small mammal taphonomy at la trinchera de atapuerca burgos spain a remarkable example of taphonomic criteria used for stratigraphic correlations and palaeoenvironment interpretations abstract palaeoecological and biostratigraphical interpretations have been traditionally based on the presence in the fossil record of certain species nevertheless there are many taphonomic factors controlling the species composition and their relative abundance in a fossil site that may alter spatial and temporal correlations between the site where fossils have been found and the place where past beings were living taphonomic studies have been conducted at different sites from atapuerca ibeas cave complex this cave complex in burgos spain includes several karstic sites with extensive evidence of human activity and a complete record of vertebrate remains of the middle pleistocene as well as abundant human fossils the small mammal taphonomic analysis of one of these sites penal is explained and discussed here in detail to show the taphonomic procedure stratigraphical correlation between levels at the penal site is particularly difficult and correlations have been proposed here based on taphonomic data since 1980 a working hypothesis suggested a sedimentary connection between penal and another site named dolina presently separated by an abandoned railway cutting in order to test this hypothesis the results of penal obtained from the present study are compared to previous analysis done in dolina it is also attempted here through taphonomic comparison of these two sites to obtain a better understanding of the past context where hominids inhabited

towards a protocol for laser scanning in fluvial geomorphology advances in spatial analytical software allow digital elevation models dems to be produced which accurately represent landform surface variability and offer an important opportunity to measure and monitor morphological change and sediment transfer across a variety of spatial scales many of the techniques presently employed aerial lidar edm theodolites gps photogrammetry suffer coverage or resolution limitations resulting in a trade off between spatial coverage and morphologic detail captured this issue is particularly important when rates of spatial and temporal change are considered for fluvial systems this paper describes the field and processing techniques required for oblique laser scanning to acquire 0 01 m resolution digital elevation data of an upland reach of the river wharfe in the uk the study site is variable with rapidly changing morphology diverse vegetation and the presence of water and these are evaluated with respect to laser data accuracy scan location frequency and distance are discussed with reference to survey accuracy and efficiency and a field protocol is proposed scan data cloud merging was achieved with a high degree of precision sub centimetre and positional data are shown to be very accurate for exposed surfaces vegetation and water decrease the accuracy as the laser pulse is often prevented from reaching the ground surface or is not returned copyright 2006 john wiley sons ltd

palaeoenvironments of the last neanderthals in sw europe mis 3 cova del coll verdaguer barcelona ne of iberian peninsula abstract marine isotope stage 3 mis 3 was characterised by marked oscillations of extreme cold episodes with very short warm events during the stadial and several regional differences have been recorded in the ice cores and marine deposits the aim of this study is to reconstruct this period by evaluating both terrestrial and regional responses cova del coll verdaguer a site located on the iberian peninsula preserves a sedimentary deposit dated to between 34 and 56 ka bp and provides an opportunity for evaluating the impact of climate changes on the regional landmass during a period that coincided with the last neanderthal population on the iberian peninsula several dating methods including u series electron spin resonance amino acid racemization and radiocarbon 14c were applied to the site and the ages obtained show good agreement the biotic evidence obtained is substantial comprising floristic data from palynology and charcoal analysis and faunal data from large and small mammals birds and gastropods environmental reconstruction points to an initially open meadow landscape at the base of the sequence 56 ka that progressively changes to a woodland environment dominated by conifers 34 ka the presence of few thermophilous taxa in contrast with lower latitudes of the iberian peninsula is also detected the environmental conditions of mid altitude mediterranean limestone mountains for the last neanderthal populations appear to have been dominated by a forested landscape comprising boreal or mixed coniferous forest characterised by a low usable biomass with poor comestible plant resources and dispersed herbivore populations

paleoenvironmental context of neanderthal occupations in northeastern iberia the small mammal assemblage from abric romani capellades barcelona spain the abric romani site capellades barcelona spain constitutes a key site for understanding the latest neanderthal occupations in western europe here we present a comprehensive systematic and taphonomic analysis of a small mammal assemblage from level o of the abric romani site with the aim of reconstructing the paleoecological context in which the neanderthals lived the assemblage which probably dates from a stadial episode between interstadial 15 and interstadial 14 contains fifteen small mammal species including species uncommon for the northeast of iberia such as sciurus vulgaris nyctalus lasiopterus and pipistrellus pipistrellus taphonomic studies suggest a predatory origin for the assemblage probably related to strix aluco and paleoecological inferences suggest lower temperatures 3 4 c and higher rainfall 70 170 mm than at present and a landscape dominated by an open forest with watercourses the new data improve our knowledge of trends associated with marine isotope stage 3 that affected neanderthal populations in the iberian peninsula showing that the neanderthals were well adapted to cooler and wetter conditions across iberia

flood driven topographic changes in a gravel cobble river over segment reach and morphological unit scales regulated rivers generally incise below dams that cut off sediment supply but how that happens and what the consequences are at different spatial scales is poorly understood modern topographic mapping at meter scale resolution now enables investigation of the details of spatial processes in this study spatial segregation was applied to a meter scale raster map of topographic change from 1999 to 2008 on the gravel cobble regulated lower yuba river in california to answer specific scientific questions about how a decadal hydrograph that included a flood peak of 22 times bankfull discharge affected the river at segment reach and morphological unit scales the results show that the river preferentially eroded sediment from floodplains compared to the channel and this not only promoted valley wide sediment evacuation but also facilitated the renewal and differentiation of morphological units especially in the channel at the reach scale area of fill and mean net rate of elevational change were directly correlated with better connectivity between the channel and floodplain while the mean rate of scour in scour areas was influenced by the ratio of slope to bankfull froude number a ratio indicative of lateral migration versus vertical downcutting hierarchical segregation of topographic change rasters proved useful for understanding multiscalar geomorphic dynamics this article is protected by copyright all rights reserved

a framework for modeling connections between hydraulics water surface roughness and surface reflectance in open channel flows this paper introduces a framework for examining connections between the flow field the texture of the air water interface and the reflectance of the water surface and thus evaluating the potential to infer hydraulic information from remotely sensed observations of surface reflectance we used a spatial correlation model describing water surface topography to illustrate the application of our framework nondimensional relations between model parameters and flow intensity were established based on a prior flume study expressing the model in the spatial frequency domain allowed us to use an efficient fourier transform based algorithm for simulating water surfaces realizations for both flume and field settings had water surface slope distributions positively correlated with velocity and water surface roughness however most surface facets were gently sloped and thus unlikely to yield strong specular reflections the model exaggerated the extent of water surface features leading to underestimation of facet slopes a ray tracing algorithm indicated that reflectance was greatest when solar and view zenith angles were equal and the sensor scanned toward the sun to capture specular reflections of the solar beam reflected energy was concentrated in a small portion of the sky but rougher water surfaces reflected rays into a broader range of directions our framework facilitates flight planning to avoid surface reflected radiance while mapping other river attributes or to maximize this component to exploit relationships between hydraulics and surface reflectance this initial analysis also highlighted the need for improved models of water surface topography in natural rivers

through water terrestrial laser scanning of gravel beds at the patch scale acquiring high resolution topographic data of natural gravel surfaces is technically demanding in locations where the bed is not exposed at low water stages often the most geomorphologically active surfaces are permanently submerged gravel beds are spatially variable and measurement of their detailed structure and particle sizes is essential for understanding the interaction of bed roughness with near bed flow hydraulics sediment entrainment transport and deposition processes as well as providing insights into the ecological responses to these processes this paper presents patch scale laboratory and field experiments to demonstrate that through water terrestrial laser scanning tls has the potential to provide high resolution digital elevation models of submerged gravel beds with enough detail to depict individual grains and small scale forms the resulting point cloud data requires correction for refraction before registration preliminary validation shows that patch scale tls through 200 mm of water introduces a mean error of less than 5 mm under ideal conditions point precision is not adversely affected by the water column the resulting dems can be embedded seamlessly within larger sub aerial reach scale surveys and can be acquired alongside flow measurements to examine the effects of three dimensional surface geometry on turbulent flow fields and their interaction with instream ecology dynamics copyright 2011 john wiley sons ltd

dating of the basal aurignacian sandwich at abric romani catalunya spain by radiocarbon and uranium series abric romani a rock shelter located near barcelona spain contains a charcoal bearing basal aurignacian occupation level sandwiched between beds of moss generated carbonate the aurignacian culture is the oldest artefact industry in europe with which anatomically modern human remains have been associated radiocarbon analysis of charcoal fragments by accelerator mass spectrometry ams dates the basal aurignacian to about 37 2 ka bp u series analyses by alpha spectrometry as and mass spectrometry ms date the enclosing carbonate to 43 1 ka bp these results confirm the great antiquity of the aurignacian in northern spain and support the similar ams dates from el castillo and l arbreda caves they also show that radiocarbon dates are significantly younger than u series at 40 ka bp as predicted by theory

puzzling out a palimpsest testing an interdisciplinary study in level o of abric romani abstract cultural deposits especially those accumulated in caves and rock shelters are usually the results of several occupational events in the same space forming palimpsests in addition the materials of these occupational events tend to be deposited along with remains of natural origin and may be altered partially destroyed or reworked due to the process of superimposition the work presented here focuses on dissecting the palimpsest of level o at abric romani through an interdisciplinary analysis we analyzed a particular area located in the northeastern corner of the site this work is based on the study of the lithic and faunal remains recovered in this area with the aim of dissecting the palimpsest into the smallest possible units to do this we used different methods and techniques including archaeostratigraphy intra site spatial archaeology zooarchaeology tooth microwear taphonomy lithic technology and faunal and lithic refits these methods allowed us to identify two archaeolevels in this area oa and ob oa comprises a maximum of three accumulations and ob holds two accumulations of archaeological remains these accumulations are generally related to combustion structures based on the results obtained from zooarchaeological taphonomic and lithic technology analyses we characterized each accumulation the analysis of the lithic and faunal refits helped to identify synchronic and diachronic links after having processed all of the results we were able to interpret the intra area organization and its role in relation to the rest of the site our results have shown that it is possible to obtain high resolution data for dissecting a palimpsest using different methodologies it is however important to remember that although we were able to distinguish these finer units we were still working with palimpsests nevertheless the study of these finer units makes it possible to work with time scales that are closer to ethnographic time thereby facilitating further ethno archaeological interpretation

placing late neanderthals in a climatic context attempts to place stone age events in climatic context are hampered by the difficulty of calibrating the radiocarbon calendar beyond 21 000 radiocarbon years ago and the lack of a master chronology for climate events but there is a way round this problem radiocarbon years can be related to palaeoclimate via the excellent cariaco basin deep sea record in this way the disappearance of neanderthals in europe can be related to known climatic events applying this analysis to dates linked to neanderthal artefacts from gorham s cave gibraltar suggests that they survived there up to the onset of a major environmental shift attempts to place palaeolithic events in climatic context are hampered by the difficulty of calibrating the radiocarbon calendar beyond around 21 000 radiocarbon years ago and the absence of a master calendar chronology for climate events but this is circumvented by relating radiocarbon years to the paleoclimatic record through the excellent cariaco basin deep sea record in this way it is possible to relate the disappearance of neanderthals in europe to known climatic events attempts to place palaeolithic finds within a precise climatic framework are complicated by both uncertainty over the radiocarbon calibration beyond about 21 500 14c years bp1 and the absence of a master calendar chronology for climate events from reference archives such as greenland ice cores or speleothems2 here we present an alternative approach in which 14c dates of interest are mapped directly onto the palaeoclimate record of the cariaco basin by means of its 14c series3 circumventing calendar age model and correlation uncertainties and placing dated events in the millennial scale climate context of the last glacial period this is applied to different sets of dates from levels with mousterian artefacts presumably produced by late neanderthals from gorham s cave in gibraltar first generally accepted estimates of about 32 000 14c years bp for the uppermost mousterian levels4 5 second a possible extended middle palaeolithic occupation until about 28 000 14c years bp6 and third more contentious evidence for persistence until about 24 000 14c years bp6 this study shows that the three sets translate to different scenarios on the role of climate in neanderthal extinction the first two correspond to intervals of general climatic instability between stadials and interstadials that characterized most of the middle pleniglacial and are not coeval with heinrich events in contrast if accepted the youngest date indicates that late neanderthals may have persisted up to the onset of a major environmental shift which included an expansion in global ice volume and an increased latitudinal temperature gradient more generally our radiocarbon climatostratigraphic approach can be applied to any snapshot date from discontinuous records in a variety of deposits and can become a powerful tool in evaluating the climatic signature of critical intervals in late pleistocene human evolution

removing sun glint from optical remote sensing images of shallow rivers sun glint is the specular reflection of light from the water surface which often causes unusually bright pixel values that can dominate fluvial remote sensing imagery and obscure the water leaving radiance signal of interest for mapping bathymetry bottom type or water column optical characteristics although sun glint is ubiquitous in fluvial remote sensing imagery river specific methods for removing sun glint are not yet available we show that existing sun glint removal methods developed for multispectral images of marine shallow water environments over correct shallow portions of fluvial remote sensing imagery resulting in regions of unreliable data along channel margins we build on existing marine glint removal methods to develop a river specific technique that removes sun glint from shallow areas of the channel without overcorrection by accounting for non negligible water leaving near infrared radiance this new sun glint removal method can improve the accuracy of spectrally based depth retrieval in cases where sun glint dominates the at sensor radiance for an example image of the gravel bed snake river wyoming usa observed vs predicted r2 values for depth retrieval improved from 0 66 to 0 76 following sun glint removal the methodology presented here is straightforward to implement and could be incorporated into image processing workflows for multispectral images that include a near infrared band this article is protected by copyright all rights reserved

a predictive typology for characterising hydromorphology abstract whilst traditionally poorly quantified the link between physical habitat and ecological response in rivers is widely recognised and is currently rising up legislative and policy agendas in europe this is reflected in the water framework directive which dictates that hydromorphological condition of water bodies should be capable of supporting good ecological status methods are developed that integrate river system hydrology geomorphology and ecology and the complex interplay between these three variables whilst hydrological and biological methods for characterisation are relatively well established geomorphological methods are not effective characterisation of geomorphology physical habitat with full spatial coverage at a range of scales can be used to explore spatial interactions between habitat and biological data and potentially further our understanding of ecological response managers need to know what aspects of physical habitat and at which critical locations intervention will lead to greatest improvements in ecological condition this requires information on hydromorphological character and condition existing applied approaches for capturing geomorphological data are highly dependent on intensive fieldwork which is unlikely to be resourced at sufficiently extensive scales to meet management needs this paper outlines a typology approach for characterising the physical template of rivers it draws on a range of hydromorphological data to develop a framework for a channel typology with data collation from secondary sources followed by targeted fieldwork to i assess to what extent individual channel types are characteristic of field conditions and ii to collect information on reach scale variability within each type results suggest that characterisation of channel types based on stream power floodplain width and stream order does result in a distinct set of channel types field survey subsequently found that these types had a characteristic suite of patch scale habitat features flow types the approach was applied to a catchment where geomorphological processes exert a dominant control over physical habitat

microstratigraphic and multi analytical evidence for advanced neanderthal pyrotechnology at abric romani capellades spain abstract the complexity of social behaviour by neanderthal communities is consolidated by illustrating the sophistication of fire linked activities in their home based contexts this was achieved by relating the microfacies analysis of cultural deposits to combustion structures at the abric romani capellades spain the geometry and nature of cultural microfacies from a selection of hearths and their surrounding empty areas were characterized in thin sections the related bulk fraction from the distinctive individual microstrata was extracted water sieved and examined under the binocular microscope the selective micro sampling was performed from the collection of undisturbed blocks in combustion structures of layer j 1995 excavation the procedure was applied to combustion structures from the lower layer o 2009 excavation the integrated micromorphological observation and binocular sorting allowed identification of a similar assemblage of components that are closely linked to distinctive anthropic microfacies individual grains were characterized by esem edax x ray diffraction and raman spectrometry x ray fluorescence analysis was performed on the host matrix the specific association of remarkable components cultural microfacies is identical for the combustion structures of layers o and j the four groups components identified comprise carbonaceous polymorphs allochthonous mineral clasts organo phosphatic compounds and native metals the phase association of organic and mineral phases allowed recognition of a common natural precursor rich in hydrocarbon species and metallic compounds that were probably extracted from a miocene source microscale analysis in thin sections linked the combustion microfacies to the transformation contexts of the metal rich carbonaceous precursors heat resistant polymers and graphitic components associated with wood ash are suggested to trace pyrolitic residues from flaming combustion the intimate mixing of the metal rich carbonaceous polymorphs to finely crushed heated bones allowed identification of pyrogenic transformations of the fossil fuel with fresh biomass analysis at microscale in thin sections linked the processed by products to finely prepared and meticulously consolidated surfaces showing distinctive colours yellow brown blue green red white and black the repeated surface preparation and their exceptional preservation at microscales illustrate the great concern of neanderthal occupants for maintaining the long term memory of their carefully designed home space the recognition of advanced pyrotechnology by using fossil fuels for lighting firing spatial design colouring in the combustion structures of abric romani incites speculation on the exceptional social status of this home based camp site further development of the microfacies multi analytical analysis should more deeply penetrate the social sophistication of neanderthal communities

quantifying submerged fluvial topography using hyperspatial resolution uas imagery and structure from motion photogrammetry quantifying the topography of rivers and their associated bedforms has been a fundamental concern of fluvial geomorphology for decades such data acquired at high temporal and spatial resolutions are increasingly in demand for process oriented investigations of flow hydraulics sediment dynamics and in stream habitat in these riverine environments the most challenging region for topographic measurement is the wetted submerged channel generally dry bed topography and submerged bathymetry are measured using different methods and technology this adds to the costs logistical challenges and data processing requirements of comprehensive river surveys however some technologies are capable of measuring the submerged topography through water photogrammetry and bathymetric lidar are capable of reasonably accurate measurements of channel beds in clear water whilst the cost of bathymetric lidar remains high and its resolution relatively coarse the recent developments in photogrammetry using structure from motion sfm algorithms promise a fundamental shift in the accessibility of topographic data for a wide range of settings here we present results demonstrating the potential of so called sfm photogrammetry for quantifying both exposed and submerged fluvial topography at the mesohabitat scale we show that imagery acquired from a rotary winged unmanned aerial system uas can be processed in order to produce digital elevation models dems with hyperspatial resolutions c 0 02 m for two different river systems over channel lengths of 50 100 m errors in submerged areas range from 0 016 m to 0 089 m which can be reduced to between 0 008 m and 0 053 m with the application of a simple refraction correction this work therefore demonstrates the potential of uas platforms and sfm photogrammetry as a single technique for surveying fluvial topography at the mesoscale defined as lengths of channel from c 10 m to a few hundred metres this article is protected by copyright all rights reserved

characterising physical habitats and fluvial hydromorphology a new system for the survey and classification of river geomorphic units geomorphic units are the elementary spatial physical features of the river mosaic at the reach scale that are nested within the overall hydromorphological structure of a river and its catchment geomorphic units also constitute the template of physical habitats for the biota the assessment of river hydromorphological conditions is required by the european water framework directive 2000 60 wfd for the classification and monitoring of water bodies and is useful for establishing links between their physical and biological conditions the spatial scale of geomorphic units incorporating their component elements and hydraulic patches is the most appropriate to assess these links given the weakness of existing methods for the characterisation and assessment of geomorphic units and physical habitats e g lack of a well defined spatiotemporal framework terminology issues etc a new system for the survey and characterisation of river geomorphic units is needed that fits within a geomorphologically meaningful framework this paper presents a system for the survey and classification of geomorphic units gus geomorphic units survey and classification system aimed at characterising physical habitats and stream morphology the method is embedded into a multiscale hierarchical framework for the analysis of river hydromorphological conditions three scales of geomorphic units are considered i e macro units units sub units organised within two spatial domains i e bankfull channel and floodplain different levels of characterisation can be applied depending on the aims of the survey broad basic and detailed level at each level different complementary information is collected the method is applied by combining remote sensing analysis and field survey according to the spatial scale and the level of description required the method is applicable to most of fluvial conditions and has been designed to be flexible and adaptable according to the objectives e g reach characterisation assessment monitoring and available data e g image resolution the method supports integrated hydromorphological assessment at the reach scale e g the morphological quality index mqi and therefore contributes to better establishing links between hydromorphological conditions at the reach scale characteristic geomorphic units and related biological conditions

assessing the ability of airborne lidar to map river bathymetry airborne bathymetric lidar was collected for 220 river kilometers in the yakima and trinity river basins in the united states concomitant with the aerial data collection ground surveys of the river bed were performed in both basins we assess the quality of the bathymetric lidar survey from the perspective of its application toward creating accurate precise and complete streambed topography for numerical modeling and geomorphic assessment measurement error is evaluated with respect to ground surveys for magnitude and spatial variation analysis of variance statistics indicate that residuals from two independent ground surveys in similar locations do not come from the same population and that mean errors at different study locations also come from different populations systematic error indicates a consistent bias in the data and random error falls within values of expected precision

hyperscale terrain modelling of braided rivers fusing mobile terrestrial laser scanning and optical bathymetric mapping quantifying the morphology of braided rivers is a key task for understanding braided river behaviour in the last decade developments in geomatics technologies and associated data processing methods have transformed the production of precise reach scale topographic datasets nevertheless generating accurate digital elevation models dems remains a demanding task particularly in fluvial systems this paper identifies a threefold set of challenges associated with surveying these dynamic landforms complex relief inundated shallow channels and high rates of sediment transport and terms these challenges the morphological wetted channel and mobility problems respectively in an attempt to confront these issues directly this paper presents a novel survey methodology that combines mobile terrestrial laser scanning and non metric aerial photography with data reduction and surface modelling techniques to render dems from the resulting very high resolution datasets the approach is used to generate and model a precise dense topographic dataset for a 2 5 km reach of the braided rees river new zealand data were acquired rapidly between high flow events and incorporate over 5 x 109 raw survey observations with point densities of 1600 pts m 2 on exposed bar and channel surfaces a detailed error analysis of the resulting sub metre resolution is described to quantify dem quality across the entire surface model this reveals unparalleled low vertical errors for such a large and complex surface model between 0 03 and 0 12 m in exposed and inundated areas of the model respectively copyright 2013 john wiley sons ltd

a coastal reservoir of terrestrial resources for neanderthal populations in north eastern iberia palaeoenvironmental data inferred from the small vertebrate assemblage of cova del gegant sitges barcelona coastal areas as reservoirs of resources for hominid groups have been widely studied in recent years these areas combine marine with terrestrial and wetland resources and would have been optimum sites for hominids including neanderthals this is the case with the cova del gegant a cave that today opens directly onto the mediterranean sea and is located in the north eastern iberian peninsula the geomorphological evolution of the massis del garraf has provided evidence that during the late pleistocene there was a littoral platform between 8 and 13 km wide in front of the cova del gegant within this framework the data derived from analysis of the small vertebrates and large mammals recovered from cova del gegant including taxa currently absent from the massis del garraf suggest that the landscape surrounding the cave provided a richer terrestrial ecosystem for neanderthals than is available in this zone today analysis of the small vertebrate association from the cave reveals that the landscape surrounding the cave was dominated by woodland edge and open environments and that the climate was mediterranean the results have been compared with the only iberian site with similar characteristics to the cova del gegant gorham s cave southern iberia gibraltar revealing differences and similarities in the landscape and climate on the basis of the small mammal assemblages as well as the differences in the accessibility to terrestrial mammalian resources for the neanderthal groups the landscape and the climate were reasonably similar at the two sites but the differences in the accessibility of resources for the neanderthals are directly related to the location of the sites and the coastal position whereas the cova del gegant was on a route of mammal migration between the ebro valley and france suited for securing terrestrial resources gorham s cave is located on a small peninsula with a lower abundance of terrestrial mammal resources this is probably why the neanderthal groups at gorham s cave exploited marine resources whereas there is no evidence of marine resources having been exploited at cova del gegant even though the seashore was nearby copyright 2011 john wiley sons ltd

palaeoecology of neanderthals during dansgaard oeschger cycles in northeastern iberia abric romani from regional to global scale abstract the sequence from abric romani has provided several palaeoecological studies this paper presents a synthesis of the results yielded by palynology including the data from the entire non excavated deposits and the data obtained through the study of large mammals micromammals herpetofauna and anthracology from the excavated layers the palaeobotanical studies show that the sequence is mainly related to pine forests and near or within these dominant forests there were smaller plant formations and or secondary species with a mediterranean and or atlantic character nevertheless continuous forest did not dominate the entire region the fauna occupying the territory indicate open spaces in which seasonal grasslands proliferated dry assemblages in sunny areas and humid ones in mountain shadows the non excavated archaeological layers correspond to mis 4 initially characterized by temperate and humid conditions and thereafter cool and humid until hs 6 and mis 3 afterwards at the beginning of the mis 3 the dansgaard oeschger cycles 1500 yr rapid and abrupt climatic changes occurred during the deposition of the archaeological levels o n m l k and j later these events were interrupted by a cold and dry phase between ca 49 and 47 ka bp which affected levels ja i and h culminating with hs 5 finally this cold episode was followed by the hengelo interstadial or do 12 characterized by a temperate and humid climate identified in levels e and d

geospatial organization of fluvial landforms in a gravel cobble river beyond the riffle pool couplet abstract morphological units mu are landforms with distinct local form process associations at 1 10 channel widths scale that may be the fundamental building blocks describing the geomorphic structure of a river past research has disproportionately focused on the two mus of pool and riffle conjecturing that they are the central linked couplet in the process form association the goal of this study was to delineate and map spatially explicit fluvial landforms in two dimensional planview within a gravel cobble bed river using two dimensional hydrodynamic delineation and then to statistically examine mu geospatial patterns for indicators of deterministic geomorphic control this procedure is not discharge dependent like mesohabitat methods but gets at the geometry of underlying landforms statistical testing confirmed that eight delineated in channel mu types comprise a complex and diverse channel morphology in which pools and riffles are not directly coupled specifically gravel cobble river channels 1 exhibit nonrandom spatial organization of their longitudinally and laterally variable landform morphology 2 consist of a variety of mu types not just pools and riffles and 3 show distinct mu collocations and avoidances with riffles linked to chutes and runs while pools are linked to slackwaters and glides planview mu delineation with two dimensional hydrodynamic modeling provides a bottom up approach to understanding and linking channel morphology with ecosystem services and geomorphic processes and is being used to guide river management and rehabilitation strategies

evidence of paleoecological changes and mousterian occupations at the galeria de las estatuas site sierra de atapuerca northern iberian plateau spain here we present a new site in the sierra de atapuerca burgos spain galeria de las estatuas ge which provides new information about mousterian occupations in the iberian plateau the ge was an ancient entrance to the cave system which is currently closed and sealed by a stalagmitic crust below which a detritic sedimentary sequence of more than 2 m is found this has been divided into five litostratigraphic units with a rich assemblage of faunal and lithic remains of clear mousterian affinity radiocarbon dates provide minimum ages and suggest occupations older than 45 14c ka bp the palynological analysis detected a landscape change to increased tree coverage which suggests that the sequence recorded a warming episode the macromammal assemblage is composed of both ungulates mainly red deer and equids and carnivores taphonomic analysis reveals both anthropic and to a lesser extent carnivore activities the ge was occupied by neanderthals and also sporadically by carnivores this new site broadens the information available regarding different human occupations at the sierra de atapuerca which emphasizes the importance of this site complex for understanding human evolution in western europe

monitoring channel responses to flood events of low to moderate magnitudes in a bedrock dominated river using morphological budgeting by terrestrial laser scanning abstract changes to channel morphology reflect geomorphic work by flood events of differing magnitude and frequency advances in remote sensing and digital terrain processing now allow for sophisticated analysis of spatial and temporal changes in erosion and deposition although the morphological budgeting approach using digital elevation models of difference has been widely applied to track volume estimation of changes to erosion and deposition over time appraisals of geomorphic effectiveness in high energy confined and partly confined channels are still lacking this study applied terrestrial laser scanning to monitor three reaches of the liwu river a bedrock dominated river in eastern taiwan from 2009 to 2012 to investigate channel responses to flood events of low to moderate magnitude and appraise their geomorphic effectiveness variability in geomorphic effectiveness reflected valley confinement and the composition configuration of geomorphic units on the channel bed annual low magnitude flood events reworked gravel and sand deposits creating local scour and fill

neandertal extinction and the millennial scale climatic variability of ois 3 population models seeking climate as a triggering factor for the extinction of neandertals and the colonisation of europe by anatomically modern humans are contradictory due to uncertainties in the dating methods in the cultural attribution of archaeological layers and to the lack of terrestrial continuous and well dated palaeoclimatic sequences this is particularly the case for the iberian peninsula where neandertal populations seem to have survived later than in other regions of europe a review of the available palaeoclimatic evidence for ois3 of iberia reveals that this mainly consists of low resolution fragmentary ill dated and often ill interpreted records correlation between palaeoenvironmental sequences from two images pollen rich deep sea cores and archaeological data from western europe the electronic archive of the radiocarbon dates is available at qsr website http www elsevier nl locate quascirev indicates that aurignacian moderns colonised france and the north of iberia at the onset of the h4 event during this cold episode a probable contraction of neandertal populations is recorded in southern iberia where no aurignacian settlements are detected such a decline in population density is correlated with the particular desert steppe like environments made up of artemisia chenopodiaceae and ephedra characterising the h4 of this area while reducing the size of neandertal populations this inhospitable environment may have favoured their persistence in this region mainly exploiting herds of herbivores adapted to graminees rich grasslands the aurignacian moderns were probably not interested in colonising these arid mediterranean biotopes and did that only after the h4 event

evaluation of multispectral fine scale digital imagery as a tool for mapping stream morphology abstract multispectral digital imagery acquired from soda butte and cache creeks montana and wyoming was used in conjunction with field data to classify and map hydrogeomorphic stream units on four stream reaches the morphologic units that were field mapped were eddy drop zones glides low gradient riffles high gradient riffles lateral scour pools attached bars detached bars and large woody debris unsupervised and supervised classifications of the imagery were used to develop a maximum joint probability classification and an alternative joint probability classification of the stream reaches the maximum joint probability classification allowed only one of the image classes to represent each hydrogeomorphic unit on the field map and resulted in relatively low overall accuracies for identification of these units of 10 to 50 the alternative joint probability classification allowed each image class to represent any geomorphic unit where the probability of a correct classification was greater than random in this technique two or three image classes were assigned to represent each hydrogeomorphic unit resulting in higher overall accuracies of 28 to 80 accurate classification of hydrogeomorphic units was hampered by poor rectification of imagery with the field maps because of inadequate ground control points in general the largest hydrogeomorphic units were most accurately classified whereas units that were small in area or spatially linear were least likely to be accurately classified the results of this study demonstrated that multispectral digital imagery has the potential to be a useful tool for mapping hydrogeomorphic stream units at fine scales imagery to be an effective tool however careful measures such as accurate documentation of ground control points must be taken to ensure accurate rectification of the imagery with field maps

high resolution record of northern hemisphere climate extending into the last interglacial period high resolution record of northern hemisphere climate extending into the last interglacial period

additional evidence about an early intense flux of c asteroids and the origin of phobos abstract the preponderance of cm clasts among the foreign fragments in polymict meteoritic breccias including basaltic achondritic hosts indicates collisions of cm carbonaceous parent bodies believed to be c class asteroids with noncarbonaceous asteroids after differentiation of some of the latter this supports the suggestion developed in an earlier paper that a flux of predominantly c like asteroids was scattered around the solar system as jupiter approached its present mass together with the low density measured for phobos this supports a hypothesis of origin for phobos and certain other satellites as captured carbonaceous c like asteroids

high resolution interpretative geomorphological mapping of river valley environments using airborne lidar data the availability of airborne lidar data provides a new opportunity to overcome some of the problems associated with traditional field based geomorphological mapping such as restrictions on access and constraints of time or cost the combination of airborne lidar data and gis technology facilitates the rapid production of geomorphological maps of floodplain environments however unfiltered lidar data which include vegetation and buildings are currently more suitable for geomorphological mapping than data that have been filtered to remove these features classification of lidar data according to elevation in a gis enables the user to identify and delineate geomorphological features in a manner similar to field mapping but it is necessary to use a range of classification intervals in order to map the various types of feature that occur within a single reach comparison of a lidar derived geomorphological map with an independently produced field geomorphological map showed a high degree of similarity between the results of the two methods although ground truthing is essential in cases where a high degree of accuracy is required ground truthing of a lidar derived geomorphological map showed that around 80 of features mapped using both methods were identified from the lidar data suggesting that the method is suitable for applications such as production of base maps for use in field mapping and selection of sites for detailed investigation copyright 2007 john wiley sons ltd

mapping hydraulic biotopes using terrestrial laser scan data of water surface properties for more than a decade habitat mapping using biotopes in channel hydraulically defi ned habitats has underpinned aquatic conservation in the uk through a providing baseline information on system complexity and b allowing environmental and ecological change to be monitored and evaluated the traditional method used is the subjective river habitat or corridor survey this has recently been revised to include the fl oodplain via georhs but issues still exist concerning development of a national database due to the labour intensive nature of the data collection subjectivity issues between samplers temporal changes the fuzzy nature of perceived habitats and habitat boundaries this paper takes an innovative approach to biotope defi nition using high resolution spatial data to defi ne water surface roughness for two representative reaches of the river south tyne cumbria and the river rede northumberland uk data was collected using a terrestrial laser scanner tls and hydraulic variability simply expressed through assigning a local standard deviation value to a set of adjacent water surface values statistical linkage of these data with biotope locations defi ned visually in the fi eld allowed complete mapping of the surveyed reach defi ning habitat and biotope areas to the fi ne scale resolution of the tls data despite issues of data loss due to absorption and transmission through the water the refl ected signal generated an extremely detailed and objective map of the water surface roughness which may be compared with known biotope locations as defi ned by visual identifi cation in the fi eld the tls accuracy achieved in the present study is comparable with those obtained using hyperspectral imagery with 84 of the pool glide marginal deadwater amalgamated biotope 88 of riffl es 57 of runs and 50 of the amalgamated cascade rapid biotope successfully plotted it is clear from this exercise that biotope distribution is more complex than previously mapped using subjective techniques and based upon the water surface roughness delimiters presented in this study the amalgamation of pools with glides and marginal deadwaters riffl es with unbroken standing waves and cascades with rapids is proposed

step by step error assessment in braided river sediment budget using airborne lidar data abstract sequential airborne lidar surveys were used to reconstruct the sediment budget of a 7 km long braided river channel in southeastern france following a 14 year return period flood and to improve its accuracy step by step data processing involved i surface matching of the sequential point clouds ii spatially distributed propagation of uncertainty based on surface conditions of the channel and iii water depth subtraction from the digital elevation models based on water depths measured in the field the respective influence of each processing step on sediment budget computation was systematically documented this showed that surface matching and water depth subtraction both have a considerable effect on the net sediment budget although dem of difference thresholding based on uncertainty analysis on absolute elevation values had a smaller effect on the sediment budget this step is crucial for the production of a comprehensive map of channel deformations a large independent data set of rtk gps checkpoints was used to control the quality of the lidar altimetry the results showed that high density 7 9 points m 2 airborne lidar surveys can provide a very high level of detection of elevation changes on the exposed surfaces of the channel with a 95 confidence interval level of detection between 19 and 30 cm change detection from lidar data revealed that 54 of the pre flood active channel was reworked by the flood the braided channel pattern was highly disturbed by the flood owing to the occurrence of several channel avulsions

high spatial resolution hyperspectral mapping of in stream habitats depths and woody debris in mountain streams this article evaluates the potential of 1 m resolution 128 band hyperspectral imagery for mapping in stream habitats depths and woody debris in third to fifth order streams in the northern yellowstone region maximum likelihood supervised classification using principal component images provided overall classification accuracies for in stream habitats glides riffles pools and eddy drop zones ranging from 69 for third order streams to 86 for fifth order streams this scale dependency of classification accuracy was probably driven by the greater proportion of transitional boundary areas in the smaller streams multiple regressions of measured depths y versus principal component scores x1 x2 xn generated r 2 values ranging from 67 for high gradient riffles to 99 for glides in a fifth order reach r 2 values were lower in third order reaches ranging from 28 for runs and glides to 94 for pools the less accurate depth estimates obtained for smaller streams probably resulted from the relative increase in the number of mixed pixels where a wide range of depths and surface turbulence occurred within a single pixel matched filter mf mapping of woody debris generated overall accuracies of 83 in the fifth order lamar river accuracy figures for the in stream habitat and wood mapping may have been misleadingly low because the fine resolution imagery captured fine scale variations not mapped by field teams which in turn generated false misclassifications when the image and field maps were compared the use of high spatial resolution hyperspectral hsrh imagery for stream mapping is limited by the need for clear water to measure depth by any tree cover obscuring the stream and by the limited availability of airborne hyperspectral sensors nonetheless the high accuracies achieved in northern yellowstone streams indicate that hsrh imagery can be a powerful tool for watershed wide mapping monitoring and modeling of streams d 2003 elsevier science b v all rights reserved

revealing the natural complexity of fluvial morphology through 2d hydrodynamic delineation of river landforms abstract fluvial landforms at the morphological unit scale 1 10 channel widths are typically delineated and mapped either by breaking up the one dimensional longitudinal profile with no accounting of lateral variations or by manually classifying surface water patterns and two dimensional areal extents in situ or with aerial imagery mapping errors arise from user subjectivity varying surface water patterns when the same area is observed at different discharges and viewpoints and difficulty in creating a complete map with no gaps or overlaps in delineated polygons this study presents a new theory for delineating and mapping channel landforms at the morphological unit scale that eliminates in field subjective decision making adds full transparency for map users and enables future systemic alterations without having to remap in the field delineation is accomplished through a few basic steps first near census topographic and bathymetric data are used in a two dimensional hydrodynamic model to create meter scale depth and velocity rasters for a representative base flow second expert judgment and local knowledge determine the number and nomenclature of landform types as well as the range of base flow depth and velocity over each type this step does require subjectivity but it is transparent and adjustable at any time third the hydraulic landform classification is applied to hydraulic rasters to quickly completely and objectively map the planform pattern of laterally explicit landforms application of this theory will reveal the true natural complexity yet systematic organization of channel morphology

was grass more prevalent in the pronghorn past an assessment of the dietary adaptations of miocene to recent antilocapridae mammalia artiodactyla abstract molar teeth of both tertiary and quaternary representatives of the family antilocapridae were examined using mesowear and light stereomicroscopy microwear taxa from the central and southern great plains and the northern and southern great basin were included in the analyses and results compared to those obtained on the modern pronghorn antilocapra americana species included spanned from the early miocene late hemingfordian to the late pleistocene rancholabrean results are concordant with well known trends toward increasing aridity and shifts in vegetational structure in the late miocene early pliocene of north america both mesowear and microwear results indicate a shift toward more abrasive diets beginning in the hemphillian late miocene pliocene and then a return to a less abrasive dietary regime for the duration of the pleistocene and into the recent the more derived antilocaprines more hypsodont relatively longer limbs apparently depended more on grass than the less advanced merycodontines but even the earliest of the latter seem to have relied more on grass as a dietary staple than the modern pronghorn seasonal grit encroachment on food items encountered by fossil antilocaprids coupled with a heavier reliance on grasses may provide a possible explanation for the extreme hypsodonty present in the modern pronghorn despite its mainly browsing dietary behavior

neanderthal firewood management evidence from stratigraphic unit iv of abric del pastor eastern iberia abstract this paper presents anthracological data from abric del pastor alcoi spain a middle paleolithic rock shelter site analysis of 1077 wood charcoal remains from stratigraphic unit iv s u iv collected within archaeological combustion structures and from loose sediment outside of structures allowed us to characterise the local landscape as well as to approach the interaction between neanderthal groups and their local environment taxonomic identification suggests that firewood was gathered from nearby sources with predominance of juniper juniperus sp followed by thermophilous shrubby taxa additional analysis focussing on post depositional processes affecting charcoal have shown features indicative of biodegradation and mechanical action the results of this study contribute significant anthracological data towards our understanding of late pleistocene mediterranean landscapes and neanderthal forest management in this region

the early middle pleistocene palaeoenvironmental change based on the squamate reptile and amphibian proxies at the gran dolina site atapuerca spain abstract although still ongoing the archaeological and palaeontological excavations in the gran dolina cave sierra de atapuerca burgos every year since 1976 have already revealed a long culturally and palaeontologically rich sequence dated by biostratigraphy esr u series and the palaeomagnetic record at between roughly 1 my and 250 ky gran dolina has one of the longest and most continuous vertical profiles the section 19 m thick divided into 11 stratigraphic levels represents a time span of nearly 700 000 years the gran dolina sequence was partially excavated during a preliminary evaluation of its archaeological and palaeontological richness this excavation known as the gran dolina sondeo south lasted from 1993 to 1999 hominin remains were unearthed in 1994 from level 6 of gran dolina and level 6 was dated to somewhat more than 780 ky based on palaeomagnetic and microfaunal evidence making these the oldest known hominins in europe given the importance of this discovery every effort is being made to reconstruct the landscapes where these hominins once thrived the gran dolina sondeo south tds has furnished a great number of microvertebrate remains and of these around 40 000 bones are attributed to amphibians and squamates the faunal list of the squamates and amphibians of the tds comprises at least 22 species a diversity similar to what exists nowadays in spain triturus sp alytes obstetricans pelobates cultripes pelodytes punctatus bufo bufo bufo calamita hyla arborea rana temporaria rana cf dalmatina rana cf iberica pelophylax ridibunda sp blanus cinereus lacerta s l small sized indeterminate lacertids anguis fragilis natrix natrix natrix maura coronella austriaca coronella cf girondica rhinechis scalaris vipera cf aspis and vipera cf latasti these ectotherm vertebrates show variations in their taxonomic diversity throughout the sequence although they do not differ specifically from the extant herpetofauna of the iberian peninsula they do so in the composition of their taxonomic assemblage when the squamates and amphibians of tds are grouped by habitat categories the habitat weightings method and studied in terms of their vertical evolution throughout the sequence it is possible to follow environmental changes across the early middle pleistocene transition results from the squamate and amphibian studies indicate that the landscape had open habitats in the vicinity of the atapuerca caves throughout the sequence with wet points in the surrounding area open dry microhabitats were more developed during warm periods whereas during cold periods the environment was slightly more humid and wooded these results are compared with studies in small mammals pollen analysis and geomorphology giving a scenario for the palaeoclimatic and palaeoenvironmental changes that occurred during the early to middle pleistocene boundary in atapuerca and hence a scenario for the hominins that once lived in the sierra de atapuerca

feature based image processing methods applied to bathymetric measurements from airborne remote sensing in fluvial environments bathymetric maps produced from remotely sensed imagery are increasingly common however when this method is applied to fluvial environments changing scenes and illumination variations severely hinder the application of well established empirical calibration methods used to obtain predictive depth colour relationships in this paper illumination variations are corrected with feature based image processing which is used to identify areas in an image with a near zero water depth this information can then be included in the depth colour calibration process which results in an improved prediction quality the end product is an automated bathymetric mapping method capable of a 4 m2 spatial resolution with a precision of 15 cm which allows for a more widespread application of bathymetric mapping copyright 2006 john wiley sons ltd

contrasting impacts of dansgaard oeschger events over a western european latitudinal transect modulated by orbital parameters abstract terrestrial and marine proxies pollen planktic and benthic foraminiferal oxygen isotopes alkenone and foraminifer derived sea surface temperatures ssts ice rafted debris from images deep sea cores md95 2042 and su81 18 37 n 10 w md99 2331 and md03 2697 42 n 9 w and md04 2845 45 n 5 w show that western european and offshore environments were strongly affected by dansgaard oeschger d o and heinrich h events we concentrate here on latitudinal variability in the forest cover extent and composition of western europe during the succession of d o events showing new pollen records for core md04 2845 and for marine isotopic stages mis 3 and 4 of core md99 2331 in general cold ssts characteristic of greenland stadials were contemporaneous with the expansion of semi desert or steppic vegetation while greenland interstadials were synchronous with the expansion of forest our data reveal that the amplitude of atlantic and mediterranean forest expansions differs for any given d o warming during the glacial period 74 18 ka in the western mediterranean d o 16 17 and d o 8 and 7 corresponding to minima in precession were associated with strong expansion of forest cover contrasting with weak expansion of forest cover during d o 14 and 12 the opposite pattern is revealed at the atlantic sites further north the strongest greenland warmings are recorded for d o 19 11 and 8 this contrasting latitudinal climatic scenario is compared with other northern hemisphere records revealing similarities between the mediterranean climate and the asian monsoon regime which may relate to a summer atmospheric teleconnection between the two regions comparable to the present day situation parallels between mediterranean climate enhancement and peaks in global methane ch 4 during the last glacial period suggest a significant role of monsoon activity in determining ch 4 emission from wetlands

in situ characterization of grain scale fluvial morphology using terrestrial laser scanning the grain scale morphology of fluvial sediments is an important control on the character and dynamics of river systems however current understanding of its role is limited by the difficulties of robustly quantifying field surface morphology terrestrial laser scanning tls offers a new methodology for the rapid acquisition of high resolution and high precision surface elevation data from in situ sediments to date most environmental and fluvial applications of tls have focused on large scale systems capturing macroscale morphologies application of this new technology at scales necessary to characterize the complexity of grain scale fluvial sediments therefore requires a robust assessment of the quality and sources of errors in close range tls data this paper describes both laboratory and field experiments designed to evaluate close range tls for sedimentological applications and to develop protocols for data acquisition in the former controlled experiments comprising high resolution scans of white grey and black planes and a sphere were used to quantify the magnitude and source of three dimensional 3d point errors resulting from a combination of surface geometry reflectivity effects and inherent instrument precision subsequently a methodology for the collection and processing of grain scale tls data is described through an application to a coarse grained gravel system the river feshie d50 32 to 63 mm this stepwise strategy incorporates averaging repeat scans and filtering scan artefact and non surface points using local 3d search algorithms the sensitivity of the results to the filter parameter values are assessed by careful internal validation of digital terrain models dtms created from the resulting point cloud data the transferability of this methodology is assessed through application to a second river bury green brook dominated by finer gravel d50 18 to 33 mm the factor limiting the resolution of dtms created from this second dataset was found to be the relative sizes of the laser footprint and smallest grains copyright 2009 john wiley sons ltd

small mammal taphonomy of gran dolina atapuerca burgos spain abstract the middle pleistocene sequence at the atapuerca burgos complex of caves is most completely represented at gran dolina eleven stratigraphic units are distinguished seven of which contain abundant small mammal fossils these seven units are analysed in order to determine the taphonomic processes present during the accumulation of their faunal remains the fossil bones are extensively broken both before and after burial fossils from six of the units show evidence of localized pre depositional acid corrosion which occurred both before and after breakage in the upper levels there is also evidence of post depositional corrosion both from alkaline and from acid environments of deposition and in the top level some fossil bones also show evidence of weathering and root marks images of these modifications by means of the scanning electron microscope and their comparison with a large comparative data base of recent modifications from known causal agents permits the identification of the agents responsible for many of the modifications and consequently the reconstruction of the sequence of events leading to the accumulation and preservation of the fossil assemblages predators are implicated for some of the breakage and all of the pre depositional corrosion which is the result of digestion in the predators stomachs in all cases the category of predator can be identified and at three stratigraphic levels the actual species can be identified with moderate degrees of reliability post depositional corrosion is linked with observations on local acidity alkalinity of different levels and the incidence of weathering is linked with evidence for roof collapse over parts of the cave taking account of the effects of these processes particularly the selectivity resulting from predator hunting methods allows estimates to be made of the degree of bias in the faunal composition and the palaeoecology thereby indicated

evidence for geographic variation in the diets of late pleistocene and early holocene bison in north america and differences from the diets of recent bison abstract during the late pleistocene and early holocene bison was widely dispersed across north america and occupied most regions not covered by ice sheets a dietary study on bison paleopopulations from alaska new mexico florida and texas was performed using two methods that relate dental wear patterns to diet mesowear analysis and microwear analysis these data were compared to a mixed sample of extant bison from the north american central plains extant wood bison from alberta canada and a variety of other modern ungulates mesowear relates macroscopic molar facet shape to levels of dietary abrasion the mesowear signature observed on fossil bison differs significantly from the hyper abrasive grazing diet of extant bison tooth microwear examines wear on the surface of enamel at a microscopic scale the microwear signal of fossil samples resembles to modern bison but the fossil samples show a greater diversity of features suggesting that fossil bison populations regularly consumed food items that are texturally inconsistent with the short grass diet typical of modern plains bison mesowear and microwear signals of fossil bison samples most closely resemble a variety of typical mixed feeding ungulates all with diets that are substantially less abrasive than what is typical for modern plains bison furthermore statistical tests suggest significant differences between the microwear signatures of the fossil samples thus revealing geographic variability in pleistocene bison diets this study reveals that fossils are of value in developing an understanding of the dietary breadth and ecological versatility of species that in recent times are rare endangered and occupy only a small remnant of their former ranges

virtual velocity of tracers in a gravel bed river using size based competence duration virtual velocity vi of river gravels is commonly used to determine sediment transport rates and gravel dispersion dynamics virtual velocity is calculated from tracer gravel step length data as the distance travelled divided by the duration of competence however no allowance is usually made for differences in competence duration according to grain size in this investigation vi of gravel tracer clasts for the river rede northumberland uk is calculated using a method that takes into consideration an approximation of size based competence duration although scaled transport distance data compared favourably to past studies it was the comparatively smaller clasts that tended to have lower vi in comparison to coarser clasts because of their longer competence duration contrasting with previously published research the key findings of the study serve as proof of concept and should be adopted in future studies that focus upon vi estimation

abrupt climatic changes during the last glaciation based on pollen analysis of the abric romani catalonia spain the abric romani continental pollen record provides evidence of abrupt climate variations during the last glaciation the pollen record reveals a pattern of high frequency variations similar to that in ice cores as shown by oxygen isotopes or dust content analyses of 14 travertine samples yield coherent u series ages in correct stratigraphic order ranging from 40 000 to 70 000 yr according to changes in the composition and structure of the vegetation five paleoclimatic phases have been differentiated the oldest ranging from 70 200 to 65 500 yr ago records thermophilous taxa which correspond to the last warm events of isotopic stage 5 the next phase from 65 500 to 56 800 yr records a cold humid climate that correlates with isotope stage 4 during the third phase from 56 800 to 49 500 yr relatively warm and cold events alternate the fourth phase from 49 500 to 46 200 yr records a cold dry climate the fifth phase ranging from 46 200 to 40 800 yr records a milder phase that is similar in appearance to the beginning of the holocene