hummocky cross stratification and megaripples a geological double standard abstract hummocky cross stratification in ancient sedimentary deposits is considered to be diagnostic of inner shelf storm deposits the geometry of the cross strata sets implies a low relief oval bedform of a few meters spacing orientation is poorly defined or random hummocky cross strata sets have been attributed to the action of strong storm wave surges megaripples of 2 5 m spacing are typical responses of the inner atlantic shelf of north america to storm flows side scan sonar records have shown that megaripples on the inner shelf are commonly hummocky oval to circular in plan view and lack asymmetry box cores and vibracores reveal gently inclined to horizontal lamination as the characteristic primary structure the megaripples am produced by combined flow storm currents these are alongcoast geostrophic flows with a mean flow component of 20 60 cm sec 1 a high frequency wave orbital current of similar or weaker intensity is present but its role in megaripple formation is subordinate to that of the mean flow the high velocity coastal margin of the flow is often jetlike and downwelling in nature and is characterize by a down current decrease in sand flux and rapid deposition of sand the bottom boundary layer of such flows is characterized by dense sediment suspensions 40 60 mgl 1 and is highly turbulent due to the interaction of the mean flow and wave orbital current components eddy diffusivity up to 200 cm2 sect at 40 cm above the bed sand transport in this coastal boundary zone is obliquely offshore but neither the density of the sediment suspension nor storm surge ebb appear to be important driving forces it is difficult to account for either modern hummocky megaripples or ancient hummocky cross stratification as responses to purely oscillatory flows combined flow currents are the typical response of mostmodern shelves and epicontinental seas to storms and presumably were so in the past hummocky cross stratified beds are generally too thick 20 80 cm to be accounted for by in situ resuspension they are more likely to have been despoited by combined flow currents in areas where these currents were experiencing a downstream velocity decrease and sediment deposition throughout much of the storm s duration evidence for strong scour in swales between hummocks and the smoothly rounded surface of the hummocks suggests a transitionlike bed regime measurements on the atlantic shelf likewi e suggest a transitionlike regime whose boundary layer is characterized by lower velocity than the transitional regime of unidirectional flow in flumes but more intense turbulence and a higher suspended sand concentration the lack of normal cross bedding in bothmodern and ancient hummocky bedforms indicates that these features did not migrate this characteristic may be a consequence of the complex trajectories followed by near bottom water particles in response to combined flow currents

combined flow processes and sedimentary structures on the shoreface of the wave dominated grande riviere de la baleine delta abstract shoreface sediments exposed in raised deltaic deposits along the hudson bay coast are characterized by a thick succession of predominantly parallel laminated and small scale cross laminated fine sand ripple forms where preserved include both combined flow and wave ripple geometries hummocky cross stratification is present in lower parts of the section similar facies have been found in cores from the present day shoreface measurements of waves currents and suspended sediment concentrations in 10 m water depth conducted over a 15 day period in the fall of 1999 captured four different meteorological periods these included an intense four day storm which sustained significant wave heights over 3 m for 15 hours and a storm surge of over 1 m height fair weather conditions produce weak alongshore tidal flows but oscillatory motions generated by small local waves predominate during storms orbital motions dominate the flow but a strong inertial flow generated by wind forcing is also present comparison with a published combined flow bedform stability diagram suggests that the predominant bedforms at 10 m depth would be small 2 d wave dominated ripples and small weakly asymmetrical 3 d ripples under fair weather conditions and large 3 d ripples and upper plane bed under storm wave conditions the predominantly interbedded parallel laminated and small scale cross laminated facies is therefore interpreted to be characteristic of the upper shoreface where the seabed experiences intense oscillatory motions under all storms and even some fair weather conditions combined flow ripples would form during storm events because of the stronger wind driven mean residual current hummocky cross stratification forms in deeper water during storms where the ratio of maximum orbital velocity to mean residual current velocity remains for longer periods in the large 3 d ripple field during the waning phase of storms a numerical bed predictor model using the 15 day data set as input also suggests bimodal conditions fluctuating between wave ripples and upper plane bed at 10 m water depth this model further indicates that combined flow ripples would form rarely but tends to underestimate the threshold of sediment suspension

origin of giant wave ripples in snowball earth cap carbonate the most extreme climate transitions in earth history are recorded by the juxtaposition of neoproterozoic glacial deposits with overlying cap carbonate beds some of the most remarkable sedimentary structures within these beds are sharp crested trochoidal bedforms with regular spacing of as much as several meters that are often interpreted as giant wave ripples formed under extreme wave conditions in a nonuniform postglacial climate here we evaluate this hypothesis using a new bedform stability diagram for symmetric oscillatory fl ows that indicates that the fi rst order control on the formation of trochoidal rather than hummocky bedforms is sediment size not wave climate new measurements of bedform wavelengths and particle sizes from the ca 635 ma nuccaleena formation australia indicate that the giant ripples are generally composed of coarse to very coarse sand most are within the trochoidal bedform stability phase space for normal wave climates moreover numerical simulations of flover fi xed bedforms show that symmetric trochoidal ripples with a nearly vertical angle of climb may be produced over long time periods with variable wave climates in conjunction with rapid seabed cementation these data reveal that rather than extreme wave conditions the giant wave ripples are a consequence of the unusual mode of carbonate precipitation during a global carbon cycle perturbation unprecedented in earth history

a lower palaeolithic industry from the cromerian mis 13 baginton formation of waverley wood and wood farm pits bubbenhall warwickshire uk artefacts of cromerian mis 13 age recovered from extensions to the classic site of waverley wood farm pit warwickshire give new insights into the lower palaeolithic and pleistocene geological record of the english midlands the baginton formation in the area to the south and southwest of coventry has been the major source of lower palaeolithic artefacts in the midlands since the first discoveries in the 1930s current sand and gravel workings at waverley wood and wood farm pits near the village of bubbenhall have provided artefacts of quartzite andesite and flint together with sparse large mammal material some of the lower palaeolithic finds were in situ in the succession providing for the first time firm evidence of their geological provenance the variety and number of the artefacts allows detailed evaluation of the largest group of lower palaeolithic tools to be found in the west midlands the petrology of some of the tools and associated clasts in the gravels at the base of the baginton formation allow speculation on the origin of the rock types from northwest and eastern england which may have been brought to the west midlands by a pre anglian glaciation or just possibly by human transport copyright 2006 john wiley sons ltd

late middle pleistocene interglacial deposits at upper strensham worcestershire england pleistocene deposits containing the disarticulated skeleton of a mammoth and associated faunal and floral remains were discovered in july 1990 at upper strensham worcestershire the environmental evidence from the fauna and flora together with limited geological evidence indicates that the deposits accumulated within a low energy fluvial environment with a surrounding marsh and restricted tree cover on or close to the floodplain the patchy occurrence of trees in a species rich grassland is discussed and the climatic significance of the fauna and flora is considered the strensham site lies within the valley of the river avon which is known to contain at least five altitudinally distinct river terraces the deposits at strensham lie beneath a terraced surface that cannot be accommodated within the existing framework of terrace development in the valley and evidence is presented which may suggest that these deposits form a previously unrecognised fluvial unit the strensham member of the avon valley formation amino acid age estimates from shells taken from the fossiliferous sediments of the strensham member suggest a correlation with oxygen isotope stage 7 this correlation suggests that the temperate deposits at this site should be correlated with the temperate phase recorded at marsworth buckinghamshire and stoke goldington in the vafley of the great ouse journal of quaternary science

provenance and depositional environments of quaternary sediments from the western north sea basin as the majority of the data on quaternary sediments from the north sea basin are seismostratigraphical we analysed the elsterian swarte bank formation the late saalian fisher formation and the late weichselian dimlington stadial bolders bank formation in order to determine genesis and provenance the swarte bank formation is a subglacial till containing palynomorphs from the moray forth and the northeastern north sea and metamorphic heavy minerals from the scottish highlands the fisher formation was sampled from the northern and central north sea in the north it is interpreted as a subglacial till with glaciomarine sediments cropping out further south these sediments exhibit a provenance signature consistent with the midland valley of scotland the eocene of the north sea basin the grampian highlands and northeast scotland the bolders bank formation is a subglacial till containing palynomorphs from the midland valley of scotland northern britain and a metamorphic heavy mineral suite indicative of the grampian highlands southern uplands and northeast scotland these data demonstrate that there was repeated glaciation of the north sea basin during the middle and late pleistocene with ice sheets originating in northern scotland there was no evidence for a scandinavian ice sheet in the western north sea basin

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

storm influences on a tidal sandbank s surface middelkerke bank southern north sea the results are presented of two types of pre storm and post storm surveys carried out on the middelkerke bank southern north sea the first type of survey was planned to detect detailed morphological changes in two selected areas of the bank totalling 3 km2 for the survey in these shallow waters to be completed in a fast and accurate way use was made of a special hovercraft based hydrographic system the other type of survey concerned grab samplings covering the sandbank in order to study spatial variations in surficial grain size the pre storm and post storm morphological surveys showed that small and medium dunes disappear under stormy conditions a 5 m westerly displacement of most of the large and very large dunes has been interpreted as the result of bedform migration under normal fair weather locally dominant ebb flow the lowering of the large dunes crests by up to 1 2 m is considered an effect of the storms the accretion of the lower part of the northwestern flank is attributed to the deposition of sand derived from shallow parts of the sandbank during storms the grain size surveys showed that especially the central and northern parts of the sandbank were affected by grain size changes the northwestern flank showing a clear coarsening and the landward southeastern flank a fining with respect to the fair weather situation it is put forward that the waves approaching from the north cause an extra winnowing on the exposed flank of the bank on the southeastern flank of the bank which is better protected against the wave action fine particles are then deposited

observations of time dependent bedform transformation in combined wave current flows although combined wave current flows in the nearshore coastal zone are common there are few observations of bedform response and inherent geometric scaling in combined flows our effort presents observations of bedform dynamics that were strongly influenced by waves currents and combined wave current flow at two sampling locations separated by 60 m in the cross shore observations were collected in 2014 at the sand engine mega nourishment on the delfland coast of the netherlands the bedforms had wavelengths ranging from 14 cm to over 2 m and transformed shape and orientation within at times as little as 20 min and up to 6 hr the dynamic set of observations was used to evaluate a fully unsteady description of changes in the bedform growth with the sediment transport continuity equation exner equation relating changes in bedform volume to bedload sediment transport analysis shows that bedform volume was a function of the integrated transport rate over the bedform development time period the bedform development time period time lag of bedform growth adjustment is important for estimating changes in bedform volume results show that this continuity principle held for wave current and combined wave current generated bedforms

geological and oceanographic perspectives on event bed formation during hurricane katrina 1 storm deposits in ancient shelf sediments typically form thick sequences of interbedded sand and mud deposited during shoreline regression whereas modern shelf sediments are generally thin veneers deposited during shoreline transgression in this paper we present a preliminary comparison between ancient and modern storm beds deposited in these disparate contexts hurricane katrina deposited a storm bed on the louisiana shelf with a maximum observed thickness of 0 58 m which thinned to approximately 0 1 m at 200 km west of landfall this thickness is similar to event beds observed in both ancient and modern sediments using data for tropical cyclone landfalls in the gulf of mexico we estimate the return time for a storm of this size to be 40 50 years in this region this estimated frequency for deposition of storm beds is useful in evaluating ancient storm sequences that were deposited during similar climatic conditions

field investigation of bedform morphodynamics under combined flow abstract fieldwork was conducted at the red cliff sandbar located in the upper humber estuary in order to investigate bedform dynamics under different hydrodynamic conditions related to combinations in tidal and wave generated currents a fixed mooring was deployed to obtain current flow and wave properties across the sand bar site at both spring and neap tidal flows and during conditions of high wind generated waves a terrestrial laser scanner was used to scan the sandbar during low water across the various forcing conditions acquiring detailed information of ripple geometries under spring tide and calm wave conditions two dimensional asymmetrical ripples with straight crest lines were generated on the sandbar surveys were also conducted during strong winds prior to high wind waves two dimensional symmetrical and washed out ripples were observed during spring and neap tidal conditions respectively the lengths of these ripples were almost the same as those generated under current only conditions but their heights were relatively smaller after the strong wind periods 2d current induced ripples were replaced by flatbed conditions and 2d symmetrical wash out ripples which indicates wave induced bed shear stress is enhanced by the presence of a tidal current most pertinently our study reveals discrepancies between field observations and existing predictions of bed configurations that are largely based on laboratory investigations this is likely due to a larger grain size distribution in field conditions and due to turbulence dampening by high concentrations of suspended clay particles the study thus highlights a need to extend a range of field investigations that explore the current deficiencies in our abilities to predict bedforms and bedform dynamics in estuarine systems

sediment transport patterns in the san francisco bay coastal system from cross validation of bedform asymmetry and modeled residual flux abstract the morphology of 45 000 bedforms from 13 multibeam bathymetry surveys was used as a proxy for identifying net bedload sediment transport directions and pathways throughout the san francisco bay estuary and adjacent outer coast the spatially averaged shape asymmetry of the bedforms reveals distinct pathways of ebb and flood transport additionally the region wide ebb oriented asymmetry of 5 suggests net seaward directed transport within the estuarine coastal system with significant seaward asymmetry at the mouth of san francisco bay 11 through the northern reaches of the bay 7 8 and among the largest bedforms 21 for 50 m this general indication for the net transport of sand to the open coast strongly suggests that anthropogenic removal of sediment from the estuary particularly along clearly defined seaward transport pathways will limit the supply of sand to chronically eroding open coast beaches the bedform asymmetry measurements significantly agree up to 76 with modeled annual residual transport directions derived from a hydrodynamically calibrated numerical model and the orientation of adjacent flow sculpted seafloor features such as mega flute structures providing a comprehensive validation of the technique the methods described in this paper to determine well defined cross validated sediment transport pathways can be applied to estuarine coastal systems globally where bedforms are present the results can inform and improve regional sediment management practices to more efficiently utilize often limited sediment resources and mitigate current and future sediment supply related impacts

river terrace systems in north west europe an archive of environmental change uplift and early human occupation abstract staircases of large scale aggradational river terraces are a notable feature of many valleys in the temperate lattitudes particularly in areas beyond the reach of the erosive activities of pleistocene ice sheets it is now recognized that the cyclic fluctuations of climate during the quaternary have driven the generation of terraces through the direct and indirect influence of both temperature and precipitation on fluviatile activity where fossiliferous deposits are preserved within terrace sequences it is often possible to date these and to correlate them with the oceanic record thus providing an important framework for the evidence of environmental change on land middle and late pleistocene terraces in different areas can commonly be seen to have formed in synchrony with glacial interglacial cycles or with longer periodicity megacycles climatic forcing alone is insufficient to cause terraces to form however uplift is also necessary so that terrace sequences can provide a useful record of crustal movement in northwest europe where some of the best known studies of river terrace sequences have been carried out the fluviatile deposits are also an important repository for palaeolithic artefacts from which a record of early human occupation can be reconstructed

the olduvai buffalo pelorovis and the origin of bos the origin of the genus bos is a debated issue from 0 5 ma until historic times the genus is well known in the eurasian large mammal assemblages where it is represented by bos primigenius this species has a highly derived cranial anatomy that shows important morphological differences from other plio pleistocene eurasian genera of the tribe bovini such as leptobos bison proamphibos hemibos and bubalus the oldest clear evidence of bos is the skull fragment asb 198 1 from the middle pleistocene 0 6 0 8 ma site of asbole lower awash valley ethiopia the first appearance of bos in europe is at the site of venosa notarchirico italy 0 5 0 6 ma although the origin of bos has traditionally been connected with leptobos and bison after a detailed anatomical and morphometric study we propose here a different origin connecting the middle pleistocene eurasian forms of b primigenius with the african late pliocene and early pleistocene large size member of the tribe bovini pelorovis sensu stricto the dispersal of the bos lineage in western europe during middle pleistocene times seems to coincide with the arrival of the acheulean tool technology in this continent 2007 university of washington all rights reserved

sand waves on an epicontinental shelf northern bering sea abstract sand waves and current ripples occupy the crests and flanks of a series of large linear sand ridges 20 km 5 km 10 m high lying in an open marine setting in the northern bering sea the sand wave area which lies west of seward peninsula and southeast of bering strait is exposed to the strong continuous flow of coastal water northward toward bering strait a hierarchy of three sizes of superimposed bedforms all facing northward was observed in successive cruises in 1976 and 1977 large sand waves height 2 m spacing 200 m have smaller sand waves height 1 m spacing 20 m lying at a small oblique angle on their stoss slopes the smaller sand waves in turn have linguoid ripples on their stoss slopes repeated studies of the sand wave fields were made both years with high resolution seismic reflection profiles side scan sonographs underwater photographs current meter stations vibracores and suspended sediment samplers comparison of seismic and side scan data collected along profile lines run both years showed changes in sand wave shape that indicate significant bedload transport within the year gouge marks made in sediment by keels of floating ice also showed significantly different patterns each year further documenting modification to the bottom by sediment transport during calm sea conditions in 1977 underwater video and camera observations showed formation and active migration of linguoid and straight crested current ripples current speeds 1 m above the bottom were between 20 and 30 cm s maximum current velocities and sand wave migration apparently occur when strong southwesterly winds enhance the steady northerly flow of coastal water many cross stratified sand bodies in the geologic record are interpreted as having formed in a tidal or storm dominated setting this study provides an example of formation and migration of large bedforms by the interaction of storms with strong uniform coastal currents in an open marine setting

sand intraclasts as evidence of subglacial deformation of middle pleistocene permafrost north norfolk uk sand intraclasts are common within the bacton green till member a glacitectonic mlange subjected to polyphase deformation during the middle pleistocene in north norfolk uk the intraclasts range from a few tens of centimetres to 10 m in length and have sharp contacts with the surrounding till sand within the intraclasts is unconsolidated and contains well preserved primary stratification the wrapping of glacitectonic foliation around the intraclasts and the development of folds relating to mechanical instabilities indicate that the intraclasts acted as competent masses within a more easily deformable fine grained till that accommodated the majority of the strain sharp contacts and distinctive heavymineral assemblages indicate little intermixing between the sand and till five hypotheses about the entrainment and evolution of the intraclasts are tested against sedimentological structural and mineralogical observations the most reasonable hypothesis attributes the intraclasts to glacitectonic deformation of warm permafrost initial ice advance caused large scale thrusting of proglacial permafrost that led to the stacking of pre glacial and ice marginal sediments that were subsequently deformed sub marginally to generate the intraclasts preservation of primary stratification within the intraclasts is attributed to deformation at temperatures slightly below the pressure melting point when pore ice cemented the intraclasts as rigid bodies at the same time deformation was concentrated into the surrounding finer grained till because of its significant liquid water content and ductile rheology it is concluded that the intraclasts provide a criterion to identify past glacierepermafrost interactions and a potential means of differentiating between subglacial deformation under unfrozen and partially frozen conditions

palaeoclimatic record in the loess palaeosol sequence of the strelitsa type section don glaciation area russia deduced from rock magnetic and palynological data

a note on megaripples in the surf zone evidence for their relation to steady flow dunes megaripples in the combined flow environment of the nearshore are proposed to behave like dunes or large ripples in rivers tidal estuaries and deserts their profile basically is symmetric and thus significantly different from the traditional asymmetric triangular features observed in steady flows similarly their planform often exhibits little directionality unlike crescentic or lunate steady flow dunes that point in the downstream direction these characteristics are the result of complex combined flows in the nearshore including oscillatory flows wave skewness and steady currents undertow rips and alongshore flows recent observations of megaripples in the nearshore suggest that they occur frequently however they are rarely considered in studies of flow resistance or sediment transport in addition megaripples are thought to be the source of hummocky cross stratification in sedimentary sequences and are generally attributed to storm waves on inner continental shelves however observations show that they also exist inside the surf zone and under lower energy conditions a better understanding of their dynamics and thus their occurrence and characteristics would improve the understanding of nearshore wave and circulation dynamics sediment transport large scale morphodynamics and the resulting sedimentary sequences it is hypothesized that megaripples in the nearshore are dynamically similar to steady flow features which are observed in rivers estuaries and deserts and have been studied in much more detail

field observations of bedforms and sediment transport thresholds of fine sand under combined waves and currents abstract seabed video images and s4 wave current meter data collected during the build up of a moderate storm on the scotian shelf are analysed for bedform development and sediment transport threshold of fine sand under combined waves and currents as the storm built up the following sequence of bedforms was observed 1 relict wave dominant ripples with worm tubes and animal tracks during the preceding fairweather period 2 irregular sinuous asymmetrical current dominant and intermediate wave current ripples under bedload transport 3 regular nearly straight or sinuous asymmetrical to slightly asymmetrical wave dominant ripples under saltation suspension 4 upper plane bed under sheet flow conditions 5 small crest reversing transitory ripples at the peak of the storm and 6 large scale lunate megaripples which developed when the storm decayed these data also show that only single sets of asymmetrical intermediate wave current ripples will form when waves and currents are co linear the development of the crest reversing transitory ripples indicates a high energy transition stage under quasi sheet flow conditions a direct comparison of the skin friction combined shear velocity and the critical shear velocities for bedload suspension and sheet flow transport under estimated the onset of these sediment transport modes as the presence of ripples causes the shear stress to increase from ripple trough to ripple crest the ripple enhanced skin friction shear velocity must be used to determine properly the initiation of bedload transport at high transport stages the boundary layer dynamics is controlled mainly by the thickness of the bedload transport layer thus a transport related bedload shear velocity predicted based upon the sum of the grain roughness and bedload roughness has to be compared against the conventional threshold criterion to properly define the onset of suspension and sheet flow transport modes

the molluscan fauna of the cromerian type site at west runton norfolk abstract an updated and revised list of the non marine molluscs of the west runton freshwater bed wrfb the type site of the cromerian stage is presented a minimum total of 73 species is now known consisting of 46 aquatic and 27 terrestrial taxa the molluscan fauna suggests a sluggish base rich stream choked with aquatic vegetation upstream of any brackish influence the banks were bordered with marshland sandy facies with a greater proportion of fluvial species indicate more active flow within small channels four aquatic and 5 terrestrial species no longer live in the british isles and 3 6 5 of the aquatic species tanousia runtoniana borysthenia goldfussiana and pisidium clessini are extinct the cromerian molluscan fauna lacks southern thermophiles and apart from the extinct taxa is remarkably similar to modern faunas from eastern england indeed 91 of the species of aquatic mollusc found in the wrfb still inhabit east anglia a number of the species that no longer live in britain have ranges that are central or eastern european implying that the climate may have been more continental the stratigraphical ranges of both b goldfussiana and t runtoniana extend into the late early pleistocene in the netherlands and in britain they seem to occur only in temperate stage deposits falling within the early part of the cromerian complex or earlier

new 40ar 39ar stratigraphic and palaeoclimatic data on the isernia la pineta lower palaeolithic site molise italy abstract the archaeological deposits of isernia la pineta are a milestone in the european context being composed of very rich and large sized occupation layers the archaeological remains are characterised by the use of anvils in a very opportunistic and rapid way to produce a large number of flakes and residual cores usually of very small size the lithic instruments are associated with remains of large mammals which give a clear indication of the diet they are represented by bison schoetensacki freudenberg stephanorhinus hundsheimensis toula elephas palaeoloxodon namadicus falconer e cautley ursus deningeri von reichenau hippopotamus cf antiquus desmarest sus scrofa l hemitragus cf bonali harle e stehlin megaceroides solilhacus robert cervus elaphus cf acoronatus beninde dama dama cf clactoniana falconer capreolus sp and panthera leo fossilis von reichenau the rodent fauna is represented by clethrionomys sp pliomys episcopalis mehely pliomys lenki heller microtus aff arvalis pallas microtus brecciensis gieber microtus terricola gr multiplex subterraneus and arvicola cantiana hinton the insectivores are talpa sp sorex cf runtonensis hinton and crocidura sp two main archaeological layers have been identified the lower one sector i layer 3c rests on a phytoclastic travertine passing laterally to a phytohermal travertine which generated a small step in the watercourse a sandy silt layer of lacustrine environment layer 3b deposited inside travertine pools and very limited phytostromatolitic travertine sediments cover this layer the second occupation layer layer 3a rests on these sediments as well as on the travertines cross bedded fine gravelly sands cover the deposits and are interlayered with tuffs very rich in pyroxene and sanidine the latter gave 40ar 39ar ages of 610 10 and 606 2 ka 2 error this layer is covered by cross bedded gravels weathered by a thick alfisols with a well expressed bt horizon the uppermost part of the series is composed of gravels and colluvia containing another pyroclastic layer sanidines of this layer yield scattered ar ar ages with a main population at about 504 14 ka a maximum age of 474 3 ka is inferred for this layer the isernia travertines are not associated with hot water springs and indicate that the area was frequented at the end of an interglacial period the new ages demonstrate that the human frequentation occurred at the beginning of the middle pleistocene

the nihewan basin of north china in the early pleistocene continuous and flourishing or discontinuous infrequent and ephemeral occupation the prevailing interpretation of the evidence for early pleistocene hominin occupation of the nihewan basin north china is that it indicates continuous settlement by hominins that were able to adapt to a wide variety of environmental conditions ranging from full interglacial to full glacial it has further been suggested that they were able to do so by the routine hunting of large mammals this paper argues that there is no evidence that hominins inhabited the nihewan basin year round or under cold conditions and no evidence that they hunted instead it is suggested that hominins are likely to have visited nihewan during the summer months and probably avoided it when conditions were significantly colder than today this scenario is consistent with what is known of the climatic sensitivity of the earliest hominin occupation of other regions in eurasia at comparable latitudes such as the chinese loess plateau tajikistan the caucasus and spain and in similar strongly seasonal environments with sub freezing winters such as britain overall hominin settlement in the nihewan basin was likely discontinuous infrequent and ephemeral

quaternary glaciations of northern europe this paper presents the outcome of a workshop held in berlin in february 2009 concerned with current research on the glacial history of northern europe including the british isles the methodologies presently used to resolve this topic are outlined particular attention is given to new analytical methods deriving from high resolution remote imaging of glacial terrain both on land and on the sea bed key new stratigraphic sections higher resolution results from conventional geochronological methods like radiocarbon and more recently developed technologies such as luminescence and cosmogenic radionuclide dating the relationships between the results derived from these two methods are discussed in further detail along with possible explanations for these differences an outline of a most likely glacial history of the scandinavian and british and irish ice sheets is presented along with possible links to global climate change as represented by the marine isotope mis record tentative evidence for glaciation is identified in mis 22 16 12 10 8 6 4 and 2 and correlations of phases within the last glaciation are also explored for both the scandinavian and british and irish ice sheets the results show that the character and extent of glaciation in different parts of the region are not synchronous and much more geochronological work is required before regional correlations can be established with confidence

monitoring underwater nourishments using multibeam bathymetric and backscatter time series natural and man induced coastal erosion endanger life and environment in coastal areas worldwide for sedimentary barrier coasts beach and underwater nourishments are an efficient coastal protection strategy to optimize nourishments and to understand their impact on the marine environment monitoring strategies are required in this study we investigate the potential of multibeam echosounder mbes data providing both bathymetry and backscatter bs for monitoring the evolution of the nourished sediment and morphodynamics over time a time series of seven mbes measurements as well as two sets of box cores vibrocores and seismic data were acquired of a channel side nourishment near the wadden sea island ameland the netherlands between april 2017 and may 2019 in general a high confidence of the acoustic reliability of the bs time series measurements is demonstrated the unsupervised bayesian classification method supported by ground truthing is employed to produce a time series of sediment maps revealing sediments ranging from sandy mud to sand with varying amounts of shell fragments based on the sediment maps the nourished sediment could be distinguished from the natural sediment within one year the shell rich pre nourishment seabed is recreated by washing out finer sediments which are deposited towards the main tidal channel using the seismic data and vibrocores the shell rich pre nourishment seabed could be identified in the subsurface after being buried by the nourishments supporting the general findings furthermore a rapid development of steep bedforms with increasing sediment sorting is observed in parts of the nourished areas this study shows that high resolution sediment maps obtained from a time series of mbes bs together with bathymetry reveal morphodynamic and sedimentary processes of nourishment evolution and can advance underwater nourishment strategies

the quaternary of the british isles factors forcing environmental change this paper considers the processes that have controlled cool temperate latitude terrestrial environments over the last ca 3 ma with particular reference to the british isles a scheme is proposed that is based on the processes that act on the land over any given period of time and are the product of climate modulated by rock type the resisting agent and relief determined by tectonics and antecedent relief forming factors climate is generalised in terms of the range and rates of climate change determined by orbital forcing during precession cycles climate change was small and insolation levels were forced by chemically and biologically driven processes the period of obliquity cycles is characterised by patterns of climate change in which physical processes became effective and high magnitude fluvial and slope processes were reinforced by periglaciation and glaciation in susceptible regions eccentricity cycles include climate extremes of longer duration and glaciation and periglaciation were the major contributors to landscape change sediment transfer and sediment mixing these climate forced processes produce distinctive landform sediment and soil assemblages characteristic of particular episodes of quaternary time the lags between the successive systems are identified copyright 2010 john wiley sons ltd

sedimentological effects and palaeoecological implications of the tube building polychaete lanice conchilega pallas the tube building polychaete lanice conchilega forms intertidal mounds in association with macroalgae this assemblage produces structures that can record tidal and seasonal cycles in the stratigraphic record they mark low tide levels because the assemblage occurs below neap low tide and many of the structures form when water drains off the assemblage mounds are created by disturbance of the sediment surface around aggregations of the assemblage and accumulation of sediments within the aggregations the initial aggregations may be relict patches of adult worms new clumps of juveniles or both juvenile worms and drift algae easily settle and survive in high density patches whereas predators and waves more readily disturb low density patches algae and tubes extend through accumulated sediment and create a new higher surface through this interactive process the high density patches increase height rapidly while the low density patches erode regardless of density when the initial distribution is regular the surface remains flat rising evenly or eroding evenly accumulation and erosion increases during spring tides and decreases during neap tides mound development also follows a seasonal pattern the recruitment of juvenile worms in spring facilitates algal settlement and initiates mound buildup the rate of tube building and algal growth increases in early summer as the erosive forces of storms decline this leads to the greatest development of mounds in late summer just before the macroalgae begin to die the loss of algae coincides with autumnal storms and causes catastrophic erosion of the mounds into relict patches of dormant tube worms patches of tubes that survive the winter enhance spring recruitment and renewal of mound development the shape of the mounds is often obscured during burial and preservation because of this it may be difficult to distinguish the original form of ancient mounds without contemporaneous cementing organisms but cycles of deposition and erosion are recorded in lanice tubes and other biogenic structures these structures can be used in conjunction with physical structures to define tidal height seasonality or current regime in general however the presence of tube aggregations per se is not diagnostic of a specific hydraulic environment

a 3 d ground penetrating radar and wavelet transform analysis of the morphology of shoreface deposits in the upper cretaceous ferron sandstone member utah wavelengths of hummocky cross stratified hcs beds a common sedimentary feature of storm dominated shorefaces are documented for the first time using measurements in three dimensional 3 d ground penetrating radar gpr data for a well developed upper cretaceous lower shoreface succession at dry wash in the ferron sandstone member utah the shallow marine sequence consists of upward thickening hcs sand beds alternating with interstorm deposits the thickness variation of the storm beds indicates locally steadily growing storm intensity with at least four cycles weakly coarsening upward mud to very fine grained sand fair weather background deposits suggest a slow progradation of deposition with no significant change in environment the gpr interpretation mapped three conformable high continuity high amplitude reflections throughout the 3 d gpr data volume the interpreted radar surfaces rss are well correlated with tops of hcs sand beds and thus paleotopographic surfaces the associated radar units rus have a uniform thickness on average 0 8 m 2 6 ft the rus and the adjacent outcrop observations suggest that the shoreface sandstone at the dry wash site has a simple layered internal architecture the hummocky swaley surfaces generally dip westerly as a product of postdepositional structural alterations that are mostly in the shoreline direction and contain variable size structurally undulating rounded features a 2 d continuous wavelet transform analysis is applied to the detrended rss producing a multiresolution image decomposition of the gpr surfaces surface features with a wavelength range of 1 7 m 3 23 ft are in good agreement with the observations on modern hummocky shallow marine seabeds quantitative measurements indicate that the hummocky surfaces at the dry wash site are dominated by uniformly distributed circular to elongate bed forms with maximum correlation at 1 5 3 5 m 4 9 11 4 ft wavelength and that the deltaic sedimentary layers were simultaneously deformed by the middle campanian compressional stress of the sevier orogeny transmitted from the northwest quantitative information on the subseismic scale surface geometry of the hcs beds is expected to result in more refined reservoir models in addition the connectivity of units indicated by the scale of the morphology can be an indirect indicator of unit correlation and permeability paths

experiments on bed configurations in fine sands under bidirectional purely oscillatory flow and the origin of hummocky cross stratification abstract we made experiments on bed configurations in bidirectional purely oscillatory flows at a wide range of oscillation periods t and maximum orbital velocities um in two closed flow ducts 0 1 m and 0 4 m wide the motivation was that understanding of bed configurations in oscillatory flows with long periods and high velocities during storm induced deposition in the shallow ocean is needed for interpreting the stratification in such deposits the ripples produced were classified geometrically as two dimensional 2d or three dimensional 3d in plan view geometry and dynamically as oscillatory current ripples dependent upon the patterns of flow and sediment transport specific to the existence of the oscillation itself and reversing current ripples dependent on he existence of the current in one direction or the other during the oscillation runs in the small duct with effectively 0 19 mm and 0 30 mm sand showed the familiar small 2d oscillatory current ripples at short t and low um passing into much larger ripples with spacing up to 2 m at periods of 6 20 s and velocities up to 1 m s with no apparent limit on size with increasing t and um even in such a narrow duct there was some evidence of 3d geometry of the large ripples runs in the large duct with effectively 0 11 mm sand at a single period of about 9 5 s showed a progression from small 2d oscillatory current ripples through small 3d reversing current ripples to large round crested 3d oscillatory current ripples with prominent superimposed 3d to 2d reversing current ripples the large 3d ripples which increased in spacing to 1 3 m at the h ghest attainable um of 1 m s shifted in position and changed in size with time seemingly at random causing substantial local and temporary erosion and deposition at a given point on the bed there was no net aggradation during the runs but a deposit was synthesized by taking a time series of sidewall bed profiles during a run in which large 3d ripples developed from an initially plane bed and changed irregularly in size and position as they grew toward equilibrium and then plotting the profiles one above the previous with a constant upward increment the resulting stratification is strikingly similar to much hummocky cross stratification in ancient sandstones this suggests that some hummocky cross stratification is generated during sediment fallout from strong purely oscillatory flows at moderate to long oscillation periods as large 3d oscillatory current bed forms develop from a planar bed during strong but waning flow

biostratigraphic and aminostratigraphic constraints on the age of the middle pleistocene glacial succession in north norfolk uk considerable debate surrounds the age of the middle pleistocene glacial succession in east anglia following some recent stratigraphical reinterpretations resolution of the stratigraphy here is important since it not only concerns the glacial history of the region but also has a bearing on our understanding of the earliest human occupation of north western europe the orthodox consensus that all the tills were emplaced during the anglian marine isotope stage mis 12 has recently been challenged by a view assigning each major till to a different glacial stage before during and after mis 12 between trimingham and sidestrand on the north norfolk coast datable organic sediments occur immediately below and above the glacial succession the oldest glacial deposit happisburgh till directly overlies the sidestrand unio bed here defined as the sidestrand hall member of the cromer forest bed formation dating of these sediments therefore has a bearing on the maximum age of the glacial sequence this paper reviews the palaeobotany and describes the faunal assemblages recovered from the sidestrand unio bed which accumulated in a fluvial environment in a fully temperate climate with regional deciduous woodland there are indications from the ostracods for weakly brackish conditions significant differences are apparent between the sidestrand assemblages and those from west runton the type site of the cromerian stage these differences do not result from contrasting facies or taphonomy but reflect warmer palaeotemperatures at sidestrand and a much younger age this conclusion is suggested by the higher proportion of thermophiles at sidestrand and the occurrence of a water vole with unrooted molars arvicola rather than its ancestor mimomyssavini with rooted molars amino acid racemisation data also indicate that sidestrand is significantly younger than west runton these data further highlight the stratigraphical complexity of the cromerian complex and support the conventional view that the happisburgh till was emplaced during the anglian rather than the recently advanced view that it dates from mis 16 moreover new evidence from the trimingham lake bed sidestrand cliff formation above the youngest glacial outwash sediments briton s lane formation indicates that they also accumulated during a middle pleistocene interglacial probably mis 11 all of this evidence is consistent with a short chronology placing the glacial deposits within mis 12 rather than invoking multiple episodes of glaciation envisaged in the new glacial stratigraphy during mis 16 12 10 and 6 copyright 2009 john wiley sons ltd

sedimentary characteristics and interactions among volcanic terrigenous and marine processes in the late permian kuishan member eastern block of the north china craton abstract understanding the variability of depositional environment and depositional processes of the late permian kuishan member north china craton is crucial for unraveling the evolution of sedimentary basin and epicontinental sea in shandong tectonic domain the kuishan member in the eastern block of the north china craton formed in association with general regression of an epicontinental sea is composed of abundant volcanic deposits and nearshore sedimentary deposits three lithofacies assemblages together with eleven lithofacies are identified in the study area including volcanic deposits of the turbidity lithofacies assemblage epiclastic deposits of the nearshore lithofacies assemblage and mixed volcaniclastic and epiclastic sedimentary deposits of the terrestrial lithofacies assemblage these alternating volcanic epiclastic lithofacies assemblages illustrate the depositional environments induced by volcanic activities and nearshore wave influence syn eruptive lithofacies in the shallow water area were formed by high density turbidity currents and ash fall into water introduced by rising sea levels and high rainfall due to volcanic eruptions to the north whereas thin bedded shallow marine silty mud developed in the distal area inter eruptive lithofacies were represented by tuffaceous mudstone deposited in an exposed and oxidized setting due to falling sea level whereas epiclastic nearshore deposits accumulated by wave or current flow regimes paleocurrent measurements show that the predominant regression direction changes from uniform southwest to divergent southwest and southeast during volcanic inter eruptive periods the kuishan succession therefore can be regarded as a volcano related sequence in which the input of volcaniclastic and epiclastic deposits were significantly modulated by controls of volcanism with frequently changing coastline position of the epicontinental sea and alternating depositional environments

tidal induced large scale regular bed form patterns in a three dimensional shallow water model the three dimensional model presented in this paper is used to study how tidal currents form wave like bottom patterns inclusion of vertical flow structure turns out to be necessary to describe the formation or absence of all known large scale regular bottom features the tide and topography are treated as a coupled system and the potential free instabilities in this system are investigated a linear stability analysis is used to study the dynamics of bed forms this yields information on the role of physical mechanisms such information cannot be obtained by direct numerical nonlinear simulation the basic state represents a horizontal elliptical flow veering in vertical direction over a flat bottom it is shown that in such a system modes can grow which have characteristics of both tidal sand banks and sand waves the model predictions are compared with observations and show good agreement

pre weichselian quaternary glaciations of the british isles the netherlands norway and adjacent marine areas south of 68 n implications for long term ice sheet development in northern europe within this paper we review the pre weichselian glacial history of northern europe focussing on evidence from the british isles netherlands norway and adjacent marine areas that record the activity of the british bis and scandinavian sis ice sheets the objective of the paper is to examine the long term evolution of the two ice sheets in order to determine their level of synchronicity and their relationship to the plio pleistocene record of northern hemisphere glaciation geological evidence demonstrates striking long term similarities between the behaviour of the bis and sis with a step wise intensification in the glacial signal 1 first ice rafted debris ird input onto the continental margin at ca 2 7 2 6 ma and restricted glaciation prior to ca 1 1 ma 2 initiation of more lowland style glaciation from 1 1 ma 3 repeated shelf edge glaciations from 0 45 ma these steps coincide with a major intensification of the northern hemisphere climate signal at the beginning of the quaternary and the mid pleistocene transition temporal and spatial variabilities in the behaviour of different sectors of the bis and sis appear to reflect regional scale geographic latitude elevation climatic moisture temperature and glaciological deformable beds controls that modulate the build up of ice volume in the main ice accumulation areas relative to global climate forcing and its subsequent lateral expansion 2010 nerc

age of middle pleistocene fauna and lower palaeolithic industries from kent s cavern devon abstract kent s cavern has long been known as potentially among the oldest palaeolithic sites in the country with the basal breccia deposit containing a sparse lower palaeolithic industry the sediment consists of a chaotic clayey conglomerate emplaced as a series of debris flows which entered the cave via blocked entrances at its southwest end the breccia contains a fauna dominated by the bear ursus deningeri with lion felis leo and the voles arvicola cantiana and microtus oeconomus establishing a late cromerian age for the deposit the artefacts comprise an industry of crudely manufactured handaxes and flakes and show damage suggesting that they were brought into the cave by the debris flows and may thus predate the sediment and fauna we demonstrate an age of 340 ka for the breccia using two independant dating methods consistent with existing models of the age of the british middle pleistocene sequence

exploratory flow duct experiments on combined flow bed configurations and some implications for interpreting storm event stratification abstract experiments were conducted to define equilibrium combined flow bed configurations developed under a wide range of oscillatory uo and unidirectional uu velocity components with a constant oscillation period of 8 5 sec and median grain size of 0 09 mm in the range of flows studied uo 0 0 80 m sec uu 0 0 25 m sec the bed phases are no movement small 2d ripples small 3d ripples large 3d ripples and plane bed small 2d ripples are stable at low uo and uu by increasing either velocity component the plan view bed configuration becomes progressively less regular as small 3d ripples develop small 3d ripples are stable at low to moderate uo and a wide r nge of uu under purely oscillatory flow as uo increases beyond about 0 40 m sec large scale hummocky bed forms become stable when a unidirectional component is applied these bed forms quickly develop a downstream asymmetry and generally move in the direction of uu the dip angles of the lee flanks increase with increasing uu although they remain less than the angle of repose at high oscillatory velocities uo 0 70 0 80 m sec plane bed is the stable bed phase when uu 0 05 m sec much hummocky cross stratification shows a preferred dip direction of the coset laminae our experiments support the idea that such cross stratification is produced by combined flow the large 3d ripples produced at high oscillatory velocities and small to moderate unidirectional velocities would presumably generate what might be called anisotropic hummocky cross stratification if we had been able to aggrade the bed during the runs this would be the case even in dominantly oscillatory flow the experiments show that even a weak unidirectional current of several centimeters per second superimposed upon a strong oscillatory flow results in bed forms that move predominantly in a single direction and that leave sets of laminae that dip predominantly in that direction in runs at large uo the purely oscillatory large scale bed forms were quickly planed off as uu was increased from zero but a series of almost stationary gentle undulations on the bed surface persisted for indefinitely long times where the original topographic highs were situated even at the highest unidirectional flow investigated 0 25 m sec this suggests a possible origin for the gentle undulation observed in cretaceous parallel laminated shallow marine sandstones described by arnott 1987 1988 with spacings up to a few meters and heights not much more than a centimeter

processes controlling the dynamics of compound sand waves in the north sea netherlands the understanding of the morphodynamics of harmonic bed forms on the seabed is essential for modeling marine sediment transport and coastal morphologic development previous research has mainly focused on the type and distribution of bed forms but areally extensive data and time series of seabed features are scarce multibeam and side scan sonar data from four expeditions reveal the contrasts between a coastal site with asymmetric and flattened three dimensional 3 d compound sand waves on a shoreface connected ridge and an offshore site with asymmetric and sharp crested 2 d compound sand waves migration rates of the coastal sand waves are 6 5 20 m yr 1 while migration rates of the offshore sand waves are 3 6 to 10 m yr 1 this contrasting morphology and dynamic behavior of compound sand waves at the two north sea sites is explained by differences in the relative importance of tidal currents and wave activity near the bed these new field data provide parameters and boundary conditions for sand transport models while the empirically derived behavior of sand waves may be used to validate sand transport and sand wave models 2005

timing and depositional environments of a middle pleistocene glaciation of northeast england new evidence from warren house gill county durham at various times during the quaternary north eastern england was a zone of confluence between dynamic ice lobes sourced from the pennines northern scotland the cheviots and scandinavia the region thus has some of the most complex exposures of middle to late pleistocene sediments in britain with both interglacial and glacial sediments deposited in terrestrial and marine settings we investigated sedimentary sequences exposed on the coastline of county durham at warren house gill and present a new model of british and fennoscandian ice sheet interaction in the north sea basin during the middle pleistocene the stratigraphy at warren house gill consists of a lower diamicton and upper estuarine sediments both part of the warren house formation they are separated from the overlying weichselian blackhall and horden tills by a substantial unconformity the lower diamicton of the warren house formation is re interpreted here as an mis 8 to 12 glaciomarine deposit containing ice rafted lithics from north eastern scotland and the northeast north sea and is renamed the ash gill member it is dated by lithological comparison to the easington raised beach middle pleistocene amino acid racemisation values and indirectly by optically stimulated luminescence the overlying shallow subaqueous sediments were deposited in an estuarine environment by suspension settling and bottom current activity they are named the whitesides member and form the uppermost member of the warren house formation during glaciation ice rafted material was deposited in a marine embayment there is no evidence of a grounded onshore scandinavian ice sheet in county durham during mis 6 which has long been held as the accepted stratigraphy this has major implications for the currently accepted british quaternary stratigraphy combined with recent work on the middle pleistocene north sea drift from norfolk which is now suggested to have been deposited by a scottish ice sheet the presence of a scandinavian ice sheet in eastern england at any time during the quaternary is becoming increasingly doubtful

observations of bedform migration and bedload sediment transport in combined wave current flows bedload transport is an important mechanism for sediment flux in the nearshore yet few studies examine the relationship between bedform evolution and net sediment transport our work contributes concurrent observations of bedform mobility and bedload transport in response to wave dominant current dominant and combined wave current flows in the nearshore bedload sediment flux from migrating bedforms during combined wave current conditions accounted for at least 20 more bedload transport when compared with wave dominant flows and at least 80 more than current dominant flows bedforms were observed to transport the most sediment during periods with strong currents with high energy skewed waves and while bedform orientation and transport direction were aligned regardless of flow type bedform migration rates were directly proportional to the total kinetic energy contained in the flow field eleven bedload transport models formulated to be used in combined flows both shear and energetics based were compared with sediment flux estimated from measured bedform migration an energetics based sediment transport model was most representative for our data

early and middle pleistocene river systems in eastern england evidence from leet hill southern norfolk england pleistocene sediments at leet hill southern norfolk are examined in terms of their sedimentary structures palaeocurrent indicators clast and heavy mineral lithology and litho and morphostratigraphic position colour of the quartzite and vein quartz clasts is used to differentiate the bytham and the kesgrave sands and gravels with the bytham sands and gravels having a significantly higher proportion of coloured material the kirby cane sands and gravels are the lower sedimentary unit and were deposited by the bytham river which drained a catchment extending into central england at leet hill erosion of the kesgrave sands and gravels by the bytham river has given the kirby cane sands and gravels a distinctive lithological assemblage trace clast lithologies suggest that the kesgrave sands and gravels in the region of leet hill were deposited in a coastal location with an input from northern sources as well as southern and welsh sources diagnostic of the thames catchment the glaciofluvial leet hill sands and gravels were deposited by outwash from the anglian scandinavian ice sheet initially the flow direction of the outwash was determined by the bytham river valley but this changed to a southerly direction once the valley had been infilled this paper provides the first indication of the location of the boundary early pleistocene coastline between the fluvial kesgrave sands and gravels and the marine equivalent reworked by coastal processes and demonstrates the way the pre glacial relief initially controlled patterns of glaciofluvial sedimentation during the early part of the anglian glaciation copyright 1999 john wiley sons ltd

horizontal and vertical sediment sorting in tidal sand waves modeling the finite amplitude stage the bed of coastal seas displays a large number of rhythmic bed features of which sand waves are relevant to study from an engineering perspective sediments tend to be well sorted over these bed forms which is so far poorly understood in terms of modeling of finite amplitude sand waves using delft3d we employ bed stratigraphy and consider four different grain size classes which are normally distributed on the phi scale the standard deviation sortedness is then varied whereas the geometric mean grain size is kept constant the results show that typically the crests of sand waves are coarser than the troughs residual flow causes net sedimentation on the lee side of the crest and consequently the general sorting pattern is distorted since larger grains experience a larger settling velocity they are deposited on the upper lee slope whereas the smaller grains are found on the lower lee slope due to sand wave migration also the internal structure of the sand wave is revealed which follows the same sedimentation pattern as the lee slope surface these results qualitatively agree with sorting patterns observed offshore the sorting processes lead to longer wavelengths and lower wave heights as a function of standard deviation this relates to the dampening effect of suspended sediment transport for fine grains finally it appears that the modeled wave heights fall in the same range as observations in the north sea these results are valuable for e g predicting the morphological response after engineering activities and determining suitable aggregates for sand extraction

amino acid geochronology its impact on our understanding of the quaternary stratigraphy of the british isles this review aims to act as a brief primer to amino acid racemization and protein breakdown as well as to document the major applications and results of amino acid dating on british quaternary sediments amino acid results from fossil shells have had far reaching effects in developing our current understanding of british quaternary stratigraphy and its links to continental europe and the marine record to appreciate the potential for amino acid geochronology the technique s limitations and recent developments are discussed as well as the future of the field copyright 2009 john wiley sons ltd

amino acid geochronology of the type cromerian of west runton norfolk uk aminostratigraphic studies of continental deposits in the uk have hitherto relied almost exclusively on data from the aragonitic shells of non marine molluscs for dating pleistocene sequences this is usually based on the d l value of a single amino acid d alloisoleucine l isoleucine a i in the total shell proteins two genera of freshwater gastropods valvata and bithynia are used to explore the value of using multiple amino acids from the intra crystalline fraction which should be more protected from the effects of diagenesis than the inter crystalline component results are compared from both the aragonitic shells and opercula composed of calcite a more stable form of calcium carbonate in order to put the amino acid data from the west runton freshwater bed into perspective statistical analyses are used to compare them with results from the hoxnian mis 11 site at clacton on sea essex twelve protein decomposition indicators revealed that the results from the shells were not as clear cut as those from the opercula five indicators from the valvata shell suggest that west runton is older than clacton at a 95 significance level but two actually suggested a younger age seven indicators show that the bithynia shells from west runton are older than congeneric shells from clacton in marked contrast all 12 indicators isolated from the opercula demonstrate that west runton is significantly older than clacton the data are also compared with results from waverley wood an important archaeological site in the english midlands falling within the cromerian complex contrary to earlier interpretations the new amino acid data from bithynia opercula indicate that west runton is older than waverley wood a relationship now consistent with the available biostratigraphy

internal waves vs surface storm waves a review on the origin of hummocky cross stratification hummocky cross stratification hcs is considered a diagnos tic structure of surface storm activity at the shoreface offshore transition however the origin of hcs is still debated laboratory experiments have not yet reproduced it and direct observations on the continental shelves do not exist most hydrodynamic interpretations invoke pure oscilla tory flows unidirectional dominated combined flows and oscillatory dominated flows but they all share the assump tion of hcs to reflect the combined action of surface storm waves and related currents within this context of uncertain ties internal waves gravity waves propagating along the pycnocline provide an alternative mechanism to explain the origin of hcs internal waves breaking on the shelf create episodic high turbulence events and induce upslope and downslope currents as well as oscillatory flows at the depth where the pycnocline intersects the sea floor in this scenario both the oscillatory and the unidirectional components needed for hcs to form are not necessarily linked to surface storm waves but can occur at various depth as far and near there is a pycnocline where internal waves can form

linking the morphology and ecology of subtidal soft bottom marine benthic habitats a novel multiscale approach high resolution surveying techniques of subtidal soft bottom seafloor habitats show higher small scale variation in topography and sediment type than previously thought but the ecological relevance of this variation remains unclear in addition high resolution surveys of benthic fauna show a large spatial variability in community composition but this has yet poorly been linked to seafloor morphology and sediment composition for instance on soft bottom coastal shelves hydrodynamic forces from winds and tidal currents can cause nested multiscale morphological features ranging from metre scale mega ripples to sand waves and kilometre scale linear sandbanks this multiscale habitat heterogeneity is generally disregarded in the ecological assessments of benthic habitats we therefore developed and tested a novel multiscale assessment toolbox that combines standard bathymetry multibeam backscatter classification video surveying of epibenthos and box core samples of sediment and macrobenthos in a study on the brown bank a sandbank in the southern north sea we found that these methods are greatly complementary and allow for more detail in the interpretation of benthic surveys acoustic and video data characterised the seafloor surface and subsurface and macrobenthos communities were found to be structured by both sandbank and sand wave topography we found indications that acoustic techniques can be used to determine the location of epibenthic reefs the multiscale assessment toolbox furthermore allows formulating recommendations for conservation management related to the impact of sea floor disturbances through dredging and trawling

observations of sand waves megaripples and hummocks in the dutch coastal area and their relation to currents and combined flow conditions 1 this paper aims to investigate the distribution and stability of large scale bed forms in response to storm and fair weather conditions in a shallow marine environment multibeam and side scan sonar data off the dutch coast median grain size 0 25 0 35 mm were collected to monitor sand waves 100 800 m and superimposed megaripples 1 40 m through multiple storm and fair weather events box cores were used to observe the vertical bed structure and grain size in the dutch coastal area two dimensional 2 d megaripples x 1 15 m are the dominant bed forms in current dominated 0 4 m s tidal flow regimes with oscillatory flows 0 4 m s undulating bed topography of mound like 3 d bed forms 20 40 m is observed immediately after storms these bed forms are covered by smaller 3 d megaripples which are related to sets of low angle converging laminae in box cores interpreted as hummocky cross stratification hcs the sand waves form compound bed forms of sets of 2 d and 3 d megaripples the morphology of the sand waves is a function of the general wind wave climate of the marine environmental setting with flat topped 3 d sand waves occurring in shallow wave dominated settings and 2 d sand waves occurring in the tide dominated environment farther offshore copyright 2005 by the american geophysical union

palaeogeographical changes in response to glacial interglacial cycles as recorded in middle and late pleistocene seismic stratigraphy southern north sea offshore stratigraphic records from the north sea contain information to reconstruct palaeo ice sheet extent and understand sedimentary processes and landscape response to pleistocene glacial interglacial cycles we document three major middle to late pleistocene stratigraphic packages over a 401 km2 area norfolk vanguard boreas offshore wind farm offshore east anglia uk through the integration of 2d seismic borehole and cone penetration test data the lowermost unit is predominantly fluviatile yarmouth roads formation marine isotope stage mis 19 13 including three northward draining valleys the middle unit swarte bank formation records the southernmost extent of tunnel valley fills in this area of the north sea providing evidence for subglacial conditions most likely during the anglian stage mis 12 glaciation the yarmouth roads and swarte bank deposits are truncated and overlain by low energy estuarine silts and clays brown bank formation mis 5d 4 smaller scale features including dune scale bedforms and abrupt changes in cone penetration test parameters provide evidence for episodic changes in relative sea level within mis 5 the landscape evolution recorded in deposits of mis 19 5 are strongly related to glacial interglacial cycles although a distinctive aspect of this low relief ice marginal setting are opposing sediment transport directions under contrasting sedimentary process regimes

evidence for a grounded ice sheet in the central north sea during the early middle pleistocene donian glaciation interpretation of 3d seismic data from the central north sea yields evidence of a pre mis marine isotope stage 12 grounded glaciation the glaciotectonic complex shows buried push moraines resulting from the thrusting of multiple ice advance phases with horizontal shortening of 35 50 the earliest feature observed within the complex a hill hole pair represents the initial glaciation of the area this is overlain and deformed by multiple thrust units with numerous inferred ice flow directions the thrust deformation observed shares characteristics with kinematic processes push moraines and static gravity processes seen as gravity spreading and contraction the glaciotectonic complex in its entirety is interpreted to correlate to a pre elsterian glaciation becaue of its stratigraphic position below central north sea tunnel valleys estimated to be elsterian in age mis 12 450 ka the study proposes that the thrust complex correlates to the donian glaciation in russia mis 16 600 ka with ice sourced from norway the complex therefore represents a glaciation where a significant area of the central north sea was covered by an ice sheet 200 kyr prior to the elsterian this study highlights the fragmentary record of pre elsterian glaciations and the importance of incorporating offshore sedimentary archives and regional frameworks when reconstructing pleistocene climate change

new detection of tremor triggered in hokkaido northern japan by the 2004 sumatra andaman earthquake 1 the transient stress change caused by the passage of surface waves resulting from the 26 december 2004 sumatra andaman earthquake triggered seismic tremor in two regions in hokkaido in the northernmost part of the japanese islands where tectonic tremor associated with the subducting plate has not previously been detected the amplitude pattern of the tremor envelope in both regions is characterized by a periodic enhancement at an interval of about 20 s which correlates with the surface wave one tremor that was triggered in central hokkaido at a depth of around 10 20 km coincides with active seismicity linked to previously known deep low frequency microearthquakes related to volcanic activity another tremor occurred in northernmost hokkaido where there are no known active faults volcanoes or microearthquake seismicity if the source of the northern tremor is located near the ground surface it would be possible that the tremor is related to fluid pressure change because the periodic enhancement of tremor amplitude is in phase with the largest compressional strain caused by surface waves

the bytham river reconsidered abstract the english midlands is one of the most important regions for british pleistocene geology the middle pleistocene glacial sediments of the region termed the wolston formation overlie deposits of a pre existing river system the baginton formation the latter are characteristically composed of quartz rich sediment derived from underlying triassic bedrock this sw ne aligned proto soar system was overridden by the wolstonian ice its lack of terraces or discrete sedimentary units implies that the river can only have existed for a limited period the deposits accumulated during a period of climate change from boreal interstadial to subarctic conditions a reinterpretation of these sediments as the headwaters of a pre anglian bytham river aligned towards east anglia across the fenland where they were linked to the ingham formation deposits found favour for two decades this was especially so when the wolston formation sediments were reassigned to the earlier anglian stage however recent work has shown that the bytham river could not have existed in the form suggested by some authors since pre anglian age fluvial sediments are absent from the eastern fenland margin except possibly certain deposits at high lodge suffolk therefore a re examination of the evidence is required it is concluded that the wolstonian glaciation late saalian marine isotope stage mis 6 indeed post dates that during the anglian stage elsterian mis 12 in addition it appears that the baginton proto soar stream as originally conceived almost certainly did not exist before the early wolstonian early saalian stage following a significant period of fluvial incision rather than being aligned towards east anglia the substantial proto soar flowed into south lincolnshire and thence potentially to the north sea via the wash and the silver pit depression by contrast the pre anglian ingham formation deposits of central east anglia were almost certainly deposited by a separate proto trent river that drained the east midlands over an extended period as a left bank thames tributary together these conclusions reinforce the view that the main drainage alignment in southern england during the pre anglian period was nw to se parallel to the regional tilt of the landmass

combined flow model for vertical stratification sequences in shallow marine storm deposited beds abstract we develop a model to help explain the wide variety of vertical stratification sequences in shallow marine sandstones this model embodied in a set of vertical sequence cartoons predicts or accounts for vertical stratification sequences in beds of free sandstone deposited from a full range of decelerating combined flows as well as from purely unidirectional and oscillatory flows according to the model vertical stratification sequences in storm deposited sandstone beds are the outcome of the time history of the bed configuration as deposition proceeds the idealized sequences are based on the initial velocities and subsequent deceleration histories of the unidirectional and oscillatory flow components twenty qualitatively different sequences starting with plane bed are generated and an additional 26 sequences result from omitting one or more of the lowermost intervals in succession the model thus accounts for 46 distinct kinds of sequences five major simplifying assumptions are built into the model bidirectional flows linear deceleration of both unidirectional and oscillatory flow components time independent deposition rate time independent sediment size and equilibrium bed configurations owing to these assumptions the model is likely to be applicable to only a small subset of vertical stratification sequences observed in shallow marine sandstones as more information on combined flow bed configurations becomes available these assumptions could be relaxed to provide a more refined and complete representation of vertical stratification sequences since the model generates vertical sequences formed from any kind of decelerating flow the bouma sequence for deposits from purely unidirectional turbidity currents and also sequences resulting from decelerating purely oscillatory flows similar in appearance to many proposed generalized tempestite sequences are end member cases in the model the model is also extended slightly to explain the geometry of the uppermost bedding surfaces of storm generated sandstones by consideration of disequilibrium effects

pre anglian fluvial and coastal deposits in eastern england lithostratigraphy and palaeoenvironments abstract clast lithology and derived microflora are used to provide a basis for correlating pre anglian fluvial and coastal deposits in eastern england and to provide a lithostratigraphic framework for these early and early middle pleistocene sediments three fluvial systems are recognised i the thames which drained an area from wales through midland england to the thames basin and southern east anglia the catchment was truncated over the period concerned and the western headwaters diverted to other river systems ii the bytham river which drained midland england and the southern pennines and reached the southern north sea delta in the region of north central east anglia this river extended its catchment over the period concerned iii the ancaster river which drained the southern pennines and received sediment from northeast england each of these catchments contributed sediment to the southern north sea delta estuary and contributed to the lithologies of the red norwich and wroxham crag formations the lithostratigraphic subdivisions are based on the fact that i the pliocene and early pleistocene rivers and the equivalent red and norwich crags are characterised by far travelled microflora which was transported in suspension and a locally derived clast assemblage transported as bedload and ii the later early and early middle pleistocene rivers and the equivalent wroxham crag are characterised by a far travelled microflora and a far travelled clast assemblage variations in the amount and composition of far travelled materials is determined by the relative importance of the three river systems this provides a basis for identifying different formations of the thames river sediments older sudbury formation and younger colchester formation and different members of the wroxham formation dobb s plantation member local material with minor components of thames and ancaster river sediments how hill member local material with major components of thames and ancaster river sediments mundesley member with major components of bytham river sediments these lithostratigraphic units are related to established north european biostratigraphy and oxygen isotope stratigraphy the factors forcing the changes in river energetics are explained in terms of the relative importance of geomorphic processes operating within the river catchments determined by the patterns of milankovitch orbital forcing

discontinuity in the record for hominin occupation in south western europe implications for occupation of the middle latitudes of europe abstract recent discoveries of evidence for hominin activity in britain before mis 13 challenge previous understanding of the nature of the earliest colonization of nw europe insights into the nature of colonization in this region may be obtained by examining the much richer fossil and archaeological record from iberia it has generally been assumed that southern europe was permanently occupied after the first appearance of hominins in the region and that it provided a reliable source for populations re colonizing areas further north however continuity of occupation in these southern areas is still to be demonstrated this paper provides an outline of the palaeoenvironmental archaeological and fossil evidence from iberia during the early pleistocene and early middle pleistocene this evidence is used to argue that hominin occupation in this region and time period was discontinuous this may help to address a number of questions about the earliest occupation history of nw europe who were the colonists and where did they come from were they strongly limited by climatic conditions were source populations always available in nearby areas and did this influence the permanency of occupation in this region

bed load transport on the shoreface by currents and waves tide driven bed load transport is an important portion of the net annual sediment transport rate in many shoreface and shelf environments however bed load transport under waves cannot be measured in the field and bed load transport by currents without waves is barely measurable even in spring tidal conditions there is consequently a strong lack of field data and validated models the present field site was on the shoreface and inner shelf at 2 to 8 5 km offshore the central dutch coast far outside the surfzone where tidal currents flow parallel to the coast bed load transports were carefully measured with a calibrated sampler in spring tidal conditions without waves at a water depth of 13 18 m with fine and medium sands the near bed flow was measured over nearly a year and used for integration to annual transport rates an empirical bed load model was derived which predicts bed load transports that are a factor of n5 smaller than predicted by existing models however they agree with laboratory data of sand and gravel transport in currents near incipient motion the damped transport rates may have been caused by cohesion of sediment or turbulence damping due to mud or biological activity the annual bed load transport rate was calculated using a probability density function pdf derived from the near bed current and orbital velocity data which represented the current and wave climate well when compared to 30 years of data from a nearby wave station the effect of wave stirring was included in the transport calculations the net bed load transport rate is a few m 2 year this is much less than predicted in an earlier model study which is partly due to different bed load models but also due to the difference in velocity pdf the annual transport rate is very sensitive to the probability of the largest current velocities

the first british record of actinidia faveolata c reid and e m reid actinidiaceae family abstract archaeological artefact bearing pleistocene fluvial sediments which form part of the cromer forest bed formation below the modern beach just south east of happisburgh norfolk uk happisburgh site 1 yielded a diverse plant macrofossil assemblage that included a seed fragment of actinidia faveolata c reid and e m reid an extinct relative of the modern kiwi fruit actinidia deliciosa a chev c f liang and a r ferguson actinidiaceae family this is the first record of this taxon in the british isles previously this extinct species has been found in upper oligocene sediments from west siberia and from miocene pliocene and early pleistocene sediments in europe the stratigraphical and palaeoenvironmental setting of this find is briefly considered followed by a detailed description of the fossil with a comparison of specimens from the type area the archaeological and biostratigraphical implications of this record are also discussed

on the behaviour of tidal current directions due to the presence of submarine sand waves abstract side scan sonar records reveal that the crestlines of megaripples in the troughs as well as on both sides of the slopes of sand waves form an angle with the crestline of the sand waves itself the existence of such an angle between the crestline of megaripples and sand waves indicates that changes of the tidal current direction across sand waves can be expected direct evidence that such tidal current direction changes occur above sand waves is derived from measurements of the air sea interaction drift buoy asib system at the sea surface and from side scan sonar records of the sea bed both systems were operated from on board research vessels during two c star field experiments in the hoek van holland study area off the dutch coast in april 1996 and in april 1997 measurements performed by electrical resistance wires on board the asib system indicate that variations of the short and moderate wave direction and the wave directional spread are associated with changes of the tidal current direction at the sea surface according to the results of the measurements derived from the asib system and the side scan sonar records it can be summarised that the variation of the direction of short and moderate period water waves as well as changes of the tidal current speed and direction across large sand waves must be considered for correct modelling of the wave current interaction mechanism

grain sorting effects on the formation of tidal sand waves a model is developed to investigate the process which leads to the formation of sand waves in shallow tidal seas characterized by a heterogeneous sea bed composition the main goal of the analysis is the evaluation of the effects that a graded sediment has on the formation of the bottom forms and the investigation of the sorting process induced by the growth of the bottom forms the analysis is based on the study of the stability of the flat bed configuration i e small amplitude perturbations are added to the flat bottom and a linear analysis of their time development is made for an oscillatory tidal current dominated by one tidal constituent the results show that the graded sediment can stabilize or destabilize the flat bottom configuration with respect to the uniform sediment case depending on the standard deviation sigma of the grain size distribution and on the ratio r over cap between the horizontal tidal excursion and the water depth for moderate values of r over cap i e values just larger than the critical value for which the sediment is moved and sand waves appear the presence of a sand mixture stabilizes the flat bed on the other hand for large values or r over cap the mixture has a destabilizing effect in both cases the effect that a sand mixture has on the stability of the flat bed configuration is relatively small moreover for moderate values of r over cap the fine fraction of the mixture tends to pile up at the crests of the bottom forms while the coarse fraction moves towards the troughs for large values or r over cap the grain size distribution depends on the value of sigma the results are physically interpreted and provide a possible explanation of the apparently conflicting field observations of the grain size distribution along the sand wave profile carried out in the north sea

the distribution of macrozoobenthos in the southern north sea in relation to meso scale bedforms this study investigates the distribution of macrozoobenthos in relation to meso scale bedforms in the southern north sea three sites on the dutch continental shelf were sampled that are representative of large areas of the north sea and show diverse morphological settings these sites are i part of a shoreface connected ridge ii the lower part of a concave shoreface and iii a sandwave area within these sites two or three different morphological units were distinguished sampling was undertaken in two seasons for two consecutive years the species composition was analysed for differences in benthic assemblage within sites based on the meso scale morphology and between sites and seasons in addition the benthic assemblage was correlated to water depth median grain size d50 and sorting d60 d10 results show that significant differences in the benthic assemblage can be found related to meso scale bedforms but macro scale morphological setting and seasonal effects are more important 2006 elsevier ltd all rights reserved

the middle pleistocene deposits of waverley wood pit warwickshire england a complex of channels underlying the baginton lillington gravel baginton formation at waverley wood quarry warwickshire is described fossil pollen and plant macrofossils coleoptera ostracoda mollusca and mammalia are described from the channel fill deposits consideration of all the evidence allows the identification of four separate stages of channel fill which largely occurred under a cool temperate climate at the top of channel 2 evidence for a cold continental climatic episode can be recognised suggesting that the whole complex was deposited under a fluctuating climate at the end of a temperate stage at two levels in the channels human artefacts were recovered confirming the presence of palaeolithic people in warwickshire during the deposition of the sediments amino acid geochronology suggests an age within the cromerian complex stage for the channels the small vertebrate and molluscan faunas indicate that the deposits are no older than the latter part of the cromerian complex stage of east anglia the regional stratigraphic significance of the waverley wood succession is outlined

middle and late pleistocene glacial lakes of lowland britain and the southern north sea basin focusing on lowland britain and the southern north sea basin this article reviews the sedimentary and geomorphic evidence for the main glacial lakes inferred during the middle and late pleistocene and evaluates their impacts on drainage basin development glacial lakes are best known from glaciations during marine isotope stages mis 12 6 and 2 although glacial lakes have also been inferred during mis 10 and 4 some lakes for example bosworth low level humber and the lakes of the eastern fenland margin are reconstructed from unequivocal sedimentary evidence including rhythmites and subaqueous outwash whereas others lakes for example lapworth and fenland are inferred mostly from erosional features and remain to be substantiated the largest known glacial lake developed in the southern north sea basin between an ice sheet to the north and a chalk bedrock ridge in the strait of dover area first during the anglian elsterian glaciation of mis 12 and again during the late wolstonian late saalian drenthe glaciation of mis 6 the palaeohydological impacts of lake drainage are thought to include cutting of the strait of dover as a result of catastrophic drainage from the north sea lake during mis 12 incision of a number of gorges and river valleys in england and diversion or even reversal of major rivers such as the thames and the proto soar avon system recently varve chronologies have been correlated with the greenland ice core record although caution is needed to discriminate between varves and non annual rhythmites future work on pleistocene glacial lakes needs to test chronologies of lake development by luminescence dating of glaciolacustrine sediments deposited in non ice proximal locations 1 fine grained rainout deposits and 2 wave rippled sands deposited in shallow water and to model the impacts of glacial isostasy in order to reconstruct lake extents all of this work should be based on the rigorous application of sedimentology to interpret sedimentary facies and depositional environments

sedimentation and iithostratigraphy of the north sea drift and lowestoft till formations in the coastal cliffs of northeast norfolk england the most complete terrestrial sequence of anglian elsterian glacial sediments in western europe was investigated in northeast norfolk england in order to reconstruct the evolution of the contemporary palaeoenvironments lithostratigraphically the glacial sediments in the northeast norfolk coastal cliffs can be divided into the northn sea drift and lowestoft till formations three of the diamicton members of the north sea drift formation happisburgh walcott and cromer diamictons were deposited as lodgement and or subglacial deformation till by grounded ice but one the mundesley diamicton is waterlain and was deposited in an extensive glacial lake sands and fine sediments interbedded between the diamictons represent deltaic sands and glaciolacustrine sediments derived not solely from the melting ice in the north but also from extra marginal rivers in the south the lowestoft till formation is not well preserved in the cliffs but includes lodgement till marly drift till and most probably associated meltwater deposits extensive glaciotectonism in the northern part of the area is shown to relate to oscillating ice that deposited the cromer diamicton and also partially to the ice sheet that deposited the marly drift till it is suggested that during the anglian stage the present day northeast norfolk coast was situated on the northwestern margin of an extensive glaciolacustrine basin this basin was dammed by the scandinavian ice sheet in the north and northeast because the grounding line of this ice sheet oscillated in space and time part of the north sea drift diamictons were deposited directly by this ice however during ice retreat phases glaciolacustrine deposition comprised waterlain diamicton sands and fines when the scandinavian ice sheet was situated in northernmost norfolk the british ice sheet responsible for depositing the marly drift facies entered the area from the west this ice sheet partially deformed the north sea drift formation sediments in the northern part of the area but not in the south where the british ice sheet apparently terminated in water the interplay of these two ice sheets on the northern and western margins of the glacial lake is thought to be the major determining factor for the accumulation of thick glacial deposits in this area during the anglian glaciation

terrestrial environments during mis 11 evidence from the palaeolithic site at west stow suffolk uk abstract multidisciplinary investigations of the sequence at beeches pit west stow suffolk uk have a direct bearing the age of the hoxnian interglacial and its correlation with the continental holsteinian and with the global marine record at this site glacial deposits till and outwash gravels referable to the anglian lowestoft formation fill a subglacial channel cut in chalk bedrock above these glacial deposits a series of interglacial sediments occurs consisting of limnic tufaceous and colluvial silts lacking pollen but rich in shells ostracods and vertebrates lower palaeolithic flint artefacts of acheulian character have also been recovered including refitting examples charred material is abundant at certain horizons and many of the bones have been burned several discrete areas of burnt sediment are interpreted as hearths the molluscan fauna comprises some 78 taxa and includes species of considerable zoogeographical and biostratigraphical importance the land snail assemblage from the tufa consists of woodland taxa with no modern analogue including species that are either extinct e g zonitoides sepultus or which no longer live in britain e g platyla polita p similis neniatlanta pauli this is also the type locality of retinella lyrodiscus skertchlyi which belongs to a subgenus of zonitid land snail now living only on the canary islands there are indications from this fauna the lyrodiscus biome that the climate was wetter and perhaps warmer than the present day the vertebrate fauna is also noteworthy with species of open habitats such as rabbit oryctolagus cf cuniculus and of closed forest such as squirrel sciurus sp and garden dormouse eliomys quercinus present at different times the occurrence of southern thermophiles such as aesculapian snake zamenis longissimus indicates temperatures warmer than those of eastern england today the upper levels include much material reworked from the interglacial sediments although there is clear faunal evidence for climatic deterioration both the molluscan and vertebrate faunas suggest correlation of the interglacial sediments with the hoxnian uranium series dates from the tufa 455 ka bp tl dates from burnt flints 414 30 ka bp and a range of amino acid racemization data all support correlation of this interglacial with mis 11 however four osl dates from sand beneath the interglacial sequence yield a mean age of 261 31 ka bp far younger than all other age determinations and far younger than implied by the biostratigraphy archaeologically the site is unusual in showing prolonged human occupation within closed deciduous forest and evidence for controlled use of fire in a lower palaeolithic context biostratigraphical correlations with other lower palaeolithic sites support the suggestion that acheulian and clactonian industries both occurred in southern britain during the same substage of the hoxnian although not necessarily at precisely the same time the characteristics of the mis 11 interglacial in britain are discussed in the light of evidence from beeches pit and elsewhere

sea level changes river activity soil development and glaciation around the western margins of the southern north sea basin during the early and early middle pleistocene evidence from pakefield suffolk uk this paper outlines evidence from pakefield northern suffolk eastern england for sea level changes river activity soil development and glaciation during the late early and early mid dle pleistocene mis 20 12 within the western margins of the southern north sea basin during this time period the area consisted of a low lying coastal plain and a shallow offshore shelf the area was drained by major river systems including the thames and bytham changes in sea level caused sev eral major transgressive regressive cycles across this low relief region and these changes are identi fied by the stratigraphic relationship between shallow marine wroxham crag formation fluvial cromer forest bed and bytham formations and glacial happisburgh and lowestoft formations sediments two separate glaciations are recognised the happisburgh mis 16 and anglian mis 12 glaciations and these are separated by a high sea level represented by a new member of the wroxham crag formation and several phases of river aggradation and incision the principal driving mechanism behind sea level changes and river terrace development within the region during this time period is solar insolation operating over 100 kyr eccentricity cycles this effect is achieved by the impact of cold climate processes upon coastal river and glacial systems and these climatically forced processes obscure the neotectonic drivers that operated over this period of time british geological survey natural environment research council copyright 2005 reproduced with the permission of bgs nerc published by john wiley sons ltd

age limits on middle pleistocene glacial sediments from osl dating north norfolk uk the lowland region of north norfolk contains some of the best preserved evidence for glacial deposition during the middle pleistocene in northwest europe despite the importance of these deposits there is limited chronological control and it is debated whether they belong to a single glaciation equated to the anglian glaciation marine isotope stage 12 or represent deposition over a number of middle pleistocene cold stages in order to develop an improved chronology for glaciation in this region we obtained 18 samples for optical stimulated luminescence osl dating from glacial outwash facies samples of coarse grained quartz sand were measured using the sar single aliquot regenerative dose protocol the low radioactive isotope concentrations in sediments of this region enable the traditionally accepted age limit of luminescence dating to be extended the form of the dose response curves pre heat plateaux tests and dose recovery experiments also indicate that laboratory doses can be reliably measured in these samples age overestimation due to partial bleaching is thought to be insignificant the osl ages suggest that the glacial sediments studied were deposited during mis 12 rather than in different post mis 12 stages

reappraisal of middle pleistocene fluvial deposits near brandon warwickshire and their significance for the wolston glacial sequence recent exposures at pools farm pit brandon have allowed a reinvestigation of strat igraphic relationships critical to the debate concerning the status of the wolstonian stage of the british pleistocene central to the original case for maintaining the type site of the wolstonian stage at wolston warwickshire is the acceptance that the fluviatile baginton formation shotton s baginton lillington gravel and baginton sand forms together with the glacigenic wolston formation a series of sediments shotton s wolston series deposited during a single post hoxnian i e post oxygen isotope stage 9 glacial stage evidence presented in this paper suggests this interpretation is no longer tenable the sediments of the baginton formation exposed at pools farm pit record the facies changes identified by shotton in 1968 a predominantly gravel unit the brandon gravels baginton gravel member is overlain by a sandy unit the brandon sands baginton sand member the bounding surface being erosional two newly exposed fine grained organic channel fills are described the brandon lower organic sands and silts lie within the brandon gravels and contain a temperate coleopteran fauna and a boreal forest flora correlation of these organic deposits on fauna1 grounds with the nearby site of waverley wood suggests a correlation with oxygen isotope stage 15 the upper organic silts and clays lie within the brandon sands and contain a cold climate fauna and flora the brandon sands are overlain locally by the brandon upper sands and gravels which are correlated with the ailstone member of the avon valley formation stage 6 the younger avon valley formation is known to extend back to at least stage 9 and therefore given that the wolston formation is younger than the baginton formation as indicated by a borehole nearby it could represent any of the cold stages 10 12 or 14 however stage 12 the anglian remains the most likely attribution

the early pleistocene praetiglian and ludhamian pollen stages in the north sea basin and their relationship to the marine isotope record in this paper the currently accepted correlation of the early pleistocene ludhamian stage of england with the tiglian a sub stage of the netherlands is challenged recent investigations of early pleistocene marine north sea deposits from a borehole near noordwijk the netherlands yielded evidence from molluscs dinoflagellate cysts and sporomorphs for an alternation of warm temperate and arctic intervals within the praetiglian and tiglian stages marine equivalents of the terrestrial based pollen sub stages tiglian a and b have been recognised in the upper part of the sequence a praetiglian age can be assigned to the lower part of the sequence on the basis of mollusc analysis within the praetiglian an alternation of warm and cold phases has been recognised from both the dinoflagellate cyst and molluscan records three cold phases within the praetiglian are tentatively correlated with marine isotope stages mis 96 100 the molluscan assemblages provide evidence for climate forcing of the sea level highest sea levels are reached in the warm temperate intervals within the praetiglian an interval with an acme zone of the dinoflagellate cyst impagidinium multiplexum is correlated with the ludhamian and tentatively linked to mis 97 and or mis 96 the cold molluscan assemblages from the noordwijk borehole include an acme zone of megayoldia thraciaeformis the first and only occurrence of this north pacific bivalve in the north sea basin copyright 2006 john wiley sons ltd

a study of the dynamics of a marine sandwave the movement of the crest of a sandwave was studied using cross sectional profiles obtained from lines of sea bed reference stakes measurements were made over a six month period before and after flood and ebb tides in relation to both spring and neap tides and surface wave conditions additional observations were obtained on a daily basis over an equinoctial neap to spring to neap tidal period in conjunction with boundary layer flow measurements tracer experiments were conducted to study the dispersion of sediment from the sandwave crest the results showed that the sandwave was relatively stable at neap tides whilst at higher tidal ranges the crest position oscillated with successive flood and ebb tides net flank erosion occurred on the less steep upstream slope during the dominant ebb tide this together with increased deposition on the lee slope caused the crest to advance it was not possible to extrapolate sandwave migration over long periods as the tidal dynamic trends were interrupted by wind stress and surface wave activity high particle orbital velocities generated at the sea bed by storm waves caused major reductions in crestal heights calculated volumes of sediment eroded and accreted were used with boundary layer flow measurements to calculate threshold velocities for the movement of the sediment and sediment transport rates

introduction to special section on marine sand wave and river dune dynamics marine sand waves and river dunes are rhythmic patterns formed at the interface between a sandy bed and turbulent flows driven by tidal and river currents their origin development and dynamics are far from being fully understood to enhance the discussion on this topic we organized the international conference marine sand wave and river dune dynamics marid in april 2004 in enschede netherlands scientific papers that originated from the marid conference are presented in this special section this introduction places these papers in the context of recent progress

micromammals from the 1995 mammoth excavation at west runton norfolk uk morphometric data biostratigraphy and taxonomic reappraisal abstract in this paper the small mammals recovered from sediments associated with the west runton elephant have been analysed and compared with sites in other parts of europe major taxonomical problems are indicated and we suggest ways of utilising such morphological complexity to refine biostratigraphical and chronostratigraphic attributions the micromammal assemblage from the west runton elephant site so far totals 16 species from the west runton freshwater bed wrfb there are strong similarities with the arvicolid spectrum of basal layer h8 in the kon prusy c 718 profile czech republic which accumulated under cooler conditions preceding the thermal maximum of an early middle pleistocene interglacial rare steppic indicators e g cricetus at west runton also imply a somewhat cooler and more continental climate than the present day but overall the fauna is fully temperate in character west runton shares several stratigraphically significant small mammal taxa with voigtstedt central germany and morphometric comparisons suggest that voigtstedt may be slightly younger than west runton the presence of mimomys savini with a latest occurrence in the early part of marine isotope stage mis 15 together with the palaeomagnetic evidence suggests the wrfb may have been emplaced during the early part of mis 17 however given the complexity of the marine isotope curve during the early part of the brunhes chron and differences between global and regional climatic evolution it is difficult to assign the normally magnetised wrfb to a particular marine isotope stage mis

the stratigraphical significance of deer species in the cromer forest bed formation deer species provide a valuable biostratigraphical tool through cromer forest bed times due particularly to species turnover between the early and early middle pleistocene this study is based on the reidentification of 348 fossil antlers the provenance of most large mammal fossils from the cf bf collected over 150 years was recorded only by the nearest coastal village none the less analysis of the cervid taxa by these localities reveals interesting patterns the fauna of the west runton freshwater bed is of early middle pleistocene complexion and that from the foreshore at east runton is of early pleistocene pure or nearly pure early middle pleistocene assemblages also occur at kessingland pakefield and at trimingham at overstrand sidestrand mundesley bacton and happisburgh there is a mixture of early and early middle pleistocene elements analysis of savin s data shows that fossils of earlier species were generally found further down the beach than those of later ones late nineteenth century geological surveys made when bone collecting was at its peak give additional information about fossil horizons which in several cases can be related to modern stratigraphical units most early pleistocene large mammal bones came from pastonian conglomerates in contrast to small mammal and molluscan assemblages mostly extracted from pre pastonian crag however the diversity of early pleistocene cf bf cervid species in comparison with continental faunas and their pattern of distribution between sites suggests they may span more than one chronostratigraphic stage early middle pleistocene assemblages came from strata now referred to the cromerian and the differing proportions of taxa between sites provide limited evidence of time transgression

inner shelf to lower shoreface hummocky sandstone bodies with evidence for geostrophic influenced combined flow lower cretaceous west greenland abstract hummocky sandstone bodies were deposited on the margin of an early cretaceous rift basin in an overall progradational inner shelf to lower shoreface unit excellent outcrops of this unit permitted a detailed study of sedimentary structures and paleocurrents in relation to sandstone geometries the sandstone bodies are lensoid and 0 5 4 m thick with lateral extensions from a few meters to more than 30 m laterally they pinch into thin sandstone sheets that continue for at least 130 m along the entire outcrop or swell within a distance of 20 30 m to form another sandstone lens the lower boundaries are sharp with local erosional relief up to 1 m hummocky cross stratification wave ripple cross lamination and low angle cross stratification are closely interbedded within the sandstone aminated mudstone beds 10 60 cm thick separate the sandstone bodies and are generally continuous over the entire length of the outcrop sedimentary structures in the sandstone bodies were produced by high energy wave generated oscillatory currents and unidirectional geostrophic currents vertical stratification successions from individual storm events reflect deposition during both increasing storm current velocity succeeded by waning storm deposits and more typically waning storm facies successions deposition of the unusual vertical successions was probably controlled by an episodically high sediment supply the local presence of the hummocky sandstone bodies on a regional scale was controlled by a paleogeographic setting where the bathymetric contours locally caused geostrophic cu rents to decelerate

comparison between predicted and observed sand waves and sand banks in the north sea for the first time a prediction model of regular morphological patterns on the seabed was tested against observations of sand wave and sand bank occurrence in the entire north sea the model which originates from first physical principles predicts this occurrence via two dimensionless parameters on the basis of the water depth the tidal velocity amplitude the level of zero intercept above the seabed z0 and a viscosity variation parameter alt epsilon the latter two quantities were varied in a number of predictions for the entire north sea whereas for the first two local values were used the range of realistic values of alt epsilon and z0 was large enough to let these two parameters distinguish between the possible combinations of bed forms as is shown in the shallower southern bight of the north sea the results were more sensitive to variations in z0 than in alt epsilon a slightly more detailed approach focused on sand waves only in the southern north sea and estimated local values for z0 using depth information quantification of the results showed that the model was able to predict the contours of the sand wave patches but it could not account for the absence of the bed features within this area the type of bed deposit partly explains the smaller scale variation the work confirms the validity of the theoretical bed form prediction model and verifies the hypothesis that the large scale seabed features are formed as free instabilities of tide topography interactions

dating the earliest lowland glaciation of eastern england a pre mis 12 early middle pleistocene happisburgh glaciation this paper outlines the evidence for the happisburgh glaciation the first middle pleistocene glaciation of lowland eastern england and the adjacent margins of the north sea basin we propose that this glaciation occurred during a pre elsterian anglian mis 12 cold stage based on evidence of clasts of till erratics and heavy minerals from the third youngest terrace of the pre glacial bytham river in southern norfolk the heavy minerals show a progressive increase in glacially sourced materials from the bottom to the top of the bytham river third terrace sediments the till clasts are correlated with the extensive deposits of the happisburgh formation on the basis of their colour heavy minerals and particle size properties thus the happisburgh glaciation occurred during the accumulation of the bytham river terrace deposits and prior to mis 12 when the bytham river system was destroyed by the anglian glaciation in the absence of any geochronology or robust biostratigraphy the age of the happisburgh glaciation is estimated by the synchronisation of the pattern of large scale river activity with patterns of milankovitch forced global climate change on this basis and assuming the british ice sheet acted in phase with global patterns of ice volume the happisburgh glaciation is considered to have occurred during mis 16 and be equivalent of the don glaciation of eastern europe