dating the quaternary progress in luminescence dating of sediments abstract luminescence dating comprises a collection of numerical age techniques that are among the most significant chronological tools currently used in quaternary research this paper briefly reviews the key historical developments in luminescence dating from its roots in thermoluminescence dating of heated minerals to the development of optical dating methods for sunlight exposed sediments we describe the principles and practicalities of the various techniques commonly used in luminescence dating including multiple aliquot single aliquot and single grain procedures and we discuss some of the latest approaches to recognising and minimising potential errors in age estimation e g by means of component analysis and dose distribution methods in optical dating the overview also introduces the other papers in this special issue of quaternary science reviews which address a selection of important issues in basic research technique development and application of luminescence dating to critical questions in the geological and archaeological sciences illustrated with examples from around the world and the last million years of earth history

the loess and loess like deposits along the sides of the western mediterranean sea genetic and palaeoclimatic significance abstract the loess and loess like deposits on the northern and southern sides of the western mediterranean generally dating to the upper pleistocene are derived from aeolian mobilization of dust from local sources and from their sedimentation where trapped in a dense steppe environment these aeolian deposits however differ from each other as regards the nature of the source material the sedimentary processes and the post depositional weathering loess deposits are more frequent on the north side of the mediterranean where deposited in attenuated periglacial conditions than in north africa where they accumulated in peridesert areas during pluvial periods

geochronology of middle and upper pleistocene loess sections in hungary abstract the application of both thermoluminescence and infrared stimulated luminescence dating to the extensively studied classical hungarian loess paleosol sequences from basaharc mende and paks provides a reliable chronological framework and climatostratigraphic reconstruction for the last interglacial glacial cycle based on this combined luminescence dating study a new chronology is proposed for the young loess in hungary luminescence dating suggests that the loess below the mf2 horizon formed during the penultimate glaciation the mf1 horizon probably formed during an interstade within oxygen isotope stage 3 for the youngest loess overlying mf1 a very high accumulation rate was determined large time gaps occur above mf2 and mf1 indicating that most of the record of the last glaciation is missing in the standard sections at basaharc mende and paks either large discontinuities or a very low accumulation rate occurred in all three type sections during the soil forming periods high resolution studies of climatic proxies using this combined luminescence dating approach provide a reliable chronological framework for loess and loess derivatives of the last glacial cycle in hungary although a precise and complete chronostratigraphic reconstruction cannot be achieved from the incomplete records found at these sites

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

rivers and loess the significance of long river transportation in the complex event sequence approach to loess deposit formation abstract rivers are essential for loess deposit formation river systems which relate directly to loess deposit formation include the danube and the rhine the mississippi and the missouri the thames and the medway the indus ganges and brahmaputra the dnepr don and volga the clutha mataura and rakaia new zealand rivers the yellow river rivers in south america siberian rivers flowing north the odra and the wisla between the mountains and the ice the syr darya and amu darya into the desert the contention is that rivers are not just important in major loess deposit formation they are mandatory necessary imperative obligatory essential indispensable requisite for a complete and satisfactory study of a loess deposit we need to know how the material is produced how it is transported and distributed across the landscape how intermediate deposits are formed how transportation provides the defining properties i e open structure collapsibility draping across the landscape and what may happen post deposition e g chernozemisation fragipan formation increased collapsibility etc if rivers are essential then it would appear that the british loess is probably alpine material delivered by the proto rhine and the polish loess is not derived from the ice sheet to the north but from the mountains to the south the lack of loess in canada is explained by the absence of suitable rivers the loess in russia and neighbouring countries can be classified as jefferson et al jefferson i f evstatiev d karastenev d mavlyanova n g smalley i j 2003b the engineering geology of loess and loess like deposits a commentary on the russian literature engineering geology 68 333 351 suggested on the basis of associated rivers a new deposit of glacial loess is recognised associated with the dnepr don and volga rivers the uswr loess the smalley leach smalley i j leach j a 1978 the origin and distribution of the loess in the danube basin and associated regions of east central europe a review sedimentary geology 21 1 26 available from www geo edu ro sgr mod downloads pdf smalley sedgeo 1978 pdf vision of the loess in the danube basin and east central europe is probably misconceived they assigned a great significance to glacial action and put loess in a northern band it appears that this proposed glacial influence is minimal and that the danube loess is essentially mountain loess derived from the alps the carpathians the sudeten mountains and other high regions the danube system is a classic example of a river controlling loess distribution

14c dating of loess only indirect age determinations up to 50 ka bp can be carried out on loess using the 14c dating method organic materials such as charcoal wood and bones embedded in loess are suitable for dating soil horizons are less suitable due to the mobility of humic acids which are used for dating snail shells constitute the best kind of organic carbonates for age determination loess concretions loess kindl calcrete are frequently unsuitable as they may have been formed and or diagenetically altered long after the loess was deposited two dating techniques are available radiometric detection by liquid scintillation proportional and miniature counters and accelerator mass spectrometry which vary as to the amount of sample required 5 5000 mg carbon equivalent and the dating costs 100 1000 per sample there are various problems inherent in the interpretation of 14c dates of pleistocene loess samples for comparison with absolute dates it must be kept in mind that 14c ages may be smaller by several thousands of years than the true ages this is due to dendrochronological calibration problems which have not yet been satisfactorily solved for samples exceeding 10 000 years in age besides this age deviations of several tens of thousand years may occur due to contamination with allochthonous carbon compounds in spite of these mentioned problems 14c dating of samples found embedded in loess will continue as material suitable for other dating techniques is often not available

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

optical dating of young coastal dunes on a decadal time scale we explore the use of quartz optically stimulated luminescence osl dating for reconstructing coastal evolution on a time scale of decades to a few hundred years samples are taken from the accretionary south west coast of texel a barrier island just offshore of the northern netherlands the ages of dune ridges are known from historical sources an excellent chronology with a decadal accuracy exists for the past 260 years osl ages of less than 10 years on the youngest samples indicate that the osl signal of the quartz grains is very well zeroed prior to deposition and burial osl ages of five samples from a 250 year old dune ridge are indistinguishable and the osl ages on 17 out of 20 samples are in excellent agreement with the well known independent age controls our results highlight the potential of osl dating for high resolution reconstruction of coastal evolution over the past few centuries

aeolian dust dynamics in central asia during the pleistocene driven by the long term migration seasonality and permanency of the asiatic polar front loess paleosol sequences preserve detailed archives of climate change reflecting the dynamics of aeolian dust sedimentation and the paleodust content of the atmosphere the detailed investigation of particle size distributions psds of windblown sediments is an increasingly used approach to assess the paleorecord of aeolian dust dynamics the central asian loess belt offers the potential to reconstruct pleistocene atmospheric circulation patterns along an adjacent west east transect within interior eurasia through granulometric studies in this study we present the aeolian dust record of the loess sequence at remisowka se kazakhstan which reflects a detailed signal of glacial interglacial climate and atmospheric dynamics in central asia on the basis of radiocarbon and amino acid geochronologic data long term semicontinuous trends in the aeolian dust record of the last glacial cycle are observed and interpreted to reveal their paleoclimate signal in consideration of the modern synoptical atmospheric circulation patterns and aeolian dust transport in central asia it is likely that the observed trends reflect the long term migration seasonal duration and permanency of the polar front during the late pleistocene previously published models which focused on the reciprocal glacial interglacial influence of the zonal westerlies and the asiatic high on the aeolian dust transport in central asia were overly simplified and should be modified to include the major influence of the asiatic polar front as the polar front activity is intimately connected with the development and position of the interhemispherically active high level planetary frontal zone hpfz the presented data give insight to long term aeolian dust dynamics and climate variability of interior eurasia which are linked with interhemispheric climates

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

avo effects of a hydrocarbon source rock layer the organic content of petroleum source rock layers can be determined from seismic data with a suitable avo technique since the source rock has a layered structure the best forward model is a transversely isotropic layer between two isotropic half spaces parameterized by the layer thickness and the amount of organic material this limited number of parameters is essential to obtain a robust inversion method here i compute the pp and ps reflection coefficients of the source bed as a function of layer thickness and organic content including attenuation mechanisms related to different stages of maturation the source rock is modeled as a viscoelastic medium composed of illite smectite solid organic matter kerogen and fluids oil and water the properties of the kerogen oil water mixture are obtained with the kuster and toksoz model assuming that oil and water are the inclusion in a kerogen matrix then backus averaging gives the complex stiffnesses of the layer to derive the reflection coeffic

the last glacial aeolian record of the island of susak croatia as seen from a high resolution grain size and rock magnetic analysis abstract the loess palaeosol record on the island of susak in croatia is a unique archive of late glacial climate changes in the adriatic region possibly even in the wider area on susak up to 90 m of thick quaternary sediments were deposited and are accessible for detailed palaeoclimate reconstructions in this paper the results of a high resolution grain size and rock magnetic investigation on the last glacial upper pleniglacial sand pit section from susak are presented in spite of its significant thickness the sand pit section does not represent a continuous record it is a result of a very dynamic environment there the deposition of dust and formation of loess has been interrupted by pedogenesis periods of increased sand accumulation erosion due to slope wash and water activity redeposition and wildfires and all in the time period of about 10 000 years of the upper pleniglacial as seen from the irsl dating results the grain size data clearly show a shift towards coarser grain sizes which differs from typical loess regions such predominance of the coarser grained over the fine grained fraction very likely resulted from the predominance of deposition over pedogenesis increased wind activity and proximal source of material the rock magnetic signal preserved in the sediment also differs compared to loess palaeosol records from other regions the susceptibility values are several times higher than in the records from the pannonian basin and from typical eurasian loess both the increased susceptibility values and the grain size are very likely the result of a significant proximal material input from the po river plain

diagnostics of titan s stratospheric dynamics using cassini cirs data and the 2 dimensional ipsl circulation model abstract the dynamics of titan s stratosphere is discussed in this study based on a comparison between observations by the cirs instrument on board the cassini spacecraft and results of the 2 dimensional circulation model developed at the institute pierre simon laplace available at http www lmd jussieu fr titandbase rannou p lebonnois s hourdin f luz d 2005 adv space res 36 2194 2198 the comparison aims at both evaluating the model s capabilities and interpreting the observations concerning 1 dynamical and thermal structure using temperature retrievals from cassini cirs and the vertical profile of zonal wind at the huygens landing site obtained by huygens dwe and 2 vertical and latitudinal profiles of stratospheric gases deduced from cassini cirs data the modeled thermal structure is similar to that inferred from observations cassini cirs and earth based observations however the upper stratosphere above 0 05 mbar is systematically too hot in the 2d cm and therefore the stratopause region is not well represented this bias may be related to the haze structure and to misrepresented radiative effects in this region such as the cooling effect of hydrogen cyanide hcn the 2d cm produces a strong atmospheric superrotation with zonal winds reaching 200 m s 1 at high winter latitudes between 200 and 300 km altitude 0 1 1 mbar the modeled zonal winds are in good agreement with retrieved wind fields from occultation observations cassini cirs and huygens dwe changes to the thermal structure are coupled to changes in the meridional circulation and polar vortex extension and therefore affect chemical distributions especially in winter polar regions when a higher altitude haze production source is used the resulting modeled meridional circulation is weaker and the vertical and horizontal mixing due to the polar vortex is less extended in latitude there is an overall good agreement between modeled chemical distributions and observations in equatorial regions the difference in observed vertical gradients of c 2 h 2 and hcn may be an indicator of the relative strength of circulation and chemical loss of hcn the negative vertical gradient of ethylene in the low stratosphere at 15 s cannot be modeled with simple 1 dimensional models where a strong photochemical sink in the middle stratosphere would be necessary it is explained here by dynamical advection from the winter pole towards the equator in the low stratosphere and by the fact that ethylene does not condense near the winter pole 80 n some compounds c 4 h 2 c 3 h 4 exhibit an interior minimum in the observed abundance vertical profiles whereas 2d cm profiles are well mixed all along the atmospheric column this minimum can be a diagnostic of the strength of the meridional circulation and of the spatial extension of the winter polar vortex where strong descending motions are present in the summer hemisphere observed stratospheric abundances are uniform in latitude whereas the model maintains a residual enrichment over the summer pole from the spring cell due to a secondary meridional overturning between 1 and 50 mbar at latitudes south of 40 50 s the strength as well as spatial and temporal extensions of this structure are a difficulty that may be linked to possible misrepresentation of horizontally mixing processes due to the restricted 2 dimensional nature of the model this restriction should also be kept in mind as a possible source of other discrepancies

ubiquity of anomalous fading in k feldspars and the measurement and correction for it in optical dating anomalous fading rates were measured in k feldspars separated from 49 sediment samples mainly from north america the intensity of the optically stimulated luminescence was found to decrease linea

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

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

stratigraphy and palaeoenvironmental significance of the loess deposits on susak island dalmatian archipelago abstract the loess of susak island is the most impressive aeolian deposit in the dalmatian archipelago as it reaches about twenty metres in thickness the base of the sedimentary sequence consists of a shore platform which in the southern part of the island is covered by late middle pleistocene fossil dunes elsewhere the shore platform has been affected by gelifraction and is covered by slope waste deposits above these a thick sequence of aeolian deposits occurs composed in the lower part of cross laminated sandy loam and thick loess cover interstratified with a level reworked by running water and slightly developed chernozems the upper part of the sequence has been strongly affected by anthropogenic reworking in historical times the loess is composed of unweathered subrounded quartz feldspar mica and limestone granules the heavy mineral association is mainly from metamorphic paragenesis and has the same composition as the sediments of the po plain the aeolian sediments are rather homogeneous and composed mainly of coarse silt they are coarser in comparison with those of losinj island 12 km northeast of susak which are typical silty loess indicating a wind direction from southwest to northeast on the basis of the pedostratigraphic data loess sedimentation is referred to the first pleniglacial period of the upper pleistocene the loess of susak island originated in a dry environment by wind deflation of the po river sediments the quick progradation of alluvial and deltaic deposits towards the east southeast due to the sea level drop provided large barren areas exposed to wind erosion

the nature origin and accumulation of loess abstract loess can be defined simply as a terrestrial clastic sediment composed predominantly of silt size particles which is formed essentially by the accumulation of wind blown dust there are three fundamental requirements for its formation 1 a sustained source of dust 2 adequate wind energy to transport the dust and 3 a suitable accumulation site most loess has been modified to some degree by local reworking bioturbation and syn depositional weathering but a process of loessification is not necessary for a dust deposit to qualify as loess the terms primary loess and secondary loess have previously been used to described wind deposited loess and redeposited loess respectively but it is more accurate to describe material reworked and redeposited by non aeolian processes as loess derived colluvium or loess derived alluvium during the quaternary loess formed in three main situations 1 mid continental shield areas beyond the limits of ice sheets periglacial loess 2 on the margins of high mountain ranges perimontane loess and 3 on the semi arid margins of some lowland deserts peridesert loess peridesert loess is relatively poorly developed partly due to the limited efficiency of silt generating mechanisms in low land deserts compared with glaciation but also important is the tendency in arid areas for dust to be dispersed over a wide area and to be rapidly reworked after deposition particularly in areas which experience frequent climatic changes the remarkably thick loess of china and central asia results from an unusual combination of conditions which has persisted for much of the last 2 3 million years namely rapid uplift of the tibetan plateau and surrounding mountain ranges high rates of sediment production and supply to adjacent basins a strong northwesterly and westerly wind regime and the existence of effective dust traps downwind of the source regions

luminescence dating of late holocene dunes showing remnants of early settlement in cuddalore and evidence of monsoon activity in south east india abstract in this study dunes from south east india were dated using optically stimulated luminescence osl to reconstruct the depositional history a belt of dunes has developed parallel to the coast between pondicherry and karikal in tamil nadu south east india in the area between cuddalore and porto novo the dune belt is 5 km wide a transect from the coast to the most western dune inland was investigated changes in the environmental conditions are recorded in the dunes they show features including unconformities changes in the direction of bedding erosional features water escape structures and remnants of human settlements the osl results show that strong changes in the environmental conditions occurred about 100 and 300 years ago the latter event marks also the termination of settlement in this place the settlement period started about 1500 years previously the periods of sand mobility and stabilisation of the land surface by soil formation correlate with changes in the precipitation record of india the investigated dunes very likely reflect fluctuations in the monsoon activity during the last 3500 years in south east india

mineralogical and geochemical indicators of the polygenetic nature of terra rossa in istria croatia abstract terra rossa in istria is situated on the jurassic cretaceous paleogene carbonate plain and is considered a polygenetic reddish soil which bears typical terra rossa fe oxide characteristics e g fe d and fe d fe t the difference in particle size mineralogy and geochemistry observed between terra rossa and the insoluble residue of limestones and dolomites clearly indicates that the additions of external materials might have diminished the influence of insoluble residue of limestones and dolomites as the primary parent material of terra rossa in istria terra rossa is clay and silty clay composed of quartz plagioclase k feldspar micaceous clay minerals illitic material and mica kaolinites kl d and kl chlorite vermiculite low charge vermiculite or high charge smectite mixed layer clay minerals other than illitic material hematite goethite and xrd amorphous inorganic compound calcite dolomite and boehmite are sporadically present and are of local importance kaolinites and illitic material are dominant clay mineral phases in the clay fraction of all terra rossa from istria kaolinite which does not form intercalation compounds with dimethylsulfoxide dmso is the dominant mineral phase in fine clay and is considered predominantly authigenic rather then inherited from parent materials neither the content and particle size distribution nor the bulk and clay mineralogy of the insoluble residue of limestone and dolomite support development of terra rossa entirely by dissolution of carbonate rock if terra rossa has developed only from the insoluble residue of limestone and dolomite its clay content due to weathering should be higher than that in the insoluble residues which is not the case plagioclase was found only in one insoluble residue while all terra rossa samples contain this mineral moreover insoluble residues do not contain vermiculite which was observed in small amounts in clay fraction of all terra rossa samples na 2 o k 2 o 100 zr nb and zr ti 1000 ratios in the majority of terra rossa samples are much higher than in the insoluble residue of limestones and dolomites which also supports external material influence in the genesis of terra rossa materials other than the insoluble residue of limestones and dolomites which might have contributed to terra rossa are loess sediments whose deposition was very important recurrent process in istria probably since the early middle pleistocene and flysch sediments which extended much more southwards from its present position analyses performed indicate that both loess older than that of the upper pleistocene age and flysch might have contributed in the genesis of terra rossa

correlation of loess paleosol sequences in east and central asia with se central europe towards a continental quaternary pedostratigraphy and paleoclimatic history abstract as recent small climatic fluctuations on a 102 103 year time scale can be correlated worldwide and represent a decline of mean annual temperature of only 1 c major climatic changes on at least a 105 year scale glacial interglacial cycles and probably a 104 year scale the approximate length of an interglacial must be of similar ages throughout the temperate climatic belt of the northern hemisphere this concept allows continental pedostratigraphical correlations detailed knowledge of the genesis of paleosols is needed to establish loess paleosol stratigraphies that can be used for paleoclimatic reconstruction most paleosols however are truncated and largely recalcified from overlying loess micromorphological studies allow primary and secondary carbonates to be distinguished and provide unequivocal evidence of clay illuviation this enables the recognition of typical loess weathered loess and the recognition of different genetic soil horizons such as cb bc ah bw and bt horizons for the brunhes epoch the sequence at karamaydan tadjikistan is more detailed than the corresponding section in luochuan china and even more than in se central europe except for the last glaciation the very good correlation with the deep sea oxygen isotope record which includes the development of an accurate astronomical time scale allows a detailed chronostratigraphical subdivision of the loess paleosol sequence in karamaydan which therefore should be regarded as a key sequence for reconstructing the climatic history of the brunhes epoch this implies that the loess paleosol sequences in se central europe are less complete than thought earlier pedocomplexes in karamaydan correspond with single paleosols in se central europe e g the f6 paleosol in stari slankamen correlates with pedocomplexes pk vi and v at karamaydan which were formed over a period of about 140 ka although pedogenesis was interrupted several times by loess deposition the f6 soil is therefore an example of a welded paleosol as are the f5 the f4 and the f2 paleosols in se central europe for most of the matuyama epoch the central and lower parts of the sequence at chashmanigar show more pronounced paleosols than the equivalent parts at luochuan in se central europe only at stari slankamen are three strongly developed though truncated paleosols f9 f11 above neogene sediments mineralogical investigations of the silt and clay subfractions show that there is little difference in the type and amount of pedogenic clay mineral formation between the holocene soils and the paleosols of the brunhes epoch at karamaydan and of the matuyama epoch at chashmanigar this suggests that the interglacial climates represented by the b or bt horizons of the buried paleosols of late middle and early pleistocene age were similar to that of the holocene

mineralogical and geochemical characteristics of quaternary sediments from the island of susak northern adriatic croatia middle and upper pleistocene loess palaeosol sequences up to 90 m thick are exposed on the island of susak located in the northern adriatic sea in croatia during glacial times the sea level was up to about 120 m lower and a significant part of the adriatic became land the source area of the primary aeolian sediments was in the vicinity of the island and is related to the southward extended river po plain the loess has a mainly clayey to sandy silt or sand grain size and is intercalated by at least three tephras numerous palaeosols and calcareous segregations the heavy mineral association points to metamorphic and igneous rocks from alpine regions as source material of the loess geochemical and mineralogical properties of loess and palaeosols differentiate one from another and reflect the intensity of weathering and pedogenesis the oldest tephra contains vitroclasts and serrated clinopyroxene while the middle and the youngest tephra along with vitroclasts contain idiomorphic augite as diagnostic volcanic features based on bulk rock and vitroclast chemistry morphology of pyroxenes and the age of the loess sandwiching the tephra the potential source of this volcanic material could very likely be the campanian or aeolian volcanic province in southern italy infrared stimulated luminescence dating results show that the major part of the aeolian deposits including the tephra layers correlates to mis 3 mis 5

middle and late pleistocene loess sequences at batajnica vojvodina serbia abstract loess sequences in the vojvodina region northern serbia reveal a continuous record of paleoclimatic variations during the middle and late pleistocene the most detailed stratigraphic information comes from remarkable exposures on the cliffs of the right danube bank from vukovar to belgrade the batajnica loess section has been recognized as one of the most complete middle and late pleistocene records in this region a more than 40 m thick loess paleosol succession represents environmental transition from relative thin loess layers and rubified soils in lower part of profile to thick loess and fossil chernozems characterizing the last three glacial interglacial cycles the proposed stratigraphic model is based on a detailed magnetic susceptibility ms record which is related to the deep sea isotope stratigraphy and on correlation with other eurasian loess records using the distinct ms pattern of selected loess paleosol couplets this new stratigraphic model suggests serious revision of previous chronological interpretations ms as function of depth shows a well known pattern of low values in loess and high values in paleosols indicating strong enhancement of magnetic minerals during soil formation with the exception of the recent soil v s0 which is strongly contaminated by archaeological artifacts the third paleosol v s3 reveals the highest values in ms and a very distinct double peak the rock magnetic signal at batajnica resembles the typical pattern of the enviromagnetic records determined from other eurasian loess sites the paleopedological interpretations rubification index values and rock magnetic record at batajnica yield valuable data for the reconstruction of paleoclimatic fluctuations for the last 5 glacial interglacial cycles at least moreover the record provides an important link between the classical central european loess sites and the central asian and chinese loess provinces

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

the loess profile at albertirsa hungary improvements in loess stratigraphy by luminescence dating abstract a very detailed upper pleistocene record is exposed in a loess palaeosol sequence at the section at albertirsa in hungary luminescence dating was carried out to establish a more reliable chronological framework for the hungarian loess record the lowermost palaeosol of the section probably an equivalent of the mf2 horizon at the mende key section is superimposed on penultimate glacial loess an irsl age estimate of about 65 ka bp was determined for the lower part of this palaeosol indicating soil formation late in oxygen isotope stage ois 5 or early in ois 3 a significant hiatus most likely occurs in the lower part of the lower fossil soil the loess between the upper and and lower palaeosol yielded a mean luminescence age of about 50 ka bp the upper palaeosol is probably an equivalent of the mf1 horizon at the mende type section formed between 37 and 25 ka bp and so this palaeosol represents the hengelo and or denekamp interstadial of northwestern european stratigraphy the loess is intercalated by a humic horizon which yielded a mean luminescence age estimate between 21 and 19 ka at the albertirsa section

thermoluminescence ages for three sections in hungary abstract samples were collected from sections at mende paks and tapiosuly ages for the loess above the mf1 soil at mende were in agreement with the radiocarbon dates on charcoal fragments from the soil ages for loess from tapiosuly were also in agreement with radiocarbon ages for younger soils however tl age estimates for loess above or below the mf2 soil at each of the three sites suggested that this soil had an age of around 76 ka it has not been confirmed whether these ages are underestimated however they are older than previously thought on the basis of other tl studies they imply that the underlying mb soil is much older than the last interglacial

radiocarbon calibration curve spanning 0 to 50 000 years bp based on paired 230 th 234 u 238 u and 14 c dates on pristine corals abstract radiocarbon dating is the most widely used dating technique in the world recent advances in accelerator mass spectrometry ams and sample preparation techniques have reduced the sample size requirements by a factor of 1000 and decreased the measurement time from weeks to minutes today it is estimated that more than 90 percent of all measurements made on accelerator mass spectrometers are for radiocarbon age dates the production of 14 c in the atmosphere varies through time due to changes in the earth s geomagnetic field intensity and in its concentration which is regulated by the carbon cycle as a result of these two variables a radiocarbon age is not equivalent to a calendar age four decades of joint research by the dendrochronology and radiocarbon communities have produced a radiocarbon calibration data set of remarkable precision and accuracy extending from the present to approximately 12 000 calendar years before present this paper presents high precision paired 230 th 234 u 238 u and 14 c age determinations on pristine coral samples that enable us to extend the radiocarbon calibration curve from 12 000 to 50 000 years before present we developed a statistical model to properly estimate sample age conversion from radiocarbon years to calendar years taking full account of combined errors in input ages and calibration uncertainties our radiocarbon calibration program is publicly accessible at http www radiocarbon ldeo columbia edu along with full documentation of the samples data and our statistical calibration model

luminescence and amino acid racemization chronology of the loess paleosol sequence at suttő hungary abstract the loess paleosol sequences in hungary provide an excellent upper pleistocene climate archive of the carpathian basin loess deposits up to 20 m thick cover the sutt travertine complex located in the very northern part of hungary next to the right bank of the danube river the loess is intercalated with two weakly developed greyish horizons two thinner brownish steppe like soils and a pedocomplex including a reddish brown clay enriched horizon covered by a chernozem like paleosol infrared optically stimulated luminescence irsl dating was applied on polymineral fine grain material to determine the depositional age of the loess the uppermost loess yields irsl age estimates ranging from 15 to 40 ka the loess on top of the pedocomplex yields irsl age estimates ranging from 48 to 60 ka the pedocomplex most likely correlates with the marine oxygen isotope stage mis 5 interglacial period the loess from below the pedocomplex was deposited during the penultimate glaciation as evidenced by amino acid racemization aar results further independent age control is provided by radiocarbon dating for the upper part of the profile and by uranium series 230th 234u ages correlating the travertine below the loess with mis 7 8 the magnetic susceptibility record through the sequence shows a strong correlation with the loess layers and soil horizons

a new osl chronology for dust accumulation in the last 130 000 yr for the chinese loess plateau abstract a sensitivity corrected multiple aliquot regenerative dose protocol has been developed for fine grained quartz osl dating of chinese loess its reliability has been assessed on the basis of the methodology and by dating reference samples of known age close to the transition from the last interglacial paleosol s 1 to the last glacial loess l 1 which corresponds to the marine oxygen isotope stage mis 5 4 transition on the basis of the fine grained quartz osl age estimates for 33 loess samples from the upper part of the luochuan profile a detailed chronostratigraphy of continuous dust accumulation in the past 130 ka has been proposed changes in the accumulation rate occurred during the last glacial period mis 4 to mis 2 unexpectedly high accumulation rates were found in the weakly developed l 1 2 s paleosol of the last interstadial mis 3 rather than in the classic l 1 1 and l 1 3 loess of the cold dry glacial condition mis 2 and 4 the osl ages show some disagreement with the previous numerical chronology for the loess paleosol sequence based on correlation of variations in grain size with sedimentation rate the latter method resulted in an almost constant accumulation rate from 72 to 12 ka

luminescence dating of upper pleistocene loess from the island of susak in croatia abstract the loess paleosol sequence on the island of susak is a detailed late pleistocene archive of climate change in the north adriatic sea of croatia quaternary deposits on susak are up to 90 m thick and consist of loess loess derivatives and sand intercalated by numerous paleosols and at least three tephra layers infrared stimulated luminescence irsl dating was carried out on polymineral fine grained material thirteen samples were collected from two sections on susak to study the timing of loess accumulation and soil formation the single aliquot regenerative sar protocol as well as the multiple aliquot additive dose maad protocol were applied for equivalent dose d e determination the irsl ages were fading corrected independent age control is provided by radiocarbon dating of charcoal remains the results show that loess and loess derivatives from the investigated sections represent a very detailed record correlating to the marine isotope stage mis 3 with short periods of stronger sand deposition and occasional volcanic activity the extraordinary thickness of the deposits is very likely related to the vicinity of the river po plain which extended to the southeast due to marine regressions of the adriatic sea during the cold periods of the pleistocene

optical dating of sediments a new method for dating sediments is proposed which determines the time since the sediment was last exposed to sunlight an argon ion laser is used to excite electrons from thermally stable light sensitive traps and the subsequent luminescence used as a measure of the past radiation dose two sample sequences spanning the periods 0 700 kyr and 0 6 kyr show steadily increasing luminescence with age an age of 62 8 kyr is obtained for a silt radiocarbon dated at 58 8 0 3 kyr problems were found with two much younger samples