late holocene sea level changes and isostasy in western denmark abstract cores and exposed cliff sections in salt marshes around ho bugt a tidal embayment in the northernmost part of the danish wadden sea were subjected to 14c dating and litho and biostratigraphical analyses to reconstruct paleoenvironmental changes and to establish a late holocene relative sea level history four stages in the late holocene development of ho bugt can be identified 1 groundwater table rise and growth of basal peat from at least 2300 bc to ad 0 2 salt marsh formation 0 to ad 250 3 a freshening phase ad 250 to ad 1600 culminating in the drying out of the marshes and producing a distinct black horizon followed by an aeolian phase with sand deposition and 4 renewed salt marsh deposition ad 1600 to present from 16 calibrated ams radiocarbon ages on fossil plant fragments and 4 calibrated conventional radiocarbon ages on peat we reconstructed a local relative sea level history that shows a steady sea level rise of 4 m since 4000 cal yr bp contrary to suggestions made in the literature the relative sea level record of ho bugt does not contain a late holocene highstand relative sea level changes at ho bugt are controlled by glacio isostatic subsidence and can be duplicated by a glacial isostatic adjustment model in which no water is added to the world s oceans after ca 5000 cal yr bp

numerical models of lithospheric deformation forming the southern alps of new zealand compression of the entire continental lithosphere is considered using two dimensional numerical models in order to study the influence of the lithospheric mantle on the geometry of continental collision in its initial stages the models are based on the central section of new zealand southern alps where continental collision has occurred along the alpine fault since about 7 ma they incorporate brittle elastic ductile rheology heat transfer surface processes and fault localisation the models are compared to the surface relief the gps convergence velocity the measured electrical conductivity and the geometry of the crustal root imaged from seismic velocity measurements the crustal deformation is characterized by localized uplift at the plate boundary alpine fault and by two secondary zones of faulting one is located about 60 to 80 km east of the alpine fault at the start of upper crust bending or tilting and the other is located about 100 to 130 km east of the alpine fault as a result from shear strain propagating to the surface through the ductile lower crust the observed asymmetric shape of the crustal root is best reproduced for a mantle lithosphere strength of the order of 200 mpa and an intermediate rate of strain softening a lower strength of the mantle lithosphere can produce symmetric thickening but provides an amplitude of the crustal root too small when compared to observations the observed 20 km offset between the maximum in surface relief and the crustal root was not satisfactorily reproduced this offset is most likely due to the three dimensionality of oblique collision in new zealand southern alps

climate control on late holocene high energy sedimentation along coasts of the northeastern atlantic ocean abundant sedimentological and geochronological data gathered on european sandy coasts highlight major phases of increased high energy sedimentation in the north atlantic ocean during the late holocene owing to an inconsistent use of the terminology it is often difficult to determine whether studies have described storm built or wave built deposits both deposits can be identified by overall similar coarse grained sedimentary facies but may provide contradictory paleoenvironmental interpretations the aim of this study is to address this issue by analysing a set of published 14c ages recovered from wave built sediment bodies of the pertuis charentais france integration of 14c data highlights seven coarse grained sedimentation pulses csps that reflect a synchronous increase in wave induced sediment supply occurring around 2650 2420 1240 970 800 650 and 450 cal yr b p csps can be matched with geochronological data published on other exposed sandy coasts of the western europe in first order csps were preserved during phases of decreased storm activity and thus limited coastal erosion in the north atlantic ocean from 2700 to 2000 and from 1200 to 600 cal yr b p in second order csps occurred during positive nao and or negative ea wr peaks which are known from previous studies to induce higher waves and to enhance wave induced sediment transport in the pertuis charentais chronological boundaries of csps could be used as a diagnostic tool to differentiate storm deposits indicative of sudden episodic very high energy sedimentation from wave deposits resulting from the sustained action of above average westerly winds blowing across the north atlantic ocean

wind sedimentation in the jafurah sand sea saudi arabia the jafurah sand sea of the eastern province of saudi arabia extends along the arabian gulf coastline from kuwait in the north to the rub al khali in the south a distance of about 800 km sand drifts southward to south eastward from regions of high wind energy in the north to low wind energy in the south the aeolian landscape is zoned with areas of deflation transport and deposition from north to south drift rates in the zone of transport near abqaiq range from 2 m3 m w 1 yr 1 on sabkhas to 29 m3 m w 1 yr 1 on the crests of dunes average drift rates of approximately 18 m3 m w 1 yr 1 observed during the study can cause about 1 m of accumulation per 5500 yr in a 100 km zone of deposition downwind not including the bulk transport represented by the forward advance of dunes dune advance ranged from 23 m 2 9 m high dune to 3 m 23 m high dune during april october 1980 the study area consists of dune interdune sand sheet and siliciclastic sabkha terrains each of which is characterized by differing drift rates and differing rates of erosion or deposition sedimentation occurs by lateral movement of dunes and interdunes and vertical accretion by sand sheets and sabkhas

marine magnetotellurics imaged no distinct plume beneath the tristan da cunha hotspot in the southern atlantic ocean the tristan da cunha tdc is a volcanic island located above a prominent hotspot in the atlantic ocean many geological and geochemical evidences support a deep origin of the mantle material feeding the hotspot however the existence of a plume has not been confirmed as an anomalous structure in the mantle resolved by geophysical data because of lack of the observations in the area marine magnetotelluric and seismological observations were conducted in 2012 2013 to examine the upper mantle structure adjacent to tdc the electrical conductivity structure of the upper mantle beneath the area was investigated in this study three dimensional inversion analysis depicted a high conductive layer at 120 km depth but no distinct plume like vertical structure the conductive layer is mostly flat independently on seafloor age and bulges upward beneath the lithospheric segment where the tdc islands are located compared to younger segment south of the tdc fracture zone while the bathymetry is rather deeper than prediction for the northern segment the apparent inconsistency between the absence of vertical structure in this study and geochemical evidences on deep origin materials suggests that either the upwelling is too small and or weak to be resolved by the current data set or that the upwelling takes place elsewhere outside of the study area other observations suggest that 1 the conductivity of the upper mantle can be explained by the fact that the mantle above the high conductivity layer is depleted in volatiles as the result of partial melting beneath the spreading ridge 2 the potential temperature of the segments north of the tdc fracture zone is lower than that of the southern segment at least during the past 30 myr

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

ground penetrating radar and its use in sedimentology principles problems and progress abstract ground penetrating radar gpr also referred to as ground probing radar surface penetrating radar subsurface radar georadar or impulse radar is a noninvasive geophysical technique that detects electrical discontinuities in the shallow subsurface

towards realistic aquifer models three dimensional georadar surveys of quaternary gravel deltas singen basin sw germany abstract understanding sedimentary heterogeneities has nowadays become crucial for sophisticated aquifer management the methods used so far for aquifer characterization e g pump test coring analysis cannot provide the needed resolution for a sufficient prediction of the subsurface properties e g sudicky 1986 this calls for the application of the outcrop analogue approach to aquifers e g macfarlan et al 1994 aigner 1995 in this project we used georadar ground penetrating radar or gpr to acquire the subsurface information for high resolution three dimensional images and radar facies mapping of glaciolacustrine delta sediments in the singen basin sw germany a three dimensional reconstruction of sedimentary heterogeneities for a detailed aquifer characterisation becomes possible by combining gpr profiling and outcrop information a case study is presented showing a complex three dimensional architecture of a quaternary gravel body consisting of the following three types of architectural elements 1 glaciolacustrine delta foresets 2 erosional surfaces with scour pool fills and 3 horizontal glaciofluvial gravel sheets although this seems a relatively simple architectural inventory the three dimensional georadar profiling shows considerable internal heterogeneities the radar data are interpreted following the seismic stratigraphic approach i e the delineation of radar facies types and of radar sequences the three dimensional heterogeneities are visualized by means of time slices 3 d block or chair diagrams or series of radar facies maps

8000 years of environmental evolution of barrier lagoon systems emplaced in coastal embayments nw iberia the rocky and indented coast of nw iberia is characterized by the presence of highly valuable and vulnerable small and shallow barrier lagoon systems structurally controlled the case study was se

a holocene coastal aeolian system vejers denmark landscape evolution and sequence stratigraphy stratigraphical studies of holocene aeolian strata formed at the inner margin of the vejers dunefield on the west coast of jutland have contributed to an understanding of aeolian landscape evolution in a storm influenced temperate climate belt the aeolian system was characterized by alternating periods of activity and stabilization intense inland sand transport occurred just after 4000 bc 2300 bc 600 bc and ad 300 500 periods of sand movement were apparently initiated during climatic shifts towards more stormy conditions and they may be linked to a millennial scale cycle in north atlantic holocene climate preservation of the accumulated aeolian sand records a long term rise in ground water level water table behaviour was initially controlled by sea level but after about 2300 bc water table rise was linked to coastal outbuilding and to an overall change towards a more humid climate

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

tidally flooded back barrier dunefield guerrero negro area baja california mexico a 45 km long barrier island exists west of the town of guerrero negro mexico along the western coast of the baja california peninsula about 720 km south of san diego california this barrier has developed in a mesotidal arid climate regime characterized by steady strong onshore winds from the nw the barrier island w of guerrero negro has prograded seaward about 1 6 km in the last 1800 years while an aeolian dunefield fed by sand blown from beaches has advanced inland up to 13 km landward progradation of the dune system from the barrier has occurred during relative rise in sea level thus aeolian sediments exist at or below the water table over a wide area the progradation of dunes across marshes tidal flats and tidal channels as well as the repeated submergence of interdune areas by tidal waters has created a complex suite of mixed aeolian and subaqueous sediments in the back barrier the complexity of the suites of aeolian sedimentary structures together with the inclusion of subaqueously formed structures such as current and oscillation ripples would make recognition of the aeolian origin of much of the sediments difficult in ancient rocks in addition to the scientific importance of recognizing the aeolian deposits the sedimentation model represented by the guerrero negro barrier has applications in petroleum exploration and development currently most preservational models for barrier islands attach little volumetric importance to aeolian deposits this modern example suggests that volumetrically significant aeolian deposits can be preserved behind a barrier particularly in an arid climate regime if preserved and charged with oil the resulting productive sandstone could have an extremely irregular landward edge comprised in part of onshore prograded aeolian dune sandstone with excellent reservoir characteristics as with current barrier models the reservoir would be sealed landward and above by lagoonal mudstone and silt evaporites or evaporitic sandy sabkha deposits high organic productivity occurs in lagoons immediately adjacent to the dunefields of guerrero negro suggesting that organic rich source rock may exist near aeolian sandstone in ancient settings similar to guerrero negro

the impact of north atlantic storminess on western european coasts a review abstract instrumental and documentary records of storminess along the atlantic coast of western europe show that storm activity exhibits strong spatial and temporal variability at annual and decadal scales there is evidence of periods of increased storminess during the little ice age lia ad 1570 1990 and archival records show that these periods are also associated with sand movement in coastal areas independent evidence of sand movement during the lia is derived from dating the coastal sand deposits using luminescence or radiocarbon methods the holocene record of sand drift in western europe includes episodes corresponding to periods of northern hemisphere cooling particularly at 8 2 ka and provides the additional evidence that these periods like the lia were also stormy

geochemical and isotope identification of warm groundwaters in coastal basins near tauranga new zealand abstract chemical and isotope analyses of warm waters from wells and springs in the coastal basins extending from katikati to maketu on the bay of plenty coast of the north island new zealand are examined except for a small number influenced by shallow seawater intrusion most of the waters are potable although they have been underground for up to thousands of years there is no evidence that the waters have ever encountered high temperature geothermal conditions rather each sample has acquired a chemical signature characteristic of the igneous rocks it has encountered while circulating underground it is possible to distinguish waters predominantly influenced by andesitic or rhyolitic host rocks on the basis of the molar ratio na k ca mg bicarbonate contents reach relatively high values in some localized areas

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

unveiling past aeolian landscapes a ground penetrating radar survey of a holocene coastal dunefield system thy denmark abstract the southern part of the hvidbjerg coastal dunefield and the adjacent part of the lodbjerg coastal dunefield system in northwestern denmark has been mapped using ground penetrating radar coastal cliff exposures and 14 c datings indicate that the presently stabilized dunefield is underlain by a 10 15 m thick succession of holocene aeolian sand deposits and interbedded peaty palaeosols this succession is superimposed on a weichselian till towards the south and a mid holocene beach ridge and swash bar complex towards the north the peaty palaeosols represent preceding periods of dunefield stabilization these palaeosols reveal ages about ad 1100 1200 700 bc and 2100 bc and act as marker horizons in the study area more than 16 km of high resolution gpr data covering an area of 6 km 2 were collected in the near coastal part of the dunefields and enabled a correlation of these marker horizons across the dunefields these data allowed the elaboration of topographic subsurface and isopach maps and enabled an interpretation of the accumulation history of the aeolian system since about 2200 bc this accumulation history tells of alternating periods with a stabilization of the dunefields and periods with high sand accumulation basically a perched ground water level and the morphology of the previous stabilized dunefield made it possible to generate an accumulation space large enough to preserve the sand during periods with stronger winds and marked aeolian activity this 3d mapping of the stabilized dunefield subsurfaces has made it possible to unveil the development of the past aeolian landscape

combining ground penetrating radar surveys and optical dating to determine dune migration in namibia ground penetrating radar gpr profiles across a complex linear dune in the namib sand sea have been used to image sets of cross stratification and their bounding surfaces a combination of radar facies analysis and radar stratigraphy has been used to interpret the radar profiles and define a relative chronology thick sets of cross stratification indicate when the dune was most active whereas thin sets of cross stratification are interpreted to indicate the increased prevalence of wind reversals and lower rates of dune migration with bounding surfaces formed during periods of stabilization non deposition or erosion a drilling and dating campaign was designed on the basis of the dune stratigraphy as defined by the gpr survey sampling was targeted at large sets of cross stratification formed when the dunes were most active and avoiding bounding surfaces formed when the dune was stable or even eroded the results from optical dating give ages between 0 34 0 02 ka and 1 57 0 07 ka indicating a time averaged dune migration rate of 0 12 m a 1 over the past 1600 years

sources of solutes and heat in low enthalpy mineral waters and their relation to tectonic setting new zealand abstract approximately 90 of the low enthalpy spring systems in new zealand are distributed along the present day convergence of the pacific and australian plates which varies from subduction to oblique plate collision forearc subducted waters rising in the hikurangi accretionary prism consist of pore waters containing labile organic material water of hydration from clays and seawater these subducted waters are traceable in the north island axial ranges and the northern marlborough fault system in the south island albeit modified by temperature mixing with surface and heated meteoric waters and protracted interaction with the rock the signature of subducted marine sediments in the hikurangi trench is retained in the chemical and isotopic compositions of the taupo volcanic zone magmatic arc type waters the concentrations of b ba br ca cl i k li mg na rb and sr solutes found in high concentrations in forearc subducted waters increase from northeast to southwest towards the incipient subduction zone in the puysegur trench southwest of south island most thermal mineral waters in the south island are expelled along the alpine fault zone where plate collision results to rapid uplift of the southern alps elevated geothermal gradients and fault shearing of rocks in the alpine fault zone variations in temperatures 175 30 c and mineral water compositions are affected by elevation hydrological gradient intensity of tectonic activity permeability fluid volume and rate of throughput and rates of uplift as the main trace of the alpine fault zone is approached concentrations of cl and other solutes generally increase suggesting increasing contributions from ascending cl rich metamorphic waters outside the active convergent zone low enthalpy springs discharge diagenetically modified ancient forearc waters na cl sedimentary formation waters and heated seawater na hco 3 cl waters and na hco 3 deep circulating heated meteoric waters the total surface heat flow in the north island low enthalpy mineral waters is more than 10 higher than in the south island with projected subsurface temperatures as high as 250 c this is because of the widespread occurrence of shallow magmatic and mantle sources associated with pliocene to holocene volcanism and back arc continental rifting the sources of heat and solutes in low enthalpy mineral waters outside the taupo volcanic zone and ngawha are decoupled except for rapidly ascending hot pore waters in the hikurangi accretionary prism and low temperature serpentinization ca cl waters in fiordland

sediment transfer from beach to shoreface the sediment budget of an accreting beach on the danish north sea coast abstract the sediment budget along the southern part of the exposed danish north sea coast was assessed through a combination of cross shore profile analysis numerical modeling and field measurements of cross shore and longshore sediment transport at the boundary between the upper and the lower shorefaces the beaches along this coast are accreting but observed sediment storage is far smaller than sediment supplied by southerly directed wave driven currents the excess sediment volumes are transferred seaward across the shoreface by systematically offshore migrating nearshore bars that deliver sediment to the lower shoreface from where it is eventually removed by northward directed wind generated currents in the geological past sediment storage rates were much larger than at present and it is likely that the rate of storage along this coastline decreased as shoreface geometry adjusted towards equilibrium associated with shoreface steepening

foredunes and blowouts initiation geomorphology and dynamics this paper reviews the initiation dynamics geomorphology and evolution of incipient foredunes established foredunes and blowouts incipient foredunes may be initiated in a variety of ways leading to the formation of ramps terraces or ridges depending on progradation rates vegetation type and cover sediment transport rates and scale of erosional processes vegetation cover morphology growth rates and types combine with aerodynamic processes to determine dune and swale morphology established foredunes are classified into five morpho ecological types and the flow behaviour over two types is detailed a new model of foredune evolutionary paths at various possible time scales is presented blowout initiation dynamics and sediment transport and evolution is examined throughout the review the gaps in present understanding of dune processes and a range of ideas for new research possibilities are provided

evolution of a dune from crescentic to parabolic form in response to short term climatic changes rabjerg mile skagen odde denmark abstract rabjerg mile a complex parabolic dune reaches a height of 20 m above the deflation plain the width of the dune is 900 m and the length of the whole dune is 1500 m the dune is covered by 0 5 1 5 m high transverse dune ridges the dune has migrated approximately 1 km since 1887 a d accompanied by a change in the migration direction from ese 100 to ene 68 the morphology of rabjerg mile through the last 100 years is illustrated by a geographical information system arc info applied to a series of high quality topographical maps based on the digitized contour lines the evolution of rabjerg mile can be followed from an initial crescentic form in 1887 a d to a complex parabolic dune in this century dune dynamics and sites of erosion and deposition are evaluated from the digital terrain models changes in vegetation cover documented from the maps and air photos indicate that vegetation in the study area steadily increased with time calculations of resultant drift directions and gross bedform normal transport are based on climatic data from the skagen changed from an almost perfect transverse bedform 1887 1924 to an oblique imperfectly transverse bedform 1966 to present the bedform alignment followed the gross bedform normal transport rule in most years the evolution of a parabolic dune after 1924 is related to a period of reduced wind energy and increased vegetation cover this parabolic dune was maintained after 1960 when wind energy increased and the wind regime was more complex at the same time the dune became markedly asymmetric because of the frequent occurrence of strong southerly and easterly winds

variations in chemical composition and particle size of dune sediments along the west coast of jutland denmark abstract geochemical and textural variations in frontal dune sediments along the western coast of jutland denmark have been investigated in order to identify possible sediment provinces and transport pathways an understanding of sediment sources and sinks is important for both for an understanding of the nature of sedimentary environments and for applied coastal engineering and management purposes four coastal sectors were identified on the basis of geochemical composition one sector is compositionally different from the other three units having higher concentrations of the trace elements ni cr v sc zn pb ba zr and many rare earth elements dune sediments on this section of coast also have higher al2o3 to k2o ratios and lower al2o3 to fe2o3 ratios reflecting a lower content of feldspar and higher content of heavy minerals it is inferred that different or additional sediment source s have supplied sediment to this section of coast beach nourishment has contributed to the observed compositional differences but previous data obtained from the lodbjerg area indicate that aeolian sands on this section of coast naturally have a relatively high si fe and ti content reflecting high quartz feldspar ratio and relatively high content of heavy minerals compared with those on other sections of the coast frontal dunes along the most northern section show high abundances of k2o rb and ba reflecting a relatively high k feldspar content derived from local sources alongshore trends were also identified in the mean particle size and sorting of the frontal dunes although there is no direct correspondence with the observed geochemical differences three coastal units can be identified on the basis of particle size frontal dune sediments in the middle section are relatively coarser and less well sorted than those to the north and south probably reflecting both the addition of beach nourishment material and greater exposure to strong westerly winds which are a capable of transporting a wide range of particle sizes the three units defined on this basis do not correlate directly with the units defined on the basis of geochemical composition

late holocene sand invasion and north atlantic storminess along the aquitaine coast southwest france holocene forested coastal dunes of different morphology fringe the atlantic coast of southwest aquitaine infra red stimulated luminescence irsl dating has been applied to sands from these dunes in the aquitaine region in order to test the validity of dune classification theories the ages obtained from the dunes show three phases of sand invasion and dune development during the late holocene 3000 4000 years ago 900 1300 years ago 250 550 years ago the timing of the most recent phase of sand mobilization as dated by irsl is supported by historical maps and records from the fifteenth to the eighteenth centuries ad showing problems for human settlement in the region and village abandonment due to dune drift sand invasion is driven by an increase in frequency of severe storms in the north atlantic associated with the cooler periods of the little ice age and early mediaeval warm period the dunes emplaced 900 1300 years ago were naturally fixed by a mixed deciduous and maritime pine forest durin

storminess variation during the last 6500 years as reconstructed from an ombrotrophic peat bog in halland southwest sweden cores taken from an ombrotrophic peat bog in the coastal zone of halland southwest sweden were examined for wind transported mineral grains pollen and humidity indicators the core covers the period from 6500 cal yr bp to present ombrotrophic conditions existed from ca 4200 cal yr bp onwards bog surface wetness fluctuated strongly until ca 3700 cal yr bp with an apparent dominance of dry summer conditions from 4800 4500 cal yr bp local wet shifts occurred around 4300 2800 2400 and 1500 cal yr bp whereas the most recent 600 years of the record show increasingly dry conditions mineral grain content interpreted as aeolian sand influx asi was used as a proxy for winter storm frequency and intensity until ca 1500 cal yr bp after which increasing human impact as reconstructed by pollen analysis became a second important potential cause for increased sand drift strongly increased storminess occurred at 4800 4200 2800 2200 1500 1100 and 400 50 cal yr bp indicating a dominance of cold and stormy winters during these periods many of these storm periods apparently coincide with storm events in other sites in southwestern scandinavia suggesting that our asi record reflects a regional scale climatic signal furthermore these stormy periods correlate to well known cold phases in the north atlantic region suggesting a link to large scale fluctuations in atmospheric circulation patterns less

a middle late quaternary age for the adakitic arc volcanics of hautere solander island southern ocean abstract hautere solander island and five nearby mainly submerged volcanic centres represent the only known subduction related volcanism on the australian pacific plate boundary south of new zealand two new ar ar biotite ages from hautere indicate magmatism they were active between 150 and 400ka middle to late quaternary this contrasts with the previously proposed pliocene to early quaternary age range based on less well constrained k ar dating the new radiometric ages are consistent with revised pollen ages new trace element analyses confirm the subduction related and adakitic nature of the igneous rocks

sedimentary architecture of a plio pleistocene proto back arc basin wanganui basin new zealand the sedimentary architecture of active margin basins including back arc basins is known only from a few end members that barely illustrate the natural diversity of such basins documenting more of these basins types is the key to refining our understanding of the tectonic evolution of continental margins this paper documents the sedimentary architecture of an incipient back arc basin 200 km behind the active hikurangi subduction margin north island new zealand the wanganui basin wb is a rapidly subsiding plio pleistocene sedimentary basin located at the southern termination of the extensional back arc basin of the active central volcanic region tvz the wb is asymmetric with a steep thrust faulted outer arc ward margin and a gentle inner craton ward margin it contains a 4 km thick succession of plio pleistocene sediments mostly lying offshore composed of shelf platform sediments it lacks the late molasse like deposits derived from erosion of a subaerial volcanic arc and basement observed in classical back arc basins detailed seismic stratigraphic interpretations from an extensive offshore seismic reflection data grid show that the sediment fill comprises two basin scale mega sequences 1 a pliocene 3 8 to 1 35 ma sub parallel regressive bpre growthq sequence that overtops the uplifted cratonward margin above the reverse taranaki fault and 2 a pleistocene 1 35 ma to present divergent transgressive bsyn growthq sequence that onlaps i the craton ward high to the west and ii uplifted basement blocks associated with the high angle reverse faults of the arc ward margin to the east along strike the sediments offlap first progressively southward mega sequence 1 and then southeastward mega sequence 2 with sediment transport funnelled between the craton and arc ward highs towards the hikurangi trough through the cook strait the change in offlap direction corresponds to the onset of arc ward thrust faulting and the rise of the axial ranges at ca 1 75 ma resulting in 5100 5700 m of differential subsidence across the fault system sedimentation has propagated south to southeast ward over the last 4 myrs at the tip of successive back arc graben volcanic arcs and the associated thermally uplifted parts of the north island following the southward migration of the hikurangi subduction margin subsidence occurred by mantle flow driven flexure the result of active down drag of the lithosphere by locking of the hikurangi subduction interface and sediment loading the wb is considered to be a proto back arc basin that represents the intermediate stage of evolution of an epicratonic shelf platform impacted by active margin processes

late holocene intensification of colds fronts in southern brazil as indicated by dune development and provenance changes in the sao francisco do sul coastal barrier abstract holocene coastal barriers from southern brazil present great geomorphological changes during their late stages of development in this study we investigate the holocene evolution of the sao francisco do sul sfs barrier through geomorphological heavy minerals and grain size analyses constrained by optically stimulated luminescence osl dating the sfs barrier stands out among the southern brazilian barriers due to its well preserved morphology with a parabolic dune belt in the seaward portion the progradation of the sfs barrier started at least 4914 478 years ago and had a pronounced morphodynamic shift around 1891 155 years ago this shift is characterized by episodic development of parabolic dunes migrating to nnw associated with sand coarsening and a marked variation in sediment provenance represented by the input of sands derived from local coastal watersheds southward from the sfs barrier this morphodynamic provenance shift resulted from the strengthening of sse winds and associated wave systems responsible for the northward alongshore drift implying intensification of cold fronts coupled with higher precipitation since 1891 155 years ago osl dating combined with grain size heavy minerals and geomorphological analyses allowed assessing the response of coastal barriers to the impacts of centennial to millenial climate events occurred during the late holocene reconstruction of the late holocene climate variability and associated impacts on coastal sedimentation is a key issue to evaluate the sensitivity of coastal barriers to future climate changes

aeolian sand movement and relative sea level rise in ho bugt western denmark during the little ice age this study documents an extensive aeolian sand sheet buried in the salt marshes of the ho bugt embayment in western denmark the extent of the sand sheet was mapped from c 60 cores and sections which were also used to reconstruct late holocene changes in relative sea level based on diatom analyses chronology was provided by optically stimulated luminescence osl and radiocarbon dating our study shows that since 2000 cal yr bp relative sea level in ho bugt has risen by approximately 1 5 m the overall rise was punctuated by two periods with higher than average rates of sea level rise the first between 2000 and 1400 cal yr bp and the second commencing c 500 cal yr bp around 700 cal yr bp the evolution of the skallingen spit may have been responsible for a reduction in the local tidal range and the formation of an extensive black layer in the western part of the embayment osl analyses date the sand sheet to between ad 1460 40 and ad 1550 30 490 40 and 400 30 cal yr bp consistent wi

environmental controls on coastal dune formation skallingen spit denmark abstract many coastal dune systems in western europe were emplaced during the little ice age lia the formation of such dune fields has generally been ascribed to a combination of low sea level and strong winds during that time period providing a supply of sand from the exposed shoreface and sufficient wind energy to transport this sand landward however little information exists on the processes that controlled sediment supply to the beach and why this onshore supply was initiated at all in this contribution we consider the origin and development of older dune fields on a barrier spit complex skallingen located in the northern part of the danish wadden sea maps and new data on dune litho and chrono stratigraphy the latter based on osl dating allow a precise estimate of the initiation and termination of dune emplacement dune formation at skallingen started at a relatively late stage of the lia and it can be temporally correlated with a phase of relative sea level rise in north western europe and with a high frequency of storm surges along the danish west coast these are the conditions during which nearshore bars currently migrate onshore across the shoreface off skallingen the bars eventually merge with the beach and constitute a source of sand for modern foredune accretion it is probable that the onshore bar migration occurred under similar conditions in the past and the migration was triggered or enhanced by the sea level recovery from the mid lia low stand and the associated frequent storm surge activity consequently at skallingen onshore sand supply was caused by marine rather than aeolian agents this supply provided the basis for subsequent dune formation indications are however that the sediment supply to the beach dunes was a factor of 2 3 larger in the past dune aggradation eventually ceased around 1900ad because of dyke construction hence the association between dune formation and sea level surge variation at skallingen is somewhat contrary to other statements of coastal dune development during the lia in north western europe

storm generated eolian sand shadows and their sedimentary structures vejers strand denmark abstract two morphological types of shadow dunes tongues and ridges were observed after a recent storm on the west coast of jylland denmark sand shadow tongues form where vegetation is a weak obstruction to the sand transporting wind whereas sand shadow ridges form behind vegetated coastal dunes which interact more effectively with the wind the sand shadow tongues consist of low to medium angle dipping strata which dip in a uniform direction and reflect almost uninterrupted downwind transport of sand the longitudinal ridges consist of medium to high angle cross strata which are bidirectional and reflect secondary winds that blow obliquely towards the crest line of the dune three kinds of oppositely dipping cross strata occur 1 tepee like cross strata 2 chevron like cross strata with both stoss side and lee side laminae preserved double bundles and 3 chevron like cross strata with only lee side laminae preserved tepee like cross strata form during vertical accretion of the dune ridge whereas the chevron like pattern forms when the dune crest migrates from side to side if the angle of climb of the toss side is supercritical stoss side laminae are preserved and double bundles are formed the cross strata contain a significant amount of plane bed stratification due to their formation during high wind velocities

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

stokes surfaces and the effects of near surface groundwater table on aeolian deposition abstract stokes surfaces in aeolian deposits are caused by wind scour of unconsolidated material to a roughly planar horizon controlled by near surface water tables stokes 1968 a water table forms a downward limit of scour through the cohesion of damp or wet sand near water table and through early cementation by evaporites precipitated in the sediments as water evaporates near the sand air interface study of modern analogues reveals that stokes surfaces exist in a variety of depositional settings including a coastal offshore prograding sand sea jafurah saudi arabia a coastal onshore prograding sand sea guerrero negro mexico and a continental sand sea white sands new mexico usa these modern analogues indicate that our concept of stokes surfaces must be broadened to include the following i modern analogues for stokes surfaces described here cover areas on the order of 25 km2 these may be as representative of similar surfaces in ancient rocks as hypothesized plains of deflation requiring removal of entire sand seas ii stokes surfaces occupy a continuum in scale from local to extensive and erosional surfaces of different magnitude may be stacked closely in the sediments iii stokes surfaces although erosional in nature are commonly associated with deposits both above and below the stokes bounding surface which plainly reveal the influence of a near surface groundwater control on wind sedimentation moreover the erosional relief of the bounding surface itself as well as other features reveals the influence of a groundwater table iv stokes surfaces may be diachronous representing the lateral shift of a zone of scour within a sand sea rather than simultaneous removal of all dunes from the area encompassed by the erosional surface v stokes surfaces and associated deposits are often laterally transitional to surfaces and deposits of adjacent depositional environments including interdunes tidal flats lagoons beaches lakes and non aeolian sabkhas finally modern examples from different depositional settings suggest that while most stokes surfaces have many features in common such as erosional ridges due to early cementation there are some features which may with further study be revealed to be distinctive of an individual depositional setting

a sand budget for the alexandria coastal dunefield south africa the sand in the alexandria coastal dunefield is derived from the sandy beach which forms the seaward boundary of the dunefield sand is blown off the beach onto the dunefield by the high energy onshore directed dominant wind the dunefield has been forming over the past 6500 years sand transport rates calculated from dune movement rates and wind data range from 15 to 30 m3 m 1 yr 1 in an ene direction the sand transport rate decreases with increasing distance from the sea due to a reduction in wind speed resulting from the higher drag imposed upon the wind by the land surface aeolian sand movement rates of this order are typical of dunefields around the world the total volume of sand blown into the dunefield is 375 000 m3 yr 1 sand is being lost to the sea by wave erosion along the eastern third of the dunefield at a rate of 45 000 m3 yr 1 the dunefield thus gains 330 000 m3 of sand per year this results in dunefield growth by vertical accretion at about 1 5 mm yr 1 and landward movement at about 0 25 m yr 1 the dunefield is a significant sand sink in the coastal sand transport system the rate of deposition in coastal dunefields can be 10 times as high as rates of deposition in continental sand seas the higher rate of deposition may result from the abundant sand supply on sandy beaches and the higher energy of coastal winds wind transport is slow and steady compared to fluvial or longshore drift transport of sediment and catastrophic aeolian events do not seem to be significant in wind laid deposits

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

influence of organic matter in soils on radar wave reflection sedimentological implications abstract soils are excellent reflectors of ground penetrating radar gpr signals because of the ability of organic matter to hold water in this paper gpr profiles of an eolian sedimentary succession are combined with textural dielectric and moisture retention characteristics to illustrate the influence of soil moisture on radar wave reflection organic matter in this succession varies strongly from lt 0 15 for clean sand to 7 for the most prominent soil whereas grain size distributions are comparable moisture retention curves show a complex relationship between suction potential pf and volumetric water content as a result of their uniform pore size distribution clean sand and weakly developed soils with lt 1 organic matter experience a sudden loss of water between pf 1 5 and pf 1 8 going directly from saturated to almost dry conditions in contrast the most prominent soil shows a more gradual decrease in with increasing suction potential it follows that the dielectric contrast between clean sand and this soil increases sharply above pf 1 5 reaches a maximum value at field capacity conditions and then decreases slowly synthetic gpr images for different suction potentials show that field capacity conditions when reflection coefficients are high are favorable for tracing one single soil dry sediments are preferable when imaging widely spaced soils whereas saturated sediments are best when imaging closely spaced soils

the termination of the last major phase of aeolian sand movement coastal dunefields denmark optically stimulated luminescence osl dating of sand samples from stabilized or inactive coastal dunes in denmark provides information on the age of the termination phase of the last major aeolian activity period a total of 26 sand samples were taken from four different coastal dunefields around the north sea skagerrak and kattegat coasts of denmark the osl dates indicate that the last major phase of aeolian activity terminated between ad 1860 and 1905 most of the dunes examined in this study were active around 1820 during a period documented to have been very stormy a dune management scheme started around 1792 and this no doubt was a major cause of dunefield stabilization but an overall decline of storminess particularly spring and summer storminess around the end of the 19th century must also have contributed to the increasing inactivity of coastal dunes the new osl dates on aeolian sand movement agree well with historical data and data from topographic maps on dune movement this agreement supports the observation from earlier work that osl dating of recent aeolian sand movement is accurate over the last few decades to centuries copyright 2005 john wiley sons ltd

pliocene exhumation and landscape evolution of central north island new zealand the role of the upper mantle 1 mudstone porosity analyses show that over 2 km of exhumation has occurred in central north island new zealand since 5 ma this combined with a coeval surface uplift of 500 m indicates a maximum 2 5 km of rock uplift in central north island the magnitude and wavelength 400 km of the rock uplift is similar to some topographic doming observed in continental areas associated with mantle upwelling yet central north island is recognized as a region of back arc extension marine terraces 100 150 km from the center of maximum exhumation show uplift rates of 0 2 0 3 mm yr 1 consistent with about 1 km of exhumation if averaged over 4 5 myr which compares well with mudstone porosity analyses seismic attenuation and slow pn velocities indicate that a thermal anomaly in the upper mantle is the source of this rock uplift the rock uplift may be explained by the replacement of a 100 km thick mantle lid by asthenosphere with a density 66 kg m 3 less than the lid about half this density contrast can be explained by thermal expansion and the rest is ascribed to partial melts in the upper mantle southward migration for the locus of maximum rock uplift is consistent with the zone of maximum incision erosion being 50 km south of the southernmost volcano such a migration is in keeping with other geological markers of volcanic and thermal phenomena and further strengthens the link of landscape evolution at active continental margins with processes in the mantle

formation of bedrock cut ventifacts and late holocene coastal zone evolution county donegal ireland abstract wind etched rocks ventifacts at gweebarra bay county donegal northwestern ireland are located 2 m above mean high water springs mhws on a glacially eroded bedrock shore platform 10 m wide 200 m long at mhws prevailing southwesterly winds transport sand across the platform from the adjacent beach ventifacts found on the windward most 20 m of the platform decrease in frequency and degree of wind alteration with distance near the beach ventifacts have two to three wind etched faces facets both linear and serrated keels and are pitted grooved and polished farther from the beach ventifacts are less frequent have fewer facets pits and grooves and show curved keels facets nearest the beach lie perpendicular to prevailing winds but are wind parallel farther away this reflects structural control on the shape and orientation of bedrock blocks protruding into the wind stream nine possible ventifact morphologies are identified on the basis of wind approach angle and dip angl

effects of storminess sand supply and the north atlantic oscillation on sand invasion and coastal dune accretion in western portugal holocene forested coastal dunes fringe the atlantic coast of western portugal mapping of dunes in the field and using air photographs shows a range of forms reflecting dominant northwest and westerly onshore wind regimes planting of maritime pine forests in the thirteenth and twentieth centuries was initiated because of sand invasion causing problems for human settlement and agriculture early holocene dunes have a well developed podsol and date to 9 7 and 8 2 ka suggesting at least some of these sands may have been emplaced during a global cooling event significant transgressive dune accretion at 2 2 and 1 5 ka implies abundant sand supply and strong onshore winds the most recent dune building period dates to ad 1770 1905 and coincides with a predominantly negative winter north atlantic oscillation index naoi accretion of dunes along the portuguese coast appears out of phase with dune development in southwest france which may reflect different atlantic storm tracks driven by changes in the domin

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

slow slip and frictional transition at low temperature at the hikurangi subduction zone temperature changes with depth do not appear to be a primary control for either slow slip or fault locking processes at the hikurangi margin north island new zealand both slow slip events and the geodetically observed transition from fault locking to free slip at depth occur at temperatures as low as 100 c shallow portions of faults exhibit brittle stick slip behaviour that gives way to more stable sliding with increasing depth limiting the depths to which earthquake inducing slip can occur the increase of temperature with depth is often assumed to transform friction in the fault from velocity weakening unstable to velocity strengthening stable and to change conditions from brittle to ductile1 2 3 4 5 a temperature of 350 c has been suggested to mark the base of the frictionally unstable portion of the fault which becomes free slipping at depth where temperatures rise above 450 c refs 2 4 6 here we show that both slow slip events and the geodetically observed transition from fault locking to free slip at the hikurangi subduction zone east of the north island new zealand occur at temperatures as low as 100 c suggesting that temperature is not a primary control on either slow slip or fault locking processes at the hikurangi margin although globally shallow slow slip events are rare five out of seven events observed so far at the hikurangi margin are less than 15 km deep

storm controlled oblique dunes of the oregon coast the large mean height 25 m spacing 300 m relatively straight crested dunes of the central oregon coast migrate an average of 3 8 m yr toward an azimuth of 26 the dunes are transverse to the strong south southwesterly winter storm winds that are responsible for their basic form orientation and migration the dry moderate north northwesterly summer winds modify the dune form but not the dune trend comparison of the sand transport calculated from wind data and the transport measured from dune migration indicates that the actual transport by the wet southerly winds is only one third of the amount calculated assuming dry conditions the resultant vector mean transport rate as recalculated by comparison of the measured and initially calculated rates is 34 m 3 m yr toward an azimuth of 45 the dunes are thus oblique by our definition of an oblique dune angle between dune trend and resultant transport direction between 15 and 75 the internal structures of the dunes confirm northward migration during wet conditions evidence for deposition during wet conditions includes slipface deposits deformed mostly by sliding and various structures formed by the adhesion of sand grains to wet surfaces most summer deposits are not preserved but those on the basal apron the gentle north slope at the base of the winter slipface have a high preservation potential a depositional model based on dune climbing predicts that the preserved record of oblique dunes formed by an obtuse bimodal wind regime would consist of tabular sets of crossbeds in which the dip angles increase upward from the base of each set

an 8000 year record of sea level change from grain size parameters data from beach ridges in denmark the low energy beach ridge system near the town of jerup in the extreme north of denmark was sampled at 154 sites on a pattern of one per ridge intervals of 50 51 years starting about 7800 bp

mid to late holocene aeolian activity recorded in a coastal dunefield and lacustrine sediments on andoya northern norway in an effort to reconstruct past aeolian activity a foredune stratigraphy and a continuous lake sediment record from the largest dunefield on andoya northern norway have been investigated the dunefield extends landwards in a north eastward direction and consists of several parabolic dunes foredunes and blowouts the sediment record 169 cm from the nearby lake latjonna and the foredune stratigraphy 10 m covers the last 6200 and 3700 cal yr bp respectively both sites possess sediments deposited after the tapes transgression maximum 6800 cal yr bp which reached a level of 7 8 m a s l at the study site the lake sediment record consists of several units dominated by sand grains interspersed by more organic rich beds the core has been examined by x ray fluorescence xrf magnetic susceptibility ms and loss on ignition loi mineral grains were detected by wet sieving of the ignition residue ir and the influx of sand grains to latjonna was calculated based on the weight of sand grains

luminescence dating of holocene sedimentary deposits on romo a barrier island in the wadden sea denmark this study presents an optically stimulated luminescence osl based chronology for the evolution of the barrier island romo and related back barrier lagoon deposits in the danish wadden sea the chronology is constructed using 78 quartz osl ages obtained using a single aliquot regenerative dose sar protocol samples were retrieved from seven sediment cores each up to 25 m long taken from locations on the island and within the back barrier lagoon the reliability of the osl results is assessed using preheat plateaus thermal transfer tests and dose recovery measurements and by comparison with independent age control the osl ages compare favourably with three 14c age estimates and range between 220 20 and 15 800 1200 years romo appears to have developed as a progradational barrier system and the island appeared for the first time approximately 8000 years ago it then gradually expanded towards the west north and south as a result of an abundant sediment supply luminescence dating is concluded t

proxy records of holocene storm events in coastal barrier systems storm wave induced markers abstract extreme storm events in the coastal zone are one of the main forcing agents of short term coastal system behavior as such storms represent a major threat to human activities concentrated along the coasts worldwide in order to better understand the frequency of extreme events like storms climate science must rely on longer time records than the century scale records of instrumental weather data proxy records of storm wave or storm wind induced activity in coastal barrier systems deposits have been widely used worldwide in recent years to document past storm events during the last millennia this review provides a detailed state of the art compilation of the proxies available from coastal barrier systems to reconstruct holocene storm chronologies paleotempestology the present paper aims i to describe the erosional and depositional processes caused by storm wave action in barrier and back barrier systems i e beach ridges storm scarps and washover deposits ii to understand how storm records can be extracted from barrier and back barrier sedimentary bodies using stratigraphical sedimentological micro paleontological and geochemical proxies and iii to show how to obtain chronological control on past storm events recorded in the sedimentary successions the challenges that paleotempestology studies still face in the reconstruction of representative and reliable storm chronologies using these various proxies are discussed and future research prospects are outlined