fossils from quaternary fluvial archives sources of biostratigraphical biogeographical and palaeoclimatic evidence fluvial sedimentary archives have the potential to preserve a wide variety of palaeontological evidence ranging from robust bones and teeth found in coarse gravel aggradations to delicate insect remains and plant macrofossils from fine grained deposits over the last decade advances in quaternary biostratigraphy based on vertebrate and invertebrate fossils primarily mammals and molluscs have been made in many parts of the world resulting in improved relative chronologies for fluviatile sequences complementary fossil groups such as insects ostracods and plant macrofossils are also increasingly used in multi proxy palaeoclimatic and palaeoenvironmental reconstructions allowing direct comparison of the climates and environments that prevailed at different times across widely separated regions this paper reviews these topics on a regional basis with an emphasis on the latest published information and represents an update to the 2007 review compiled by the flag inspired igcp 449 biostratigraphy subgroup disparities in the level of detail available for different regions can largely be attributed to varying potential for preservation of fossil material which is especially poor in areas of non calcareous bedrock but to some extent also reflect research priorities in different parts of the world recognition of the value of biostratigraphical and palaeoclimatic frameworks which have been refined over many decades in the core regions for such research particularly for the late middle and late pleistocene of nw europe has focussed attention on the need to accumulate similar palaeontological datasets in areas lacking such long research histories although the emerging datasets from these understudied regions currently allow only tentative conclusions to be drawn they represent an important stage in the development of independent biostratigraphical and palaeoenvironmental schemes which can then be compared and contrasted

surface tension and bubble nucleation in phonolite magmas abstract explosive plinian eruptions tap a wide range of magma compositions including highly alkaline phonolite magma such eruptions are driven by volatiles exsolving from those magmas and so determining how gas bubbles form is important to understanding those eruptions nucleation of bubbles in silicate melts is dictated strongly by the surface tension of the melt and so this study focuses on determining for phonolite melts cylinders cored from a sodium rich phonolite were hydrated with 5 37 0 09 wt dissolved water at 150 mpa and 1150 c and then decompressed at either 1150 c or 875 c bubbles nucleated at 1150 c only when pressure dropped below 95 mpa in number densities of 10 4 5 cm 3 at 875 c bubbles nucleated only when pressure dropped below 53 mpa in number densities of 10 4 7 cm 3 depending on whether the pressure within critical bubble nuclei equals the saturation pressure or a variable lower pressure the observed number densities and nucleation rates imply that surface tension for na rich phonolite is 0 061 or 0 068 n m 1 at 875 c and 0 052 or 0 066 n m 1 at 1150 c importantly temperature has little or slightly negative impact on in contrast to the thermal impact on of rhyolite melts regardless of pressure assumption the inferred surface tensions indicate that na rich phonolite can become highly super saturated with water before bubbles nucleate which could cause them to explosively degas and erupt similar to highly viscous rhyolites

biostratigraphy of the upper pleistocene upper neopleistocene holocene deposits of the lemeza river valley of the southern urals region russia numerous caves and terraces with late late pleistocene upper neopleistocene according to the russian stratigraphic scale holocene deposits are located in the lemeza river valley in the surroundings of the atysh waterfall the native reserve territory of the bashkortostan republic lemeza river runs in the southern part of the western slope of the urals and belongs to the belaya river valley system russian federation a summary of the biostratigraphical investigations between 1992 and 2007 in this area is given deposits of cave and fluvial origin are characterized in the framework of the regional stratigraphy the results of mammalian investigations and radiocarbon dating provide the basis for the stratigraphical subdivision palynology mollusca fishes amphibian and reptiles are used for the reconstruction the palaeoenvironments the southern urals stratigraphic subdivisions are correlated with western european weichselian holocene eastern european russia leningrad ostashkov shuvalov and uralian nevyansk polar urals gorbunovsky stratigraphic schemes r 2008 elsevier ltd and inqua all rights reserved

holocene warming in western continental eurasia driven by glacial retreat and greenhouse forcing the global temperature evolution during the holocene is poorly known whereas proxy data suggest that warm conditions prevailed in the early to mid holocene with subsequent cooling model reconstructions show long term warming associated with ice sheet retreat and rising greenhouse gas concentrations one reason for this contradiction could be the under representation of indicators for winter climate in current global proxy reconstructions here we present records of carbon and oxygen isotopes from two u th dated stalagmites from kinderlinskaya cave in the southern ural mountains that document warming during the winter season from 11 700 years ago to the present our data are in line with the global holocene temperature evolution reconstructed from transient model simulations we interpret eurasian winter warming during the holocene as a response to the retreat of northern hemisphere ice sheets until about 7 000 years ago and to rising atmospheric greenhouse gas concentrations and winter insolation thereafter we attribute negative 18o anomalies 11 000 and 8 200 years ago to enhanced meltwater forcing of north atlantic ocean circulation and a rapid decline of 13c during the early holocene with stabilization after about 10 000 years ago to afforestation at our study site we conclude that winter climate dynamics dominated holocene temperature evolution in the continental interior of eurasia in contrast to regions more proximal to the ocean models and proxy data diverge on the global temperature evolution of the holocene perhaps due to representation of the seasons isotopic analyses of stalagmites from the ural mountains suggest that winter climate dominated in the eurasian interior

quaternary fauna and flora of the southern urals region bashkortostan republic from the 1960s a considerable amount of data on mammals molluscs and vegetation from quaternary deposits of the southern urals region has been produced the age of key stratigraphic localities was established by using different geological and palaeontological evidence palaeomagnetic and absolute dating the flora and fauna history is summarized for the southern part of the urals the result is that the history of fossil organic forms and plant associations could be traced characteristic complexes could be recognized and a curve with changes in the vegetation could be constructed results of biostratigraphical investigations are given in the review

rapid changes of glacial climate simulated in a coupled climate model abrupt changes in climate termed dansgaard oeschger and heinrich events have punctuated the last glacial period approximately 100 10 kyr ago but not the holocene the past 10 kyr here we use an intermediate complexity climate model to investigate the stability of glacial climate and we find that only one mode of atlantic ocean circulation is stable a cold mode with deep water formation in the atlantic ocean south of iceland however a warm circulation mode similar to the present day atlantic ocean is only marginally unstable and temporary transitions to this warm mode can easily be triggered this leads to abrupt warm events in the model which share many characteristics of the observed dansgaard oeschger events for a large freshwater input such as a large release of icebergs the model s deep water formation is temporarily switched off causing no strong cooling in greenland but warming in antarctica as is observed for heinrich events our stability analysis provides an explanation why glacial climate is much more variable than holocene climate

biostratigraphical characteristics of the holocene deposits of the southern urals abstract this paper is a synthesis of previously published and unpublished materials dealing with the stratigraphy of the holocene deposits of the southern uralian region easternmost part of europe results of the mammalian amphibian reptilian malacological and palynological investigations as well as radiocarbon data provide the basis for stratigraphical subdivision and reconstruction of the palaeoenvironments the holocene is represented by the agidel horizon with three subhorizons the holocene deposits form the high and lower flood plain terraces and the unconsolidated deposits in the caves the vegetation development is based on betula coniferous forests at the beginning of this interval which were replaced by pinus picea forests with broad leaved trees admixture early holocene at the beginning of the middle holocene birches decreased and the broadleaved trees and picea increased in the forest compositions the climate was warmer and more humid than the modern one during the late holocene the type of vegetation was close to the modern one picea pinus birch tree forest was growing in the northern part of the southern fore urals with broad leaved trees in the southern part the percentage of open woodlands with artemisia chenopodiaceae herbage associations increased towards the end of that time the mollusc fauna is represented by terrestrial and freshwater species the variety and quantity of the terrestrial species increased compared with the late neopleistocene the main part of the modern amphibian fauna of southern urals was formed during the early holocene modern amphibian fauna developed at the end of the late holocene and is represented by forest species the modern fauna of reptiles of the southern urals formed at the end of the late holocene when steppe species disappeared nowadays steppe biotopes exist in the southern part of this area in the southern urals the early holocene small mammal steppe biotopes were replaced by the modern forest biotopes in the trans urals the faunas were steppe species throughout the period the holocene large mammal fauna was characterized by the transition from the mammoth to the holocene complex when late pleistocene species disappeared during the early holocene

biostratigraphy of the late palaeolithic site of bajslan tash cave the southern urals the bajslan tash cave locality is situated in the southern part of the urals in the belaja river valley russian federation the post glacial period of environmental development of the southern urals is represented in the bajslan tash cave site unconsolidated sediments were studied with the help of faunal palynological and radiocarbon methods descriptions of the unconsolidated deposits of the cave are given in this article preliminary results of a stratigraphical subdivision of the investigated sediments and palaeoenvironmental reconstructions are submitted

surface wind stress threshold for glacial atlantic overturning 1 using a coupled model of intermediate complexity the sensitivity of the last glacial maximum lgm atlantic meridional overturning circulation amoc to the strength of surface wind stress is investigated a threshold is found below which north atlantic deep water formation dwf takes place south of greenland and the amoc is relatively weak above this threshold dwf occurs north of the greenland scotland ridge leading to a vigorous amoc this nonlinear behavior is explained through enhanced salt transport by the wind driven gyre circulation and the overturning itself both pattern and magnitude of the nordic sea s temperature difference between strong and weak amoc states are consistent with those reconstructed for abrupt climate changes of the last glacial period our results thus point to a potentially relevant role of surface winds in these phenomena

ocean thermohaline circulation and sedimentary 231pa 230th ratio holocene sediments from the atlantic are characterized by 231pa 230th ratios below the production ratio of the two radionuclides in the water column 0 093 whereas holocene sediments from the southern ocean have 231pa 230th 0 093 this pattern of 231pa deficit and excess was ascribed to southward 231pa export from the atlantic by the atlantic thermohaline circulation thc as pa is scavenged less efficiently by marine particles and more effectively transported by the thc than th the same pattern is observed in deposits of the last glacial maximum lgm which led to a previous contention that the thc strength did not vary markedly through the last glacial termination here we embed a description of trace metal scavenging into a zonally averaged circulation biogeochemistry ocean model to explore the sensitivity of 231pa 230th in atlantic and southern ocean sediments to thc changes our results show that the production of biogenic opal which unlike other marine particles poorly fractionates th and pa in the southern ocean water column determines the spatial pattern of the sensitivity also 231pa 230th increases in the north atlantic but changes little in the south atlantic and decreases in the southern ocean as thc is reduced the mean 231pa 230th of the whole atlantic is therefore less sensitive to thc changes than the mean 231pa 230th of the north atlantic the current uncertainties in atlantic mean 231pa 230th are too large to rule out a twofold reduction of the thc at the lgm however the increase in north atlantic mean 231pa 230th simulated in response to a twofold thc reduction is larger than the observed change in the north atlantic mean 231pa 230th from the lgm to holocene comparing this change with the modeled sensitivity of north atlantic 231pa 230th to thc variations indicates that the thc at the lgm could not have been reduced by 30 of its present strength experiments of transient thc changes indicate that high resolution 231pa 230th records from north atlantic sediments could also document thermohaline oscillations on century to millennial timescales

comparison of oxygen isotope records from the gisp2 and grip greenland ice cores recent results1 2 from the greenland ice core project grip summit ice core suggest that the climate in greenland has been remarkably stable during the holocene but was extremely unstable for the time period represented by the rest of the core spanning the last two glaciations and the intervening eemian inter glacial here we present the complete oxygen isotope record for the greenland ice sheet project 2 gisp2 core drilled 28 km west of the grip core we observe large rapid climate fluctuations throughout the last glacial period which closely match those reported for the grip core however in the bottom 10 of the cores spanning the eemian interglacial and the previous glacia tion there are significant differences between the two records it is possible that ice flow may have altered the chronological sequences of the stratigraphy for the bottom part of one or both of the cores considerable further work will be necessary to evaluate the likelihood of this and the extent to which it will still be possible to extract meaningful climate information from the lowest sections of the cores

biostratigraphy of the late upper pleistocene upper neopleistocene to holocene deposits of the belaya river valley southern urals russia abstract cave and terrace localities containing upper pleistocene and holocene deposits have been biostratigraphically investigated in the mountainous part of the southern urals in the latitudinal oriented valley of the belaya river russian federation the main fieldwork was undertaken in 1999 2000 its purpose was to save all the possible geological information before the building of the yumaguzino reservoir nowadays most of the localities described in the paper are under water biostratigraphical and archaeological data were studied at the same time artefacts from the late palaeolitic to the early iron age were found in the caves the main characteristics of the upper quaternary terraces and of the cave deposits as well as the results of the paleontological investigations are given

malacological characteristics of the middle to upper pleistocene transitional interval mis 7 5 observed in the batajnica locality serbia abstract the batajnica loess section is one of the most complete middle and late pleistocene records known in the vojvodina region serbia the main aim of the malacological investigations was to study the latest middle pleistocene cold interval and to see how the mollusc successions reacted to the climate changes during the cold warm transition the deposits which belong to the upper part of pedocomplex v s2 v l2 loess and partly to the v s1 soil were sampled the penultimate glacial loess v l2 of the batajnica site corresponds to the cold interval marine isotope stage mis 6 the molluscs indicate moderate or sometimes warm climate and dry or moderate steppe like environment composed of adjacent mosaics of drier and humid habitats the mollusc complexes of v s2 soil mis 7c v l2 loess mis 6 and v s1 paleosol mis 5e show almost the same species composition which suggests the existence of a comparatively moderate or warm climate during the late middle pleistocene cold interval in contrast the mollusc complexes mis 6 from western and eastern europe have less species and few individuals compared with the batajnica section comparison with the late middle pleistocene mollusc associations from the northern and southern margins of the fruska gora mountain confirms its environmental originality the northern side of the mountain was characterized by a humid and relatively colder environment than the other areas of the vojvodina region batajnica irig and ruma the mollusc fauna obtained in the batajnica site suggests that this adjacent area represented a refugium for the thermophilous and arid tolerant species where they were able to survive during the cold periods of the pleistocene and thus confirms the hypothesis of p sumegi

last glacial maximum and holocene climate in ccsm3 abstract the climate sensitivity of the community climate system model version 3 ccsm3 is studied for two past climate forcings the last glacial maximum lgm and the mid holocene the lgm approximately 21 000 yr ago is a glacial period with large changes in the greenhouse gases sea level and ice sheets the mid holocene approximately 6000 yr ago occurred during the current interglacial with primary changes in the seasonal solar irradiance the lgm ccsm3 simulation has a global cooling of 4 5 c compared to preindustrial pi conditions with amplification of this cooling at high latitudes and over the continental ice sheets present at lgm tropical sea surface temperature sst cools by 1 7 c and tropical land temperature cools by 2 6 c on average simulations with the ccsm3 slab ocean model suggest that about half of the global cooling is explained by the reduced lgm concentration of atmospheric co2 50 of present day concentrations there is an increase in the antarctic circumpolar current an

sea surface temperature anomalies in the oceans at the lgm estimated from the alkenone u37k index comparison with gcms 1 u k 37 sea surface temperature sst estimates for the last glacial maximum lgm are discussed and compared to coupled general circulation model gcm results we conclude that u k 37 estimates and most numerical models agree in the magnitude of the large scale sst cooling features of the glacial ocean there was a larger cooling in the northern than in the southern hemisphere the eastern boundary currents and equatorial regions were also colder there is a consensus between models and alkenone data for a tropical cooling of about 2 c which is in disagreement with both a smaller cooling as suggested by the climap project reconstruction or a more pronounced cooling as suggested from coral proxy records the comprehensive hadcm3 simulation examined reproduces a puzzling feature of the u k 37 sst reconstruction i e the warming of the glacial north atlantic which needs further investigation using numerical modelling and proxy data reconstruction

carnivores mammalia carnivora of the urals in the late pleistocene and holocene abstract carnivore assemblages from localities of the late pleistocene and holocene of northern middle and southern urals were studied analysis of species composition of the carnivore fauna was performed for seven chronological periods mis 5e mis 3 mid mis2 lgt late mis 2 baic early mis 1 preboreal boreal mid mis 1 atlantic subboreal late mis 1 subatlantic in the urals changes in carnivore fauna were occurring during the late pleistocene and holocene faunal composition included the species from european siberian and european siberian faunal complexes throughout the late pleistocene and holocene dominated by the species from european siberian faunal complexes the general trend of fauna changes is represented by a decreasing percentage of species from the european faunal complex and an increasing percentage of those from the siberian faunal complex faunal composition has changed due to two main reasons range shifts and extinction sixteen out of 24 species that inhabited the urals during the late pleistocene and holocene underwent range shifts the ranges shifted in different directions reduction increased and fluctuations the ranges of several species have not changed three species became extinct

dust size evidence for opposite regional atmospheric circulation changes over east antarctica during the last climatic transition three east antarctic ice cores dome b epica dome c and komsomolskaia give evidence for a uniform dust input to the polar plateau during the last glacial maximum lgm holocene transition 20 to 10 kyr bp and the 87sr 86sr versus 143nd 144nd isotopic signature of the mineral particles highlights a common provenance from southern south america at that time however the size distribution of dust from the three ice cores highlights important differences within the east antarctic during the lgm and shows clearly opposite regional trends during the climatic transition between dome b and dome c the timing of these changes is also different a geographical diversity also arises from the different phasing of the short term multi secular scale dust size oscillations that are superposed at all sites on the main trends of glacial to interglacial changes we hypothesize the dust grading is controlled by size fractionation inresponse to its atmospheric pathway either in terms of horizontal trajectory or in altitude of transport such mechanism is supported also by the dust size changes observed during a volcanic event recorded in vostok ice ice core dust size data suggest preferential upper air subsidence over the edc kms region and easier penetration of relatively lower air masses to the db area during the lgm at the end of the last glacial period and during the climatic transition the region of relatively higher subsidence progressively moved southward the scenario proposed supported also by the lgm holocene regional changes of snow accumulation likely operates even at sub millennial time scale

biostratigraphy of the upper pleistocene upper neopleistocene of the southern urals abstract this paper is a synthesis of the previously published and unpublished materials dealing with the stratigraphy of the upper pleistocene upper neopleistocene according to the russian stratigraphic scheme of the southern urals it is the second review about the characteristics of the pleistocene deposits of the easternmost part of europe it follows a previous paper concerning the biostratigraphy of the late middle pleistocene of this region the deposits which constitue the regional stratigraphic units are characterized the results of the mammalian malacological and palynological investigations as well as the radiocarbon data provide the basis for the stratigraphical subdivision and the reconstruction of the palaeoenvironments the main geological and biotical events of the southern urals region which took place during late pleistocene are characterized in the paper erosional processes became active at the beginning of kushnarenkovo time when uplift took place in the urals and when the late chosarian regression began on the caspian sea basin territory fluvial deposits can be observed at the base of the second terrace which developed above the floodplain a soil was formed on the subhorizontal surfaces forest steppe and steppe landscapes characterized this interval the climate was warm and humid the saigatka horizon formed under cold conditions slope processes and solifluction were the main relief forming processes and fluvial erosion processes became weaker floodplain sediments accumulated in the river valleys and formed the upper parts of the second terraces above the floodpain which were intensively eroded the plains were covered by steppe and the mountainous areas were occupied by tundra and forest tundra landscapes the next erosional cycle began during the following tabulda period because of the lowering of base level of the erosion and increased uplift of the territory the fluvial sediments now form the lower parts of the first terraces above the floodplain a soil was formed on the watersheds sites contain late palaeolithic artifacts the floral association was close to southern uralian flora of the present day the climate was moderately warm in the plains and drier and cooler in the mountains the subsequent kudashevo event can be correlated with the late glacial when the climate became colder loess like sediments and floodplain deposits form the upper parts of the first terrace above the floodplain and cover the watersheds where they contain cryogenic structures the climate was moderately cold late palaeolithic sites attributed to the kudashevo time are known in the southern urals region the stratigraphical positions of the main upper neopleistocene localities of the southern urals are discussed the southern urals subdivisions are correlated with the western european stratigraphical scheme eemian weichselian interval

continuous record of microparticle concentration and size distribution in the central greenland ngrip ice core during the last glacial period 1 a novel laser microparticle detector used in conjunction with continuous sample melting has provided a more than 1500 m long record of particle concentration and size distribution of the ngrip ice core covering continuously the period approximately from 9 5 100 kyr before present measurements were at 1 65 m depth resolution corresponding to approximately 35 200 yr particle concentration increased by a factor of 100 in the last glacial maximum lgm compared to the preboreal and sharp variations of concentration occurred synchronously with rapid changes in the 18o temperature proxy the lognormal mode of the volume distribution shows clear systematic variations with smaller modes during warmer climates and coarser modes during colder periods we find 1 7 m diameter during lgm and 1 3 m during the preboreal on timescales below several 100 years and the particle concentration exhibit a certain degree of independence present especially during warm periods when generally is more variable using highly simplifying considerations for atmospheric transport and deposition of particles we infer that 1 the observed changes of in the ice largely reflect changes in the size of airborne particles above the ice sheet and 2 changes of are indicative of changes in long range atmospheric transport time from the observed size changes we estimate shorter transit times by roughly 25 during lgm compared to the preboreal the associated particle concentration increase from more efficient long range transport is estimated to less than one order of magnitude

on the driving processes of the atlantic meridional overturning circulation because of its relevance for the global climate the atlantic meridional overturning circulation amoc has been a major research focus for many years yet the question of which physical mechanisms ultimately drive the amoc in the sense of providing its energy supply remains a matter of controversy here we review both observational data and model results concerning the two main candidates vertical mixing processes in the ocean s interior and wind induced ekman upwelling in the southern ocean in distinction to the energy source we also discuss the role of surface heat and freshwater fluxes which influence the volume transport of the meridional overturning circulation and shape its spatial circulation pattern without actually supplying energy to the overturning itself in steady state we conclude that both wind driven upwelling and vertical mixing are likely contributing to driving the observed circulation to quantify their respective contributions future research needs to address some open questions which we outline

late pleistocene and holocene mammal fauna of the southern urals the present paper analyses changes in the composition and ecological structure of large and small mammal faunas in mountains in comparison with the transuralian peneplain region during the late pleistocene and holocene at present the study area is one of a small number of regions in northern eurasia where a series of local faunas have been dated small mammal fauna changes occurred mostly due to shifts in species ranges while large mammal fauna changes occurred as a result of both range shifts and of extinctions large and small mammal faunas varied synchronously across the southern urals the transition from the periglacial mammoth to the holocene assemblage is recorded approximately at the pleistocene holocene boundary and seemingly occurred over all of the southern urals changes in the species composition both of small and of large mammal faunas were directed largely along the same line from the end of the pleistocene through the holocene both groups of faunas show an increase in the number of inhabitants of partly forested landscapes and forests and a decrease in the number of open landscape species this trend was more strongly pronounced in the mountain region in comparison to the peneplain changes in species composition of mammal fauna in the southern urals the southern part of eastern europe and the altay mountains southern siberia and the baikalian region followed the same basic pattern