a new approach to the relief of great britain ii a classification of rocks based on relative resistance to denudation abstract we have assembled a digital database for great britain containing square by square data for the 1 km squares of the national grid on altitude and geology age and lithology as well as other variables it is used here to classify the 71 most common rocks of great britain i e all outcrops over 500 km2 in terms of the degree to which they form high ground the empirical classification utilised a large number of measures eventually 19 to allow for the varying location and spatial pattern coastal vs inland large continuous outcrops vs scattered patches of these outcrops and several different combinations of variables produced very similar sequences when the rocks were arranged in rank order a six fold classification provides a basis for further work which will seek to remove the influence of varying resistance to denudation from the pattern of relief for rocks of similar age rank order is determined by lithology but for all rocks age is a stronger influence than lithology it is shown that variations in the resistance of rocks to erosion account for a large part of the local relative relief of britain the pattern of mean altitude predicted from river distance values using regressions for each rock resistance class simulates remarkably closely the overall pattern of british relief

hydraulic geometry river sediment and the definition of bedrock channels a growing literature deals with bedrock channels erosion processes within them and their role in landscape evolution formal definitions currently in use classify channels as bedrock when alluvial cover is discontinuous or thin this is equated with a physical property of the flow using up to date erosion laws and descriptions of channel dynamics we show that existing definitions are difficult to apply and may lead to conflicting classifications we propose the definition a bedrock channel cannot substantially widen lower or shift its bed without eroding bedrock applied to channels in taiwan this leads to a different classification than previous definitions by analysing at a station hydraulic geometry of these channels we show that the classification exposes different controls of sediment effects on dynamics of channels classified as alluvial and bedrock

river profile controls on channel morphology debris flow disturbance and the spatial extent of salmonids in steep mountain streams received 29 december 2011 revised 5 september 2012 accepted 17 september 2012 published 27 october 2012 1 in the geologically and topographically diverse mountain ranges of the pacific northwest a broad scale means of prioritizing salmonid habitat conservation areas based on geomorphic process domains is examined we propose that steepness and concavity indices derived from the relation between drainage area and channel slope provide a means of identifying basins that express different reach scale morphologies fish habitat capacity and risk of episodic disturbance strongly concave river profiles that develop in mountainous terrain indicate that almost all of the relief in the drainage network occurs in headwater streams in these basins a large proportion of the channel network has low gradient morphologies which provide favorable habitat for many salmonid species the severity of pulse disturbances is also reduced because low gradient main stem channels inhibit debris flow conveyance and in these networks the distribution of fish can expand into tributaries allowing for a spatial spreading of risk in contrast rivers with poorly concave or steeper profiles have a greater abundance of high gradient reaches that limit the distribution of fish to a small portion of the channel network and facilitate debris flow passage the combined influence of a limited spatial distribution of fish and an increased risk of debris flows may cause populations in these basins to be less resilient to pulse disturbances a case example from the klamath mountains an area with broad variation in the steepness and concavity of river profiles was used to develop this approach and aid conservation planning for imperiled populations of anadromous salmonids

coastline uplift in oregon and washington and the nature of cascadia subduction zone tectonics coastline deformation resulting from great shallow thrust earthquakes can provide information concerning the paleoseismicity of a subduction zone and thus information on the nature of potential seismicity the cascadia subduction zone is different from most other subduction zones in that it has been quiescent with respect to great earthquakes for at least the past 200 yr the washington oregon coastline also differs from most other coastlines associated with subduction zones in its lack of uplifted holocene shoreline features and low overall rate of late quaternary uplift 0 2 0 6 mm yr the uplift differences suggest that repeated great earthquakes have not occurred along the cascadia subduction zone at least during the late holocene alternatively if the plate interface has generated earthquakes the differences may be explained by longer recurrence intervals for great earthquakes smaller magnitude earthquakes or a mechanism that does not result in uplift of the coastline where expected

distribution of bedrock and alluvial channels in forested mountain drainage basins mountain river networks often consist of both bedrock and alluvial channels1 5 the spatial distribution of which controls several fundamental geomorphological and ecological processes6 7 the nature of river channels can influence the rates of river incision and landscape evolution1 2 as well as the stream habitat characteristics affecting species abundance and aquatic ecosystem structure8 11 studies of the factors controlling the distribution of bedrock and alluvial channels have hitherto been limited to anthropogenic badlands12 here we investigate the distribution of channel types in forested mountain drainage basins and show that the occurrence of bedrock and alluvial channels can be described by a threshold model relating local sediment transport capacity to sediment supply in addition we find that valley spanning log jams create alluvial channels hospitable to aquatic life in what would otherwise be bedrock reaches the formation of such jams depends critically on the stabilizing presence of logs derived from the largest trees in the riverside forests suggesting that management strategies that allow harvesting of such trees can have a devastating influence on alluvial habitats in mountain drainage basins

glacially induced organization of channel reach morphology in mountain streams 1 we examine the spatial distribution of channel reach morphologies in formerly glaciated mountain drainage basins of coastal british columbia canada using field and geographic information systems derived data we show that the local channel slope and the degree of colluvial alluvial coupling imposed by the glacial valley morphology dictate the spatial organization of channel types in particular the complex glacially induced channel long profile produces characteristic sequences of channel reaches that depart from the downstream succession colluvial boulder cascade step pool rapids riffle pool distinctive of simple unglaciated mountain streams typically the presence of one hanging valley in the river long profile produces and separates two full successions of channel types a headmost one characterized by an ephemeral seasonal hydrologic regime and a downstream one where water runoff is perennial we document that channel types are well separated in plots of slope versus shear stress area versus shear stress and slope versus relative roughness in agreement with these outcomes multivariate discriminant analyses coupled with principal component analysis of 98 study reaches yield a highly successful channel type classification when slope shear stress and relative roughness are considered success rates depending on whether or not boulder cascade reaches are pooled together with step pools are 88 and 75 respectively previous work in unglaciated settings has suggested that mountain channels have distinct bed morphology states that vary primarily with slope our study reveals that even in formerly glaciated valleys where slope is largely inherited from glacial times these distinct bed states exist and vary mostly with slope adding considerable strength to this empirical knowledge

on the relationship between climate and neandertal fire use during the last glacial in south west france abstract both environmental and cultural factors dictate how when and where hunter gatherers use fire in the landscape as well as how well evidence for any one fire will preserve in the archaeological record variability in the production and preservation of anthropogenic fire traces can potentially skew our perception of fire use in the past with this in mind the research presented in this article weighs in on the debate concerning neandertal fire use and fire making specifically the assertion that neandertals were unable to produce fire for themselves sandgathe et al 2011a 2011b this hypothesis is based on the inferred correlation between climatic deterioration concurrent lowering of lightning ignited fire frequencies and reduced signals for fire use in layers presumably deposited during the lower pleniglacial marine isotope stage 4 at the middle palaeolithic sites of roc de marsal and pech de l aze iv aquitaine basin southwestern france the logic being that if neandertals could produce fire at will fire use signals would remain largely consistent throughout the deposits despite there being limited access to natural fires in the landscape during this colder period this review challenges these assertions at multiple scales by looking at regional lightning and fire regime dynamics comparing the fire signals observed at roc de marsal and pech de l aze iv to those of other sites nearby and around france and exploring the various environmental and cultural factors likely influencing these signals ultimately the data suggests that estimated reductions in lightning frequencies and fire regime during the lower pleniglacial and colder stadial periods in general were not adequate to severely limit neandertal access to natural fire while possible artefactual evidence for neandertal fire making challenges the assumption that they were at all reliant on lightning ignited fire moreover at the nearby neandertal site of combe grenal the majority of the layers exhibiting evidence of fire use have cold climatic signals suggesting the fire use trends observed at roc de marsal and pech de l aze iv are potentially local expressions of changes in regional site use patterns possibly brought on by increased reliance on highly mobile migratory reindeer prey species and reductions in local woodfuel availability during cold periods other factors potentially reducing the archaeological visibility of cold climate fire use are discussed

the hydrology and long term geomorphic significance of a flash flood in the cairngorm mountains scotland abstract on the 4th august 1978 a major flash flood occurred on the allt mor a mountain torrent within the cairngorm massif scotland this paper assesses the flood s immediate geomorphic impact as well as its longer term geomorphic significance in terms of slope and valley floor development the hydrometeorological characteristics of the flood are reconstructed and placed in the context of the catchment s flood hisotory in magnitudefrequency terms the dominant geomorphic processes in this environment are floods which occur several times a century the specific response of the allt mor to such floods varies spatially across the catchment the major impact being recorded in the entrenched and channel reaches also significant are the sequence and inter arrival times of floods of differing magnitudes the high thresholds for channel and slope adjustment and the nature of the coupling between slope and channel systems the results confirm and strengthen the findings reported from other sites in upland britain

scale dependence of lithological control on topography bedrock channel geometry and catchment morphometry in western scotland abstract we propose that a scale dependent topographic signature of erodibility arises due to fluvial and glacial erosion acting on different parts of the landscape at different times for 14 catchments in western scotland we define three levels of substrate erodibility in order of decreasing resistance quartzite rocks nonquartzite rocks and zones of fault related fracture then using digital topographic and planimetric data coupled with field measurements we identify regression based scaling relationships between substrate erodibility and morphometric parameters at two spatial scales catchment scale morphometry shows a weak to variable relationship with substrate metrics overall erodibility can be inferred from catchment steepness indices i e channel steepness index and relief ratio but the existence of multiple exceptions could confound a more general application of this approach nonetheless major valley troughs trace fault zones and nonquartzite rocks leaving much of the higher and stee

pattern of deglaciation of the last late devensian scottish ice sheet evidence from ice marginal deposits in the dee valley northeast scotland the mode of deglaciation of the last scottish ice sheet is assessed from evidence provided by geomorphological mapping and sedimentology ice marginal deposits in the dee valley have a distinctive morphological expression and a characteristically varied sedimentology that strongly resembles those from subpolar glaciers the deposits tend to occur in certain topographic situations which can be accounted for by compression of ice near the margin and formation of an ice cored supraglacial land system a series of recessional stages of the ice front can be mapped demonstrating that active retreat occurred however additional evidence shows there was probably a thin marginal zone of stagnant ice recessional stages are inferred to be stillstands that are considered to be topographically controlled rather than related to climate development of the supraglacial land system during deglaciation suggests that the ice sheet had a polythermal basal regime with a cold based margin this implies that deglaciation took place in northeast scotland while the climate remained cold probably due to a precipitation deficit which agrees well with chronostratigraphic data

the periodic nature of step pool mountain streams rhythmic sequences of steps and pools in steep mountain streams have captured the attention of numerous workers but whether periodicities exist in the occurrence of step pools has not been investigated in a comprehensive way and the implications for such periodicities have not been explored spectral analysis was applied to bed elevation data from streams in the santa monica mountains of southern california to investigate periodicity in the occurrence of step pools results indicate significant step pool periodicities confirmed by independent field measurements that vary from 0 43 channel widths to 2 40 channel widths spectral analysis of channels affected by external influences tends to indicate multiple significant peaks that reflect higher variance in step pool spacing underlying periodicities are nevertheless de tected suggesting that external factors obscure but do not destroy the effects of more general internal mechanisms periodicity in the occurrence of step pools suggests that step pools are bedforms that represent a fundamental mutual adjustment between flow channel morphology and energy expenditure a rhythmic channel thalweg supports the notion that step pools are analogous to meandering in the vertical dimension and implies that because step pool channels are not able to adjust energy expenditure in the plane dimension they instead adjust boundary roughness in the vertical dimension a continuum of rhythmic gravel bedforms that displays the results of such adjustments and that shows how step pools merge into pools and riffles in the stream channel system is discussed and illustrated with empirical data from the santa monica mountains although many differences exist between steep mountain streams and broad alluvial rivers the findings of this study suggest that generalized principles of uniform energy expendi ture may also apply to rhythmic step pool streams these findings are potentially valuable in the management and design of steep channels

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

different mechanisms of magnetisation recorded in experimental fires archaeomagnetic implications abstract we present here the archaeomagnetic and rock magnetic results obtained from the experimental recreation of prehistoric fires on a clayish soil substratum by using a system of thermocouples that allows the control of temperatures and heat penetration with depth the magneto mineralogical transformations as well as the ability to acquire magnetic remanences are studied a detailed set of rock magnetic analyses carried out both on surface and depth with a millimetre scale resolution shows the creation of post burn magnetite over the entire surface of the hearth thus promoting a distinguishable magnetic enhancement on the basis of a detailed control of temperatures interesting differences between areas centre vs periphery were observed and two different mechanisms of magnetisation have been recorded the central area which exceeded 600 c acquired a thermal remanent magnetisation trm and the periphery which was heated up to 300 c recorded a thermo chemical tcrm remanent magnetisation the most noticeable mineralogical changes are focused to the first centimetre of the central area where single domain magnetite has been created the implications of these results for archaeomagnetic and palaeointensity studies as well as their utility for the detection of fire in archaeological sites are discussed

comparative geomorphic analysis of surficial deposits at three central appalachian watersheds implications for controls on sediment transport efficiency abstract factors that control the routing and storage of sediments in the appalachian region are poorly understood this study involves a comparative geomorphic analysis of three watersheds underlain by sandstones and shales of the acadian clastic wedge these areas include the fernow experimental forest tucker county west virginia the north fork basin pocahontas county west virginia and the little river basin augusta county virginia gis based analyses of surficial map units allow first order approximation of sediment storage volumes in valley bottoms estimates of volumes are examined in tandem with morphometric analyses and the distribution of bedrock channels to make inferences regarding controls on sediment transport efficiency in the central appalachians the fernow and north fork areas are characterized by v shaped valleys with mixed reaches of alluvial bedrock channels distributed throughout the drainage network in contrast the little river valley is notably wider and gravelly alluvial fill is abundant comparator watershed parameters for the fernow north fork and little river areas include respectively 1 basin area 15 2 km 2 49 3 km 2 41 5 km 2 2 basin relief 0 586 km 0 533 km 0 828 km 3 drainage density 4 2 km 1 3 3 km 1 4 7 km 1 4 ruggedness 2 5 1 7 3 9 5 shreve magnitude 139 287 380 6 total valley bottom area km 2 0 76 km 2 1 86 km 2 3 09 km 2 7 average hillslope gradients 17 2 18 4 22 1 8 total debris fan surface area 0 113 km 2 0 165 km 2 0 486 km 2 and 9 debris fan frequency 2 0 km 2 1 0 km 2 2 8 km 2 the storage volumes in valley bottoms were estimated using map polygon areas and surface heights above channel grade the little river contains significantly higher sediment volumes in floodplain terrace and fan storage compartments total volumes of the valley bottoms are approximately twice that of the fernow and north fork areas combined unit storage volumes for the fernow north fork and little river are 5 2 10 4 m 3 km 2 5 5 10 4 m 3 km 2 and 1 6 10 5 m 3 km 2 respectively a conceptual model postulates that valley width morphometry and style of delivery from hillslopes are the primary factors controlling the efficiency of sediment transport steep debris flow prone hillslopes at the little river deliver high volumes of gravelly sediment at magnitudes greater than transport capacity of the channel patterns of stream power are complex as low order tributaries are under capacity and high order tributaries over capacity with respect to sediment load aggraded alluvial fill insulates valley floor bedrock from vertical erosion and valley widening dominates expansion of the valley width creates a positive response via increased storage capacity and lower unit stream power conversely the fernow and north fork are characterized by diffusive mass movement on hillslopes with incremental bedload transport to higher order tributaries rates of hillslope delivery are balanced by the rate of channel export mixed alluvial bedrock reaches provide the optimal channel configuration for active incision of the valley floor low expansion of valley width promotes high unit stream power and processes of vertical erosion the model implies that the fernow and north fork have been more effective at sediment transport during the late quaternary given similar climatic and tectonic settings variation in bedrock lithofacies is likely the primary factor modulating the efficiency of sediment transport

evaluating the integrity of palaeoenvironmental and archaeological records in mis 5 to 3 karst sequences from southeastern france abstract the preservation of palaeoenvironmental and archeological records in cave and rock shelter contexts is often called into question for pleistocene sequences records are always fragmentary and the preservation of sediments and archaeological remains is partial and differential according to site history the karst deposits are often frequently described as disturbed due to post depositional processes and phases of erosion over time however taphonomical analyses and some very well preserved evidence attest to the capacity of caves to record data systematic and interdisciplinary fieldwork and studies allow for the reconstruction of some characteristics of neanderthal occupations in their biostratigraphical and geochronological context the geographic area under consideration here is the rhone valley the right bank of the middle rhone valley has yielded more than ten middle palaeolithic sites some of them have been studied recently through interdisciplinary fieldwork providing new data on the end of the middle pleistocene and the beginning of the upper pleistocene for this paper we focus on four sites dated from the end of mis 5 mis 4 and the beginning of mis 3 containing layers with evidence of neanderthal occupations saint marcel abri du maras abri des pecheurs and le figuier all these sites are rock shelters or cave chambers and porches belonging to a karst system the aim of our research program is to provide as much data as possible on neanderthal occupations in their environmental contexts in order to describe subsistence strategies and land use throughout time and potential links with climatic changes in this paper we evaluate the feasibility of assessing the relationship between climatic change and behaviour during the middle palaeolithic by describing the main archaeological material and palaeoenvironmental records of these four sites then in the discussion we conjointly examine the data from each site to assess this key question even though the low resolution of cave and rock shelter records makes it difficult to establish an accurate chronology for human occupations and to provide a detailed description of the environment around the site for each human occupation

earth wind and fire ethnoarchaeological signals of hadza fires we present the preliminary results of an interdisciplinary ethno geoarchaeological project aimed at characterizing sedimentary aspects of recent combustion structures through soil micromorphology to obtain empirical parameters with which to interpret archaeological features micromorphological analyses of five different types of fires made and abandoned by the hadza of tanzania were performed and compared with ethnographic descriptions their anthropogenic nature burning intensity and type of fuel used were identified based on the composition and optical features of the microscopic components of the combustion structure the data provided elements to assess the preservation potential of open air fires and our ability to interpret their function the life history of two of the fires was reconstructed a sleeping fire showed evidence of a pre existing trampled surface and a communal cooking fire showed evidence of the scooping out of ashes for maintenance these findings substantiate the important contribution of ethnoarchaeological research conducted jointly with soil micromorphology in discovering cues of human behavior preserved in the sedimentary record

combustion structures of archaeological level o and mousterian activity areas with use of fire at the abric romani rockshelter ne iberian peninsula abstract the human use of fire generates a cultural sedimentary record that can be used to characterize prehistoric activity areas the aim of this paper is to develop a field guide for recognizing and describing combustion structures the use of fire as suggested by the results of ethnoarchaeological and prehistoric archaeological studies has served as the foundation for the analytical design of the field observations of the combustion structures at the abric romani rockshelter flat and concave combustion structure types have been uncovered in archaeological level o the systematic recording of the sedimentary and dimensional attributes of the combustion structures can be used as empirical evidence with which to characterize the use of fire differences in the use of fire represent a significant finding in the cultural repertoires of neanderthals recognizing and recording the specific organizational patterns of these activity areas such as fire use in sleeping and resting activity areas indicate the definitive emergence of home bases in the spatial record of the living floors of the archaic human groups

channel changes in badlands stripping of the vegetation and soil from a 13 hectare site in virginia underlain by coastal plain sediments created a rapidly evolving badland topography two types of channels developed 1 sand bed alluvial channels were graded to transport the bed material load supplied from slope erosion with available runoff but they also generally eroded their beds slowly and 2 steeper bedrock floored channels incised rapidly in bedrock channels the erosion rate was proportional to the 4 9ths power of drainage area and the 2 3rds power of gradient these exponents are consistent with a model in which the erosion rate is proportional to the bed shear during high flows due to rapid mass wasting and reduced runoff the alluvial channels became as much as 50 steeper during the winter than the summer with an attendant yearly cycle of winter aggradation and summer entrenchment the gradients their seasonal variability and their downstream hydraulic geometry were consistent with the predictions of total load transport formulas for sand beds and high loads the hydraulic geometry of alluvial channels in the virginia badlands were similar to that on the morrison formation in the western united states

reach scale channel geometry of mountain streams abstract the basic patterns and processes of steep channels remain poorly known relative to lower gradient channels in this analysis characteristics of step pool plane bed and pool riffle channels are examined using a data set of 335 channel reaches from the western united states nepal new zealand and panama we analyzed differences among the three channel types with respect to hydraulics channel geometry boundary roughness and bedforms step pool channels have significantly steeper gradients coarser substrate higher values of shear stress and stream power for a given discharge and larger ratios of bedform amplitude wavelength h l pool riffle channels have greater width depth ratios and relative grain submergence r d84 than the other channel types plane bed channels tend to have intermediate values for most variables examined relative form submergence r h is statistically similar for step pool and pool riffle channels despite the lesser relative grain submergence and greater bedform amplitude of step pool channels mean values of darcy weisbach friction factor do not change in response to changes in relative grain submergence these patterns suggest that adjustments along mountain streams effectively maximize resistance to flow and minimize downstream variability in resistance among the different channel types

influence of coarse lag formation on the mechanics of sediment pulse dispersion in a mountain stream squire creek north cascades washington united states 1 mountain channels closely coupled to landslide prone hillslopes often exhibit bed surface grain sizes coarser than transportable by annual high flows coarse particles within poorly sorted sediment delivered to channels by mass wasting processes may not be readily transported as bed load and can consequently form lag deposits that influence the morphology hydraulic roughness and sediment storage within mountain channel networks a tracer study and comparison of supply and bed grain size distributions from a valley spanning landslide in the north cascades of washington state were used to derive relations between shear stress and the probability of particle entrainment and erosion from the sediment pulse rapid bed surface armoring formed a relatively immobile lag deposit within 2 years covering of 20 of the bed by lag boulders with 5 probability of entrainment was sufficient to retard vertical incision and force considerable channel widening during a flood with an 8 to 152 year recurrence discharge on locally gauged streams our results imply that numerical models of sediment pulse evolution that do not explicitly incorporate the influence of lag formation may substantially overestimate long term dispersion rates the grain size distribution and lithology of a sediment input relative to the flow competence of the receiving channel are important factors influencing the rates and mechanisms of sediment pulse dispersion and the sediment capacitance provided by coarse grained sediment pulses in mountain drainage basins

a relict landscape in the centre of fennoscandian glaciation geomorphological evidence of minimal quaternary glacial erosion abstract the parkajoki area in northeastern sweden is situated near the central area of fennoscandian glaciation despite its location the area is dominated by landforms induced by subaerial weathering and erosion processes such as well developed tors and associated saprolites boulder fields and boulder depressions the glacial geomorphology is dominated by lateral and proglacial meltwater channels subglacial imprints indicative of thawed bed conditions and reshaping by glacier sliding e g fluting drumlins striae are lacking hence most of the landscape still exhibits a preglacial appearance because of its location near the central area of glaciation we attribute preservation to frozen bed conditions of overriding ice sheets the widespread distribution of well developed tors and boulder fields and the degree of chemical weathering of the bedrock indicate that the area has been protected from glacial erosion during all glacial cycles since ice sheet initiation in the late cenozoic unlike most other areas with tors in glaciated regions the parkajoki area is uniquely situated in the lowlands at 150 400 m a s l moreover this relict landscape is surrounded by glacial landscapes including drumlins ribbed moraine and eskers of varying age and at similar elevation hence topographical reasons for this area being persistently cold based cannot be invoked by inference we conclude that strain heat release never managed to cancel the initial subglacial permafrost conditions we attribute this to divergent ice flow towards the convex outline of the ice sheet margin during deglaciations and to the relative roughness of the area compared to its surroundings the implication is that to explain preservation throughout the quaternary all large scale glaciations must have had a similar evolution concerning ice sheet configuration and internal dynamics as the last glaciation for which good constraints on evolution and outline are available

does decreasing paraglacial sediment supply slow knickpoint retreat in four rivers in western scotland for which there is a well constrained record of relative base level fall the rate of postglacial bedrock erosion is quantifi ed by measuring the concentration of in situ cosmogenic 10be on strath terraces downstream of headward retreating knickpoints along channel gradients in 10be exposure age show two distinct trends upstream younging and constant age which we interpret as diagnostic of knickpoint retreat and diffusive transport limited incision respectively we show that bedrock channel incision and regional formation of strath terraces began shortly after deglaciation ca 11 5 ka and that knickpoint retreat rates peaked in the early to mid holocene erosion rates have since decreased by two orders of magnitude converging in the late holocene to low rates independent of stream power per unit channel area we infer this regional slowing in postglacial knickpoint retreat to be the result of the depletion of paraglacial sediment supply over the holocene leading to a defi ciency in tools for bedrock erosion our results imply that episodes of major fl uvial erosion may be in tune with glacial cycles and that sediment depletion following glacial interglacial transitions may be an important cause of bedrock erosion rate variations in rivers draining glaciated landscapes

channel morphology and bed load yield in fluvial formerly glaciated headwater streams of the columbia mountains canada article i nfo this study examines channel reach morphology and bedload yield dynamics in relation to landscape structure and snowmelt hydrology in headwater streams of the columbia mountains canada data collection relies on field surveys and geographic information systems analysis in conjunction with a nested monitoring network of water discharge and bedload transfer the landscape is characterized by subdued formerly glaciated upland topography in which the geomorphic significance of landslides and debris flows is negligible and fluvial processes prevail while the spatial organization of channel morphology is chiefly controlled by glacially imposed local slope in conjunction with wood abundance and availability of glacigenic deposits downstream patterns of the coarse grain size fraction bankfull width bankfull depth and stream power are all insensitive to systematic changes of local slope along the typically stepped long profiles this is an indication that these alluvial systems have adjusted to the contemporary snowmelt driven water and sediment transport regimes and as such are able to compensate for the glacially imposed boundary conditions bedload specific yield increases with drainage area suggesting that fluvial re mobilization of glacial and paraglacial deposits dominate the sedimentary dynamics of basins as small as 2 km 2 stepwise multiple regression analysis shows that annual rates of sediment transfer are mainly controlled by the number of peak events over threshold discharge during such events repeated destabilization of channel bed armoring and re mobilization of sedi ment temporarily stored behind lwd structures can generate bedload transport across the entire snowmelt season in particular channel morphology controls the variability of bedload response to hydrologic forcing in the present case studies we show that the observed spatial variability in annual bedload yield appears to be modulated by inter basin differences in morphometric characteristics among which slope aspect plays a critical part

assessment of downstream trends in channel gradient total and specific stream power a gis approach geographic information systems gis analyses of digital elevation models dems coupled with catchment area based discharge estimation techniques provide a relatively simple means of modelling contiguous downstream trends in channel gradient total stream power and in riverscapes conducive to regime analysis also specific stream power for a small high relief coastal catchment in se australia good agreement was obtained between channel gradients derived from a 25 m cell size dem and field survey equivalents over distances of several kilometres indicating that channel gradients derived from dems can have a reasonable degree of absolute as well as relative accuracy over multi kilometre reach scales assessment of downstream rates of change in channel gradient and specific stream power across four river systems suggests that some of the river reaches most responsive to high magnitude floods occur in zones where these variables rapidly decrease downstream modelling of downstream trends in channel gradient total and specific stream power from catchment wide dems has potential to provide a framework with which to investigate conceptual and empirical models between channel gradient stream power and the form and dynamics of river systems

insights on neanderthal fire use at kebara cave israel through high resolution study of prehistoric combustion features evidence from phytoliths and thin sections abstract kebara cave mount carmel israel exhibits extensive use of fire by neanderthals in the middle paleolithic phytoliths are abundant indicating that plants were common in the cave in addition micromorphological analyses of archaeological deposits furnish precise contextual background to the phytolith analysis and provide constraints on how phytolith and other micro remains can be interpreted phytolith data are coupled with micromorphological observations from undisturbed combustion features from kebara from the middle and upper paleolithic in order to maximize accuracy of interpretations different factors have been taken into account such as phytolith preservation the discrimination between anthropogenic and non anthropogenic plant deposition and the variability of plant uses the results show that dissolution is an important factor in certain areas of the cave mostly because of high ph conditions whereas in other areas of the cave secondary silica has affected the original cell morphology of the phytoliths in general wood was the main fuel used for the fires and the presence of other plant remains such as grasses or dicotyledonous leaves is in certain areas mostly related to contamination attached to the bark of the trees whereas in others it might be associated with other reasons such as tinder to help start the fires seed coats of plants from the boraginaceae family which grow around the cave entrance are abundant in certain levels and mostly related to their fall out at the cave mouth

characterisation of channel reach morphology and associated controls in deglaciated montane catchments in the cairngorms scotland abstract the morphological characteristics of 50 channel reaches were surveyed in montane streams in the river dee catchment to test an existing process based typology included in the analysis were common reach types documented elsewhere e g cascade step pool and pool riffle in addition mixed bedrock alluvial alluvial transitional and wandering reach types that have received less attention were also investigated given their common occurrence in the study area differences in geometry substrate character and flow resistance are evident particularly between principal types although differentiation of mixed bedrock alluvial and transitional types was less marked wandering reaches occupy a slope range that overlaps with other types but are distinguished by a grain size distribution that is intermediate between plane bed and pool riffle reaches and a high channel width for a given discharge the quantitative differences observed support visually based differentiation of channel types based on their bedform assemblages morphological characteristics were also related to a suite of variables to determine first order controls on reach type channel cross sectional geometry is strongly correlated with discharge whilst grain size and indices of flow resistance are strongly correlated with slope and boundary shear stress in particular in addition the paraglacially conditioned geomorphic setting constitutes an important local control the morphological properties of common channel types bedrock cascade step pool plane bed and pool riffle broadly correspond with those observed elsewhere although channel slope ranges were markedly lower we hypothesise that channel types exist in a lower domain of slope because of a lower sediment supply rate that reflects the distinctive landscape evolution of the cairngorms area

antecedent controls on river character and behaviour in partly confined valley settings upper hunter catchment nsw australia abstract a partly confined river is one along which the contemporary channel abuts the valley margin along 10 90 of its length they occur along sections of longitudinal profiles that are transitional from fully bedrock confined to fully alluvial rivers at this position in the landscape there is sufficient accommodation space for discontinuous floodplain pockets to form segregation of the river s load and dissipation of flow energy result in sediments being stored outside the channel bedrock and planform controlled variants of these rivers and associated floodplains are differentiated terraces fans and piedmont zones act as secondary confining features on channel planform and floodplain formation in these valleys the influence of these antecedent features on contemporary river character and behaviour in partly confined valleys of the upper hunter catchment new south wales australia is appraised the balance of formative and reworking processes and associated capacity for geomorphic adjustment is influenced by the site specific configuration of antecedent controls at any floodplain pocket downstream patterns of these river types are analysed along all major tributaries of the upper hunter catchment to highlight the extent of antecedent control on contemporary river forms and processes in this landscape setting

linking channel geomorphic characteristics to spatial patterns of spawning activity and discharge use by atlantic salmon salmo salar l this paper relates spatial patterns of spawning by atlantic salmon salmo salar l to channel geomorphic and hydrologic characteristics in two upland scottish streams the full length of each stream was surveyed and classified using a process based typology the precise locations of 845 spawning events were mapped over 3 successive years these locations were classified by reach type and a location specific discharge was calculated for each spawning event fish used response reach types pool riffle and transitional pool riffle plane bed preferentially avoiding transport reach types plane bed and step pool the spatial distribution of reach types contrasted markedly between the streams and as a consequence the distribution of spawning activity differed in each stream fish utilised relatively high flows for spawning with almost all spawning occurring at discharges greater than location specific median annual flows while optimum discharges defined as those where values of use most exceeded values of availability were as high as two to three times greater than reach median flows in each stream spawning occurred over a greater flow range in response than transport reach types primarily as a result of higher maximum utilised flows in the former because the channel classification procedure is process based and therefore transferable to other geographic areas the present study suggests that reach type may be used to predict the spatial distribution of atlantic salmon spawning activity within a catchment since the data indicate that discharge use by spawning fish is reach type specific the results also suggest that channel morphology should be considered when identifying environmental flow requirements

microstratigraphy and diagenesis at the upper pleistocene site of esquilleu cave cantabria spain ftir and soil micromorphology were applied to selected sediments from the archaeological deposit of esquilleu cave a late middle palaeolithic site in cantabria spain the main goal was to assess the integrity of the archaeological record before continuing with further excavation and research at the site field observations and previous sedimentological studies point to diagenetic alteration of part of the deposit but the extent and precise nature of such processes had not been established the results show that the upper layers are composed of fresh elements and have not undergone diagenetic transformations although their components have been physically disturbed by cryoturbation the rest of the deposit is well preserved with mild phosphatization due to partial dissolution of bone and calcitic ash contained in the sediment and compression from trampling further excavation is necessary to have a more complete picture of the taphonomic processes taking place at the site

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

last glacial fire regime variability in western france inferred from microcharcoal preserved in core md04 2845 bay of biscay abstract high resolution multiproxy analysis microcharcoal pollen organic carbon neogloboquadrina pachyderma s ice rafted debris of the deep sea record md04 2845 bay of biscay provides new insights for understanding mechanisms of fire regime variability of the last glacial period in western france fire regime of western france closely follows dansgaard oeschger climatic variability and presents the same pattern than that of southwestern iberia namely low fire regime associated with open vegetation during stadials including heinrich events and high fire regime associated with open forest during interstadials this supports a regional climatic control on fire regime for western europe through fuel availability for the last glacial period additionally each of heinrich events 6 5 and 4 is characterised by three episodes of fire regime with a high regime bracketed by lower fire regime episodes related to vegetational succession and complex environmental condition changes

reach scale channel geometry of a mountain river mountain rivers can be subject to strong constraints imposed by changes in gradient and grain size supplied by processes such as glaciation and rockfall nonetheless adjustments in the channel geometry and hydraulics of mountain rivers at the reach scale can produce discernible patterns analogous to those in fully alluvial rivers mountain rivers can differ in that imposed reach scale gradient is an especially important control on reach scale channel characteristics as indicated by examination of north st vrain creek in colorado north st vrain creek drains 250 km2 of the rocky mountains we used 25 study reaches within the basin to examine controls on reach scale channel geometry variables measured included channel geometry large woody debris grain size and mean velocity drainage area at the study reaches ranged from 2 2 to 245 km2 and gradient from 0 013 to 0 147 m m 1 we examined correlations among 1 potential reach scale response variables describing channel bankfull dimension and shape hydraulics bedform wavelength and amplitude grain size ow resistance standard deviation of hydraulic radius and volume of large woody debris and 2 potential control variables that change progressively downstream drainage area discharge or that are likely to re ect a reach speci c control bed gradient we tested the hypothesis that response variables correlate most strongly with local bed gradient because of the segmented nature of mountain channels results from simple linear regression analyses indicate that most response variables correlate best with gradient although channel width and width depth ratio correlate best with discharge multiple regression analyses using mallow s cp selection criterion and log transformation of all variables produced similar results in that most response variables correlate strongly with gradient these results suggest that the hypothesis is partially supported channel bed gradient is likely to be a good predictor for many reach scale response variables along mountain rivers but discharge is also an important predictor for some response variables copyright 2004 john wiley sons ltd

channel reach morphology in mountain drainage basins a classification of channel reach morphology in mountain drainage basins synthesizes stream morphologies into seven distinct reach types colluvial bedrock and five alluvial channel types cascade step pool plane bed pool rime and dune ripple coupling reach level channel processes with the spatial arrangement of reach morphologies their links to hillslope processes and external forcing by confinement ripar ian vegetation and woody debris defines a process based framework within which to assess channel condition and response potential in mountain drainage basins field investigations demonstrate character istic slope grain size shear stress and roughness ranges for different reach types observations consistent with our hypothesis that alluvial channel morphologies reflect specific roughness configurations ad justed to the relative magnitudes of sediment supply and transport ca pacity steep alluvial channels cascade and step pool have high ratios of transport capacity to sediment supply and are resilient to changes in discharge and sediment supply whereas low gradient alluvial channels pool rime and dune ripple have lower transport capacity to supply ra tios and thus exhibit significant and prolonged response to changes in sediment supply and discharge general differences in the ratio of transport capacity to supply between channel types allow aggregation of reaches into source transport and response segments the spatial distribution of which provides a watershed level conceptual model linking reach morphology and channel processes these two scales of channel network classification define a framework within which to in vestigate spatial and temporal patterns of channel response in moun tain drainage basins

a morpho statistical classification of mountain stream reach types in southeastern australia abstract the concepts of sediment transport capacity q c and sediment supply q s have shown promise in broadly differentiating mountain streams the important role of lithology in determining reach characteristics is also noted but as yet not fully included in existing process domain frameworks this study uses topographic and grain size surveys undertaken over 42 channel reaches with slopes between 0 01 and 0 20 m m to describe mountain stream morphology in southeastern australia reaches with two different lithologies are surveyed to specifically address the role of lithology in resultant channel morphology spatial autocorrelation analysis based on moran s i is used to detect the frequency and occurrence of in stream features such as bars and pools these data are combined with the grain size data to describe eight dominant reach morphologies most channel morphologies display broad characteristics similar to previous accounts of mountain streams although a number of intermediate morphologies affecting subtle variations in form and process where evident there was no significant longitudinal arrangement of the observed morphologies particularly with respect to catchment area and slope this is related to the strongly segmented longitudinal profiles characteristic of these streams where increasing catchment area does not result in a commensurate decrease in slope five of the eight channel morphologies identified are lithology dependent with respect to grain size and shape regime diagrams applied to quantify the physical controls on the different reach morphologies identified different q c q s domains for most morphologies however some lithology dependent morphologies could not be differentiated supporting the need to incorporate the effects of dominant grain shape or sphericity in assigning dimensionless critical shear stress values in determining q s overall the differences in mountain stream reach morphologies described in this study reflect the characteristic segmentation of the longitudinal profiles of these streams and contrasts in the supply and breakdown of parent material

knickpoint recession rate and catchment area the case of uplifted rivers in eastern scotland knickpoint behaviour is a key to understanding both the landscape responses to a base level fall and the corresponding sediment fluxes from rejuvenated catchments and must be accommodated in numerical models of large scale landscape evolution knickpoint recession in streams draining to glacio isostatically uplifted shorelines in eastern scotland is used to assess whether knickpoint recession is a function of discharge here represented by its surrogate catchment area knickpoints are identified using ds plots log slope versus log downstream distance a statistically significant power relationship is found between distance of headward recession and catchment area such knickpoint recession data may be used to determine the values of m and n in the stream power law e kamsn the data have too many uncertainties however to judge definitively whether they are consistent with m n 1 bedrock erosion is proportional to stream power and kps should be maintained and propagate headwards or m 0 3 n 0 7 bedrock incision is proportional to shear stress and kps do not propagate but degrade in place by rotation or replacement nonetheless the e scotland m and n values point to the dominance of catchment area discharge in determining knickpoint retreat rates and are therefore more consistent with the stream power law formulation in which bedrock erosion is proportional to stream power copyright 2005 john wiley sons ltd

the contribution of lithic production systems to the interpretation of mousterian industrial variability in south western france the example of combe grenal dordogne france disentangling the relative contribution of the various factors underlying middle palaeolithic industrial variability remains one of the foremost problems for researchers interested in neandertal technological and behavioural adaptations the site of combe grenal dordogne has figured prominently in these discussions given its long stratigraphic sequence and rich archaeological record that extends from mis 6 to mis 3 and contains all of f bordes mousterian facies departing from a strict typological approach we provide a revised vision of the site s sequence focused on individualising lithic production systems we investigate to what extent typologically different industries beyond their separation imposed by the very idea of discrete mousterian facies nevertheless portray comparable production systems by eschewing a chronology of the traditional mousterian facies our technological approach to the combe grenal assemblages succeeded in identifying a clear stratigraphic succession where strictly typological approaches had previously failed moreover comparison with other regional sequences shows the succession of mousterian technological systems identified at combe grenal not to be an exception in south western france we propose a revised chronology for the site s sequence based on a correlation of changes in the structure of regional faunal communities with independent palaeo environmental data finally comparing technological data with raw material provisioning strategies and elements of faunal exploitation such as prey availability provides insights concerning the interpretation of mousterian variability and the investigation of changing patterns of neandertal landscape use

evidence for the repeated use of a central hearth at middle pleistocene 300 ky ago qesem cave israel abstract a major debate in prehistory revolves around the time and place of the earliest habitual use of fire and the hominin species responsible for it here we present a newly discovered hearth at qesem cave israel that was repeatedly used and was the focus of hearth centered human activities as early as three hundred thousand years ago the hearth identified based on mineralogical and microscopic criteria contains two superimposed use cycles each composed of shorter episodes possibly the earliest superimposed hearth securely identified to date the hearth covers ca 4 m 2 in area making it a uniquely large hearth in comparison to any contemporaneous hearth identified thus far possibly indicating it has been used by a relatively large group of people in addition the hearth is located in the center of the cave and is associated with butchered animal remains and a dense flint assemblage the flint assemblage indicates spatially differentiated meat cutting and hide working activity areas the central location of the hearth within the cave and the activities associated with it may reflect an embedded perception of space organization of the qesem cave inhabitants since fire was habitually used throughout the 420 200 ky sequence of qesem cave where preservation conditions are alike throughout we suggest that this unique hearth may reflect a development in nature and most probably in the intensity of fire use in qesem cave from ca 300 ka ago onwards

a catchment scale model of mountain stream channel morphologies in southeast australia the position of mountain streams high in the channel network and their proportional dominance mean that channel modifications and adjustments within these systems will have important implications for downstream processes and linkages this study develops an analysis framework for examining the catchment scale distribution of reach morphologies and the relationship among reach type catchment lithology and flow competence in southeast australian mountain streams the analysis framework is applied to three catchments which have contrasting proportions of the two dominant lithologies of the region devonian granites and ordovician metasediments the model successfully delineated 68 of reach types and the resultant spatial maps allowed the effects of stream network position and catchment specific controls on channel morphology to be evaluated maximum lengths of the majority of reach morphology types were in second order streams and the maximum number of morphology types six was present in third order streams with dramatic reductions in reach type variability as the network expands the position of catchment lithology within the channel network structure was recognized as more important than the aerial extent of a particular lithology on the distribution and abundance of reach morphologies the model provides an important tool in the management of channel networks for the protection or restoration of ecological diversity by identifying river segments and tributaries with high morphological diversity

flood magnitude frequency and lithologic control on bedrock river incision in post orogenic terrain abstract mixed bedrock alluvial rivers bedrock channels lined with a discontinuous alluvial cover are key agents in the shaping of mountain belt topography by bedrock fluvial incision whereas much research focuses upon the erosional dynamics of such rivers in the context of rapidly uplifting orogenic landscapes the present study investigates river incision processes in a post orogenic cratonic landscape undergoing extremely low rates of incision the mobility of coarse bed materials up to 2 m diameter during late holocene palaeofloods of known magnitude and age is evaluated using step backwater flow modelling in conjunction with two selective entrainment equations a new approach for quantifying the formative flood magnitude in mixed bedrock alluvial rivers is described here based on the mobility of a key coarse fraction of the bed materials in this case the d84 size fraction a 350 m3 s formative flood fully mobilises the coarse alluvial cover with b 200 300 n m2 across the upper and lower gorge riffles peaking over 500 n m2 in the knickzone such floods have an annual exceedance probability much less than 10 2 and possibly as low as 10 3 the role of coarse alluvial cover in the gorge is discussed at two scales 1 modulation of bedrock exposure at the reach scale coupled with adjustment to channel width and gradient accommodates uniform incision across rocks of different erodibility in steady state fashion and 2 at the sub reach scale where coarse boulder deposits corresponding to b minima cap topographic convexities in the rock floor thereby restricting bedrock incision to rare large floods while recent studies postulate that decreasing uplift rates during post orogenic topographic decay might drive a shift to transport limited conditions in river networks observations here and elsewhere in post orogenic settings suggest to the contrary that extremely low erosion rates are maintained with substantial bedrock channel exposure although bed material mobility is known to be rate limiting for bedrock river incision under low sediment flux conditions exactly how a partial alluvial cover might be spatially distributed to either optimise or impede the rate of bedrock incision is open to speculation observations here suggest that the small volume of very stable bed materials lining sandy creek gorge is distributed so as to minimise the rate of bedrock fluvial incision over time

human actions performed on simple combustion structures an experimental approach to the study of middle palaeolithic fire we present preliminary results from the first phase of experiments from the neanderthal fire technology project aimed at understanding middle palaeolithic combustion structures our field observations and micromorphological data address the sedimentary expression of various anthropogenic actions trampling ash sweeping and dumping relighting and cooking performed on simple flat combustion structures made with pinus nigra fuel on dry and slightly vegetated calcareous sandy substrates we observed a characteristic pattern in microstructure and basic composition irrespective of the number and kind of anthropogenic actions performed trampling yielded previously documented diagnostic micromorphological features more pronounced in cases of ash sweeping and dumping relighting of fires was only identified in cases with deposits between combustion events only rare microscopic calcined bone fragments and fat derived char were identified in fires involving cooking or tossing of meat in the fire these data suggest that anthropogenic actions on simple combustion structures are highly undetectable sweeping has a stronger effect than trampling on the substrate of the combustion structure stacked hearths might involve significant amounts of time or deposits between combustion events and alternative techniques must be sought to identify cooking in fires

predicting deposition of debris flows in mountain channels an empirical model for predicting deposition of coarse textured debris flows in confined mountain channels is developed based on field measurements of 14 debris flows in the pacific northwest u s a the model uses two criteria for deposition channel slope less than 3 5 and tributary junction angle greater than 70 the model is tested by predicting travel distances of 15 debris flows in the oregon coast range and six debris flows in the washington cascades u s a the model is further tested on 44 debris flows in two lithological types in the oregon coast range using aerial photos and topographic maps on these flows only the approximate travel distance is known the model can be used by resource professionals to identify the potential for impacts from debris flows key words debris flow deposition travel erosion

tetrapyrrole pigments in united states humic coals abstract analyses of forty two united states humic coals have revealed a striking divergence between chlorophyll diagenesis in coals when compared to the more widely studied marine sediments shales asphalts and petroleums porphyrins of humic coals have been found to be dominated by the etio series to lack members above c 32 and in lower ranked samples e g sub bituminous b high volatile c to exhibit mass spectral envelopes with unique even carbon number predominances the weighted average mass as well as the carbon number maximum viz mode of these coal porphyrin homologies has been found to decrease as rank increases the generation of porphyrins of the etio series is suggested as occurring both during early coal formation including oxidative scission of the isocyclic ring at the phorbide stage and later during the catagenic alteration of surviving dpep series porphyrins a preliminary study of chlorophyll diagenesis in a south florida peat partially substantiates this suggestion and has further shown that the coal porphyrins can be derived from bacterial as well as higher plant chlorophylls

making riverscapes real abstract the structure and function of rivers have long been characterized either by 1 qualitative models such as the river continuum concept or serial discontinuity concept which paint broad descriptive portraits of how river habitats and communities vary or 2 quantitative models such as downstream hydraulic geometry which rely on a limited number of measurements spread widely throughout a river basin in contrast authors such as fausch et al 2002 and wiens 2002 proposed applying existing quantitative spatially comprehensive ecology and landscape ecology methods to rivers this new framework for river sciences which preserves variability and spatial relationships is called a riverine landscape or a riverscape application of this riverscape concept requires information on the spatial distribution of organism scale habitats throughout entire river systems this article examines the ways in which recent technical and methodological developments can allow us to quantitatively implement and realize the riverscape concept using 3 cm true color aerial photos and 5 m resolution elevation data from the river tromie scotland we apply the newly developed fluvial information system which integrates a suite of cutting edge high resolution remote sensing methods in a spatially explicit framework this new integrated approach allows for the extraction of primary fluvial variables such as width depth particle size and elevation from these first order variables we derive second order geomorphic and hydraulic variables including velocity stream power froude number and shear stress channel slope can be approximated from available topographic data based on these first and second order variables we produce riverscape metrics that begin to explore how geomorphic structures may influence river habitats including connectivity patchiness of habitat and habitat distributions the results show a complex interplay of geomorphic variable and habitat patchiness that is not predicted by existing fluvial theory riverscapes thus challenge the existing understanding of how rivers structure themselves and will force development of new paradigms

downstream coarsening in headwater channels 1 field data from four mountain drainage basins in western washington document systematic downstream coarsening of median bed surface grain size d50 and a subsequent shift to downstream fining at a drainage area of about 10 km2 analyses of network wide patterns of unit stream power derived from both channel surveys and digital elevation models reveal maximum unit stream power that in all four study areas roughly corresponds with both the grain size maxima and an inflection in the drainage area slope relation thought to represent the transition from debris flow dominated channels to fluvially dominated channels our results support the hypothesis that basin wide trends in d50 are hydraulically controlled by systematic variations in unit stream power in addition to lag deposits forced by mass wasting processes the similar relations found in our four study areas suggest that the tendency for downstream coarsening may be ubiquitous in headwater reaches of mountain drainage basins where debris flow processes set the channel gradient

spatial discontinuity and temporal evolution of channel morphology along a mixed bedrock alluvial river upper drome river southeast france contingent responses to external and internal controls abstract the rehabilitation of degraded river channels is often guided by assumptions of continuity yet in response to spatial and temporal variations in controlling conditions rivers typically display discontinuous response in space and time this study examines the development of a 5 km reach of the drome river s e france characterised by alternating alluvial and bedrock zones that are separated by abrupt downstream transitions this reach is representative of the drome river as a whole and other rivers in the european alps where braided channel planforms have been replaced by more complex discontinuous morphologies the primary aims are to understand how this spatial complexity has developed on the drome evaluate how temporal channel changes have been affected by local factors particularly bedrock exposures and by long term catchment scale changes in sediment supply and the flood activity and consider the implications of this discontinuous geomorphology for reach management the development of geomorphological zonation is examined by documenting sequential changes in channel planform between seven periods using aerial photography 1948 2006 and by analysing change in bed elevation from profiles surveyed in 1928 2003 and 2005 between 1948 and 2001 bedrock exposed in the channel bed and along the floodplain margins defined discontinuities in sediment connectivity that were largely responsible for the configuration of channel zones the impact of floods on this system was not proportional to flood magnitude a modest flood in 1978 was an important event that by incision and avulsion at key locations defined a pattern of zonation that persisted until the end of the study in 2006 during the final 5 years of the study alluvial zones that previously responded to large floods by widening underwent narrowing despite the occurrence of a large flood and led to an overall reduction in width variance this resulted from progressive incision beneath and disconnection from formerly active channel areas in response to long term catchment scale reductions in sediment supply and flood frequency in 2006 the pattern of zonation remains distinct disguising this recent change in channel response and underlining the need for long term and sequential perspectives of channel development to fully understand the processes in operation contemporary snapshots of channel form may be misleading understanding interactions between inherent channel complexity and prevailing flow and sediment conditions and how this shapes channel response to individual floods is essential when interpreting future trajectories of channel change and likely response to management intervention

glacial erosion evolution of river long profiles and the organization of process domains in mountain drainage basins of coastal british columbia 1 in glaciated british columbia canada quaternary climate changes are responsible for profound spatial reorganization of earth surface processes these changes have left a landscape characterized by topographic anisotropy associated with a hierarchy of glacial troughs the evolution of glaciated landscapes is examined by analyzing the structure of geomorphic process domains and channel long profiles to identify process domains we use channel surveys and gis analysis to construct slope area transects of the channel network this analysis reveals generalized process form disequilibrium with a mismatch between topographic signatures and currently active geomorphic process domains at the landscape scale of source colluvial channels contributing area 1 km2 the glacial paraglacial signature commonly overrides that produced by contemporary debris flows along the axis of former ice flows relict glacial cirques introduce a hanging fluvial domain at contributing areas as small as 8 10 2 km2 and produce complex channel long profiles similar to those observed for rivers responding to tectonic forcing slope area relations typical of unglaciated equilibrium environments do not apply here the concept of process domains appears to hold however some major glacially forced modifications in the alluvial colluvial transition are observed and the definition of a depositional colluvial subdomain is proposed comparison between field and gis measured slopes reveals that gis associated error is not uniform between process domains and that gis based plots do not successfully discriminate field based process domains the combination of glacial and post glacial fingerprints and the effects of ongoing earth surface processes generate a complex landscape whose glacial signatures may persist until the onset of the next ice age

the legacy of pleistocene glaciation and the organization of lowland alluvial process domains in the puget sound region article i nfo alluvial rivers of the eastern puget lowland a landscape shaped by scour and fill from the cordilleran ice sheet continue to respond to patterns of deposition and scour by the last glacial age ice sheet 18 000 years after deglaciation topography revealed by valley cross sections created from high resolution lidar digital elevation models shows that rivers are aggrading in valleys eroded by subglacial runoff and degrading in valleys incised by rivers post glaciation slope area analysis of river profiles shows that profile concavity varies systematically between river segments in the two valley contexts concavity indices in mountain headwaters 0 3b b0 9 compare to those of many world rivers 0 2b b1 0 but in the lowlands these indices differ between valleys created by subglacial fluvial erosion 5b b45 and post glacially incised river valleys that grade to base levels set by these relict glacial valleys or by post glacial sea levels 1b b7 dramatic differences in river pattern landforms and dynamics occur in valleys having contrasting aggrading vs degrading and incomplete responses to pleistocene glaciation creating discrete valley scale hetero geneities in fluvial process domains along and between rivers these results point to the importance of valley scale organization of alluvial process domains along and between rivers having profiles remaining in disequilibrium from pleistocene glaciation they also point to the potential usefulness of slope area analysis of longitudinal profiles in distinguishing among different river valley process domains in lowland alluvial landscapes

towards improved empirical isobase models of holocene land uplift for mainland scotland uk a new approach to modelling patterns of glacio isostatic land uplift during the holocene in mainland scotland uk is described the approach is based upon altitude measurements at the inner margin or locally highest point of raised estuarine surfaces dated by radiocarbon assay supported by microfossil analyses 2241 altitudes have been analysed by a technique new to studies of former sea levels gaussian trend surface analysis and isobase models for four holocene shorelines the holocene storegga slide tsunami shoreline abandoned rapidly circa 7900 sidereal years bp the main postglacial shoreline abandoned during circa 6400 7700 sidereal years bp the blairdrummond shoreline abandoned during circa 4500 5800 sidereal years bp and a speculative fourth shoreline the wigtown shoreline abandoned during circa 1520 3700 sidereal years bp are shown in a series of maps the implications of the shoreline patterns for glaicio isostasy in the area are discussed it is maintained that the statistical technique used enables broad estimates to be made of nearshore sea surface change

bedload entrainment in low gradient paraglacial coastal rivers of maine u s a implications for habitat restoration abstract the rivers of coastal maine flow through mainstem lakes and long low gradient reaches that break the continuum of bedload transport expected in nonparaglacial landscapes stream erosion of glacial deposits supplies coarse sediment to these systems the land use history includes intensive timber harvest and associated dam construction which may have altered the frequency of substrate mobilizing events these watersheds are vital habitat for the last remaining wild anadromous atlantic salmon in the united states future adjustments in channel morphology and habitat quality via natural stream processes or restoration projects depend on erosion transport and deposition of coarse sediment these factors motivate our study of competence at four sites in the sheepscot and narraguagus watersheds three of the four sites behaved roughly similarly with particle entrainment during intervals that include winter ice and spring flood conditions and relatively minor bed mobilization during moderate floods in the summer and fall with a recurrence interval of 2 3 years the fourth site on the sheepscot river mainstem exhibits more vigorous entrainment of marked particles and more complex three dimensional channel morphology this contrast is partially due to local geomorphic conditions that favor high shear stresses particularly relatively steep gradient but also likely to nourishment of the bedload saltation system by recruitment from an eroding glacial deposit upstream our results suggest that the frequency and magnitude of bedload transport are reach specific depending on factors including local channel geometry upstream sediment supply and transport and formation of anchor ice this presents a challenge for stream practitioners in this region different reaches may require contrasting management strategies our results underscore the importance of understanding channel processes at a given site and assessing conditions upstream and downstream as a prerequisite for conducting habitat restoration projects

human choices and environmental constraints deciphering the variability of large game procurement from mousterian to aurignacian times mis 5 3 in southwestern france abstract the evolution in the selection of prey made by past humans especially the neandertals and the first anatomically modern humans has been widely debated between marine isotope stages mis 5 and 3 the accuracy of absolute dating is still insufficient to precisely correlate paleoclimatic and archaeological data it is often difficult therefore to estimate to what extent changes in species procurement are correlated with either climate fluctuations or deliberate cultural choices in terms of subsistence behavior here the full development of archeostratigraphy and bayesian statistical analysis of absolute dates allows the archeological and paleoclimatic chronologies to be compared the variability in hunted fauna is investigated using multivariate statistical analysis of quantitative faunal lists of 148 assemblages from 39 archeological sequences from mis 5 through mis 3 despite significant intra technocomplex variability it is possible to identify major shifts in the human diet during these stages the integration of archeological data paleoclimatic proxies and the ecological characteristics of the different species of prey shows that the shifts in large game hunting can be explained by an adaptation of the human groups to climatic fluctuations however even if middle and early upper paleolithic men adapted to changes in their environment and to contrasting landscapes they ultimately belonged to the ecosystems of the past and were limited by environmental constraints

multi method tl and osl multi material quartz and flint dating of the mousterian site of roc de marsal dordogne france correlating neanderthal occupations with the climatic variability of mis 5 3 abstract roc de marsal has yielded numerous remains of mousterian occupations including lithics fauna and combustion features it was made famous by the discovery of the skeleton of a neanderthal child given the need to date the sequence tl and osl were applied on heated flints and quartz and osl on unheated quartz chronological results combined with palaeoenvironmental data faunal remains and micromorphological features in the sediments from the cave pollen proxies and faunal remains from the region allowed us to place climate variations in southwest france on a numerical time scale denticulate mousterian occupations were dated to the middle of mis 4 65 70 ka and quina layers either to the very end of mis 4 or to mis 3 interestingly a faunal pattern showing a mix of red deer roe deer and reindeer was found to have occurred during mis 4 which was shown to be consistent with data from other similar sites in southwest france

calculating quaternary glacial erosion rates in northeast scotland northeast scotland is an area exhibiting selective erosion by quatemary ice sheets in this area both glacial and preglacial landforms exist in close proximity the depths of erosion which this modification represents are calculated on the assumption of various depths of preglacial weathering a depth of erosion of between 34 and 62 m per unit area is indicated calculated rates of erosion are 0 021 nun a for the entire 2 3 m y of the quaternary and between 0 1 and 0 5 mm aa1 on the assumption that glacial conditions existed in this area for 500 000 years and 100 000 years respectively these figures are compared to the offshore sedimentary record in the adjacent west central north sea the volume of sediment deposited offshore is equivalent to a depth of erosion of 195 m per unit area yielding an average erosion rate of 0 085 mm a i over the entire quatemary rates of erosion were low in the preglacial pliocene 0 049 mm a 1 and early quatemary 0 063 mm a the expansion of ice sheets across the area in the middle quatematy was associated with a sharp increase in the rates of erosion 0 13 mm a but the last late devensian ice sheet in the area was less erosive 0 095 mm a the estimated rates of erosion represented by the offshore sedimentary record therefore exceed the estimated rates of glacial erosion from the onsho re geomorphological reconstruction

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

the glaciation of dartmoor the southernmost independent pleistocene ice cap in the british isles the granite uplands of dartmoor have traditionally been considered to be relict permafrost and periglacial landscapes that lay beyond the limits of quaternary glaciations but a variety of landform evidence indicates that a plateau icefield existed on the northern part of the moor constituting the southernmost independent ice cap in the british isles overdeepened or weakly u shaped valley segments fringing north dartmoor document an early extensive phase of glaciation but the most convincing landform evidence relates to more recent valley based glacier occupancy a moraine ridge on the slipper stones represents the most unequivocal palaeo glacier on north dartmoor with a palaeo ela of c 460 m above sea level asl although this relates to the youngest and most restricted phase of glaciation a longer term ela is likely to be represented by the corn ridge proto cirque at 370 410 m asl more extensive valley glaciers are recorded in each of the major drainage basins of north dartmoor by arcuate and linear bouldery ridges and hummocky valley floor drift which are interpreted as latero frontal moraines deposited by outlet lobes of a plateau icefield recession of these lobes is marked by inset sequences of such ridges and occasional meltwater channels plateau ice was predominantly thin and protective and snowblow and preferential accumulation in valley heads facilitated the modest glacial erosion and debris transport recorded in the landforms and sediments it is proposed that the highest plateaux have been occupied by ice for the longest cumulative period of time throughout the quaternary average glacial conditions explaining the distribution of different tor types on northern dartmoor this also explains the lack of tors on the most expansive of the highest plateau terrain ice dispersal centres as the product of a average glacial conditions preferentially removing tors or dampening their production rates b the survival of high relief type 1 tors during glaciation if they occupy summits too narrow to develop significant plateau icefields and or ridges that are bypassed by faster moving ice in adjacent deep valleys and c the survival of subdued type 2 tors in areas glaciated less regularly during the quaternary simple ice flow modelling indicates that a plateau icefield type glaciation is required for significant ice flow to occur and confirms thin ice cover in particular on narrow summits thereby supporting the explanation of tor class distribution the modelling allows us to spatially correlate the geomorphological evidence of margin positions into two major stages and further indicates a strong altitude mass balance feedback leading to an ice cap that is not in balance with its climate and with an extent that is limited by the length of the cold phases rather than their severity

thermal alteration of buried bone abstract burned bone is a common component of archaeological deposits traditionally associated with cremations culinary activities waste disposal fuel use and a by product of naturally occurring fires such interpretations assume responsible agents act upon bone prior to deposition or burial this sequential relationship between heating and burial is challenged by the suggestion that post burial alteration of bone is not only possible but can serve to explain the condition of burned material recovered in certain situations exposure to heat following burial incorporates several additional variables the sediment in which bone is deposited duration of exposure to a heat source and the interval between burial and burning affect the degree and extent of thermal alteration experiments have been conducted to test the hypotheses and parameters surrounding subsurface i e post burial alteration by surface fires

effective timescales of coupling within fluvial systems this paper presents a review of the coupling concept in fluvial geomorphology based mainly on previously published work coupling mechanisms link the components of the fluvial system controlling sediment transport down the system and the propagation of the effects of base level change up the system they can be viewed at several scales at the local scale involving within hillslope coupling hillslope to channel coupling and within channels tributary junction and reach to reach coupling at larger scales coupling can be considered as zonal coupling between major zones of the system or as regional coupling relating to complete drainage basins these trends are illustrated particularly by the examples of hillslope to channel coupling in the howgill fells northwest england badland systems in southeast spain alluvial fans in spain usa and uae and base level induced dissection of neogene sedimentary basins in southeast spain as the spatial scales increase so do the timescales involved effective temporal scales relate to magnitude and frequency characteristics recovery time and propagation time the relative importance changing with the spatial scale for downsystem coupling at the local scale the first two are important with propagation time increasing in importance in larger systems especially in those involving upsystem coupling related to base level change the effective timescales range from the individual event with a return period of decades through decadal to century timescales for downsystem coupling to tens to hundreds of thousands of years for the basinwide response to base level change the effective timescales influence the relative importance of factors controlling landform development

spatial organization of process domains in headwater drainage basins of a glaciated foothills region with complex longitudinal profiles 1 lithologic transitions and glaciations create complex longitudinal profiles that control contemporary erosion and deposition processes in areas with these characteristics traditional morphometric approaches for predicting process domains such as area slope plots can be augmented by considering other predictors measured from high resolution lidar derived digital elevation models dems ordinal logistic regression was used to model the distribution of hillslope swale colluvial channel and fluvial channel domains as identified during field surveys the study area was a glaciated region of the rocky mountain foothills with a complex lithostructural setting relationships between domains and a suite of geographic information system derived descriptors were explored predictors included profile anomalies measured at the reach and basin scale using a normalized stream length gradient sl k index drainage area was the dominant factor controlling domains a model with area as the only predictor was 82 accurate reach slope relations were not consistent a model that also included lithology and basin scale sl k index variation was 87 accurate domain transitions had larger area thresholds in basins with resistant conglomerate versus sandstone or shale formations and where sl k index was more variable along a profile in a restricted model of hillslope swale and colluvial channel domains profile curvature measured over 100 m was also related to domain occurrence a model for regional scale mapping applications with six additional predictors was 95 accurate the results showed that ordinal logistic regression can be used to predict and map process domains in regions with complex physiography using descriptors measured from high resolution dems

controls on the distribution of channel reach morphology in selectively glaciated catchments abstract to assess the controls on the distribution of channel reach morphology in a selectively glaciated landscape we used field mapping and a geographical information system gis in the river dee catchment northeast scotland controls on channel morphology were investigated using 1 continuous longitudinal assessment of channel morphology distribution in relation to geology glacial history topography and total stream power in two subcatchments and 2 slope s and a slope drainage area s a framework to understand the occurrence of 173 widely distributed bedrock mixed bedrock alluvial and alluvial three different types reaches the s a framework used indicators of transport capacity qc and sediment supply qs to differentiate channel types the study highlights the disjointed nature of channel reach distribution at the river scale that reflects variable lithology and glacial modification because of the subdued topography in contrast to other regions colluvial forcing of channel morphology in the headwaters was lacking however in common with other glaciated landscapes repeated sequences of channel reach type progression determined by valley steps were evident the s a analysis successfully discriminated 87 2 of alluvial and 91 4 of bedrock reaches despite the variable land use and glacial modification discrimination of the full range of channel types using s or the s a framework was poor however notably a third of the transport alluvial reaches were located in the bedrock s a domain and the majority of mixed reaches were widely distributed mostly within the bedrock domain and not close to the critical slope sc in comparison to other regions the sc above which qc qs and bedrock reaches dominate was notably higher we hypothesise that a drier climate and the higher entrainment threshold of coarse granite dominated bed materials create a higher sc

interactions between instream wood and hydrogeomorphic development within recently deglaciated streams in glacier bay national park alaska the physical and structural characteristics of instream wood were examined within five streams that represented 200 years of stream development following glacial recession within glacier bay national park alaska wood characteristics altered with watershed age as terrestrial succession progressed and wood was recruited into the riverine environment the influence of wood characteristics on the development of geomorphic diversity and hydraulic variability within the streams were assessed using detailed habitat mapping sediment analysis and hydraulic assessment using an acoustic doppler current profiler at a number of transects upstream downstream and adjacent to wood results show that the size complexity and orientation of wood accumulations are the main drivers in determining the degree of influence instream wood have on stream geomorphic and hydraulic complexity adjacent terrestrial vegetation must be of a sufficient stage of development in terms of size and maturity in order to elicit significant hydrogeomorphic changes to benefit aquatic biota such as fish macroinvertebrates and plants

sedimentary links and the spatial organization of atlantic salmon salmo salar spawning habitat in a canadian shield river abstract the segmenting of gravel bed rivers flowing through mountain valleys into a number of discrete sedimentary links each characterized by downstream fining of alluvium is a relatively recent concept which offers promise to model the large scale spatial organisation of many types of aquatic habitat reproductive feeding refuge etc strongly dependent on dominant bed sediment calibre although so far the ecological application of the concept has mainly focused on benthic invertebrates here we illustrate its application to fish atlantic salmon salmo salar moreover the link concept has also been primarily applied to alpine river environments where link formation is triggered by point sources mainly tributaries supplying coarser sediment however somewhat lower relief mountain valley landscapes of north eastern canada are often structured into sedimentary links triggered by non point supply zones of coarse sediments originating in bedrock canyon reaches or valley bottom deposits of glacial drift here we propose an adaptation and extension of the original sedimentary link concept to such landscapes and test its utility along one such system the ste marguerite river smr a salmon river draining the canadian shield in the saguenay region of quebec we first discuss a simple field and office based method of link delineation then we discuss potential sources of minor sublink scale grain size variability and their effects on how sedimentary links are defined lastly we demonstrate the usefulness of the link structure to model the distribution of atlantic salmon spawning habitat a habitat that depends critically on bed texture our results indicate that a revised sedimentary link typology is needed to describe longitudinal grain size patterns where non point valley segment scale sources of coarse sediment are important and that consideration of the research purpose and scale is important in defining meaningful link units we also show that salmon spawning zones can be directly predicted from the link structure along the smr spawning activity is apportioned within each of the discrete links in those sub zones where surface sediment size and sand content are optimal for reproduction

a methodological approach for identifying archaeological evidence of fire resulting from human activities abstract the identification of unequivocal evidence of humanly controlled fire is extremely problematic in archaeological contexts where obvious remains such as charcoal and ash have not been preserved until recently the difficulty of identification had been magnified by the lack of an established methodological approach which addressed the problem a methodological approach which can be used to identify and discriminate between archaeological evidence of fire resulting from natural processes and archaeological evidence of fire resulting from human activities is now available the approach utilizes several parameters of investigation including 1 macroscopic examinations of fire feature surfaces and profiles 2 analyses of magnetometer data 3 magnetic susceptibility studies 4 analyses of alternating field demagnetization characteristics 5 studies of isothermal remanent magnetization irm acquisition 6 analyses of coercivity of remanence characteristics and 7 palaeointensity studies the methodological approach is illustrated by comparing the results from analyses of features and samples from grass fire experiment sites isolated tree stump fire experiment sites multiple burn campfire experiment sites modern forest fire sites known archaeological hearths from modoc rock shelter illinois and known archaeological clay ovens from tell ashkelon israel for each available parameter of investigation comparisons revealed that multiple burn campfire sites exhibited basin shaped three dimensional configurations of oxidized sediments and diagnostic magnetic anomalies while multiple burn campfire samples displayed dramatic increases in magnetic susceptibility highly stable to very highly stable responses to alternating field demagnetization dramatic differences in irm acquisition and coercivity of remanence responses and diagnostic palaeointensity results when compared with the responses of adjacent unfired control samples archaeological hearth features and samples and samples from archaeological clay oven features exhibited results which were broadly consistent with the results from multiple burn campfire sites and samples the results displayed by grass fire isolated tree stump fire and forest fire sites and samples were generally found to be mutually exclusive from the results exhibited by multiple burn campfire and archaeological hearth and oven sites and samples for all parameters of investigation the results demonstrate that the methodological approach can be used to unequivocally identify archaeological evidence of humanly controlled fire resulting from multiple burn campfires fire hearths ovens and similar kinds of humanly produced fires

the earliest evidence of hearths in southern europe the case of bolomor cave valencia spain abstract most researchers agree about the importance of the fire during the pleistocene the controlled use of fire could allow advances in the ways of life not only for its value as a constant source of light and heat but also because it contributed to the processing of food to warding off the carnivores and especially to human socialization as fire can be understood as a focus of concentration of activities and structuring of inhabited space apart from the many utilities that the hearths may have had during the pleistocene this research does not allow specification of the chronological and geographical context of the first controlled use of fire from this perspective the present study contributes to this discussion with the data from bolomor cave valencia spain this site contains a sedimentary deposit composed of seventeen stratigraphical levels ranging from mis 9 to mis 5e c 350 100 ky the stratigraphical series presents clear evidence of the controlled and reiterative use of fire the used analytic techniques have confirmed the presence of hearths at levels ii iv xi and xiii of the site this paper discusses the hearths from level xiii chronologically located in mis 7c with an amino acid racemization aar date of 228 53 ky these combustion structures are the most ancient known today not only at bolomor cave and in spain but also in southern europe from this perspective the aim of this study is to make known the hearths from level xiii of bolomor cave and to provide data that contribute to the general debate about the presence knowledge and use of fire in the european middle pleistocene

the late middle palaeolithic in southwest france new tl dates for the sequence of pech de l aze iv the relative and numerical chronological position of the technological and typological variants of the mousterian in southwest france has been the subject of debate for over fifty years since the advent of both esr and tl dating methods in the 1980s a database of chronometric dates for a growing number of sites has been steadily accumulating a recent summary by guibert et al appears to show a complex pattern of broadly overlapping mousterian variants in the late middle palaeolithic and has led some to conclude that bordes initial interpretation of these variants as distinct cultural groups was essentially correct this paper adds to this database with new thermoluminescence dates from pech de l aze iv this site originally excavated by bordes in the 1970s contains a deep sequence of mousterian assemblages which express considerable technological and typological variability and which are associated with well preserved faunal remains excavations were undertaken from 2000 to 2003 in part to gain a better understanding of the geological context of the assemblages and also to obtain chronometric data in this paper new tl dates for the levels 3b 4c 5a and 8 are presented the deepest of these the typical mousterian of layer 8 is placed in marine isotope stage mis 5c another typical mousterian industry from level 5a dates to the transition from mis 5 to mis 4 level 4c which is rich in scrapers is placed in mis 4 while the mousterian of acheulian tradition is attributed to mis 3 at a local scale these new dates allow for the integration of the pech de l aze iv sequence with chronometric dates available for the nearby sites of pech de l aze i and ii and at a more regional scale they provide additional data points from the more poorly dated late interglacial and early mis 4 period these dates are in line with the emerging pattern suggesting that the mousterian variants as they are defined overlap considerably in time and call into question their interpretation as a succession of chronological units while a correlation with climate change of the technological units is not clear either

disequilibrium of holocene sediment yield in glaciated british columbia it is generally supposed that specific sediment yield the quantity of sediment passing a monitored river cross section per unit area drained upstream of that section declines as the area drained increases1 3 part of the sediment mobilized from the land surface is supposed to go back into storage at field edges and on footslopes and floodplains in contrast we show here that data from british columbian rivers reveal a pattern of increasing specific sediment yield at all spatial scales up to 3 104 km2 this results from the dominance of secondary remobilization of quaternary sediments along river valleys over primary denudation of the land surface the result controverts the conventional model which has been derived from studies of small highly disturbed agricultural catch ments the rivers are still responding to the last glaciation giving a landscape relaxation time greater than 10 kyr this holds pro found implications for geomorphological theory and for studies of erosion