timing of the last interglacial in northern europe derived from optically stimulated luminescence osl dating of a terrestrial saalian eemian weichselian sedimentary sequence in ne germany abstract based on the results of palynological and geochemical analyses a sediment section near the village of vevais north eastern brandenburg is assumed to encompass a succession of saalian eemian and weichselian sediments and is expected to cover a time span from marine isotope stage mis 6 to mis 2 it is regarded as a key site for the study of the last interglacial cycle in north eastern germany palynological analyses had revealed an almost complete record of the eemian mis 5e preserved within a succession of lake marls exposed in the sediment sequence but results from numerical dating methods were still missing within this study five samples from sand layers within the profile have been analyzed using luminescence dating techniques in order to set up a geochronometrical time frame for the eemian interglacial first results from optically stimulated luminescence osl dating of quartz showed severe age underestimation of some samples with regard to their relative stratigraphical position to the eemian lake marls radionuclide analyses revealed disequilibria within the 238u decay chain and inconsistencies concerning the 40k content for most of the samples in order to overcome these dosimetric problems additional infrared stimulated luminescence irsl and post infrared yellow osl post ir yosl measurements from feldspar were conducted and a subtraction dating method was successfully applied hence it was for the first time possible to set up a time frame for the eemian interglacial inferred from luminescence dating techniques of a terrestrial sedimentary archive in north eastern germany the onset of the eemian was dated to 126 16 ka the termination and beginning transition from the eemian to the weichselian cold stage was dated to 108 9 7 8 ka these results are in excellent agreement with the marine isotope record as well as with the results of the analysis of the continuous varve record of lago grande di monticchio with a period of 17 7 0 2 ka from the onset at 127 2 1 6 ka bp for the eemian interglacial

response of the chydorid faunas to rapid climatic changes in four alpine lakes at different altitudes abstract the subfossil assemblages of chydoridae from late glacial preboreal sediments of four sites from 603 m to 2290 m asl were analysed to trace the community response to rapid climatic warming that occurred at this period of time in each site distinct signals at the younger dryas preboreal boundary were recorded by density of remains species diversity or community composition however responses varied considerably among the sites this variation was attributed to the situation that the chydorid community structure is determined not only by temporal younger dryas preboreal boundary and spatial among the sites temperature gradients but also by the specific local ecological conditions at the sites in some species the classification with respect to cold tolerance should be reconsidered

palaeoenvironmental and climate changes recorded in the lacustrine sediments of the eemian interglacial mis 5e in the radom plain central poland abstract the radom plain is a region with numerous fossil palaeolakes that formed a palaeolakeland lacustrine sediments of thickness varying from 0 5 to 18 m were encountered in numerous boreholes pollen analyses of the sediments filling the palaeolakes have proven that their sedimentation began after the retreat of the saalian ice sheet mis 6 continued during the eemian interglacial mis 5e and terminated at the beginning of the weichselian glaciation mis 5d climate and palaeoenvironmental changes have been recorded in different deposits muds peats and gyttja local factors such as reservoir depth and geological conditions have influenced the type of the accumulated sediments eemian sites occur in two geomorphological positions in small depressions on the glacial plateau and in small valleys in ox bow palaeolakes eemian lakes were formed from the melting of dead ice blocks pollen data obtained from the palaeolake sediments document climate and vegetation changes characteristic of the late glacial period the eemian interglacial and the beginning of the weichselian glaciation in many sites a record of a complete eemian succession is present whereas in others it is fragmentary comparison of pollen data between the radom region and other localities in poland shows local and regional differences in the development of forest communities in the eemian in the eemian sequences of the radom plain a considerable contribution of tilia picea and abies pollen is distinct in the forest communities often higher than in other eemian sites of central poland the particularly high percentage of tilia exceeding 30 picea up to 67 and abies 30 pollen are recorded in the babin site this phenomenon may indicate favourable environmental and climate conditions facilitating further propagation of these trees in the pollen record from the babin site three distinct abrupt cool climate oscillations have been noted with the oldest one recorded in the saalian glaciation the two younger oscillations have been distinguished at the very beginning and at the very end of the last interglacial respectively eemian sites from the radom plain are important for the reconstruction of palaeoenvironmental and palaeoclimate changes in the eemian interglacial in poland and europe

late glacial early holocene environmental changes in charzykowskie lake northern poland based on oxygen and carbon isotopes and cladocera data abstract based on isotopic and cladoceran investigations of a 6 m long sediment core a reconstruction of paleoenvironmental dynamics in charzykowskie lake northern poland is proposed the sediments consist of sandy silts at the bottom followed in upward succession by gyttja characterized by increasing caco 3 content the measured 18 o values oscillate from 9 3 to 5 and 13 c from 5 7 to 0 4 we identify 24 taxa of subfossil cladocera and six phases caz of faunal development isotopic and cladoceran data together with detrended correspondence analyses dca allow reconstruction of the environmental conditions particularly changes in water level temperature and trophic status during the late glacial and early holocene the lowest water temperature connected with the inflow of cold melt water occurred in the late glacial and preboreal period since the boreal period gradual warming is observed and expressed through a positive trend in both 18 o and 13 c values and changes in cladocera species assemblages the lake was deepest at the beginning of the holocene as a result of dead ice melting supply of melt water lowering of lake bottom and or precipitation increase change in atmospheric circulation during the boreal period the fall in water level takes place despite the opposite trend observed at nearby sites in addition the cladoceran data indicate an initial decrease in trophic conditions from mesotrophic to oligotrophic and then an increase to the mesotrophic state

crustal structure and moho geometry of the northeastern tibetan plateau as revealed by sinoprobe 02 deep seismic reflection profiling abstract underthrusting of india below eurasia has resulted in the formation of the himalayan and the qinghai tibet plateau distributed deformation coupled with block translation and rotation has generated the qilian shan thrust belt and a series of east and northwest striking strike slip faults across northeastern tibet because these structures lie in a transition zone between the high plateau region to the south and the lowlands of the north china craton in the north determining their deep crustal and upper mantle structures has important implications for unraveling the mechanism of tibetan plateau formation in this paper we present new results from the sinoprobe 02 deep seismic reflection project across the eastern part of the qilian shan and the southern margin of the alxa block interpretation of the reflection profile obtained from this study is based on constraints from surface geology and detailed geometric analysis of structural relationships among key reflectors in the crust and the upper mantle our results indicate that the upper crust of the eastern qilian shan is characterized by fault bend folds and duplex systems involving phanerozoic strata that may have resulted from early paleozoic collisional tectonics and cenozoic intra continental deformation locally half graben structures hosting cretaceous strata are also present the active structures in the region are dominated by left slip haiyuan and tianjian fault systems marking the northern margin of the tibetan plateau the strike slip structures have variable dips and dip directions and sole into a common decollement with a depth of 40 45 km because the two faults do not cut and offset the moho below the active crustal and mantle deformation in the northeastern tibet must be decoupled

climate instability during the last interglacial period recorded in the grip ice core isotope and chemical analyses of the grip ice core from summit central greenland reveal that climate in greenland during the last interglacial period was characterized by a series of severe cold periods which began extremely rapidly and lasted from decades to centuries as the last interglacial seems to have been slightly warmer than the present one its unstable climate raises questions about the effects of future global warming

methodology of the last climatic cycle reconstruction in france from pollen data abstract a numerical method has been devised to reconstruct the climate of the last climatic cycle from pollen data reliable annual reconstructions have been published recently for the two french long sequences of la grande pile and les echets covering the last 140 millennia this paper gives more details on the method used it proposes new reconstructions based on an extended modern pollen data base these reconstructions are consistent with the previous ones especially detailed information is obtained on the seasonal characteristics of climate computations of gcm on the climate variations from 125 kyr to 115 kyr b p are confirmed for western europe the insolation variations have induced at that time a decrease of seasonality accompanied by an increased cyclonic activity in winter this has been the beginning of the first ice growth after the last interglacial other glacier growth phases are detected at the end of substage 5c and particularly at the end of substage 5a

palaeoecological investigations and 230 th u dating of the eemian interglacial peat sequence from neubrandenburg hinterste muhle mecklenburg western pomerania ne germany abstract the eemian interglacial sequence was explored in the gravel pit neubrandenburg hinterste muhle near neubrandenburg ne germany the sequence is situated in a former kettle hole depression between underlying late saalian till s str warthe covered by a late weichselian till today still visible a 3 m long and max 2 m wide profile is located on the edge of the former eemian depression the limnic sedimentation began during the late saalian in a landscape characterized by open herbaceous vegetation cool clear and calcium carbonate rich lake water dominated inhabited by characeae that indicates a presence of stonewort meadows most typical of waters up to 10 m in depth the beginning of the eemian interglacial succession was characterized by a dominance of scarce birch forest followed by pine forest the beginning of the mesocratic phase of the eemian was characterized by the appearance of warm climate indicators and by the development of thermophilic forest communities dominated by oak forest with the appearance of warm climate indicators the ensuing climate optimum was defined by the encroachment of hazel oak forest and later by mixed deciduous forest limnic sedimentation ceased in the basin during this phase and the end of predominantly limnic conditions is marked by a decrease in the frequency of aquatic plants and an increase in the amount of brown mosses during the interglacial optimum mixed forests reigned this phase bears a record of oligotrophication leading to transition mire and raised bog and the aquatic plants vanished the depression gradually became shallower and was overgrown by a forest cover during the telocratic phase of the eemian communities with pine birch and fir spread the end of the interglacial was characterized by a disappearance of the riparian forest and a sporadic appearance of reedswamp plants at the beginning of the early weichselian a deterioration of climatic conditions resulted in the formation of widespread heaths on acid soils and trees disappeared in the studied basin the water level fluctuated the hinterste muhle sequence shows the development of a small kettle hole lake and its transformation to an overgrowing mire including terrestrialization processes during the eemian interglacial the u th data obtained for five samples from the upper part of the studied profile which have been analyzed by the tsd technique has yielded an age of 116 13 10 kyr this date reflects the classification into the second half of the eemian interglacial and the early weichselian for the upper part of peat formation

a late saalian glaciation eemian interglacial and early weichselian pollen sequence at szklarka sw poland reconstruction of vegetation and climate abstract this paper presents the results of palinological studies of the sediments from the site of szklarka silesian lowland sw poland the pollen sequence from szklarka records the longest continuous succession of vegetation covering the late saalian eemian interglacial and early weichselian in sw poland the results of pollen analysis show phases with forest and open vegetation communities in response to climate changes the pollen zones distinquished represent cool phases of the late saalian a complete eemian interglacial succession e1 e7 r paz and two cool intervals herning and redestall and one warm one brorup from the early weichselian two main phases have been distinguished in the brorup interstadial an older birch phase and a younger pine phase during the brorup interstadial towards the end of the birch phase a cooling event has been recorded

quantification of biotic responses to rapid climatic changes around the younger dryas a synthesis to assess the presence or absence of lags in biotic responses to rapid climatic changes we 1 assume that the 18o in biogenically precipitated carbonates record global or hemispheric climatic change at the beginning and at the end of the younger dryas without any lag at our two study sites of gerzensee and leysin switzerland 2 derive a time scale by correlating the 18o record from these two sites with the 18o record of the grip ice core 3 measure 18o records in ostracods and molluscs to check the record in the bulk samples and to detect possible hydrological changes 4 analyse at gerzensee and leysin as well as at two additional sites that lack carbonates and hence a 18o record pollen plant macrofossils chironomids beetles and other insects and cladocera 5 estimate our sampling resolution using the grip time scale for the isotope stratigraphies and the biostratigraphies and 6 summarise the major patterns of compositional change in the biostratigraphies by principal component analysis or correspondence analysis we conclude that at the major climatic shifts at the beginning and end of the younger dryas hardly any biotic lags occur within the sampling resolution of 8 30 years and that upland vegetation responded as fast as aquatic invertebrates we suggest that the minor climatic changes associated with the gerzensee and preboreal oscillations were weakly recorded in the biostratigraphies at the lowland site but were more distinct at higher altitudes individualistic responses of plant and animal species to climatic change may reflect processes in individuals e g productivity and phenology in populations e g population dynamics in spatial distributions e g migrations and in ecosystems e g trophic state we suggest that biotic responses may be telescoped together into relatively short periods 50 to 150 years perhaps disrupting functional interactions among species and thus destabilising ecosystems

younger dryas and allerod summer temperatures at gerzensee switzerland inferred from fossil pollen and cladoceran assemblages linear and unimodal based inference models for mean summer temperatures partial least squares weighted averaging and weighted averaging partial least squares models were applied to a high resolution pollen and cladoceran stratigraphy from gerzensee switzerland the time window of investigation included the allerod the younger dryas and the preboreal characteristic major and minor oscillations in the oxygen isotope stratigraphy such as the gerzensee oscillation the onset and end of the younger dryas stadial and the preboreal oscillation were identified by isotope analysis of bulk sediment carbonates of the same core and were used as independent indicators for hemispheric or global scale climatic change in general the pollen inferred mean summer temperature reconstruction using all three inference models follows the oxygen isotope curve more closely than the cladoceran curve the cladoceran inferred reconstruction suggests generally warmer summers than the pollen based reconstructions which may be an effect of terrestrial vegetation not being in equilibrium with climate due to migrational lags during the late glacial and early holocene allerod summer temperatures range between 11 and 12 c based on pollen whereas the cladoceran inferred temperatures lie between 11 and 13 c pollen and cladocera inferred reconstructions both suggest a drop to 9 10 c at the beginning of the younger dryas although the allerod younger dryas transition lasted 150 160 years in the oxygen isotope stratigraphy the pollen inferred cooling took 180 190 years and the cladoceran inferred cooling lasted 250 260 years the pollen inferred summer temperature rise to 11 5 12 c at the transition from the younger dryas to the preboreal preceded the oxygen isotope signal by several decades whereas the cladoceran inferred warming lagged major discrepancies between the pollen and cladoceran inference models are observed for the preboreal where the cladoceran inference model suggests mean summer temperatures of up to 14 15 c both pollen and cladoceran inferred reconstructions suggest a cooling that may be related to the gerzensee oscillation but there is no evidence for a cooling synchronous with the preboreal oscillation as recorded in the oxygen isotope record for the gerzensee oscillation the inferred cooling was ca 1 and 0 5 c based on pollen and cladocera respectively which lies well within the inherent prediction errors of the inference models

biotic responses to rapid warming about 14 685 yr bp introduction to a case study at gerzensee switzerland abstract the late glacial climatic warming indicated in the greenland ice core record about 14 685 years before 1950 ad belongs to a type of very rapid high amplitude warming similar the onsets of dansgaard oeschger events during marine isotope stage 3 mis 3 in order to estimate the nature and rates of change of biotic responses to such a major climatic shift we need a reliable time scale as well as climatic indicators independent of the biota both are provided by a high resolution oxygen isotope record from precipitated carbonates of lake marl in gerzensee switzerland van raden et al 2013 this issue on the basis of the assumption of synchronous climatic changes between greenland and gerzensee the close correlation of the oxygen isotope changes at the two sites allows the use of the ngrip gicc05 timescale at gerzensee with the zero point at 1950 ad to maintain comparability with the numerous radiocarbon dates in europe the 18o record measured in precipitated carbonates is checked and refined by the 18o measured in mono specific ostracod samples von grafenstein et al 2013 in this issue the shift of 3 6 18o pdb in only about 112 years at the end of the gs 2 represents a very rapid temperature increase of at least 6 2 c this increase is confirmed by reconstructions based on transfer functions for pollen and chironomids by lotter et al 2012 possibly 4 7 c in the annual mean and 2 5 c in summer temperatures after this major shift the greenland late glacial interstadial gi 1 corresponding to the regional biozones bolling and allerod 18o records of both greenland and gerzensee exhibit four minor fluctuations about 1 0 1 2 18o of which the second and the fourth are especially clearly correlated with several of terrestrial records in the northern hemisphere the oxygen isotope record is used as a template for all these sediment and bio stratigraphies the biotic responses may include at least five types of process 1 changes in productivity of individuals within a year or two 2 changes in populations usually somewhat slower depending on life cycles and environmental constraints 3 changes due to migration often rather slow depending again on life cycles and environmental constraints 4 changes in the terrestrial and aquatic communities and 5 changes on the level of ecosystems including pedogenesis nutrient cycling and species interactions these biotic responses to the early rapid warming about 14 685 ka bp are elaborated in subsequent papers for plants chironomids ostracods and cladocera ammann et al 2013 a brooks and heiri in this issue von grafenstein et al in this issue novakova et al 2013 this issue in addition lake levels are reconstructed by magny 2013 this issue and vegetation dynamics and n2o emissions are modelled lischke et al 2013 pfeiffer et al 2013 the changes in the mammal fauna of the swiss plateau are summarized by nielsen 2013 this issue

reconstruction of the 2 4 million km2 late pleistocene ice sheet on the tibetan plateau and its impact on the global climate during 20 expeditions new data were obtained on the maximum extent of glaciation in tibet and the surrounding mountains evidence was found of moraines at altitudes as low as 460 m on the southern flank of the himalayas and 2300 m on the northern slope of the tibetan plateau in the qilian shan on the northern slopes of the karakorum aghil and kuen lun moraines occurred as far down as 1900 m in southern tibet radiographic analyses of erratics document former ice thicknesses of at least 1200 m glacial polishing and knobs in the himalayas and karakorum are proof of glaciers as thick as 1200 2000 m on the basis of this evidence a 1100 1600 m lower equilibrium ela line was reconstructed for the ice age which would mean 2 2 4 million km2 of ice covering almost all of tibet since the equilibrium ela line was far below the average altitude of tibet on mount everest and k2 radiation was measured up to 6650 m yielding values of 1200 1300 w m2 because of the subtropical latitude and the high altitude solar radiation in tibet is 3 4 times greater than the energy intercepted between 60 and 70 n or s with an area of 2 2 4 million km2 and an albedo of 90 the tibetan ice sheet caused the same heat loss on the earth as a 6 9 6 million km2 sized ice sheet at 60 70 n because of its proximity to the present day equilibrium ela line tibet must have undergone large scale glaciation earlier than other areas being subject to intensive radiation the tibetan ice must have performed an amplifying function during the onset of the ice age

two contrasting accretion v collision orogenies insights from early paleozoic polyphase metamorphism in the altun qilian north qaidam orogenic system nw china

palaeolithic landscapes of europe and environs 150 000 25 000 years ago an overview abstract when considering the evolution and migrations of neandertalers and early modem human beings the harsh conditions of the last glacial maximum are often implicitly or explicitly assumed as their environmental background this perception is false the conditions of the high glacial apply to a small fraction of late pleistocene time here we review the palaeoenvironmental history of europe from 150 000 to 25 000 years ago with the aid of data from long cores of ice and marine and continental sediments the results are displayed in four sketch maps that illustrate the landscapes of an interglacial glacial cycle the maps connected by palaeoenvironmental histories show that especially between 60 000 and 25 000 years ago a critical part of the palaeolithic the glacial landscapes were for much of the time less barren than is generally assumed but numerous climate changes on a scale of several millennia are evident placing a premium on accurate dating of the co evolution of humans and landscape moreover during the glacial interval abrupt climatic changes lasting from a century to a few millennia were common their importance for landscape changes and their impact on human activity remain to be ascertained

responses to rapid warming at termination 1a at gerzensee central europe primary succession albedo soils lake development and ecological interactions the transition from the oldest dryas to the bolling around 14 685 cal yr bp was a period of extremely rapid climatic warming from a single core of lake marl taken at gerzensee switzerland we studied the transition in stable isotopes of oxygen and carbon on bulk sediment and charophyte remains as well as on monospecific samples of ostracods after pisidium a in addition pollen chironomids and cladocera were analyzed the 18o record serves as an estimate of mean air temperature and by correlation to the one from ngrip in greenland it provides a timescale the timing of responses the statistically significant zone boundaries of the biostratigraphies are telescoped at the rapid increase of about 3 in 18o at the onset of bolling biotic responses may have occurred within sampling resolution 8 to 16 years although younger zone boundaries are less synchronous gradual and longer lasting responses include complex processes such as primary or secular succession during the late glacial interstadial of bolling and allerod two stronger and two weaker cool phases were found biological processes involved in the responses occurred on levels of individuals e g pollen productivity of populations increases or decreases immigration or extinction and on the ecosystem level species interactions such as facilitation or competition abiotic and biotic interactions include pedogenesis nitrogen fixation nutrient cycling catchment hydrology water chemistry of the lake and albedo controlled by the transition from tundra to forest for the swiss plateau this major change in vegetation induced a change in the mammal fauna which in turn led to changes in the tool making by paleolithic people

equilibrium line altitudes of the last glacial maximum for the himalaya and tibet an assessment and evaluation of results abstract contemporary equilibrium line altitudes elas for glaciers in the high mountains of the himalaya and tibet have considerable variation because the region is influenced by two major climatic systems the mid latitude westerlies and the south asian summer monsoon and glaciers are subject to strong topographic controls reconstructions of past elas based on the former extent of glaciers are numerous but were estimated using a variety of methods some of which are not appropriate for high altitude glaciers which are strongly influenced by topography and have extensive supraglacial debris cover furthermore few of the reconstructions have adequate chronological control because of the difficulty of dating glacial landforms in high altitude regions where organic matter for radiocarbon dating is sparse or absent cosmogenic radionuclide surface exposure and optically stimulated luminescence dating are providing data to define the timing of glaciation and these together with objective analysis of glacier dynamics may allow better estimates of ela changes in the future however there are currently only two regions the hunza valley and the khumbu himal which are sufficiently well dated to allow reconstructions of last glacial maximum glacier extent and hence elas these two regions cannot provide an adequate assessment of ela changes for the himalayan tibetan region

shrimp zircon u pb geochronological and whole rock geochemical evidence for an early neoproterozoic sibaoan magmatic arc along the southeastern margin of the yangtze block abstract it has been generally accepted that the south china block was formed through amalgamation of the yangtze and cathaysia blocks during the proterozoic sibaoan orogenesis but the timing and kinematics of the sibao orogeny are still not well constrained we report here shrimp u pb zircon geochronological and geochemical data for the taohong and xiqiu tonalite granodiorite stocks from northeastern zhejiang southeastern margin of the yangtze block our data demonstrate that these rocks dated at 913 15 ma and 905 14 ma are typical amphibole rich calc alkaline granitoids formed in an active continental margin combined with previously reported isotopic dates for the 1 0 ga ophiolites and 0 97 ga adakitic rocks from northeastern jiangxi the timing of the sibao orogenesis is thus believed to be between 1 0 and 0 9 ga in its eastern segment it is noted that the sibao orogeny in south china is in general contemporaneous with some other early neoproterozoic 1 0 0 9 ga orogenic belts such as the eastern ghats belt of india and the rayner province in east antarctica indicating that the assembly of rodinia was not finally completed until 0 9 ga

ice complex permafrost of mis5 age in the dmitry laptev strait coastal region east siberian arctic ice complex deposits locally known as the buchchagy ice complex are exposed at both coasts of the east siberian dmitry laptev strait and preserved below the yedoma ice complex that formed during mis3 and mis2 marine isotope stage and lateglacial holocene thermokarst deposits mis1 radioisotope disequilibria 230th u of peaty horizons date the buchchagy ice complex deposition to 126 16 13 kyr and 117 19 14 kyr until 98 5 kyr and 89 5 kyr the deposit is characterised by poorlysorted medium to coarse silts with cryogenic structures of horizontal ice bands lens like and lenslike reticulated segregation ice two peaty horizons within the buchchagy ice complex and syngenetic ice wedges 2e4 m wide up to 10 m high are striking the isotopic composition d18o dd of buchchagy ice wedge ice indicates winter conditions colder than during the mis3 interstadial and warmer than during mis2 stadial and similar atmospheric winter moisture sources as during the mis2 stadial buchchagy ice complex pollen spectra reveal tundra steppe vegetation and harsher summer conditions than during the mis3 interstadial and rather similar vegetation as during the mis2 stadial short term climatic variability during mis5 is reflected in the record even though the regional chronostratigraphic relationship of the buchchagy ice complex to the last interglacial remains unclear because numerical dating is widely lacking the present study indicates permafrost ice complex formation during mis5 sensu lato and its preservation afterwards palaeoenvironmental insights into past climate and the periglacial landscape dynamics of arctic lowlands in eastern siberia are deduced from the record

paleogeography of the environment in north eastern poland recorded in an eemian sedimentary basin based on the example of the jalowka site abstract the paper presents the results of the research on biogenic sediments from the jalowka profile podlasie region ne poland situated at the foot of a dry valley slope a 35 cm monolith of sediments was collected from the excavation pit the sediments were deposited beneath 4 m thick mineral sediments interdisciplinary research helped to reconstruct the possible transformations of the local environment palynological physical and geochemical analyses were applied to organic sediments and plant macroremains were examined five local pollen zones were identified in palynological terms and correlated with the late warta stadial mis 6 of the odra glaciation saalian and four older periods of the eemian interglacial mis 5e e1 e2 e3 and e4 younger zones have not been preserved they were eroded in the early vistulian during the late mis 6 there was a eutrophic water body with highly transparent water characterized by a relative stable water level the landscape was dominated by tundra with a high proportion of juniperus artemisia curves of oxygen 18o and carbon 13c stable isotopes confirmed the boundary between mis 6 and mis 5e the beginning of the interglacial vegetation succession e1 was characterized by expansion of birch pine spruce forests probably at the end of this period the lake became shallower e2 is distinguished by the dominance of pine and birch the lake was replaced by a peat bog the sequence of vegetation succession in the landscape was as follows quercus e3 corylus fraxinus alnus and tilia e4 probably the peat bog drained in the e4 and the water level rose again in the climate optimum of the eemian interglacial the results of physical and geochemical analysis clearly corresponded with climatic changes determined by palynological analysis they provided evidence of the changing redox conditions variability and intensity of denudation the scale of biological productivity and fertility of the environment the studied sediments were characterized by reducing conditions the increase in terrigenous silica content and the relatively high n k ratio indicated the predominance of mechanical denudation during the late glacial period of the warta stadial and the e2 period

palaeoecological evidence of changes in vegetation and climate during the holocene in the pre polar urals northeast european russia this study investigated holocene tree line history and climatic change in the pre polar urals northeast european russia a sediment core from mezhgornoe lake situated at the present day alpine tree line was studied for pollen plant macrofossils cladocera and diatoms a peat section from vangyr mire in the nearby mixed mountain taiga zone was analysed for pollen the results suggest that the study area experienced a climatic optimum in the early holocene and that summer temperatures were at least 2 c warmer than today tree birch immi grated to the mezhgornoe lake area at the onset of the holocene mixed spruce forests followed at ca 9500 9000 14 c yr bp climate was moist and the water level of mezhgornoe lake rose rapidly the hypsithermal phase lasted until ca 5500 4500 14 c yr bp after which the mixed forest withdrew from the mezhgornoe catchment as a result of the climate cooling the gradual altitudinal downward shift of vegetation zones resulted in the present situation with larch forming the tree line copyright 2003 john wiley sons ltd

rapid interglacial climate fluctuations driven by north atlantic ocean circulation recent data from the grip ice core1 3 in greenland suggest that the climate of the last eemian interglacial period was much less stable than that of the present interglacial rapid transitions between warm and cold periods were found to occur on timescales of just a few decades the north atlantic climate during the eemian period was also shown to be characterized by three states respectively warmer than similar to and colder than today1 2 recent data from the nearby gisp2 ice core have revealed some discrepancies with these findings which remain to be resolved4 5 here we present simulations using an idealized global ocean model which suggest that the north atlantic ocean has three distinct circulation modes each of which corresponds to a distinct climate state we find that adding a simple random component to the mean freshwater flux which forces circulation can induce rapid transitions between these three modes we suggest that increased variability in the hydrological cycle associated with the warmer eemian climate could have caused transition between these distinct modes in the north atlantic circulation which may in turn account for the apparent rapid variability of the eemian climate

long mis 5e 3 environmental history of a paleolake in central poland recorded in the succession from kublowo abstract one of the longest above 7 m thick uninterrupted eemian vistulian weichselian pollen successions in poland is known from kublowo central poland the huge importance of this succession is manifested in the possibility of study the evolution of the lake environment under the influence of changing from interglacial to glacial climatic conditions the reconstruction of the environmental changes at kublowo and its surroundings show the short climate fluctuations and a detailed picture of the natural conditions prevailing in central poland central europe during the period from approximately 126 000 to 55 000 years bp based on the results of multi proxy analysis four lacustrine stages linked with a higher water level and three boggy stages low water level of evolution of the kublowo paleolake were observed the pollen diagram from kublowo reveals a succession of eighteen local pollen assemblage zones k1 k18 l paz the k1 to k7 lpaz zones record the interglacial succession correlated with the eemian the next pollen zones k8 to k18 are linked with the vistulian the pollen sequence shows between the eemian interglacial mis 5e and the last glaciation second stadial of the plenivistulian mis 4 3 four cold intervals that are interpreted as stadial phases herning rederstall schalkholtz and ebersdorf separated by three temperate intervals interstadials brorup odderade and oerel in the studied sediments 25 species of subfossil cladocera were identified and ten zones of fauna development were distinguished the unique feature of this profile is the good preservation of above 100 000 year old cladocera remains and a high diversity of species which are primarily littoral the middle and late eemian were periods convenient to cladocera development due to high temperatures high water levels high trophy and occurrence macrophytes a deterioration of fauna living conditions started in the late eemian and next took place in the vistulian cold events the results of isotopic and geochemical analyses of organic matter from kublowo have enabled the reconstruction of varying environmental conditions and the origin of organic matter the organic carbon content toc changes from 1 to 40 and is closely related to climatic conditions during the eemian the amount of toc systematically increased the lowest values are recorded in the coldest periods during the herning rederstall and schalkholz stadials the c n atomic ratio fluctuates from 13 to 34 and the highest values occur in the brorup interstadial the values of 13 c change from 27 9 to 12 9 and 15 n values oscillate between 1 6 and 5 3

vegetational response to climatic changes recorded in swiss late glacial lake sediments abstract high resolution pollen analysis at five lakes on an altitudinal transect in switzerland gerzensee 603 m leysin 1230 m regenmoos 1260 m zeneggen 1510 m heremence 2290 m focused on the vegetational response to the rapid climatic changes at the end and beginning of the younger dryas and to the minor gerzensee and preboreal climatic oscillations an absolute time scale transferred from the greenland grip ice core to the gerzensee and leysin records by wiggle matching the oxygen isotope stratigraphies facilitates the estimation of pollen influx and rates of change the climatic warming at the end of the younger dryas indicated by increases in oxygen isotope values and or the beginning of organic sedimentation in the lakes was immediately reflected in the vegetation at all the sites investigated the time lags at sites situated above the timberline during the younger dryas are considered to be migrational lags at the onset of the younger dryas a time lag of several decades occurred between the oxygen isotope record of climatic cooling and the major response of the vegetation whereas minor vegetation changes occurred with or without short time lags betula reacted earlier to the new environmental conditions within about 40 50 yr at gerzensee and within less than 36 yr at leysin than pinus and artemisia about 170 yr suggesting that time lags are due to the ecological requirements of the different taxa for the gerzensee and preboreal oscillations little or no change can be observed in the pollen record from gerzensee whereas at leysin both climatic oscillations produced a statistically significant vegetational response to both climatic oscillations generally the vegetation responses to climatic changes are more pronounced near vegetation ecotones at medium and higher altitudes than in the lowlands

the rare holsteinian mazovian interglacial limnic deposits in the ksiąznica outcrop at krzczonow near świdnica sudetic foreland abstract the article presents the results of research on peats muds and sands filling a palaeocavity within alluvial fans of the bystrzyca river valley in the sudetic foreland of sw poland in the 534 cm deep research profile in the central part of a palaeolake 267 samples were collected at an interval of 2 cm and lithologically structural and textural studies palaeobotanically studies of diatoms pollen plant macrofossils and fossil wood palaeozoologically cladocera mollusca and ostracoda geochemically chemical elements and isotopes and palaeomagnetically analyzed the profile consists of three parts organic with mineral layers lower mineral middle and organic upper the palynological diagram was divided into three zones that represent local sets of pollen zones this diagram although incomplete is clearly indicative of the younger part of the holsteinian mazovian pollen iii and iv periods interglacial the upper part of the diagram consists of four local pollen zones that are correlated with stadial and interstadial periods analysis of several samples of fossil wood shows the widespread presence of pinus remains and numerous fragments of rhytidome bark of betula development of the peat layer 1 36 0 68 m depth started with paludification of the forest with the betula forest analysis of cladocera shows the presence of chitin armor components species chydorus sphaericus alona rectangula and ephippia of alona rectangula in three samples lithological cladocera and palaeo magnetic research supported by geochemical studies indicate the existence of at least three main phases the lake originated during the younger part of the holsteinian mazovian intergalcial as an oxbow within the valley where the deposition of variously thick up to 1 5 m depth peats organic and minerogenic silts the first stage in the second phase a closed fairly deep late holsteinian lake continued to exist under relatively warm conditions with mainly mineral deposition from the slope the lake became shallower and wider and then more open and better oxygenated with through flow in the final phase the lake was completely filled by organic sediments under interglacial conditions the absence of diatom molluscan and ostracod communities indicates an acid lacustrine environment at this time the fluvial and limnic deposits are sealed by overlaying saalian odranian till

isotope and cladocera data and interpretation from the eemian optimum and postoptimum deposits kaliska palaeolake central poland during the eemian optimum calcareous gyttja and lake marl accumulated the characteristic feature of calcareous gyttja is an occurrence of fragments of diatoms and plants while in lake marl they are absent in the carbonate rich deposits no cladocera remains are preserved based on the results of stable isotope analyses of carbonates the eight isotopic horizons is were defined and characterised in the studied deposits 15 species of subfossil cladocera were identified and 6 zones of fauna development were distinguished the defined cladocera species are similar to ones known from the other eemian site in poland the faunal taxa indicate the low trophy status of the lake initially followed by an increase to eutrophic status the cladocera and isotopic compositions suggest that the hornbeam zone e5 was a period of higher density of macrophytes as well as of an increase of biological activity associated with the low water level the fluctuations of the isotopic curves caused by a shallowing of the basin and a change of sediment lithology are characteristic for the spruce zone e6 the palaeolake transformed into a peatbog during the pine zone e7 during the early vistulian renewed carbonate accumulation and cladocera development took place indicating the repeated reservoir existence

early paleozoic polyphase metamorphism in northern tibet china abstract the altun qilian kunlun orogenic system in the northern tibetan plateau is considered as the northernmost orogenic collage of the proto tethyan domain early paleozoic polyphase tectonothermal events related to the subduction of the proto tethyan ocean and subsequent collisional orogeny produced two dominant metamorphic belts the north altun nat north qilian nql hp lt metamorphic belt and south altun sat north qaidam nqd uhp metamorphic belt the nat nql hp lt metamorphic belt mainly consists of blueschist eclogite and hp metasediments eclogites record metamorphic conditions of 420 550 c and 21 25 kbar at 510 460 ma the hp lt metamorphic belt is associated with ophiolite subduction accretion complex and arc magmatic rocks suggesting that the nat nql is a typical early paleozoic accretionary orogenic belt in contrast the sat nqd uhp metamorphic belt is characterized by eclogite and garnet peridotite enclosed within continental orthogneiss and paragneiss these rocks record uhp metamorphism at t 700 c and p 27 kbar geochronology suggests that the uhp metamorphism occurred at 500 423 ma and eclogite protolith ages of 850 750 ma suggest that protoliths are related to neoproterozic continental rifting field relationships petrology and geochronology suggest that the sat nqd uhp metamorphic belt resulted from the deep subduction of continental crust moreover in the sat nqd uhp metamorphic belt two types of hp granulites have been recognized the first type of hp granulite was formed by overprinting of eclogites during exhumation the second type of hp granulite has a single metamorphic history and similar age to that of uhp eclogite penecontemporaneous metamorphic ages but different geothermal gradients between hp granulites and related uhp eclogite define a possible paired metamorphic belt which may be considered to be a diagnostic characteristic of collisional orogens high grade metamorphic rocks in the sat nqd commonly record barrovian type metamorphism although it remains unclear whether or not all of these rocks have an earlier u hp metamorphic history the low medium p barrovian metamorphism and associated magmatism are about 20 50 ma later than uhp metamorphism newly recognized eclogites in the northern part of the east kunlun mountains to the south of qaidam basin have a similar field relationship enclosed in continental gneiss and mineral assemblage to the nqd eclogites and a similar or slightly younger metamorphic age 410 430 ma the occurrence of similar continental type eclogites on two sides of the qaidam basin makes it necessary to reconsider the nature of the qaidam block the polyphase metamorphism in northern tibet can be linked to accretion and collisional orogenesis related to the evolution of prototethys through the early paleozoic

evidence for last interglacial chronology and environmental change from southern europe establishing phase relationships between earth system components during periods of rapid global change is vital to understanding the underlying processes it requires records of each component with independent and accurate chronologies until now no continental record extending from the present to the penultimate glacial had such a chronology to our knowledge here we present such a record from the annually laminated sediments of lago grande di monticchio southern italy using this record we determine the duration 17 70 0 20 ka and age of onset 127 20 1 60 ka b p of the last interglacial as reflected by terrestrial ecosystems this record also reveals that the transitions at the beginning and end of the interglacial spanned only 100 and 150 years respectively comparison with records of other earth system components reveals complex leads and lags during the penultimate deglaciation phase relationships are similar to those during the most recent deglaciation peaks in antarctic warming and atmospheric methane both leading northern hemisphere terrestrial warming it is notable however that there is no evidence at monticchio of a younger dryas like oscillation during the penultimate deglaciation warming into the first major interstadial event after the last interglacial is characterized by markedly different phase relationships to those of the deglaciations warming at monticchio coinciding with antarctic warming and leading the atmospheric methane increase diachroneity is seen at the end of the interglacial several global proxies indicate progressive cooling after 115 ka b p whereas the main terrestrial response in the mediterranean region is abrupt and occurs at 109 50 1 40 ka b p

geochemical changes in baslts and andesites across the archean proterozoic boundary identification and significance abstract to identify accurately changes in rock composition across the archean proterozoic boundary it is necessary to compare rocks from similar lithologic associations to constrain the effect of tectonic setting most basalts and andesites from the greenstone association volcanic dominated submarine supracrustal rocks possess a geochemical subduction zone component similar to their counterparts from modern arc systems basalts with island arc geochemical affinities dominate in archean greenstones while those with calc alkaline affinities are most abundant in proterozoic greenstones basalts with morb or oceanic within plate geochemical characteristics are rare in precambrian greenstones of all ages preserved early archean greenstone basalts 3500 ma reflect mantle sources less depleted than late archean greenstone basalts 2500 3500 ma proterozoic greenstone basalts are derived from relatively enriched mantle sources compared to all archean sources a feature which may be due to recycling of continental sediments into the mantle following rapid late archean continental growth precambrian andesites are geochemically similar to andesites from modern arcs but archean andesites are unique in that they are depleted in heavy ree and y results are consistent with archean andesite production by partial melting of descending mafic crust with amphibole garnet remaining in the residue while proterozoic and younger andesites are produced by fractional crystallization of basalts

the amphibolite facies metamorphosed mafic rocks from the maxianshan area qilian block nw china a record of early neoproterozoic arc magmatism abstract the amphibolite facies metamorphosed mafic rocks exposed in the maxianshan area qilian block nw china intruded granitic gneisses of the maxianshan group in the field they are seen to inject into and capture fragments of the surrounding granitic gneisses their rock types range from amphibole rich amphibolite to plagioclase rich amphibolite their whole rock major element compositions suggest that their protoliths were subalkalic gabbroic rocks the rare earth element patterns show slight light rare earth element enrichment with a very small europium negative anomaly the amphibolites exhibit enrichment in large ion lithophile elements and negative anomalies of titanium strontium niobium and tantalum on the basis of their spider diagrams the shrimp u pb ages of the zircon grains are 919 10 ma for the amphibole rich amphibolite and 905 6 ma for the plagioclase rich amphibolite indicating the ages of protolith formation the e nd 910 ma values are in the range of 1 6 and 2 4 consistent with generation in a continental arc tectonic discriminations by whole rock trace element compositions suggest that they originated in a continental arc environment the gabbroic protoliths were metamorphosed under amphibolite facies conditions the maxianshan amphibolite facies metamorphosed mafic rocks could be correlated with the mafic ultramafic rocks from marginal areas of the yangtze block this correlation implies that the qilian block and marginal areas of the yangtze block were active continental margins in the early neoproterozoic and provides evidence for a strong tectonic affinity of the qilian block with the south china block and even for a unified qilian south china block at that time it is inferred that the qilian block carrying maxianshan mafic rocks underwent amphibolite facies metamorphism after it was rifted away from the south china block in the late neoproterozoic as a result of the breakup of the rodinia supercontinent and collided with the alaxa block in the early paleozoic

the climate in western europe during the last glacial interglacial cycle derived from pollen and insect remains using the pollen sequence of la grande pile xx france we review problems with the application of transfer functions in paleoclimatic reconstructions one of them is to find modern analogues for the herbaceous vegetation of the cold periods we propose a method to distinguish between steppes and tundra vegetations for which the moderns are only partial analogues of the glacial periods another method to solve these problems is based on constraining by insect remains the two methods provide coherent reconstructions the results are also compared with other paleodata there is a good correlation with the six cold heinrich events between 70 and 15 ka b p a cooling event during the eemian period marked by high percentages of taxas at about 125 ka b p needs still to be correlated with high resolution ocean and ice cores

recent ecological change in a remote scottish mountain loch an evaluation of a cladocera based temperature transfer function recent ecological changes in a small scottish mountain loch loch coire fionnaraich lcfr were inferred using cladocera analysis and an application of a cladocera based temperature transfer function approach modern assemblages of cladocera from 68 mountain lakes in scotland and norway were used to derive the transfer function among 21 measured environmental variables mean summer lake surface water temperature lswt accounted for the highest 8 variation in a redundancy analysis of the modern data a quantitative inference model r2 0 72 rmsep 1 81 c for summer lswt was developed using linear partial least squares regression and calibration the resulting reconstructed summer lswt at lcfr was compared with local instrumental air temperature records over the last 20 yr and the central england temperature cet series over the last 110 yr the reconstruction showed a broadly similar pattern to the local instrumental temperature records however the relationship between the longer cet series and reconstructed summer lswt was poor suggesting that the site was relatively insensitive to temperature changes prior to the recent warming of the last few decades clear changes in cladoceran species diversity and relative abundance of littoral taxa coincident with the most recent period of climate warming recorded both locally and in the cet suggest that cladocera do respond to climate change however their response to temperature is complex and indirect the underlying mechanism leading to change in cladocera assemblages may involve changes in trophic status and habitat availability of the system it is concluded that understanding other factors such as atmospheric pollution controls of community dynamics of cladocera and the overall ecological complexity of mountain lakes is required before any reliance can be placed on a cladocera temperature transfer function for reconstructing climatic change crown copyright 2008

geochronological and geochemical evidence of amphibolite from the hualong group northwest china implication for the early paleozoic accretionary tectonics of the central qilian belt abstract the hualong group located in the central qilian belt northwest china consists mainly of schist amphibolite quartzite and marble ranging from greenschist to amphibolite facies metamorphism on the basis of the medium grade metamorphism the group has been considered to comprise proterozoic basement rocks in this study geochemical sr nd isotopic and zircon u pb geochronological analyses were performed on lentoid amphibolites from the hualong group to characterize their age petrogensis and tectonic setting uranium lead zircon dating of amphibolite revealed a formation age of 456 2 ma and a metamorphic age of 440 1 ma major trace and rare earth element data indicate that the amphibolites are predominantly basaltic andesitic to andesitic rocks with island arc affinities the trace element patterns show enrichment in large ion lithophile elements and depletion in high field strength elements relative to the n morb which confirm their island arc signatures obviously enriched light rees la yb n 2 5 16 9 to chondrite normalized ree patterns further support this interpretation the e nd t values for the amphibolites range from 4 6 to 2 1 indicating subducted sediments as a larger endmember in the source geochemical data for these rocks suggest an island arc setting and the rocks were derived from the depleted mantle that was enriched by melts of subducted sediments in an active continental margin setting at ca 456 ma together with regional evidence it suggests that the hualong group is an accretionary complex that was incorporated into the central qilian belt during the 440 400 ma orogenic event

mean july temperatures during the younger dryas in northwestern and central europe as inferred from climate indicator plant species abstract we estimated minimum mean july temperatures in northwestern and central europe during the younger dryas 10 950 10 15014c yr b p from distributions of climate indicator plant species which were reconstructed from 140 pollen and plant macrofossil diagrams paleobotanical records mainly from the central and eastern part of the study area show that the coldest conditions occurred early in the younger dryas before 10 55014c yr b p for this phase mean july temperatures at sea level of around 10 c are suggested for the northern part of the british isles and for ice free scandinavia we estimated a mean july temperature of 12 c for central england the netherlands and northern germany the 13 c mean july isotherm largely based on the modern distribution oftypha latifolia was most probably located in southern england belgium central germany and poland the reappearance of thermophilous elements in the records after 10 55014c yr b p suggests a summer warming at least temporarily of 1 to 2 c in the study area the reconstructed temperatures are comparable with temperature estimates based on beetle data however they appear rather high when compared with estimates based on glaciological evidence

geology stratigraphy and palaeoenvironmental evolution of the stephanorhinus kirchbergensis bearing quaternary palaeolake s of gorzow wielkopolski nw poland central europe

late pleistocene paleosols in the extra glacial regions of northwestern eurasia pedogenesis post pedogenic transformation paleoenvironmental inferences abstract recent revision of the eastern boundary of the last glaciation of eurasia opened new perspectives in the search of the paleopedological records in the north of eastern europe and western siberia we studied paleosol sedimentary sequences in the upper volga and middle ob basins as a regional paleoecological record for the late pleistocene thermochrons two key sections cheremoshnik and belaya gora containing mis3 and mis5 paleosol units and additional section koskovo 2 with polycyclic mis3 paleosol were investigated their timescale are based on c14 and u th datings as well as on stratigraphic and paleobotanical correlations macro meso and micromorphological observations together with fossil insects and plant macrofossil were used as paleoenvironment proxy mis3 paleosols show abundant redoximorphic and cryogenic features that allow interpreting them as gleyic cryosols sub fossil insects and plant macrofossil reflect the cold climate conditions three incipient ah horizons in koskovo 2 pedocomplex point to multiple phases of pedogenesis correlative to the mis3 paleosol levels in different sections of the eurasian loess belt and to the major interstadials of the middle pleniglacial of the nw europe mis5 paleosols are also characterized by gleyzation and peat accumulation in this case we suppose geomorphological control on hydromorphic pedogenesis however paleosol in belaya gora has clear signs of polygenesis including the phase of clay illuviation insect and plant remains from the lower paleosol level of the belaya gora section show the transition from cold terminal phase of mis6 to warm first and then to a moderately cold climate within mis5 the obtained results contribute to understanding of soil and landscape zonality in the largest plains of eurasia mostly during the warm phases of late pleistocene

correspondence to on line edition doi 10 1016 j quascirev 2007 09 015 elsevier of quaternary science reviews qsr article quaternary glacier history of the central karakoram by yeong bae seong lewis a owen michael p bishop andrew bush penny clendon luke copland robert finkel ulrich kamp john f shroder jr

differences between the last two glacial maxima and implications for ice sheet δ18o and sea level reconstructions studies of past glacial cycles yield critical information about climate and sea level ice volume variability including the sensitivity of climate to radiative change and impacts of crustal rebound on sea level reconstructions for past interglacials here we identify significant differences between the last and penultimate glacial maxima lgm and pgm in terms of global volume and distribution of land ice despite similar temperatures and radiative forcing our analysis challenges conventional views of relationships between global ice volume sea level seawater oxygen isotope values and deep sea temperature and supports the potential presence of large floating arctic ice shelves during the pgm the existence of different glacial modes calls for focussed research on the complex processes behind ice age development we present a glacioisostatic assessment to demonstrate how a different pgm ice sheet configuration might affect sea level estimates for the last interglacial results suggest that this may alter existing last interglacial sea level estimates which often use an lgm like ice configuration by several metres likely upward

numerical 230th u dating and a palynological review of the holsteinian hoxnian interglacial abstract earth scientists increasingly consider the holsteinian interglacial and mis 11 as synonyms despite the limited number of numerical dates and ambiguous stratigraphic and palynological correlation with the numerical marine isotope timescale hence we present new tims 230th u dates from two fen peat layers of the holsteinian reference site at bossel in northern germany and re evaluate published numerical data from two sites with hoxnian deposits in england a new method for the calculation of methodically controlled minimum 230th u ages mcma was developed the synopsis of the 230th u dates allows a correlation of both the holsteinian and hoxnian interglacials to mis 9 this correlation is supported by supplementary 230th u dates of fen peat from several pre eemian but non holsteinian sites in germany there is palynological evidence for a reliable correlation between precisely investigated and numerically dated holsteinian deposits in poland germany england sw ireland and france an apparently contradictory palynological correlation from the french central massif is discussed

hualong complex south qilian terrane u pb and lu hf constraints on neoproterozoic micro continental fragments accreted to the northern proto tethyan margin abstract the neoproterozoic hualong complex dominates the south qilian terrane it contains mafic to felsic magmatic rocks cherts and turbiditic sediments some of which have been metamorphosed to amphibolite grade and is traditionally regarded as a pre cambrian micro continental block rifted from the south china plate new u pb geochronology of morphologically complex zircons sheds light on the history of the complex garnet bearing amphibolite and quartzite have detrital zircon u pb main peak ages of 1 47 1 78 ga with youngest u pb ages of 967 ma and 964 ma they are intruded by neoproterozoic orthogneisses that crystallized between ca 850 and 940 ma psammitic paragneisses are dominated by 940 780 ma detrital zircon populations with a youngest u pb weighted mean age of 721 3 ma and a main peak at 906 ma metamorphic overgrowths on older zircons record amphibolite facies metamorphism of the hualong complex and correspond to the emplacement of the younger plutonic rocks during the early paleozoic northward subduction of proto tethyan oceanic lithosphere 426 ma and 455 ma detrital zircon populations that originated from synkinematic granitoids dominate quartz mica schist negative to positive hf t values for both 940 850 ma granitic orthogneisses and intruding 460 410 ma granites suggest a crustal mantle mixture source hf t dm1 model ages and inherited zircon u pb ages are the same as those for garnet bearing amphibolites and psammitic gneiss indicating that late magmatic rocks were formed by melting of the accreted neoproterozoic rocks

periodic lake peatland shifts under the eemian and early weichselian climate changes in central europe on the basis of multi proxy studies abstract long term palaeoecological sequences dated to the eemian interglacial and weichselian glaciation are crucial for understanding cyclic climate changes and ecosystem responses this article presents a multi proxy palaeobotanical zoological and geochemical study considering variable aspects of the eemian early weichselian lake mire succession in central poland the investigated sequence collected from a former small kettle hole revealed many ecosystem alterations i e warm stages led to the terrestrialisation of the lake whereas stadial coolings to its reappearance hence we examined whether i the eemian warming influenced the ecological succession of the lake ii lakes which reappeared during the herning and rederstall stadial coolings developed alike and iii the beginning of peatland functioning interglacial or interstadial had an impact on further plant succession the results show that thermal amelioration during the eemian interglacial supported domination of tetraedron minimum and pediastrum boryanum var boryanum which contributed to the sedimentation of bituminous shales the expansion of salvinia natans in the final stage of lake existence middle eemian was probably a result of the mild climate characterised by the lack of late spring frosts algae in contrast to cladocera revealed bipartition of the herning and rederstall stadials older sections were colder younger warmer however geochemical and isotopic data point to the very low productivity of the lakes during those stadials the lake that existed during the herning stadial revealed very low taxonomical diversity of cladocera whereas that during the rederstall was characterised by relatively high diversity of this group during the late eemian and brorup interstadial rich fens with some oligotrophic patches with sphagnum sp developed this study revealed that small water bodies due to their very local character and often uniqueness of palaeo records may be a very valuable source of information about climate and palaeoecology of different groups of organisms during the eemian interglacial and the weichselian glaciation

the terrestrial eemian to late weichselian sediment record at beckentin ne germany first results from lithostratigraphic palynological and geochronological analyses abstract over recent decades a growing number of well documented records from terrestrial last interglacial sites across central europe have substantially improved our understanding of eemian climate and landscape dynamics despite this progress there are also large areas from which little information is available thus constituting significant paleo geographic gaps in the last interglacial record among the regions with still inadequate paleo environmental information is the maritime influenced area of ne germany at the southern margin of the eemian baltic sea here we present first results from a geological investigation of a new last interglacial site recently discovered during archaeological excavations near beckentin sw mecklenburg the study area is located approximately 25 km to the south of the maximum mis 2 ice limit of the scandinavian ice sheet in ne germany and thus lies outside the weichselian belt of glaciation based on lithostratigraphic and sedimentological logging complemented by geochemical xrf and palynological investigations we divide the local succession into three sections 1 a basal facies comprising saalian till and associated glaciofluvial sand overlain by section 2 consisting of a fen peat which grades into laminated organic to minerogenic mud the organic deposits of section 2 preserve a near complete eemian pollen inventory encompassing pollen zones pz i to vi menke and tynni 1984 above this rest poorly sorted periglacial sands section 3 with ventifacts and evidence for cryogenic deformation geochronological results from 230th u dating of the buried organic rich deposits at beckentin show that these units accumulated in a former dead ice depression between 118 7 6 ka and 114 6 5 ka during the eemian interglacial high resolution optically stimulated luminescence osl profiling undertaken with a portable luminescence reader reveals a significant hiatus between the lacustrine fines and overlying periglacial cover sand five osl ages obtained from these cover sediments and the sand filling of an ice wedge cast show that these strata formed between during the last glacial interglacial transition

an attempt to reconstruct the late saalian to plenivistulian mis6 mis3 natural lake environment from the parchliny 2014 section central poland abstract the article presents the early results of research of sediments from a palaeolake in the kleszczow graben central poland a total of 190 samples were collected and then ca 10 30 samples were botanically diatoms pollen and woody macrofossils zoologically cladocera mollusca and ostracoda and geochemically elemental content carbon and nitrogen isotopes tested the results of muliproxy analysis of the eemian aleksandrow formation and vistulian weichselian piaski formation deposits helped to reconstruct the environmental changes occurring in the studied palaeolake palynological diagram of individual spectra parchliny 2014 was divided into five zones that represent local sets of pollen zones e3 e7 pa 1 pa 5 this diagram although incomplete reveals the distinct eemian features lithological cladocera and diatom analysis supported by geochemical studies indicate the existence of at least three main stages of the lake developed in the part of the basin the lake originated from a post saalian melt out kettle hole where the deposition of peats and organic and mineral silts of different thicknesses to 10 12 m occurred the first stage in the second stage initially existed a closed fairly deep eemian lake under relatively warm conditions the lower part of the section records an event of water body shallowing consisting in its eutrophication from oligotrophic to a lake of higher trophic status subsequently in a cooler climate of early vistulian weichselian the lake became shallower and then open flow and better oxygenated flow trough low frequency of ostracods and the absence of molluscs indicate slightly alkaline ph in the lower part of the water body and neutral or slightly acidic ph in its upper part at the bottom the dominant organisms were diatoms whereas toward the top phytoplankton disappears and benthic taxa become predominant finally in the third stage in plenivistulian it was completely covered by mineral organic and mineral sediments

quantitative interpretation of fossil pollen spectra dissimilarity coefficients and the method of modern analogs abstract dissimilarity coefficients measure the difference between multivariate samples and provide a quantitative aid to the identification of modern analogs for fossil pollen samples how eight coefficients responded to differences among modern pollen samples from eastern north america was tested these coefficients represent three different classes 1 unweighted coefficients that are most strongly influenced by large valued pollen types 2 equal weight coefficients that weight all pollen types equally but can be too sensitive to variations among rare types and 3 signal0to noise coefficients that are intermediate in their weighting of pollen types the studies with modern pollen allowed definition of critical values for each coefficient which when not exceeded indicate that two pollen samples originate from the same vegetation region dissimilarity coefficients were used to compare modern and fossil pollen samples and modern samples so similar to fossil samples were found that most of three late quaternary pollen diagrams could be reconstructed by substituting modern samples for fossil samples when the coefficients indicated that the fossil spectra had no modern analogs then the reconstructed diagrams did not match all aspects of the originals no modern analogs existed for samples from before 9300 yr b p at kirchner marsh minnesota and from before 11 000 yr b p at wintergreen lake michigan but modern analogs existed for almost all holocene samples from these two sites and brandreth bog new york

magma sources and petrogenesis of the early middle paleozoic backarc granitoids from the central part of the qilian block nw china abstract the petrology geochemistry geochronology and sr nd hf isotopes of the backarc granitoids from the central part of the qilian block are studied in the present work both s and i type granitoids are present in petrographic classification they are granite alkali feldspar granite felsic granite diorite quartz diorite granodiorite and albite syenite the shrimp ages are 402 447 ma for the s type and 419 451 ma for the i type granitoids they are mostly high k calc alkaline granitoids the s type granitoids are weakly to strongly peraluminous and are characterized by negative eu anomalies eu eu 0 18 0 79 the i type granitoids are metaluminous to weakly peraluminous and are characterized mostly by small negative to small positive eu anomalies eu eu 0 71 1 16 the initial 87 sr 86 sr values are 0 708848 0 713651 for the s type and 0 704230 0 718108 for the i type granitoids the e nd 450 ma values are 8 9 4 1 and 9 7 1 9 for the s type and i type granitoids respectively the t dm values are 1 5 2 4 ga for the s type and 1 0 2 3 ga for the i type granitoids for the qilian block the backarc granitoid magmatism took place approximately 60 million years after the onset of the southward subduction of the north qilian oceanic lithosphere and lasted approximately 50 million years partial melting of the source rocks consisting of the neoproterozoic metasedimentary rocks of the huangyuan group and the intruding lower paleozoic basaltic rocks could produce the s type granitoid magmas partial melting of basaltic rocks mixed with lower continental crustal materials could produce the i type granitoid magmas major crustal growth occurred in the late archean and meso paleoproterozoic time for the qilian block the magma generation was primarily remelting of the crustal rocks with only little addition of the mantle materials after 1 0 ga for the qilian block

palaeoecological investigations and 230th u dating of eemian interglacial peat sequence of banzin mecklenburg western pomerania ne germany abstract a novel occurrence of an eemian interglacial peat was identified in 2011 in a short lived outcrop of the nel pipeline trench near the village of banzin germany the profiles are situated in a shallow kettle hole within the undulated landscape of the saalian glaciation the distribution of dominantly till lithofacies in the banzin area confirms the regional trend of saalian tills with a locally higher abundance of cretaceous clasts in the banzin kettle at a depth of 2 2 m lies a 0 5 m thick strongly compressed eemian peat layer the buried eemian peat layer is deformed by ice wedge pseudo morphological and mega crack structures indicating a strong periglacial influence during weichselian stadial phases the post eemian sequence is subdivided into three units beginning with a mixture of aeolian and gelifluction deposits which are also modified by cryostructures the top of the banzin sequence is covered by a 0 5 m thick colluvisol layer of redeposited humic loam from the late weichselian holocene the uppermost unit suggests that solifluction processes occurred in the last few hundred years likely driven by intensive anthropogenic influence limnic sedimentation began during the late saalian period in a landscape characterized by herbaceous vegetation and heliophytes during the latest interval of saalian deglaciation shallow waters of the basin most likely attained a depth below 3 m and were abundant in calcium carbonate the beginning of eemian interglacial peat accumulation mis 5e is characterized by a dominance of light birch forests followed by pine the ensuing optimum climate was dominated by the encroachment of oak forests and then hazel oak forest and sedimentation ceased in the basin during this phase at the climatic optimum pz iii iv the eemian peat included remains of ceratophyllum submersum and species of higher temperature requirements the banzin basin gradually became shallower and overgrown until the closing of its open water at the end of phase iii iva the lack of cladocera species composition in the eemian sequence proves isolated conditions of a shallow reservoir we present the first results from ne germany for eemian peat bog samples dated by the u th disequilibrium method 230 th u using leachate alone l l and total sample dissolution tsd analytical techniques isochron corrected 230 th u ages of 118 8 10 ka l l and 121 9 13 ka tsd were obtained both 230 th u dates 118 121 ka obtained using two different techniques confirm the biostratigraphical classification into the eemian interglacial

macrofossils as records of plant responses to rapid late glacial climatic changes at three sites in the swiss alps plant macrofossils from the end of the younger dryas were analysed at three sites gerzensee 603 m asl leysin 1230 m asl and zeneggen 1510 m asl for the first two sites an oxygen isotope record is also available that was used to develop a time scale schwander et al this volume dates refer therefore to calibrated years according to the grip time scale around gerzensee a pine forest with some tree birches grew during the younger dryas with the onset of the isotopic shift initiating the rapid warming about 11 535 cal years before 1950 the pine forest became more productive and denser at leysin no trees except some juniper scrub grew during the younger dryas tree birches pine and poplar immigrated from lower altitudes and arrived after the end of the isotopic shift about 11 487 b p i e at the beginning of the preboreal at about 11 420 b p zeneggen is situated somewhat higher than leysin but single tree birches and pines survived the younger dryas at the site at the beginning of the preboreal their productivity and population densities increased simultaneously shifts from nitella to chara and from silt to gyttja are recorded all indicating rapidly warming conditions and higher nutrient levels of the lake water and probably of the soils in the catchment at gerzensee the beginning of the younger dryas was also analysed the beginning of the isotopic shift correlates within one sample about 15 years to rapid decreases of macrofossils of pines and tree birches

the role of the deep ocean in north atlantic climate change between 70 and 130 kyr ago the suggestion1 that changes in north atlantic deep water nadw production are linked through surface heat flux to the atmospheric temperature over greenland is supported by earlier indications2 3 that nadw production decreased during glacial times and by the subsequent finding4 6 that it declined during the younger dryas cool period at the end of the last glaciation changes in north atlantic surface temperatures have been found7 to mirror high frequency temperature changes recorded in greenland ice cores over the past 80 kyr but the connection to abyssal circulation has yet to be established except for one or two isolated oscillations8 9 here we present carbon and oxygen isotope analyses of benthic foraminifera in a high resolution north atlantic deep sea sediment core for the period 70 130 kyr ago these data allow us to reconstruct the history of nadw production which shows a close correlation with greenland climate variability for much of this time interval suggesting that the climate influence of nadw variability was widespread we see no evidence however for changes in nadw production during substage 5e the eemian interglacial period in contrast with recent ice core data10 which suggest severe climate instability in greenland during this time period our results may support suggestions based on data from a second ice core that this apparent instability is an artefact caused by ice flow11 alternatively the eemian climate instability may have had a different origin from the subsequent climate events

the effect of abrupt climatic warming on biogeochemical cycling and n2o emissions in a terrestrial ecosystem the large rapid increase in atmospheric n2o concentrations that occurred concurrent with the abrupt warming at the end of the last glacial period might have been the result of a reorganization in global biogeochemical cycles to explore the sensitivity of nitrogen cycling in terrestrial ecosystems to abrupt warming we combined a scenario of climate and vegetation composition change based on multiproxy data for the oldest dryas bolling abrupt warming event at gerzensee switzerland with a biogeochemical model that simulates terrestrial n uptake and release including n2o emissions as for many central european sites the pollen record at the gerzensee is remarkable for the abundant presence of the symbiotic nitrogen fixer hippophae rhamnoides l during the abrupt warming that also marks the beginning of primary succession on immature glacial soils here we show that without additional nitrogen fixation climate change results in a significant increase of n2o emissions of approximately factor 3 4 from 6 4 1 9 to 21 6 5 9 mg n2o n m 2 yr 1 each additional 1000 mg m 2 yr 1 of nitrogen added to the ecosystem through n fixation results in additional n2o emissions of 1 6 mg n2o n m 2 yr 1 for the time with maximum h rhamnoides coverage our results suggest that local reactions of emissions to abrupt climate change could have been considerably faster than the overall atmospheric concentration changes observed in polar ice nitrogen enrichment of soils due to the presence of symbiotic n fixers during early primary succession not only facilitates the establishment of vegetation on soils in their initial stage of development but can also have considerable influence on biogeochemical cycles and the release of reactive nitrogen trace gases to the atmosphere c 2012 elsevier b v all rights reserved

evidence for general instability of past climate from a 250 kyr ice core record recent results1 2 from two ice cores drilled in central greenland have revealed large abrupt climate changes of at least regional extent during the late stages of the last glaciation suggesting that climate in the north atlantic region is able to reorganize itself rapidly perhaps even within a few decades here we present a detailed stable isotope record for the full length of the greenland ice core project summit ice core extending over the past 250 kyr according to a calculated timescale we find that climate instability was not confined to the last glaciation but appears also to have been marked during the last interglacial as explored more fully in a companion paper3 and during the previous saale holstein glacial cycle this is in contrast with the extreme stability of the holocene suggesting that recent climate stability may be the exception rather than the rule the last interglacial seems to have lasted longer than is implied by the deep sea specmap record4 in agreement with other land based observations5 6 we suggest that climate instability in the early part of the last interglacial may have delayed the melting of the saalean ice sheets in america and eurasia perhaps accounting for this discrepancy

effect of climatic and palaeoenvironmental changes on the occurrence of holocene bats in the swiss alps a large scale palaeozoological study compared 45 14c dated bat remains from the southern and northern swiss alps with palaeovegetational and palaeoclimatic data four thermophilous warm demanding and four psychrophilous cold tolerant bat species mainly forest dwellers were selected for the study myotis blythii is the oldest bat species recorded in the alps i e on the southern side going back to the early holocene at 10 500 cal bp our study showed that thermophilous species e g myotis bechsteinii and rhinolophus hipposideros were most abundant during the holocene climatic optimum in central europe 10 000 4000 cal bp when warm demanding mixed forests were dominant psychrophilous species such as myotis brandtii also occurred during the climatic optimum but most of the samples fall into the onset of the late holocene sub atlantic period when summer temperatures were already declining these species declined in the southern alps after 4000 cal bp when fire was intensively used by huma

eemian climate fluctuations observed in a european pollen record recent ice core data from greenland1 2 suggest that the climate during the last interglacial period the eemian was more unstable than that of the holocene about 10 000 years ago to the present being characterized in particular by a series of cold episodes each lasting about 70 to 750 years subsequent analysis of a second greenland ice core3 4 however failed to corroborate the details of these eemian climate fluctuations a result that may be attributable to the effects of ice flow4 to resolve this discrepancy it is imperative to seek alternative sources of information about the eemian climate here we present climate reconstructions from pollen data from the annually laminated eemian lake sediment record at bispingen5 and from the eemian and holocene peat records at la grande pile6 the former record indicates that an initially warm period of 2 900 yr was followed by cooling and a series of colder episodes one of which had winter temperatures comparable to those at the end of the preceding cold stage the latter records show greater climate instability during the eemian than the holocene these results are in broad agreement with those from the grip ice core but contrast both with the gisp2 core3 4 and with recent high resolution marine records from the north atlantic7 8

u pb zircon ages of granites from the southern margin of the yangtze block timing of neoproterozoic jinning orogeny in se china and implications for rodinia assembly abstract neoproterozoic jinningian bendong granodiorite and sanfang and yuanbaoshan granites occurred in northern guangxi southern margin of the yangtze block se china and were generally considered to be of orogenic origin that is the collision between the yangtze and huanan blocks during the jinning orogeny these granites were intruded into the mesoproterozoic sibao metamorphic basement and covered unconformably by the neoproterozoic danzhou metasediments they are dominantly peraluminous asi 1 18 1 29 and have low initial end values of 4 8 to 7 6 indicating derivation from a supracrustal source with strong enrichment in rb k and th and relatively low zr hf and higher rare earth elements they are similar to post collision granites zircon u pb ages of 819 9 826 10 and 824 4 ma were obtained for the bendong granodiorite and the sanfang and yuanbaoshan granites respectively by both shrimp and conventional dating methods the age result precludes the existence of any late mesoproterozoic grenville age granitic magmatism in the southern margin of yangtze block together with previous age determinations of ophiolites along the southern margin of the yangtze block the jinning orogeny is referred to the neoproterozoic orogeny which took place between 1 0 and 0 80 ga and likely ended at 0 82 ga the granite formation age of 0 82 ga also supports the basal boundary age of 0 80 ga for the post orogenic sinian system which is probably stratigraphically correlated with the adeladean system in south australia as the link between australia east antarctica and laurentia in the configuration of the supercontinent rodinia the collision between the yangtze and huanan blocks during the neoproterozoic jinning orogeny probably marks the termination of the rodinia assembly

u pb detrital zircon geochronology from the basement of the central qilian terrane implications for tectonic evolution of northeastern tibetan plateau the tuolai group dominates the central qilian terrane and there are different opinions on the age and tectonic attribute of the tuolai group based on large scale geologic mapping and zircon dating the tuolai group is divided into four parts metamorphic supracrustal rocks neoproterozoic acid intrusive rocks early middle ordovician acid intrusive rocks and middle ordovician basic intrusive rocks the metamorphic supracrustal rocks are the redefined tuolai complex group and include gneiss and schist assemblage by faulting contact zircon u pb la mc icp ms dating was conducted on these samples of gneiss and migmatite from the gneiss assemblage quartzite two mica schist and slate from the schist assemblage the five detrital samples possess similar age spectra have detrital zircon u pb main peak ages of 1 7 ga with youngest u pb ages of 1150 ma they are intruded by neoproterozoic acid intrusive rocks therefore the tuolai group belonging to late mesoproterozoic and early neoproterozoic with this caveat in mind we believe that u pb detrital zircon dating together with the geologic constraints obtained from this study and early work in the neighboring regions we suggest that the formation age of the entire crystalline basement rocks of metasedimentary sequence from the central qilian terrane should be constrained between the late mesoproterozoic and the late neoproterozoic but not the previous paleoproterozoic the basement of the central qilian terrane contains the typical grenville ages which indicates the centre qilian terrane have been experienced the grenville orogeny event

reaction of lake environment on the climatic cooling transition from the eemian interglacial to early vistulian on the basis of solniki palaeolake sediments ne poland abstract results of cladocera and organic matter analyses from the eemian lake deposits in solniki ne poland are presented we focused on the reaction of the lake s environment to progressive cooling reflected in the changes of the organic matter and the cladocera community approximately 3 m of sediments accumulated from the optimum of the eemian interglacial e5 to the early vistulian ev2 were analyzed results of analyses of organic matter correlated with cladocera data enabled a reconstruction of varying environmental conditions and geneses of organic matter the organic carbon content is closely related to climatic conditions the lowest values are recorded in the coldest periods during the ending of the eemian interglacial and the herning stadial of the early vistulian the highest ones occur unexpectedly in the eemian post optimum at the end of the spruce phase and at the beginning of the pine phase during the eemian optimum e5 biodiversity of cladocera species was maximal 17 but the frequency of specimens was low at the end of the optimum e5 an improvement of living conditions more optimal for various ecological groups of cladocera took place algae remained a significant component of organic matter the early eemian post optimum e6 is characterized as a period of the high number of zooplankton species the highest frequency as well as biodiversity at that time probably a higher water level and an optimal temperature formed very favorable conditions for the fauna development during this period maximal values of toc tn and the slight increase of c n ratio suggest a higher primary productivity with a small supply of organic matter of terrestrial origin coexistence of two species of the family bosminidae and maximum values of 15 n suggest a high trophy mesotrophy high resolution and detailed analyses of the lake sediments accumulated during the pollen zone e7 allowed to identity a few minor environmental fluctuations recorded in varied cladocera frequency toc and c n ratio in the final period of the eemian interglacial and in the early vistulian herning stadial a drastic reduction in frequency of cladocera and the features of om the lowest amounts of toc and tn and the highest value of c n reflect the decline of lake conditions and a lack of both primary production and aquatic vegetation in the lake during the amersfoort interstadial a renewed bioproduction and slightly supply of terrestrial plants in organic matter as well as revitalize zooplankton took place

biotic responses to rapid climatic changes abstract qualitative and quantitative changes in fossil flora and fauna have been used in many studies to infer climatic change here we ask a different question how do flora and fauna respond to climatic changes such as rapid warming or cooling as an independent proxy for paleotemperature we take the ratio of oxygen isotopes in biogenically precipitated lake marl and in ostracod shells this introductory paper describes the project design and the five sites on an altitudinal transect from 600 m to about 2300 m asl in the western swiss alps as cases of climatic cooling and warming we use the beginning and end of the younger dryas as major changes and the gerzensee and preboreal oscillations as minor changes at the two sites of gerzensee and leysin these changes are recorded in stable isotope ratios and there the time scales can be derived by correlations to the grip ice core schwander et al 2000 von grafenstein et al 2000 biotic responses to climate changes are treated in individual papers using pollen wick 2000 plant macrofossils tobolski and ammann 2000 and remains of chironomids brooks 2000 beetles and other insects lemdahl 2000 and chydorid cladocera hofmann 2000 they are followed by a synthesis focusing on quantification of biotic responses ammann et al 2000 in addition a reconstruction of summer temperatures for the allerod and the younger dryas at gerzensee is provided by lotter et al 2000

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