pedogenic modification of loess significance for palaeoclimatic reconstructions abstract this review considers the role of pedogenic processes in modifying wind blown dust loess concentrating particularly on the ways that resulting properties may be interpreted as indicators of past climatic conditions and changes emphasis is placed on the sequences of palaeosols developed within loess deposits that are frequently regarded as some of the best terrestrial equivalents of marine sediment records of long term global climatic change a palaeosol is generally interpreted in terms of the broad pedogenic processes and environments assumed to be currently responsible for that type of soil forming at the present surface even the very presence of a palaeosol may have palaeoclimatic significance however in that it is often taken to indicate a period of relative land surface stability and warmer and or moister conditions between cold and or arid phases of loess accumulation in reality it may be more useful to consider many loess palaeosol sequences in terms of changing balances between pedogenesis and loess accumulation over geological time in most regions it seems that the balance swings towards pedogenesis during interglacials or interstadials when sediment supply and transport are limited and the climate is warmer and or wetter where accumulation rates are still appreciable during these soil forming intervals however the soils and palaeosols may be accretionary with surface build up keeping pace with pedogenesis welding may also occur where covering sediments are insufficiently thick to isolate an underlying palaeosol from the effects of pedogenesis active at a new land surface further complications occur due to reworking of palaeosols and syndepositional pedogenic alteration of loess units generally such pedocomplexes can only be deciphered if the different pedogenic geomorphic and sedimentary processes are identified and ordered within a pedosedimentary reconstruction a recent trend has been to treat some loess palaeosol sequences as quasi continuous time series particularly when comparing depth functions of climatic proxy properties such as magnetic susceptibility and grain size with marine and ice core isotope curves

stratigraphy and spatial and temporal paleoclimatic trends in southeastern eastern european loess paleosol sequences abstract the loess paleosol sections batajnica stari slankamen serbia mircea voda romania and stary kaydaky ukraine are presently located in areas of different types of steppe and are highly sensitive for recording climatic changes a stratigraphy for these three southeastern eastern european sections is presented based on pedostratigraphy and correlation of recently obtained susceptibility records with susceptibility data of other sections of the area koriten mostistea vyazivok of the chinese loess plateau and with the benthic 18o record of odp 677 six pedocomplexes were studied at the serbian and romanian sections and five at the ukrainian section the oldest are related to marine isotope stage mis 17 batajnica stari slankamen and mircea voda and mis 13 15 stary kaydaky some points concerning the existing loess chronostratigraphies of bulgaria ukraine and china are discussed comparative study of the profiles allows the tracing of paleoclimatic and paleoenvironmental changes in southeastern eastern europe in time and space reconstruction of paleoprecipitation based on susceptibility rainfall relationships and calculations of sedimentation rates are evaluated

late quaternary paleosols stratigraphy and landscape evolution in the northern pampa argentina the field properties micromorphology grain size geochemistry and optically stimulated luminescence osl ages of two late quaternary sections have been used to reconstruct the sequence of pedosedimentary processes and to provide insights into landscape evolution in part of the northern pampa of argentina paleosols developed in paludal sediments adjacent to the parana river at baradero and in loess at lozada can both be correlated and linked to other sites thus enabling for the first time the tentative recognition and tracing of a diachronous soil stratigraphic unit that probably spans the equivalent of at least part of marine oxygen isotope stage ois 5 the paleosol at lozada was truncated and buried beneath fluvial sediments during the time span of ois 4 and 3 eolian gradually replaced paludal inputs at baradero over this period and there were also two clearly defined breaks in sedimentation and development of paleosols the period corresponding to ois 2 was marked by significant loess accumulation at both sites with accretion continuing into the mid holocene only at lozada the more developed nature of the surface soil at baradero probably reflects a combination of a moister climate and a longer soil forming interval

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

soils as indicators of quaternary climatic change in mid latitude regions abstract soils result from changes to uppermost layers of the earth s crust occuring beneath stable land surfaces soil properties are determined by five factors or groups of factors climate organisms relief parent material and time quantitative climatic interpretation of soils depends upon mathematical relationships between individual soil properties and climatic factors i e climofunctions these are difficult to establish and often cannot be applied to diagenetically modified buried soils so most climatic interpretations of soils are qualitative or semi quantitative soil features formed by frost action are the most reliable climatic indicators most soils continue to develop over time however many soil dating techniques provide only a single date some time during the period of soil formation the beginning and end of a soil development period are best determined by reference to dated deposits over as large an area as possible but stratigraphical interpretation of soils is still impeded by imprecise definitions and procedures the soil chronosequences developed in the major loess deposits of europe and asia provide the best evidence for climatic change throughout the quaternary however only major glacial interglacial cycles are well expressed to obtain more detailed evidence of weaker interstadial cycles it is necessary to study chronosequences in mid latitude regions which were generally moister for much of the quaternary however these soils are less well preserved and present additional difficulties of interpretation because of greater variation in parent material relief and time as soil forming factors

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

loess like and palaeosol sediments from lanzarote canary islands spain indicators of palaeoenvironmental change during the late quaternary abstract on lanzarote canary islands quaternary saharan dust and weathered local volcanic material were trapped in miocence to pliocene valleys dammed by younger volcanic edifices these sediments show sequences of alternating reddish clayey and loess like yellowish silty material in order to investigate if reddish clayey layers contain material derived from local pedogenesis and if so which pedogenetic processes were active we performed sedimentological micromorphological and environmental magnetic analyses the analyses demonstrate that these layers contain material derived from local soils these soils were characterised by clay formation rubefication and the formation of superparamagnetic particles during periods of enhanced soil moisture thus they can serve as natural archives in order to reconstruct the terrestrial palaeoclimatic history of lanzarote the distribution of soil material in the profiles shows that cold periods of the late quaternary were characterised by more humid conditions than today using palaeontological remains and a comparison with recent soils on tenerife we can roughly estimate maximal palaeoprecipitation values during more humid periods

are mid latitude slopes sensitive to climatic oscillations implications from an early holocene sequence of slope deposits and buried soils from eastern germany abstract on a straight slope within the lake catchment of kleiner tornowsee brandenburg germany a sequence of slope sediments has been deposited during the late glacial the early holocene and around cal 4 2 ka before today 800 500 and 300 years ago the chronology is based on 21 radiocarbon dates and 11 osl dates and a deposition model including the numerical data as well as stratigraphic information has been calculated with oxcal 4 1 a comparison of the woody taxa of charcoal particles n 566 embedded within the sediments with the known regional vegetation history confirmed the reliability of the dates according to the age volume and distribution the deposition of the early holocene sediments at ca 10 3 kyrs ca 9 5 kyrs and ca 8 2 to 7 7 kyrs before today strongly suggests an influence of known climatic deteriorations phases on geomorphologic processes cold and dry climatic conditions probably promoted wildfires in pinus dominated forests and therefore triggered the observed repeated slope instability in consequence mid latitude slope deposits provide a potential to reconstruct the geomorphological response to climatic events at a high spatial resolution in contrast the recorded mid to late holocene soil erosion phases on the slope have been triggered by land use activities apart from traditional environmental archives slope deposits provide valuable information about the vegetation and climate history

soil mineral depletion drives early holocene lake acidification in recent decades explanations for post glacial lake acidification have focused on changing climate and biotic factors here we present a unique lake sediment data set combining diatom inferred acidity reconstruction with detailed quantitative assessment of soil base dynamics that challenges this view we show at krakenes lake in norway that historical development of soil mineral depletion inferred from the lake sediment record is consistent with the extent and timing of early holocene acidification the lake water acidification can be fully accounted for by abiotic soil mineral depletion suggesting a lesser role for alternative acidifying mechanisms such as direct climate impacts and successional changes in organic acid production there are at present few comparable data sets but those that exist suggest similar rates of soil base depletion as this acidification is not confined to water abiotic mineral depletion is likely also to impact terrestrial ecosystems and dynamic vegetation models that exclude irreversible mineral depletion will fail to capture an important element of global ecology

obliquity forcing of quaternary glaciation and environmental changes in ne siberia abstract reconstructing quaternary glacial and environmental changes in the vast high northern latitudes of siberia is essential for a better understanding of global past climate variability and its potential solar forcings two sediment outcrops in the dyanushka valley in the southwestern foreland of the verkhoyansk mountains northeast siberia were investigated using a multi proxy approach lithostratigraphy geochemistry palynology and radiocarbon and irsl dating three piedmont glaciations reached the outcrop sites the glacial advances are dated to 140 119 92 and 78 53 ka and thus within dating uncertainties correspond to obliquity minima during marine isotope stages mis 6 5d and 4 this chronology corroborates and refines previous studies that have documented the successively more restricted glacial extents in siberia during the course of the last glacial cycle the observed glaciation pattern is out of phase with global ice volume estimates and probably indicates a strong aridisation trend additionally the results show that the geochemical and mineralogical composition of the sediments contains information about provenance sediments originating from the verkhoyansk mountains are generally enriched in tio2 mgo p2o5 fe2o3 cr illite and chlorite whereas sediments derived from the lena river contain more expandable clay minerals ba sr alkane patterns as biomarker proxies turn out to be particularly valuable where poor preservation of pollen is an issue and generally speaking vegetation reconstruction helps distinguishing between warm versus cold mode sediments

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

colluvium definition differentiation and possible suitability for reconstructing holocene climate data abstract this study examines whether colluvial soils store climatic data and if these data can be used as proxies colluvial soils as the correlated sediments of soil erosion represent a widespread geoarchive these soils store the morphology data of the eroded soils and contain clues as to the processes of the eroded soils formation as well as indications of the pedogenesis which took place after the deposition all of these processes are closely related to climatic factors especially rainfall this study discusses the genesis of young soils in colluvial sediments and shows that typical soil features may be related to climatic factors furthermore the study investigates the genesis of anthropogenic colluvial sediments which must be seen as a syngenetical product of relief field size time of usage pressure of population farming technique sediment erodibility deposition area and climatic factors to this end pedogenic features are separated from the sedimentological features the results show that the reconstruction of all factors which control the genesis of the formation of a colluvium is still not yet possible this is the necessary precondition for colluvial soils to yield proxy climate data or for the data to be correlated with already existing holocene climate archives as the results of our discussion are ambiguous in their interpretation we conclude that colluvial soils which clearly include climatic information cannot be used for the reconstruction of proxy climate data at present

charcoal and wood remains for radiocarbon dating upper pleistocene loess sequences in eastern europe and central siberia abstract the present paper concerns long upper pleistocene loess sequences from eastern europe with multiple upper palaeolithic occupations rich in charcoal as well as loess sequences from central siberia with abundant wood remains these complementary records have allowed establishing a high resolution climatic sequence integrating 24 interstadial episodes between ca 42 5 and 10 kyr bp here we discuss the methodology of dating used to fix the chronological framework of this climatic sequence based on a set of 240 available radiocarbon dates mainly produced on charcoal and wood remains special attention is paid to the strategy of sampling charcoal and wood material in strict accordance with stratigraphy as well as to the preparation process in the laboratory for extraction cleaning identification and selection of the best fragments to date careful stratigraphic drawing and detailed positioning of the samples for each geological layer are also considered in order to clarify the relationship of the obtained dates with respect to any sedimentary pedological or archaeological event to be dated the reliability and accuracy of the dates obtained from loess sequences are further controlled by the internal consistency with regard to stratigraphy palaeoenvironmental implications are also discussed

pedosedimentary reconstruction of a thick loess paleosol sequence near lanzhou in north central china abstract a 38 m well section near lanzhou at the semiarid western margin of the loess plateau china contained a continuous high resolution loess paleosol sequence spanning the last 130 000 yr depth functions of micromorphological features magnetic susceptibility calcium carbonate organic carbon and median grain size provide the basis for pedosedimentary and associated paleoenvironmental reconstructions of three paleosol complexes s1 sm and s0 each pedosedimentary stage reflects the interaction of changing intensities of controlling monsoonal forces three periods of reduced dust inputs and enhanced pedogenic activity notably bioturbation and weak leaching can be identified from within the s1 pedocomplex these soil forming intervals were separated by phases of varying land surface instability characterized by arid dust deposition semiarid accretionary pedogenesis water reworking and crust formation or even freeze thaw modification the sm pedocomplex represents an interval of relatively rapid dust accumulation with only minimal syndepositional modification and minor pedogenic alteration at ephemeral land surfaces the s0 pedocomplex is clearly more pedogenically developed although erosion reworking and mixing by water have partly homogenized the property depth functions

microstructure diversity in ah horizons of black chernozemic soils alberta and british columbia canada abstract microstructure diversity was examined in a horizons of black chernozemic boroll pedons in western canada with differences reflecting the interactions of parent material faunal activity and physical processes spongy microstructures modified by frost processes to produce platy aggregates occur in silty aeolian veneers in southern british columbia in central alberta intergrain micro aggregate microstructures occur on sandy loam materials whereas coarser crumb and granular aggregates along with b horizon pedorelicts are strongly developed on clay loam morainal materials trends in carbon content with aggregate size show corresponding diversity humus forms depart significantly from the mull considered typical of chernozems with these a horizons appearing most similar to the moder type

loess record of the pleistocene holocene transition on the northern and central great plains usa various lines of evidence support conflicting interpretations of the timing abruptness and nature of climate change in the great plains during the pleistocene holocene transition loess deposits and paleosols on both the central and northern great plains provide a valuable record that can help address these issues a synthesis of new and previously reported optical and radiocarbon ages indicates that the brady soil which marks the boundary between late pleistocene peoria loess and holocene bignell loess began forming after a reduction in the rate of peoria loess accumulation that most likely occurred between 13 5 and 15 cal ka brady soil formation spanned all or part of the bolling allerod episode approximately 14 7 12 9 cal ka and all of the younger dryas episode 12 9 11 5 cal ka and extended at least 1000 years beyond the end of the younger dryas the brady soil was buried by bignell loess sedimentation beginning around 10 5 9 cal ka and continuing episodically through the holocene evidence for a brief increase in loess influx during the younger dryas is noteworthy but very limited most late quaternary loess accumulation in the central great plains was nonglacigenic and was under relatively direct climatic control thus brady soil formation records climatic conditions that minimized eolian activity and allowed effective pedogenesis probably through relatively high effective moisture optical dating of loess in north dakota supports correlation of the leonard paleosol on the northern great plains with the brady soil thick loess in north dakota was primarily derived from the missouri river floodplain thus its stratig raphy may in part reflect glacial influence on the missouri river nonetheless the persistence of minimal loess accumu lation and soil formation until 10 cal ka at our north dakota study site is best explained by a prolonged interval of high effective moisture correlative with the conditions that favored brady soil formation burial of both the brady soil and the leonard paleosol by renewed loess influx probably represents eolian system response that occurred when gradual change toward a drier climate eventually crossed the threshold for eolian activity overall the loess paleosol sequences of the central and northern great plains record a broad peak of high effective moisture across the late pleistocene to holocene boundary rather than well defined climatic episodes corresponding to the bolling allerod and younger dryas episodes in the north atlantic region

the late quaternary loess record of tokaj hungary reconstructing palaeoenvironment vegetation and climate using stable c and n isotopes and biomarkers abstract large areas of southeast europe are covered by pleistocene loess deposits with interbedded palaeosol layers reflecting interglacials or stadials these loess palaeosol sequences are valuable terrestrial archives for continuous palaeoclimatic and palaeoenvironmental information in recent years the traditional paradigm of treeless full glacial palaeoenvironments has increasingly been called into question as there is palynological anthracological and malacological evidence for the continuous presence of trees from loess palaeosol sequences in the carpathian basin this paper aims at contributing to this discussion by applying biogeochemical geophysical and sedimentological methods to a late quaternary loess palaeosol profile at tokaj ne hungary previous studies at the same location have focused on molluscs and charcoal while this study concentrated on stable c and n isotopes and lipid biomarkers long chain n alkanes c 23 c 33 which form major constituents of plant leaf waxes have successfully been used as biomarkers over the last years and allow for a reconstruction of palaeovegetation based on the differentiation of grassland vs shrubs and trees stable carbon isotopes were used to further differentiate between c 3 and c 4 palaeovegetation and stable n isotopes to reconstruct the n cycle and climatic variations magnetic susceptibility ms organic carbon and grain size distribution which may serve as proxies for e g the intensity of pedegenesis weathering and palaeowind strength were measured to complement the biogeochemical results and to establish a pedo and biostratigraphy although the results do not agree in every detail with previous studies there are surprising matches and similarities in the data alkane and stable n isotopic data indicate that pedogenesis occurred under productive fertile steppe grasslands probably in an intensified seasonal climate and during reduced sedimentation two short treeless steppe periods were found between 26 and 12 ka bp however periods characterised by a cooler climate in which trees and shrubs expanded were also found this interpretation is also supported by previous mollusc data that provide evidence for several periods of favourable conditions for tree growth

climatic reconstruction of the weichselian pleniglacial in northwestern and central europe a multiproxy approach is applied to reconstructing accurately the weichselian pleniglacial climate 72 13 ka in northwestern and central europe standardised translations are used to transform proxy data into climate parameter values for six characteristic time windows quantitative reconstructions of the temperature regime are derived from periglacial coleoptera and botanical evidence while aeolian and fluvial evidence provide qualitative information on wind activity and precipitation respectively the early pleniglacial 74 59 ka the cold period between 41 38 ka and the late pleniglacial 27 13 ka are characterised by a strong north to south climatic gradient over northwestern europe during the last glacial maximum discontinuous permafrost was established in northern france whereas the continuous permafrost zone extended from the uk belgium the netherlands germany and poland to the nordic ice sheets prominent wind activity and a relatively low precipitation typify these periods in contrast an indistinct west to east climate gradient was present in the relatively more temperate intervals e g 50 41 ka seasonally frozen ground conditions prevailed in northwestern europe whereas discontinuous permafrost may be suggested for central germany it appears that the climate conditions in northwest and central europe were controlled by three major factors the scandinavian ice sheet the north atlantic surface water circulation and the russian continent 1998 john wiley sons ltd

historical soil erosion by water in germany scales and archives chronology research perspectives abstract the published record of historical soil erosion by water in germany as deduced from dated slope deposits n 306 alluvial sediments n 120 and lake sediments is summarized in this paper the number of sediments investigated reflects the state of knowledge chronology of historical soil erosion and to a certain degree the intensity of the human impact on german landscapes during the holocene even though few data of calculated historical soil erosion intensities exist an estimation of historical soil erosion in germany combining the available data has been calculated soil erosion in germany occurred first locally during the early holocene probably triggered by climatic variability from the neolithic onward the record reflects the human impact according to agricultural land use the observed variability indicates phases of weaker and regained intensity of agricultural land use in germany few records characterise the early and middle bronze age ca 2000 1600 bc and the migration period and the early medieval times ca 400 1000 ad surprisingly for the roman emperor times ca 1 400 ad a decreasing number of soil sediments is recorded even when the data from southern germany is examined separately phases characterised by an increase in soil erosion were the late bronze age and pre roman iron age ca 1600 bc 1 ad the high and late medieval times ca 1000 1350 ad and the modern times ca 1500 ad until today some extraordinary heavy precipitation events late 18th early 19th first half of 14th century pre roman iron age topped the even high soil erosion intensities research gaps as well as potential for future research as derived from the available data are outlined

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

grain size of quartz as an indicator of winter monsoon strength on the loess plateau of central china during the last 130 000 yr the chinese loess paleosol sequence constitutes an important record of variations in asian monsoon climate over the past 2 4 myr magnetic susceptibility of loess and paleosols has been used as a proxy for summer monsoon intensity while median grain size has been regarded as a measure of the strength of winter monsoon winds that were responsible for most of the dust transport however median grain size is only an approximate index of winter monsoon strength because both paleosols and loess have been modified to various degrees by weathering processes that have produced pedogenic clay the quartz component of loess and paleosols is largely unaffected by weathering processes and therefore constitutes a more reliable proxy index of monsoon wind strength median grain size qmd and maximum grain size qmax values of monomineralic quartz isolated from the loess paleosol section at luochuan in the central loess plateau are characterized by two main intervals during the last ca 130 000 yr when these parameters were significantly greater than 9 and 85 m respectively and three main intervals when they were lower the data imply that the winter monsoon weakened during the intervals with low qmd and qmax values which coincide with marine oxygen isotope stages 5 3 and 1 and was strongest ca 67 000 and 20 000 yr ago during isotope stages 4 and 2 however both quartz grainsize records display second order high frequency high amplitude variations which are lacking in the magnetic susceptibility record that imply rapid and significant changes in atmospheric conditions that affect dust transport and deposition

chinese loess record of monsoon climate during the last glacial interglacial cycle the thick loess paleosol succession of central china contains a detailed record of changes in east asian monsoon climate since the late miocene epoch the alternating loess paleosol stratigraphy closely resembles the marine oxygen isotope record implying that episodic dust deposition and pedogenesis are in phase with global ice volume fluctuations and controlled by variations in solar radiation reaching the land surface deposits equivalent to marine isotope stages mis 5 through 1 have been dated by 14c 10be luminescence and magnetic susceptibility and grain size models malan loess mis 4 2 decreases in thickness southeastward from 30 m in the western loess plateau to 5 m east of xi an downwind asian dust is found in japan the north pacific ocean and the greenland ice sheet where it has a chemical signature that points to a primary source in western china during glacial times the mean dust flux in the central loess plateau reached 0 35 mm year whereas in interglacial times it fell to 0 1 mm year times of high dust influx and reduced soil development coincided with strengthened winter monsoon conditions which are inferred from variations in loess grain size times of decreased dust accumulation and strong pedogenesis marked by high values of magnetic susceptibility represent times of strengthened summer monsoon conditions high frequency fluctuations in dust influx during deposition of the malan loess include peaks that likely correlate with north atlantic heinrich events the younger dryas oscillation is recorded in chinese eolian and organic deposits by a shift from cool humid late glacial conditions to cold and dry conditions followed by a return to milder humid climate at the beginning of the holocene warm moist climate associated with a strong summer monsoon characterized the first half of the holocene epoch when a widespread paleosol complex developed on the loess plateau increased dust deposition during the middle to late holocene marked a shift to cooler drier conditions

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

early holocene paleosols at the southwestern ramlat as sab atayn desert margin new climate proxies for southern arabia abstract the ramlat as sab atayn desert margin near ma rib yemen displays well preserved early holocene paleosols which are documented by ams 14 c and soil data mollusc shells in bwk and bwkb horizons are dated to the period between 12 5 and 9 5 ka cal bp the buried soils above ahb and abwkb horizons indicate a period of soil formation mainly between 8 8 and 8 3 ka cal bp between 8 3 and 6 7 ka cal bp more weakly developed soils occur and those only locally in contrast to the paleosols sandy cover sediments c horizons without considerable signs of pedogenesis appear due to increasing aridity wind activity and sheet wash after 8 3 ka cal bp these results indicate an arid climate and the formation of cover sediments at the desert margin of yemen in the rain shadow of the yemen highlands after the main period of soil formation which ended around 8 3 ka cal bp at the latest at 6 7 ka cal bp calculating from geochemical data a palaeoprecipitation of about 400 to 600 mm a 1 235 mm a 1 from 12 5 to 8 3 ka bp is proposed accordingly after 8 3 ka cal bp the summer position of the itcz and the associated monsoon rain belt carrying rain to northeastern yemen is assumed not to go beyond 15 n in its whole amplitude

lake greenly eyre peninsula south australia sedimentology palaeoclimatic and palaeohydrologic cycles abstract lake greenly is a continental playa located in a mid latitude region 34 30 s 33 m above mean sea level on eyre peninsula south australia the uppermost 3 m of central lake greenly sediments contain two complete cycles and one half cycle of carbonate evaporite deposition the sequence is represented by alternating units of protodolomite and fine grained gypsarenite capped by 30 cm thick surficial low magnesian calcite mud which grades laterally into skeletal peloidal sand and beachrock near the lake margin the favoured depositional model suggests that calcite was deposited at the sediment water interface during freshening episodes marked by higher lake levels and lower salinities at the same time individual flooding events deposited skeletal peloidal sand as thin interbeds which thicken and coarsen laterally towards the lake margin the dolomite was probably deposited during periods of low levels and high brine concentrations caused by increased aridity and evaporation and represents a dolomitization front during this stage water was drawn up by evaporative pumping with subsequent precipitation of gypsum and halite at the sediment air interface although gypsum precipitation did not control dolomitization it probably assisted the process by raising the mg ca ratio and reducing the number of competing ions until formation of protodolomite by early diagenetic replacement of calcite took place

how cold was it for neanderthals moving to central europe during warm phases of the last glaciation abstract precise estimates of mean annual temperature mat for when neanderthals occupied central europe are critical for understanding the role that climatic and associated environmental factors played in neanderthal migrations and in their ultimate extinction neanderthals were continuously present in the relatively warm regions of southern and western europe in the pleistocene but only temporarily settled central europe ce presumably because of its colder and less hospitable climate here we present a new approach for more spatially and temporally accurate estimation of palaeotemperatures based on the stable oxygen isotope composition of phosphates extracted from animal teeth found at sites linked directly to concurrent neanderthal occupation we provide evidence that neanderthals migrated along the odra valley of ce during warmer periods throughout the upper pleistocene the mats during these migrations were about 6 8 c for the warm phase of oxygen isotope stage ois 5a d prior to the ois4 cold event at 115 74 000 yr bp and about 6 3 c during the early ois 3 warm phase 59 41 000 yr bp our results show that temperatures during these phases peaked 2 4 c above longer term estimates from ice cores and pollen records we argue that our approach can provide valuable insights into evaluating the role of climate in human migration patterns in the pleistocene

stable isotope compositions of mammoth teeth from niederweningen switzerland implications for the late pleistocene climate environment and diet abstract oxygen and carbon isotope compositions of well preserved mammoth teeth from the middle wurmian 40 70 ka peat layer of niederweningen the most important mammoth site in switzerland were analysed to reconstruct late pleistocene palaeoclimatic and palaeoenvironmental conditions drinking water 18o values of approximately 12 3 0 9 were calculated from oxygen isotope compositions of mammoth tooth enamel apatite using a species specific calibration for modern elephants these 18 o h 2 o values reflect the mean oxygen isotope composition of the palaeo precipitation and are similar to those directly measured for late pleistocene groundwater from aquifers in northern switzerland and southern germany using a present day 18 o h 2 o precipitation air temperature relation for switzerland a mean annual air temperature mat of around 4 3 2 1 c can be calculated for the middle wurmian at this site this mat is in good agreement with palaeotemperature estimates on the basis of middle wurmian groundwater recharge temperatures and beetle assemblages hence the climatic conditions in this region were around 4 c cooler during the middle wurmian interstadial phase around 45 50 ka bp than they are today during this period the mammoths from niederweningen lived in an open tundra like c3 plant dominated environment as indicated by enamel 13c values of 11 5 0 3 and pollen and macroplant fossils found in the embedding peat the low variability of enamel 13c and 18o values from different mammoth teeth reflects similar environmental conditions and supports a relatively small time frame for the fossil assemblage

holocene relief and soil changes in loess covered areas of south western germany the pedosedimentary archives of bretten bauerbach kraichgau based on infrared stimulated luminescence irsl dating of loess borne sediments a chronometry of holocene landscape evolution is established for a representative study site in the early settled kraichgau area in south western germany the results show that the gently rolling relief is due essentially to soil erosion and colluvial deposition triggered by humans cultivating the loess soils since the onset of agriculture in the neolithic period levelling of relief is accompanied by alterations in soil type patterns from haplic luvisols before the impact of humans over variably truncated luvisols with bt horizons prevailing at the slope surfaces in the middle ages to calcaric regosols characterizing both sites of erosion and accumulation since then the tremendous changes show that the effects of human activities have been recorded over thousands of years indicating an early anthropocene in a geomorphological and pedological sense most landscapes are probably more modified by humans than thought at first sight as the results show this recognition requires considering that current geomorphological and soil forming processes might work at different frequencies or magnitudes e g by changes of internal system thresholds such as increased erodibility following the complete erosion of a more resistant bt horizon and or in a different direction e g accumulation instead of erosion or sediment transport due to slope angles decreased by former deposition of colluvium than they would in the absence of a human controlled pre history

occurrence formation and micromorphology of gypsum in soils from the central german chernozem region occurrence of gypsum in soils from loess of the central german chernozem region indicates that local climatic conditions with low precipitation average 500 mm a 1 and a real evaporation between 450 and 460 mm do not allow leaching of weakly soluble gypsum from soils at a site close to the strip mine etzdorf gypsum is accumulated in the ck horizon of a haplic chernozem down to a depth of about 1 5 m its distribution being nonuniform calculated total gypsum in the haplic chernozem amounts from 10 20 t ha 1 the highest accumulation of gypsum obviously by solution transport and evaporation can be observed in a profile exposed to the air since about 1960 in this profile maximum so42 values however are not found on the surface of the outermost aggregates with whitish efflorescence but at 20 cm depth in the profile in a eutric podzoluvisol the precipitation of gypsum developed on living roots as well as in pores of former roots in a buried chernozem large euhedral gypsum crystals with a diameter of up to 1 5 cm were found gypsum crystals occur in different shapes and sizes such as euhedral lenticular rosette like and equigranular ones even soils having undergone leaching processes reveal unusual increases of so42 at 40 50 cm depth this may be an indicator of more recent so42 input due to atmospheric deposition since the beginning of industrialization it is supposed that gypsum is formed by the reaction of atmogenic sulfuric acid with different ca sources in the soil

micromorphology of middle pleistocene palaeosols in northern italy two long term pleistocene palaeosol sequences oleggio and mezzomerico situated in northern italy were studied by a wide range of pedological methods in both palaeosol sequences six main pedogenic units were identified representing different stages of soil formation in the present study particular emphasis was placed on micromorphological analyses in order to acquire more information about the sequence of pedogenic processes the micromorphological results reveal more precise information about the complex sequence of soil forming processes that led to the formation of each palaeosol furthermore comparison of the micromorphological feature sets of the palaeosols which occur in the same pedogenic units provided an opportunity to refine a recently established pedostratigraphy

the last million years recorded at the stari slankamen northern serbia loess palaeosol sequence revised chronostratigraphy and long term environmental trends abstract the stari slankamen loess palaeosol section is located on the northeastern part of the srem loess plateau vojvodina region north serbia the c 40 m thick cliff comprises loess intercalated with 9 major palaeo pedocomplexes and can be considered to be one of the most important quaternary sections in the carpathian panonnian basin here we present new magnetostratigraphic and aminostratigraphic evidence that demonstrates the importance of the site in terms of its age and the long term palaeoclimatic record it preserves directional palaeomagnetic data obtained through alternating field demagnetization demonstrates the presence of reversed polarity below a profile depth of 36 m indicating a matuyama chron age of this interval this interpretation is confirmed by new high resolution palaeomagnetic investigations 434 oriented samples from the lower part of the profile the new magnetic susceptibility record and aminostratigraphy indicate a missing pedocomplex v s2 with an erosional unconformity represented by a distinct gravel layer the combined new magnetostratigraphic and aminostratigraphic based age model requires a significant revision of hitherto published chronostratigraphic subdivisions at the site the relative completeness and long time frame covered by the section is unusual in european loess sequences hence the sequence could form the basis of a continental scale stratigraphic scheme that would alleviate much current chronostratigraphic uncertainty and enable more broad scale climatic reconstructions the section also provides a rare opportunity to investigate detailed and long term climatic change over the middle pleistocene in a region influenced by air masses originating from high and middle latitudes as well as the north atlantic and mediterranean the changing relative importance of these air masses through time provides insight into local and regional atmospheric systems and their evolution through the last c 1 ma the section can thus be considered as one of the key climatic archives in the europe

frost and soils implications for paleosols paleoclimates and stratigraphy abstract frost is a pedogenetic agent this paper describes the use of frost features in soil for paleoclimatic and stratigraphic interpretation it is possible to differentiate periods of frost activity from those of temperate pedogenesis by macroscopic and microscopic criteria and to distinguish between soils with pre syn and epigenetic frost effects an experimental approach is necessary to determine initial frost effects because they are usually difficult to observe at natural active sites work with ecologists also clarifies the evolution of frost affected soils under climatic and vegetational constraints vegetation has important effects on the thermal and hydraulic regimes of soils and on erosion susceptibility the recognition of fossil cryosoils often allows the reconstruction of sequences of paleoclimatic events in periods or environments with little or no micropaleontological evidence the interrelations between frost and other pedogenetic processes allow a better understanding of climatic evolution and deterioration throughout the neogene and especially during the quaternary and the holocene most of the inherited frost features in european soils are younger than 480 ka bp the differentiation between frost and tectonic perturbations is very important for calculation of soil erosional budgets