late holocene erosion in upland britain climatic deterioration or human influence the evidence for enhanced erosion in upland britain during the late holocene is evaluated though there is widespread evidence for recent soil erosion on high plateaux this has not been precisely dated radiocarbon dating confirms the occurrence of late holocene solifluction on high ground but at only one site has evidence been found for recent accelerated activity several areas however have yielded evidence of late holocene debris cone accumulation and parts of the scottish highlands experienced a drastic increase in debris flow activity over the past few centuries climatic deterioration and vegetation degradation resulting from overgrazing or burning are frequently cited as the causes of enhanced erosion but cause and effect are often related only by coincidence of timing in consequence only circumstantial evidence links erosion with climatic deterioration though anthropogenic influences have been more firmly established at a few sites the role of extreme events in initiating phases of uplan

luminescence dating of recent dunes on inch spit dingle bay southwest ireland fifteen samples of dune sand and three samples from a core taken in the beach face were collected from a sand spit which protrudes into dingle bay in southwest ireland the potassium rich feldspar grains from the samples were dated using a single aliquot luminescence protocol for infrared stimulated luminescence irsl signals no ages over 600 years were obtained which demonstrates the youth of the dune forms currently observed the youngest ages were about 150 years old but for these samples the scatter in the equivalent dose obtained as the mean of 18 measurements was higher than for the older samples

lithological anomalies in a relict coastal dune geophysical and paleoenvironmental markers 1 ground exposures of migration surfaces slipfaces of a relict holocene coastal dune along the southeastern baltic sea coast provide an ideal opportunity for establishing the causes of prominent reflections on geophysical profiles high amplitude reflections on high resolution ground penetrating radar gpr images correlate well with two major lithological anomalies 1 paleosols developed on dune slipfaces and 2 slipfaces consisting of heavy mineral concentrations hmcs paleosols serve as indicators of dune stability represent datable chronostratigraphic surfaces and help reconstruct dune paleo morphology hmcs have substantially higher magnetic susceptibility values than background quartz rich sands and where they are well developed can be also used for spatial correlation based on their occurrence at the study site these enriched horizons likely represent periods of increased wind activity storminess multiple hmcs upwind of paleosol p1 800 670 cal years bp likely reflect periods of intensified wind activity along the southeast baltic region during the medieval warm period

late holocene post 4000 years bp coastal dune development in northumberland northeast england the recent environmental history of coastal dune systems in northumberland northeast england has been examined using geomorphological stratigraphical and sedimentological techniques linked to radiocarbon and infrared stimulated luminescence irsl dating stratigraphies were determined from 22 vibracores and three sections and dune chronology was based on 28 14 c dates from peat and soil organic horizons and 26 irsl dates on k feldspar grains from within sand layers almost all dune systems are associated with regressive shorelines consequent upon a fall in relative sea level rsl from its holocene peak and indicate rsl functioned as a macroscale control on dune development where dunes are anchored on terrestrial sediment dune expansion may have been either transgressive or regressive in nature where near shore marine sediments form the dune substrate a regressive prograding dune model seems most likely most dune building occurred during the little ice age lia probably in a

a modelling study of open hole single well seismic imaging single well or uni well imaging uses an acoustic source and an array of receivers located in the same borehole to image local geological structure due to the intrinsic attenuation of the formation it is likely that a source emitting frequencies in the typical cross well range would be necessary to illuminate structure at distances above 100 m from the borehole at these frequencies a significant proportion of the source energy is converted into tube waves from which are for the purpose of these surveys noise this paper reports the results of a modeling study designed to assess the feasibility of using existing cross well hardware i e a piezo electric source and hydrophone array modified to run in a single borehole to perform single well surveys in particular the authors study the case of an open borehole in a gas filled low permeability sandstone reservoir the results suggest that the amplitudes of the tube wave reverberations generated by calliper variations are such that reflections of interest arriving in the time window after the first tube wave arrival will not be visible however reflections may be visible in the time window preceding the first tube wave arrival provided tube waves from previous shots are not still present and the long source receiver offsets requiredmore to make observations in this window can be incorporated into the tool design less

sand drift and soil formation along an exposed north atlantic coastline 14 000 years of diverse geomorphological climatic and human impacts this paper sets out the history of aeolian deposition and soil formation over the last 14 15 000 calendar years along the exposed and gale prone atlantic coastlines of the southern isles of the outer hebrides of scotland detailed palaeoenvironmental interpretation and chronological control have been provided by field mapping soil micromorphological analyses and radiocarbon and optically stimulated luminescence osl dating programmes two dominant types of aeolian sands are described in this region quartzose sands are shown to originate mainly as periglacial wind blown sands derived from glacial and periglacial deposits of late devensian age which were formerly exposed on the present continental shelf this aeolian deposition did however continue into the early holocene with re working perhaps by slope wash taking place as recently as the 4th millenniumbp quartzose sands mantle valley floors and hillslopes by the end of the devensian and early holocene a variety of soil types with extensive horizonation had developed upon them including podzolic brown earths peaty gleys and peat soils radiocarbon and osl dating demonstrate that the carbonate sands of the machair sand sheets which characterize the present atlantic shorelines began to accumulate very early for a european shoreline from approximately 8700 calendar years ago on benbecula and north uist whereas further south deposition began later osl dating suggests that non sequences and diastems are common in greater part these machair sand sheets are best interpreted as a composite of separate slivers of sand reflecting small scale and local episodes of sand drift rather than distinct layers of region wide distribution which might reflect past major storms or significant palaeoclimatic fluctuations the new evidence presented here provides little support for the following explanatory geomorphic or stratigraphic models which have previously sought to explain the development of these coastal machair landscapes continuous development layer cake or step wise prograding coastal barrier qualified support is given for the explanations that emphasize i the long term spasmodic input and re cycling of sands and ii that the present smoothed landscapes and distinctive machair grassland vegetation are essentially recent in age and reflect the interactions of natural and human processes in a stormy environment characterized by re working widespread layers of thick organic materials within the carbonate sands in the study area which have previously been regarded as dune palaeosols dating to the bronze age and iron age are suggested by soil micromorphological analysis to be in significant part anthropogenic in origin they are organically enriched layers or midden soils the consequence of human activities notably the disposal of organic wastes and other forms of soil modification during times of significant settlement in these coastal sands these periods of relatively intense human activity are therefore shown to be associated at least locally with periods of soil formation and stability not universal instability and dune drift along these shorelines in general these extensive layers of midden soil do not necessarily imply periods of decreased storminess relatively widespread soil formation in these coastal dunes did however take place in the period between 400 and 100 years ago essentially within the period of increased storminess associated with the little ice age it is suggested that at some point s within the following periods of time broadly defined in calendar yearsbp notable sand drift affecting the quartzose sands the carbonate sands or both took place within the study area 13 700 13 000 11 000 10 500 9000 8300 7500 7000 6900 6400 5800 4200 one of the most notable episodes of drift in the outer hebrides as well as elsewhere on the coast of north west europe 3800 3300 1700 1300 600 200 with individual great storms being recorded in the 17th and 18th centuries and 100 present day limited drift associated with machair stratification

late holocene inland dune activity in the uk a case study from breckland east anglia inland dune fields found in breckland east anglia uk have previously been correlated with the widespread late devensian coversands of the region and a seventeenth century sandflood which is known to have inundated the village of santon downham a programme of optically stimulated luminescence and radiocarbon dating undertaken on the dunes at wangford warren and santon downham reveals that episodic aeolian activity has taken place during the last 7000 years five sand depositional phases on breckland dunes are identified c 6500 c 1600 1100 c 500 c 400 335 and from c 200 30 years before present between c 2120 1840 years ago and within the period 1100 300 years ago quiescent periods allowed the development of fen peat and soils local controlling factors on aeolian activity in breckland appear to be related to anthropogenic activities and livestock sheep and rabbits reducing vegetation cover and decreased precipitation and sea levels which led to lowering of water tables breckland aeolian activity when compared to the national and sub continental holocene aeolian activity record shows a high level of concordance the underlying forcing factor for late holocene dune activity in the uk and elsewhere in europe appears to be climatic instability in the north atlantic associated with both the little ice age and previous similar events which led to increased storminess climatic variability and lower temperatures

quantification and implications of change in organic carbon bearing coastal dune cliffs a multiscale analysis from the northumberland coast uk eroding coastlines composed of sequences of till carbon rich peat and sand layers are characteristic of many formerly glaciated coastlines due to the interplay of relative land and sea levels dune cliffs cut into these materials represent one of the most sensitive systems to the processes of coastal change establishing appropriate scales for the quantification and analysis of change in coastal dune cliffs remains limited by the speed and nature of change the intensity of environmental processes and the challenges of achieving adequate survey control this paper presents the results from multi scale analyses into the behaviour of dune cliffs on the northeast coast uk over a 118 year period repeat unmanned aerial vehicle uav survey differences have been used to identify and quantify system behaviour set in context with historic map comparisons at the landform scale monthly dune cliff dynamics have been analysed over the course of a year with terrestrial laser scanning tls in order to gain insights into the drivers of contemporary dune cliff behaviour finally pseudo three dimensional ground penetrating radar gpr data are used to trace subsurface stratigraphy from which the potential extent of stored carbon in excess of 100 t over 50 m of monitored dune cliff at risk of release by coastal erosion over the next 50 years can be calculated the consideration of multi scale changes over time periods relevant to well constrained sea level change has revealed a complex combination of failure mechanisms that have resulted in an acceleration in dune cliff recession particularly over the last decade and a form change to shallower divergent profiles this potential acceleration in contemporary dune cliff response holds significant implications for both coastal management and the contribution of this poorly quantified input to the coastal carbon flux

the late holocene coastal dunefield at vejers denmark characteristics sand budget and depositional dynamics abstract the coastal dunefield at vejers west coast of jutland which is now stabilized by vegetation covers an area of approximately 120 km 2 and occurs in a very high energy wind regime along the coastline a narrow belt of 5 15 m high dune ridges occur the dune ridges are gradually replaced inland by 10 20 m high parabolic or irregular dune forms in the central part of the dunefield a large aeolian sand plain ca 50 km 2 occurs at the windward side of a large and up to 20 m high parabolic dune the 3d structure of the dunefield deposits have been studied by geomorphological analysis sedimentological facies analysis of borings trenches and natural exposures and most importantly by georadar mapping the aeolian deposits which overlie a middle to late holocene barrier spit depositional system can be divided into a lower unit that drapes the underlying barrier system topography and an upper unit that includes the present dunes the boundary between the two aeolian units is a well developed phragmites peat the lower aeolian unit is composed of two aeolian subunits separated by an organic rich horizon also the upper unit is composite and composed of a basal aeolian sand cover and overlying dune or sand plain deposits the dune deposits locally are composed of up to four depositional subunits separated by immature soils the base of the lower aeolian unit formed around 300 a d whereas the phragmites peat at the base of the upper aeolian unit has been dated to ca 1000 a d from historical sources we know that the present dunefield primarily formed between 1550 and 1850 a d the sand content in the upper unit is estimated to 550 10 6 m 3 which yields sand transport rates between 25 m 3 m width 1 yr 1 accumulation in 1000 years and 83 m 3 m width 1 yr 1 accumulation in 300 years the sand in the dunefield originated from beach deposits a large but pulsating supply of sand was supplied to the beaches by southwards running coastal currents the composition of the vejers dunefield deposits indicate that periods of dunefield growth alternated with periods of dunefield stabilization during the last ca 1700 years the final and most important phase of dunefield growth took place during the little ice age this period was characterized by an overall cold and stormy climate and a relative low sea level and resulted in an increased availability of sand in the shorezone and a high influx of sand into the dunefield short periods of decreased storminess are recorded by the immature soils dunefield growth prior to 1000 a d was also linked to cold and stormy climatic intervals

evolution of a large baltic beach ridge plain neudarss ne germany a continuous record of sea level and wind field variation since the homeric minimum

negatively skewed aeolian sands from a humid tropical coastal dunefield northern australia abstract this paper describes the nature and environmental significance of variations in textural parameters within a large coastal dunefield in tropical northern australia grain size parameters of modern beaches and foredunes are very similar but are distinct from those of parabolic dune and sandplain environments on average beach and foredune sands have a normal grain size distribution but parabolic dune sands are predominantly negatively skewed negative skewness is interpreted as primarily reflecting sorting of dune sediments by winnowing at dune crests and by avalanching on slip faces a general relationship between mean size and skewness is supported with finer sediments showing increased negative skewness positive skewness can therefore not be used as a diagnostic property of aeolian sediments

development and age structure of holocene coastal sand dunes at horn head near dunfanaghy co donegal ireland two areas of holocene coastal sand dunes on the western side of the horn head peninsula extend from low ground immediately inland of their respective source beaches onto flanking higher ground 100 m od stratigraphic investigations supported by 14c dating of buried organic rich horizons and shells demonstrate several phases of sand accumulation in the pollaguill croaghadara system in contrast to the larger tramore anloge hill system where the available evidence points to relatively recent dune emplacement a broadly synchronous phase of dune development occurred during the thirteenth to fourteenth centuries ad and is viewed as part of a regional northwestern europe dune building episode resulting from climatic deterio ration earlier phases pre 3300 2800 14c years bp of aeolian sand deposition at pollaguill croaghadara have no apparent equivalents at tramore anloge hill and repeated fluvial incision and sand reworking during the last 2000 14c years is also evident at the former site dated organi

arsenic incorporation in natural calcite lattice evidence from electron spin echo spectroscopy abstract quaternary travertines of the middle pecora valley tuscany italy contain up to 257 ppm arsenic such a content is environmentally relevant but low enough to make the exact chemical speciation of arsenic difficult by applying conventional investigation techniques the task was addressed by use of the electron spin echo ese spectroscopy taking advantage from the modulation by the arsenic nucleus of the decay spectrum of the paramagnetic ion mn ii occurring as replacement of ca in the calcite lattice interpretation of the spectra suggests that arsenic occurs in the calcite lattice in the position of c through the substitution co2 3 aso3 3 this mechanism of arsenic incorporation by calcite may be an effective limit of arsenic mobility under conditions where immobilization through sorption by iron and or manganese oxyhydroxides is not operating

mid to late holocene coastal dune event stratigraphy for the north coast of northern ireland an event stratigraphy of dune stability instability phases has been reconstructed using 22 radiocarbon and 13 luminescence dates for six dunefields along the north coast of northern ireland there is no evidence for dune development prior to 7000 cal years bp during the early holocene rapid rise in rsl and only limited evidence for sand accumulation in association with the rsl maximum dunefield dates correspond to either the subsequent regressive phase or later the gradual transgressive phase of rsl history in the mid and late holocene at these times accommodation space for dune development and sediment supply were maximized episodes of climatic deterioration particularly at 3100 2400 cal years bp and 650 50 cal years bp the little ice age were marked by widespread dune instability a similar coincidence in timing has been recorded for dune systems elsewhere in northwestern europe and is generally attributed to an increased frequency of storms and storm surges associated with the climat

episodic coastal dune development in the taean peninsula and anmyeon island korea during the mid to late holocene the episodic nature of coastal dune development has been widely identified in many dune areas over the world what causes such episodicity is still hotly debated sea level change climatic change and human impact have widely been reported as the main forcings though there is no agreement yet upon which factors are critical this research provides some evidence that sea level fluctuation and climatic factors controlled the episodic dune building together based upon optically stimulated luminescence osl dune ages on the west coast of korea the newly obtained and published osl dune ages on the west coast of the taean peninsula and anmyeon island korea indicate the six main periods of dune building 5 5 4 3 1 5 1 3 1 1 and 0 7 ka they correlate with evidence of colder climate in east asia that imply stronger dune forming winds during the winter under the influence of a more intense siberian high they also correlate with periods of higher sea level over the present one with fluctuations thus episodic dune activity along the west coast of the korean peninsula during the mid to late holocene appears to be linked to stronger winter winds capable of moving sand from the beach to the foredune ridges with short term fluctuations during the high stands copyright 2009 john wiley sons ltd

impact of atmospheric circulation patterns on coastal dune dynamics nw spain article i nfo dunes in temperate latitudes have experienced a significant stabilization in recent times essentially as a conse quence of the expansion of dense vegetation cover yet the causes for this gradual stabilization as well as the causes promoting antecedent aeolian mobilization remainpoorlyunderstood the traba coastal dune field located in nw spain was examined to explore the causes inducing aeolian activity and subsequent stabilization since 1940 morphological changes were identified through the combination of aerial photographs and geophysical techniques local wind field regimes were simulated using a regional climate model to obtain the variability of the most relevant modes of atmospheric circulation in the north atlantic and european regions north atlantic oscillation nao eastern atlantic ea and scandinavian scand this allows us to identify the impact of these circulation modes over dune dynamics results document an episode of aeolian activity during the 1950s followed by a gradual stabilization and fixation of the dune coincident with a decrease on storm and wind inten sity yet aeolian sand movement remained active insmall areas blowouts occurring mainly during the summer ne winds associated with a negative phase of the ea explain the movement of sand within the dune field under favorable conditions of sand supply on the other hand sand supply to the dune field from the beach was promoted by nw winds coincident with the summer negative phase of nao during winter the negative nao favored frequent sw winds associated with the passage of intense storms which in turn explain sand remobilization from the beach making sediment available for the nw winds to blow inland with this work it is proven that to understand past and future aeolian activity requires critical consideration of the variability and impact of the two principal modes of atmospheric circulation in the north atlantic nao and ea the scand mode explaining alowerpercentageofthelocalwind fieldvariabilitywasalsoincludedtoachievehigher significance levels of explained variance

complexity of holocene climate as reconstructed from a greenland ice core glaciochemical time series developed from summit greenland indicate that the chemical composition of the atmosphere was dynamic during the holocene epoch concentrations of sea salt and terrestrial dusts increased in summit snow during the periods 0 to 600 2400 to 3100 5000 to 6100 7800 to 8800 and more than 11 300 years ago the most recent increase and also the most abrupt coincides with the little ice age these changes imply that either the north polar vortex expanded or the meridional air flow intensified during these periods and that temperatures in the mid to high northern latitudes were potentially the coldest since the younger dryas event

holocene coastal change and geoarchaeology at howick northumberland uk the recent discovery of one of the earliest mesolithic occupation sites in northern britain at howick on the northumberland coast in association with multiperiod archaeological evidence nearby highlights the importance of uk coastal settings as focii of human occupation through the holocene environmental evidence from a nearby river valley 8 15 m of sediment ranging in age from about 12 000 cal bp to the present records local and regional environmental change twenty four radiocarbon dates based on plant macrofossils provide a strong chronological framework calcareous microfossil assemblages foraminifera ostracods have been recovered from the fine grained sediments recording a change from marine through to brackish and eventually freshwater conditions between about 8200 and 6500 cal bp a preliminary pollen study of the core has permitted a reconstruction of the regional vegetation as it responded to climatic amelioration and human influence upon the landscape radiocarbon dating and sedimentological evidence indicates a major hiatus between approximately 11 000 and 8000 years bp including the period of mesolithic occupation represented by a 30 cm layer of coarse sands and sandstone pebbles probably the result of a significant high energy event dated to about 8300 cal bp although not a typical tsunami deposit the age and context suggests that this may be associated with the storegga slide event already well documented along the eastern coast of scotland the sedimentary and biological remains at howick record environmental change over much of the holocene and are compared with other environmental change records from the region to provide an environmental framework for the archaeology of this coastline

assessment of temporal changes in coastal sand dune environments using the log hyperbolic grain size method three cores 9 m long recovered from late holocene coastal sand dunes in northumberland north eastern england were examined stratigraphically and dated by the infrared stimulated luminescence irsl method to the time period between the medieval warm period mwp 900 1200 ad and little ice age lia 1550 1800 ad grain size variability and caco 3 content were determined at 10 mm intervals throughout parts of the cores the sahara computer program was used to plot the log hyperbolic distribution lhd of grain size spectra from different stratigraphic levels and estimate the lhd s statistical components core samples plot variously in the depositional and erosional domains of the hyperbolic chi vs xi shape triangle which describes components of sediment sorting depositional and erosional phases discriminated within the lhd s shape triangle cannot readily be resolved from core stratigraphies or correlated between cores irsl dates from single cores show a clustering about the period 1430 1540 between the dated horizons dunes accreted at 0 02 0 05 m year 1 enabling the timing of excursions in and to be estimated these excursions which can be resolved to the subannual level between the dated horizons may be related to deposition by episodic storms or storm surges in the north sea region which is supported by historical documentary evidence this innovative use of the lhd method and its derived statistics can be used successfully to describe temporal trends in coastal depositional environments and identify likely storm events in dune sediment records

a new windstorm proxy from lake sediments a comparison of geological and meteorological data from western germany for the period 1965 2001 1 the feasibility of detecting windstorm layers in lake sediments is explored by comparing quartz grain size data from a freeze core obtained from the schalkenmehrener maar eifel region western germany to recent meteorological wind data the schalkenmehrener maar is appropriate for such a calibration study because the morphological settings of the lake allow the conservation of windstorm layers in particular there is no fluvial sediment inflow and long term wind measurements are available from nearby stations the age model for the uppermost 30 cm of the sediment core is based on measurements of 137cs and 210pb concentrations an ultra high resolution grain size analysis is performed digitally on thin sections and reveals distinct 1 mm thick layers with increased quartz grain content and sharp gaussian grain size distributions which are shifted to larger grain sizes compared to the normal lake sediment in order to compare the occurrence of these layers with meteorological wind data a windstorm index is developed combining data from meteorological stations in the eifel region and reanalyses from the european centre for medium range weather forecast a statistical evaluation of matches between the windstorm index and the core s silt fraction data indicates that the sediment layers very likely coincide with the major windstorm events in the eifel region during the last decades six historical storm are identified this pilot study identifies the main requirements and proposes a novel methodological approach for using sediment data from lakes with similar settings as the schalkenmehrener maar as a new proxy to reconstruct the windstorm record of the geological past

optically stimulated luminescence dating of late holocene raised strandplain sequences adjacent to lakes michigan and superior upper peninsula michigan usa this study evaluates the accuracy of optically stimulated luminescence to date well preserved strandline sequences at manistique thompson bay lake michigan and tahquamenon and grand traverse bays lake superior that span the past 4500 yr the single aliquot regeneration sar method is applied to produce absolute ages for littoral and eolian sediments sar ages are compared against ams and conventional 14 c ages on swale organics modern littoral and eolian sediments yield sar ages b100 yr indicating near if not complete solar resetting of luminescence prior to deposition beach ridges that yield sar ages b2000 yr show general agreement with corresponding 14 c ages on swale organics significant variability in 14 c ages n2000 cal yr b p complicates comparison to sar ages at all sites however a sar age of 4280 f 390 yr uic913 on ridge77 at tahquamenon bay is consistent with regional regression from the high lake level of the nipissing ii phase ca 4500 cal yr b p sar ages indicate a decrease in ridge formation rate after 1500 yr ago likely reflecting separation of lake superior from lakes huron and michigan this study shows that sar is a credible alternative to 14 c methods for dating littoral and eolian landforms in great lakes and other coastal strandplains where 14 c methods prove problematic