rates of sedimentation with alternating phases of relocation are the main cause for a much less differentiation into middle and upper weichselian loess paleosol units of the alsheim loess paleosol sequence compared to other loess paleosol sequences e g nussloch near heidelberg whereas the lower weichselian has distinct phases of pedogenesis resulting in ah bw and btw horizons to distinguish between different loess deposits locally and intraregional the degree of fineness is an easily applicable and suitable tool though inappropriate for interregional comparisons the chemical index of alteration cia is low 53 to gallet et al 1998 the highest weathering was detectable for btw horizons with cia values 70 a direct quantitative estimation of mean annual palaeotemperature and mean annual palaeoprecipitation can be provided by calculations based on geochemistry of soil horizons and sediments the present mean annual precipitation map in the mainz basin is 789 mm in contrast palaeoprecipitation data suggest a 150 mm higher amount for the last interglacial btw horizon a much lower amount of around 300 400 mm mapp periods of loess and sandy loess deposition and a mapp of micromorphology shows compacted granular structure and moderately to strongly developed pedality as characteristic properties for aquatic loess whereas channel microstructure with no pedality is typical for loess deposits spongy microstructure suggests a classification of the lower weichselian mosbach humus zones as chernozems the eemian paleosol btw horizon in als iii has only weak clay illuviation characteristic for drier regions in europe palaeoclimate and soil formation of the last glacial interglacial cycle calculated from geochemistry and micromorphological data are in good accordance with other proxy data in central europe this suggests that paleoclimate reconstruction based on palaeopedological analyses could be successfully implemented in europe such data may provide a useful alternative to other proxies for correlating european records

chemical dynamics of the st lawrence riverine system δdh2o δ18oh2o δ13cdic δ34ssulfate and dissolved 87sr 86sr chemical and stable isotope analyses of the st clair detroit niagara and st lawrence rivers st lawrence system and their tributaries show that the chemical and isotopic compositions of the waters are strongly controlled by the geology of their drainage basins tributaries draining the canadian shield have very low tds hco3 so42 ca2 mg2 no3 sr2 higher si and fetotal and high 87sr 86sr ratios 0 710 0 713 the grand and thames rivers that drain paleozoic limestones dolostones and evaporites are characterized by opposite attributes the st lawrence and the tributaries draining the canadian appalachians fall between these two endmembers the st clair detroit and niagara rivers do not show any pronounced seasonal variations in major component chemistry due to buffering by the great lakes in contrast pronounced seasonal variations characterize the lower st lawrence mainly because of significant tributary inputs into the overall water budget the d and 18o in the st lawrence range from 60 9 to 44 5 and from 8 5 to 6 1 smow respectively much heavier than the comparative values measured for the tributaries 92 8 to 58 3 and 13 1 to 8 5 this is a consequence of evaporative loss that over the residence time of water of 102 years equals about 7 of the water volume in the great lakes the strontium and sulfur isotopic values for the st lawrence system are relatively uniform with measured values from 0 70927 to 0 71112 for 87sr 86sr and from 4 3 to 5 6 for sulfate 34s their seasonal variations are also minor the strontium and sulfur fluxes of the st lawrence river are calculated to be 7 84 108 and 1 09 1011 mol a respectively the relative contributions of the great lakes tributaries and other sources to these fluxes are 73 16 11 for strontium and 64 13 23 for sulfur isotopic composition of dissolved inorganic carbon 13cdic in the st lawrence system ranges from 4 7 to 0 7 considerably heavier than the values for the tributaries 16 5 to 6 7 the light 13cdic values for the tributaries suggest that co2 from bacterial respiration plays an important role in the isotopic composition of riverine dic however in the main stem river s this bacterial signal is masked by isotopic equilibration with atmospheric co2 due to the long residence time of water in the great lakes seasonally the main stem river s have heavier 13c values in the fall than in the spring a consequence of preferential 12c consumption by photosynthetic plants in the epilimnion of the great lakes during the growth season in the down stream portion of the st lawrence river influx of isotopically light tributary waters causes progressive 13c depletion from 1 3 to 2 0 and 1 4 to 3 0 in the fall and spring respectively the total dic carbon flux of the st lawrence river is calculated to be 3 9 1011 mol a mass balance calculations show that the relative contributions of the great lakes tributaries decay of organic matter exchange with the atmosphere and dissolution of carbonates to this total dic flux are 81 13 2 6 10 in the spring and 83 15 2 4 0 in the fall respectively

sedimentation and erosion processes in middle to late pleistocene sequences exposed in the brickyard of langenlois lower austria abstract the correlation of sedimentary and pedogenetic processes in lower austria is difficult due to significant discontinuities and local variability in soil formation this hampers landscape reconstruction at a regional scale however at a local scale distinct landscape formation processes represented by a shift from fluvial to aeolian deposition can be observed in the brickyard of langenlois lower austria sedimentological and mineralogical analyses in combination with palaeontological finds suggest that the fluvial deposition took place during the middle pleistocene this attribution is confirmed by infra red stimulated luminescence irsl dating which gives a minimum age of 300 ka for the palaeosurface on which the fluvial sediments were deposited this is consistent with a small faunal assemblage including stephanorhinus sp dama sp and an alcine cervid such a fauna is previously unknown in austria it indicates a middle pleistocene interglacial period the low degree of weathering as well as cryosols found in the loess sequence point to loess accumulation during the last glacial the dating results 35 55 ka indicate prolonged loess deposition no signs of pedogenesis could be found this is surprising because in other areas this period is known for weak soil development the lack of soil formation seems to be specific to the western part of lower austria as is the complete erosion of the last glacial maximum lgm loess which can not be found at langenlois

concepts of sediment deposition and accumulation applied to the continental shelf near the mouth of the yangtze river a fundamental understanding of how sedimentary strata form requires distinction between deposition and accumulation of particles deposition refers to the temporary emplacement of particles on the seabed accumulation is the net sum of many episodes of sediment deposition and removal the difference between rates of deposition and accumulation affects the ability of an environment to record sedimentary events radionuclide profiles of 234 th and 210 pb within the seabed can be used to determine 100 day deposition rates and 100 yr accumulation rates respectively on the continental shelf near the mouth of the yangtze river short term deposition rates are about 4 4 cm month whereas accumulation rates integrated over a century are an order of magnitude less about 5 4 cm yr

deformation of the so called gorda plate a new compilation of magnetic anomaly identifications recent side scan sonar data and other data provide constraints on the mechanism of deformation of the area commonly known as the gorda plate a sharp boundary between the rigid juan de fuca plate and deformed material trends southeast from the northern part of the gorda ridge in material older than 2 3 ma the boundary is gradational and trends more to the east previous observations that the anomalies east of the ridge are shorter than their counterparts on the pacific plate are confirmed there is no evidence for subduction or obduction along the mendocino transform adjacent to the ridge the deformation is interpreted to be distributed nw se right lateral simple shear possibly controlled by ductile deformation of the lower crust deformation of this sense is capable of producing the observed shortening the anomalies away from the ridge apparently in crust of age 2 3 ma there must be a transition to deformation on observed ne sw left lateral faults parallel to the original spreading fabric

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

integrated crustal structure across the south central california margin santa lucia escarpment to the san andreas fault the continental margin of south central california has undergone different styles of deformation over the past 30 m y as the north america pacific plate boundary has evolved from subduction to transform tectonics results presented here identify strike slip and compressional structures in the lower crust that probably developed during this period of tectonic transition an integrated model of crustal structure along deep seismic line pg e 3 crosses the entire continental margin west of the san andreas fault near the latitude of san luis obispo a compressional wave velocity model was developed using coincident marine multi channel seismic and onshore offshore wide angle reflection refraction seismic data and was tested independently with gravity modeling a high velocity layer 6 8 7 0 km s about 6 km thick in the lower crust that extends east possibly as far as the san andreas fault is interpreted as tectonically underplated oceanic crust the upper and middle crust of the patton and sur obispo franciscan terranes extends to depths of 14 to 20 km the velocity and density modeling indicate lower average velocities and densities for the patton terrane supporting earlier interpretations that it is a distinct terrane within the franciscan complex abrupt crustal thickening associated with broken and downdropped oceanic crust beneath the santa lucia escarpment probably results from active transform faulting that occurred along the continental slope from about 22 to 16 ma following the subduction of the pacific arguello ridge an imbrication within the oceanic crust centered beneath the coast is evidence for about 15 km of shortening within the oceanic crust convergence between the monterey and arguello microplates during the final stages of farallon subduction about 24 to 16 ma probably caused the imbrication

the eltville tephra western europe age revised integrating stratigraphic and dating information from different last glacial loess localities abstract the eltville tephra et is an important stratigraphic marker bed in the western european loess stratigraphy at the boundary between the regional last glacial maximum lgm in the sense of the maximum extent of glaciation of the scandinavian ice sheet and a terrestrial lgm with the highest degree of aridity and coldness stratigraphic marker beds such as tephra layers are commonly dated at more than one location and often with more than one method the sediments surrounding the et were dated 87 times at 15 localities with different luminescence techniques yielding ages between 13 5 and 49 6 ka based on individual sections the deposition of the et was supposed to have taken place between 20 and 23 ka this raises the question of whether a quantitative combination of individual ages can give a reproducible common age including uncertainties after screening the dataset and applying selection criteria a bayesian resampling approach is applied to obtain a common age consistent with a high percentage of observations from multiple localities four new luminescence ages bracketing the et and two ages directly generated from the tephra horizon are presented and combined with all available data the 1 age range of the bayesian age modelling yields a deposition age between 23 2 and 25 6 ka which is in excellent agreement with two new luminescence ages from the tephra of 24 1 1 9 ka quartz and 24 3 1 8 ka pirir290 and a peak of volcanic minerals in the dehner maar core around 24 3 ka this age is clearly older than previously suggested for the et volcanic eruption but fits better with stratigraphic and paleoenvironmental evidence therefore the et was deposited during phases of strong aeolian activity of the greenland stadial 3 additionally for the first time a correlation can be made between the et and tephra layers recognized in the eifel maar lake cores

polycyclic aromatic hydrocarbon distribution within lower hudson river estuarine sediments physical mixing vs sediment geochemistry abstract sediments and porewaters from two cores one from the east river new york and one from newark bay new jersey were sampled for polycyclic aromatic hydrocarbons pahs and other geochemical markers including 210 pb specific activities despite what appears to be similar sources of pahs to sediments within each core as inferred by ratios of alkylated to non alkylated pahs and pah isomer ratios sediments and associated pahs have undergone distinctly different depositional processes at each site sediments from the core in the east river appear to have been subject to intense physically driven resuspension resulting in selective depletion of low molecular weight pahs within the core presumably due to processes such as enhanced desorption and scouring of particle surfaces although sediment pah concentrations were higher in the east river core compared to the newark bay core porewaters were depleted of the majority of pahs analysed in the east river core relative to the newark bay core precluding quantifying sediment porewater pah distribution coefficients in this core sedimentary variables such as c n ratio particle surface area and sedimentary soot carbon were not related to organic carbon normalized pah distribution coefficients k oc obs rather in the core from the newark bay site k oc obs were influenced by sediment mixing and porewater dissolved organic carbon doc results indicate that in urban coastal areas the physical factors influencing time scales of sediment resuspension and deposition may be of primary importance over particle geochemistry in determining whether pahs will likely equilibrate between sediments and pore waters

upper pleistocene loess stratigraphy in southern germany abstract the detailed loess paleosol sequences of southern germany provide a highly sensitive record of the regional climate and environmental changes of the upper pleistocene combined infrared stimulated luminescence irsl and thermoluminescence tl dating was carried out on loess and loess derivatives at upper pleistocene type sections from the mainz basin the middle neckar valley and the alpine foreland with the aim of setting up a reliable chronological framework for the past 130 000 years the irsl and tl age estimates are in agreement with the geological estimates up to 70 000 years however the chronostratigraphic position of the first truncated brown forest soil in the sections at bockingen bonnigheim and bobingen considered to be the eemian soil or equivalent to oxygen isotope oi substage 5e remains uncertain the methodological results indicate that irsl dating is the more advantageous technique for the upper and middle weichselian periglacial deposits as demonstrated for the loess paleosol sequence in mainz weisenau

late pleistocene loess palaeosol sequences in the vojvodina region north serbia late pleistocene loess palaeosol sequences are widespread in the vojvodina region with thicknesses reaching a maximum of about 20 m our investigations include more than 40 of these loess sections geochronology of the last glacial loess palaeosol sequences based on lumines cence dating and amino acid racemisation provides correlations between upper pleistocene loess palaeosol sediments in vojvodina and comparable deposits at other european localities sedimentary logs of magnetic susceptibility grain size measurements and carbonate content combined with malacological evidence indicate two main relatively cold and arid phases during the last glacial period related to intensive accumulation of loess units l1l1 and l1l2 as well as many brief episodes of dry and windy climatic conditions suggesting a possible relationship with cold events recorded in the north atlantic region generally late pleistocene climate in the region was dry and relatively warm compared with glacial period sites in central europe and was characterised by sharp differences between glacial and interglacial modes new data and interpretations presented in this study emphasise the significance of loess palaeosol sequences in vojvodina for the reconstruction of the temporal and spatial evolution of late pleistocene palaeoclimate in this part of europe copyright 2007 john wiley sons ltd

soil evolution over the quaternary period in a mediterranean climate se spain palaeosols in the granada basin se spain have been studied in two different situations surface soils on geomorphically stable surfaces since the early pleistocene with younger pedogenic overprinting and buried soils on unstable surfaces from the middle late pleistocene on which successive erosional depositional episodes have alternated with pedogenic episodes for each soil clay and iron accumulation indices the fet alt sit ratio clay mineralogy and micromorphological features were used to estimate the degree of soil development from the early to the early late pleistocene the main pedogenic processes were the leaching of carbonates weathering illuviation and rubification which resulted in bt horizons with red colours clay texture clay coatings and kaolinite neoformation the degree of weathering and the development of these bt horizons varied over time and the soils that formed on the surfaces from the early pleistocene show strongest weathering and development however after their formation there were periods in which they were partially truncated and recalcified resulting in polygenetic soils the different degrees of development of the buried soils during the last 474 000 years indicate that the wettest warm period was stage 7 and the driest stage 5 stages 9 and 11 must have had climates with intermediate wetness since the clay accumulation and iron oxide accumulation indices the differences in fet alt sit ratio between bt and c horizons the extent of kaolinite neoformation and the micromorphological features of the soils formed during stage 7 are all similar to the surface soils that formed on early pleistocene deposits these features cannot be used to date surfaces older than 242 000 bp by contrast the soils that formed during stage 7 and later periods show different extents of development and thus can be used for the approximate dating of landforms d 2002 elsevier science b v all rights reserved

discovery of a landscape wide drape of late glacial aeolian silt in the western northern calcareous alps austria first results and implications abstract aeolian deposits record palaeoenvironmental conditions and may coin soil properties whereas periglacial loess is extensively investigated for 200 years the study of the intramontane wind blown deposits of the alps has just stuttered along herein we describe a drape of polymictic siliciclastic silt interpreted as an aeolian deposit that veneers extensive areas in the western northern calcareous alps nca from kames terraces near valley floors up to last glacial nunataks the nca part of the eastern alps mountain range consist mainly of triassic carbonate rocks these are overlain by deposits of the last glacial maximum lgm and its deglacial paraglacial aftermath e g glacial tills fluvio lacustrine successions alluvial fans scree slopes and a regional drape of polymictic silt newly described herein the drape is typically a few decimeters in thickness and slightly modified by soil formation it consists mainly of well sorted silt of quartz feldspars phyllosilicates muscovite chlorite biotite amphiboles and rarely calcite or dolomite the drape is unrelated to the substrate it overlies carbonate bedrock and in lateral continuity abandoned deposystems such as colluvial slopes of redeposited till kames alluvial fans scree slopes and rock avalanche deposits the drape was spotted from near the present valley floors up to lgm nunataks over a vertical range of some 2000 m it is also present in catchments of the nca that were not overridden by far travelled ice streams and that lack metamorphic rock fragments two osl quartz ages of the drape from two distinct locations 18 77 1 55 ka 17 81 1 68 ka fall into the early alpine late glacial interval shortly after the collapse of pleniglacial ice streams this fits with geological and geomorphological evidence respectively that the drape should be of early late glacial age and that it accumulated during a specific interval of time in the nca localized minor deposition of aeolian dust is documented by other authors from plateaus deglaciated only during the late glacial to holocene no evidence however exists for another phase of similarly widespread aeolian deposition such as that which gave rise to the described regional drape of silt intense aeolian transport and deposition was probably a direct consequence of the liberation of huge amounts of unsorted sediment during deglacial ice collapse perhaps combined with climatic aridification this provides a hitherto unappreciated element of the deglacial to paraglacial phase intramontane dust storms because of its large extent and the availability to osl dating the aeolian drape provides an excellent geochronological marker level identified in terrestrial post glacial successions of the eastern alps because of its fine grained siliciclastic composition the drape gives rise to widespread development of atypical cambisols on carbonate bedrocks with comparatively high water storage capacity and nutrient supply

seasonal variation of sediment deposition in the hudson river estuary abstract during and following the spring freshet rapid rates of sediment deposition were observed in the hudson river estuary side scan sonar surveys and sediment coring studies revealed a large amount of spatial variability in sedimentation within the estuary and a distinct seasonal progression during the freshet sediment was deposited in the seaward reaches of the estuary in the two month period after the freshet this sediment was eroded and sedimentation occurred 10 30 km further landward at the estuarine turbidity maximum etm zone the thickness of the new freshet deposit was as great as 40 cm in the etm indicating intense trapping and rapid deposition the location of this depocenter corresponded to a frontal zone where water column observations and modeling studies have indicated enhanced sediment trapping the mass of the new deposits was estimated at 300 000 metric tons during both 1998 and 1999 with similar spatial distributions in 1998 the estimated fluvial input was 560 000 metric tons significantly greater than the 120 000 metric tons estimated for 1999 thus the mass of the observed deposits appear to be more influenced by the redistribution of sediment within the estuary due to seasonal variations in erosion deposition conditions rather than by the direct input of sediment from the watershed

geoarchaeology of upper palaeolithic loess sites located within a transect through moravian valleys czech republic abstract the middle and upper palaeolithic sites situated within the system of moravian and south silesian valleys are key localities for understanding the patterns of seasonal mobility that enabled humans to exploit the north european plain and a possibility to distinguish the importance of the weather and climate for their subsistence practises loess accumulations that have covered the best preserved open air palaeolithic sites in central europe display the climatic record covering at least 30 000 years the sedimentological microstratigraphical and geochemical record of three studied upper palaeolithic loess sites show significant changes documenting increased precipitation towards the north a progressive coarsening of the loess deposits during the upper pleniglacial contrasting with the progressive fining toward the north european glaciation was detected this methodological approach explains more precisely the context of formation processes connected also with human activity within the corridor between the north european plain and the danube basin through which a wide range of organisms including humans and their prey species were channelled

european middle pleistocene loess chronostratigraphy some considerations based on evidence from the wels site austria a combination of site logging luminescence dating and comparison with different long and continuous records of past environmental conditions is used to elaborate an age model for the wels loess palaeosol site austria according to this model marine isotope stage mis 7 is reflected in the development of three red forest soils luvisols at this particular site this is contrary to previous assumptions that suggested the development of such soils in the region at 100 ka cyclicity if these results are correct this may question some previous conclusions regarding the general loess stratigraphy in many parts of europe

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

late pleistocene eifel eruptions insights from clinopyroxene and glass geochemistry of tephra layers from eifel laminated sediment archive sediment cores

moho orientation beneath central california from regional earthquake travel times table al is available with entire article on microfiche order from american geophysical union 2000 florida avenue n w washington dc 20009 document b84 011 2 50 payment must accompany order analysis of relative pn travel times recorded by 238 stations of the u s geological survey central california seismic network calnet from 77 regional earthquakes and explosions shows that arrivals are progressively delayed to the northeast in both the coast ranges and sierra nevada foothills by dividing the calnet into 10 subarrays and assuming laterally uniform velocities for a crust over an upper mantle half space the orientation of a planar moho beneath each subarray is calculated by inversion of relative pn arrival times the results show that the moho dips to the northeast between 3 and 6 beneath the coast ranges and 8 17 beneath the great valley and is horizontal beneath the foothills pn residuals west of the san andreas fault are relatively early by 0 35 s but are interpreted as resulting from a lateral velocity contrast across the fault rather than variations in crustal thickness unexplained pn travel time variance improves by approximately 60 after correction for the travel time due to dip and mean pn residual at each station the pn data corrected for the travel time due to a dipping moho indicate an isotropic upper mantle velocity of 7 97 0 05 km s beneath the coast ranges great valley and foothills evidence of upper mantle velocity anisotropy in the azimuthal variation in pn apparent velocity corrected for dip is only marginally significant at the 5 level however large azimuthal variations in corrected apparent velocity do exist and may be attributed to velocity heterogeneities in the crust unmodeled higher order mantle structure and gradients in upper mantle velocity arrival times of cape mendocino earthquakes recorded in the coast ranges south of san francisco bay indicate lateral variations in upper mantle velocity the 7 4 km s apparent velocity estimate from travel times of the oroville earthquake recorded in the coast ranges out to distances greater than 400 km is anomalous in that pn is normally observed at distances greater than 200 km these arrivals may originate from updip propagation along a 6 9 km s layer in the lower crust of the coast ranges subparallel to the moho

oxygen isotope stage 3 fluvial and eolian successions in europe compared with climate model results abstract fluvial and eolian successions of oxygen isotope stage 3 are compared with global gcm and regional climate rcm modeling experiments of the stage 3 and last glacial maximum climate in europe differences in precipitation between stage 3 stades and interstades were minor which is confirmed by the fluvial successions the fluvial response to climate variation is non uniform and in southern europe more pronounced than in northern europe the model simulations indicate a strong western winter circulation over europe during stage 3 which is supported by the eolian deposits data wind speeds in the last glacial maximum simulation appear modest compared with those of stage 3 which contrasts with the abundance of eolian deposits this suggests that during glacial climates the stabilizing effect of vegetation determines eolian sedimentation rates rather than wind speed stage 3 can be divided into an older part 45 000 cal yr b p with a relatively stable landscape and moist climate and a younger part with more frequent climate change and decreasing landscape stability