direct determination of the timing of sea level change during termination ii an outcrop within the last interglacial terrace on barbados contains corals that grew during the penultimate deglaciation or termination ii we used combined 230th and231pa dating to determine that they grew 135 8 0 8 thousand years ago indicating that sea level was 18 3 meters below present sea level at the time this suggests that sea level had risen to within 20 of its peak last interglacial value by 136 thousand years ago in conflict with milankovitch theory predictions orbital forcing may have played a role in the deglaciation as may have isostatic adjustments due to large ice sheets other corals in the same outcrop grew during oxygen isotope 18o substage 6e indicating that sea level was 38 5 meters below present sea level about 168 0 thousand years ago when compared to the 18o signal in the benthic v19 30 v19 28 record at that time the coral data extend to the previous glacial cycle the conclusion that deep water temperatures were colder during glacial periods

transgressive dune formation along a cliffed coast at 75 ka in sardinia western mediterranean a record of sea level fall and increased windiness transgressive dunes develop frequently along strandplain coastlines however they may also form along rocky coasts dominated by cliffs and embayments two lithified transgressive dune systems developed along the cliffed alghero coast nw sardinia italy have been investigated one aeolian system forms a cliff front anchored aeolian dune accumulation the other is a valley head anchored sand ramp system optically stimulated luminescence ages indicate that both systems formed around 75 ka this period which corresponds to the beginning of mis 4 was characterized by a relatively low sea level stand 15 m below the present sea level and was preceded by a sea level highstand 1 m asl around 81 ka mis 5a our results show that this rapid sea level fall exposed an enormous amount of marine sand which was transported inland by strong northerly winds and deposited in front of cliffs or in valley heads therefore sediment supply and sea level fall seem to be critical factors controlling dune formation along rocky coasts which generate time transgressive aeolianites terra nova 00 000 000 2010

late pleistocene relic ultisols and alfisols in an alluvial fan complex in coastal tuscany detailed stratigraphic sedimentary facies and palaeosol analyses were performed on an outcrop on late quaternary deposits in the coastal area of tuscany the outcrop was selected as representative of one of the major quaternary alluvial fan complexes of central italy the ancient cecina river fan and as showing contrasting if related palaeosols the oldest relic palaeosol was identified as an ultisol representative of the most developed soil type normally found as relic soil in italy and about whose possible ages only approximate interpretations presently exist osl dating set the whole succession of sediments palaeosols and geomorphic surfaces into a firm chronological setting as a result evolution of the cecina fan complex in late pleistocene could be fully reconstructed assessment of the age of the relic ultisol produced results contrasting with current interpretations showing how such a soil type can have developed in italian conditions in a relatively short time i e since about mis 5d

evidence of saharan dust in upper pleistocene reworked palaeosols of north west sardinia italy palaeoenvironmental implications abstract a multi disciplinary approach was followed to investigate two thick palaeosolstrata that alternate with wind blown dominated deposits developed along thealghero coast north west sardinia italy optically stimulated luminescenceages reveal that both palaeosols were developed during cooler drier periods the rst one at around 70 ka marine isotope stage 4 and the latter around 50 ka marine isotope stage 3 in contrast the pedological features indicate that thepalaeosols underwent heavy weathering processes under warm humid to sub humid conditions characteristic of the sardinian climate during the lastinterglacial stage marine isotope stage 5e to reconcile this apparent datadiscrepancy a range of sedimentological and pedological analyses wereconducted these analyses reveal that the palaeosols possess a complexhistory with accumulation and weathering occurring during marine isotopestage 5e and erosion colluviation and nal deposition taking place during thefollowing cold stages thus even if these reddish palaeosols were last formedduring the glacial period the sediments building up these strata probablyrecord the climate of the last interglacial stage marine isotope stage 5e traceelement and x ray diffraction analyses together with scanning electronmicroscope images reveal the presence of saharan dust in the parentmaterial of the palaeosols however no evidence of any far travelled africandust has been observed in the marine isotope stage 4 3 aeolian deposits it ispossible to conclude that in the west mediterranean islands saharan dustinput even if of modest magnitude is preserved preferentially in soilsaccumulated and weathered during interglacial stages keywords marine isotopic stage mediterranean osl dating trace elementgeochemistry xrd analysis sedimentology 2012 59 917 938

late pleistocene coastal evolution of san giovanni di sinis west sardinia western mediterranean abstract the upper pleistocene succession of coastal deposits outcropping at san giovanni di sinis west sardinia has been studied since the 1960s however the absence of consistent radiometric ages has allowed the production of competing stratigraphic subdivisions of these deposits with different isotopic stage ois mis attributions the succession is composed of sandy to gravelly shallow marine coastal aeolian and alluvial fan plain deposits facies analysis and log correlations show the presence of three unconformities t1 t2 t3 always overlain by shallow marine deposits cutting through the substrate alluvial fan or aeolian sediments we have collected three samples for optically stimulated luminescence osl dating at the top of each shallow marine deposit the succession is composed of four unconformity bounded units u1 u2 u3 u4 and the new osl dates indicate the presence of three different sea level highstands the first unit u1 which is composed of shallow marine to aeolian deposits and overlies transgressive surface t1 is related to a marine transgression during ois 7 186 13 ky unit 2 is composed of continental deposits and formed during ois 6 unit 3 represents ois 5 and overlies a transgressive surface t2 more precisely subunit u3a is related to ois 5e 120 10 ky eu tyrrhenian or eemian sensu strictu and is characterized by shallow marine to aeolian deposits developed during both transgressive and highstand phases the following bay deposits of subunit 3b are associated with ois 5c 100 5 ky and record a second transgressive event t3 and highstand phase occurred during the neo tyrrhenian the succession of san giovanni di sinis ends with continental deposits of unit 4 associated to a sea level fall that took place at the beginning of the last glacial phase ois 4

progradational gravel beach sequences in a moderate to high energy microtidal marine environment the anatomy of progradational gravel beaches was analysed in two different tectonic settings the strongly subsiding messinian foreland basin of the eastern southern alps and the rising pleistocene marine terraces of the outer margin of the apenninic chain progradation took place near the mouths of fan delta or braid delta distributaries debouching in microtidal landlocked basins palaeo adriatic and palaeo ionian seas a wind wave climate comparable to that of the present day was characterized by periodic intense storm activity most of the beachface progradation is thought to have taken place during the post storm recovery and fair weather stages whereas the impact of storms is mostly recorded by the cutting of erosional surfaces on the beachface and by emplacement of poorly sorted and coarse grained gravels on the shoreface by storm intensified seaward trending flows and behind the highest berms by washover processes analysis of the sequences led to the identification of a number of typical divisions which are differently developed in the two settings compared here the characteristics of the apenninic sequences suggest a strongly variable wind wave climate with periodic changes from a relatively dissipative barred morphology during storms accompanied by strong longshore currents and rip development to a more reflective state typical of recovery and fair weather stages the southern alpine sequences on the other hand are characterized by poor evidence of barred morphology and of longshore currents and widespread effects of shear and gravity sorting in the lower beachface gravels these features indicate a comparatively more reflective average state due to location of beaches along the deeply embayed head of the palaeo adriatic and the very narrow directional width of the incoming wave spectrum which was almost shore normal most of the time in addition to well developed shape zonation of gravels the common presence of wave generated gravel megaripples in the southern alpine sequences indicates the greater influence of long period waves due to the greater available fetch distances in both settings the cyclicity is thought to be genetically related to minor changes of sea level

thin section grain size analysis revisited existing proposals for converting thin section data to their sieve equivalents are all flawed in various ways while questions concerning the significance of the grain size of spherical grains measured on a volume frequency basis in thin section using units and of non spherical ellipsoidal grains using both millimetres and units have not been satisfactorily resolved in the literature it can be shown mathematically that the mean thin section diameters of spherical grains or axis lengths of a series of parallel sections through ellipsoidal grains will underestimate the dimensions of the corresponding central section i e one passing through the grain centre by 0 2023 when measured on a volume frequency basis in order to approximate the effect of measuring particle size on random cuts through ellipsoidal grains the dimensions of a series of sections cut in 49 unique directions symmetrically arranged and evenly spread with respect to the ellipsoidal axes were calculated this calculation was carried out for five different ellipsoids which between them covered the mean sphericity and thin section axial ratio values normally encountered among naturally occurring quartz grain populations the data indicated that the mean true nominal diameters d of ellipsoidal quartz grains can be obtained in thin sections from the mean nominal sectional diameters d and major axes of the central sections derived from the observed values by multiplying the millimetre means by 1 1318 and subtracting 0 2023 from the means using the following equations a rough estimate to within c 5 of both the mean nominal diameters and the mean long axes of ellipsoidal quartz grains can be arrived at by applying a simple correction factor to the mean long axis lengths as measured in thin section using either millimetres or units

late quaternary coastal evolution and aeolian sedimentation in the tectonically active southern atacama desert chile abstract analyses of aeolianites and associated dune surficial carbonate and marine terrace sediments from north central chile 27 54 s yield a record of environmental change for the coastal southern atacama desert spanning at least the last glacial interglacial cycle optically stimulated luminescence dating indicates phases of aeolian dune construction at around 130 111 98 77 69 and 41 28 ka thin section and stable carbon and oxygen isotope analyses suggest a predominantly marine sediment source for the three oldest dune phases aeolianites appear to have accumulated mainly from tectonically uplifted interglacial marine sediments that were deflated during windier and or stormier intervals bedding orientations indicate that sand transporting winds varied in direction from s ese during mis 5e and wnw ese during mis 5c 5a winds from the southeast quadrant are unusual today in this region of the atacama suggesting either major shifts in atmospheric circulation or topographic airflow modification thin section evidence indicates that the aeolianites were cemented by two phases of vadose carbonate tentatively linked to wetter periods around 70 and 45 ka tectonic uplift in the area has proceeded at an average rate of 305 542 mm kyr 1 the study illustrates the complexity of understanding onshore offshore sediment fluxes in the context of late quaternary sea level fluctuations for an area undergoing rapid tectonic uplift

middle pleistocene to holocene coastal evolution of nw sardinia mediterranean sea italy abstract the middle pleistocene holocene sardinian stratigraphy has been revised to identify the roles played by sea and climate changes in controlling sedimentation the succession dated through optically stimulated luminescence quartz k feldspar and 14 c the most recent was grouped into eight major stratigraphic units mainly represented by coastal dunes shallow marine and alluvial systems these units range in age from mis 8 300 ka to mis1 6 ka little information is available for the period between mis 8 and 6 the available data however allow some comments on climate changes over the last 125 ka the last interglacial mis 5 is subdivided into five substages e a mis5e eemian is considered the climate optimum of this interglacial sea level was 4 6 m higher than today and climate conditions were warmer and more humid mis 5c is the second high stand peak sea level was about 1 5 m above the modern level and paleoclimatic and paleogeographic conditions were similar to the present during mis 4 at the beginning of the glacial phase a climatic deterioration occurred temperatures dropped by 6c relative to mis 5e in about 5 ka and sea level fell about 60 m this led to a progressive disruption of inland vegetation cover and to repeated valley slope denudation the sea level fall created the accommodation space for fan development in sheltered and cliffed areas where debris flows developed and filled almost completely the terminal parts of the narrow coastal valleys coves in wider areas however coastal dune fields developed contemporaneous presence of alluvial fan and dune systems is associated with the local morphology that could mitigate or amplify moist conditions within a generally arid environment during mis 3 several climate fluctuations occurred wet arid d o h events however the shallow sardinian shelf was continuously sufficiently exposed to become the source area of bioclastic sands these sands were blown inland and formed extensive dunefield systems dunes dominated the west coasts of sardinia under cold and relatively dry conditions in some areas these dunefield systems were eventually almost completely dismantled and reworked into water flow dominated alluvial fans by catastrophic rainfall events thus the local climate quickly switched from arid to humid conditions no record of the last glacial maximum deposits mis 2 was observed along the nw sardinian coast during the holocene transgression mis1 coastal dune systems developed and progressively migrated inland and temperature rose to reach the present day condition

aeolianite sedimentation along the northwestern coast of egypt evidence for middle to late quaternary aridity abstract aeolian sediments along the northwestern coast of egypt are described analyzed for oxygen and carbon isotopes and dated using radiocarbon u series and amino acid geochronology although deposition of the aeolianites along the northwestern mediterranean coast of egypt does not necessarily indicate regressive sea level events their development is often associated with arid climatic conditions the study of the aeolian sediments which constitute part of the coastal calcarenite ridges that are distributed parallel to the presen shoreline reveals the presence of at least four arid climatic phases following four major humid phases associated with high marine levels the aeolian phases are characterized by high positive 18 o and 13 c values and are related to aminozones a holocene c oxygen isotope substage 5a 5c e oxygen isotope substage 5e and g oxygen isotope stage 9 which are represented by the coastal ridge el max abu sir ridge and the complex cycles of gebel maryut ridge respectively a positive increasing trend of both 18 o and 13 c values is observed from gebel maryut ridge to the coastal ridge this indicates a general increasing of aridity with short intermittent moist conditions during which the reddish brown palaeosols were developed with their characteristic low 18 o and 13 c values

optical dating of young coastal dunes on a decadal time scale we explore the use of quartz optically stimulated luminescence osl dating for reconstructing coastal evolution on a time scale of decades to a few hundred years samples are taken from the accretionary south west coast of texel a barrier island just offshore of the northern netherlands the ages of dune ridges are known from historical sources an excellent chronology with a decadal accuracy exists for the past 260 years osl ages of less than 10 years on the youngest samples indicate that the osl signal of the quartz grains is very well zeroed prior to deposition and burial osl ages of five samples from a 250 year old dune ridge are indistinguishable and the osl ages on 17 out of 20 samples are in excellent agreement with the well known independent age controls our results highlight the potential of osl dating for high resolution reconstruction of coastal evolution over the past few centuries

middle to late pleistocene coastal deposits of alghero northwest sardinia italy chronology and evolution the shallow marine to coastal deposits of alghero have been dated using the optically stimulated luminescence osl method and studied to define the palaeoenvironmental evolution of coastal areas in northwest sardinia dating coupled with sedimentological and stratigraphical analyses allowed the subdivision of the succession in four unconformity bounded units u2 u3a u3b u4 unit u2 of penultimate glacial stage mis 6 ca 150 ka is composed of dune deposits formed intermittently along rocky coastal areas under strong wind conditions subunit u3a is composed of cliff bounded gravelly dominated pocket beach deposits commonly highly fossiliferous and is assigned to the interglacial mis 5e ca 125 ka subunit u3b is characterized by sandy beach to coastal systems of the isotopic sub stage mis 5c ca 100 ka the unconformity between u3b and u4 marks the initiation of last glacial regression mis 5a 4 ca 77 ka during which shelf areas were exposed and small incised valleys developed along the valley flanks colluvial or sheetflood sediments were deposited and in the central part thick reddish paleosols formed valleys were eventually filled by thick aeolian dune deposits mis 4 3 indicating persistent inland sand transport around alghero coastal carbonate rich dunes preferentially formed and migrated inland during lowstand and falling stages when the climate is relatively cold vegetation is quite open winds are fairly strong and sediment supply from exposed shelf areas is high

stratigraphy facies analysis and chronology of quaternary deposits at capo s marco sinis peninsula west sardinia italy abstract capo s marco is the southernmost termination of the sinis peninsula in the northwestern border of the oristano gulf western sardinia italy in the area there are some of the most controversial and debated quaternary deposits of sardinia consisting of beach aeolian and slope sediments whose chronological attribution changed according to different authors and in different times by the same authors these discrepancies have not been solved by new radiometric dates as radiocarbon and optically stimulated luminescence osl methods provided ages that are significantly different during recent investigations at capo s marco beach notches filled with bioclastic sands gravels and boulders were discovered up to an elevation of 4 5 m which is the highest elevation of the known beach notches these sediments rest on aeolian deposits and form a marine terrace in two sites in some places these sediments also include small colonies of the coral cladocora caespitosa in living position that have been recently dated by u th at 70 4 ka and attributed to the end of mis 5 here we report new u series analyses of two samples of c caespitosa collected on the uppermost part of the sequence the u th ages of 153 0 8 and 149 0 6 ka would correspond to mis 6 but the high values for the initial 234u 177 and 179 compared to the modern seawater value 147 point to an open system addition of 234u and or 230th the corrected ages using the open system model of thomson et al are 141 6 2 and 132 2 ka however these deposits and the beach notches are not buried under aeolian or colluvial sediments as are almost all the tyrrhenian marine deposits found in sardinia they also rest on aeolian sediments which at san giovanni di sinis were dated to mis4 or late mis2 by osl and radiocarbon dating of buried organic palaeosols respectively accordingly the stratigraphic evidence would suggest their attribution to the holocene although this contrasts with the holocene sea level models available and the u th dating results

sea level and climate changes during ois 5e in the western mediterranean palaeontological geomorphological and sedimentological data supported by isotopic dating on oxygen isotopic stage ois 5e deposits from the spanish mediterranean coast are interpreted with the aim of reconstructing climatic instability in the northern hemisphere data point to marked climatic instability during the last interglacial ois 5e with a change in meteorological conditions and consequently in the sedimentary environment the oolitic facies generated during the first part of ois 5e ca 135 kyr shift into reddish conglomeratic facies during the second part ca 117 kyr sea surface temperature sst and salinity are interpreted mainly on the basis of warm senegalese fauna which show chronological and spatial differential distribution throughout the western mediterranean present hydrological and meteorological conditions are used also as modern analogues to reconstruct climatic variability throughout the last interglacial and this variability is interpreted within the wider framework of the north atlantic record all the available data indicate an increase in storminess induced by an increase in the influence of northwesterlies a slight drop of sst in the northern western mediterranean and an important change in meteorological conditions at the end of ois 5e 117 kyr these changes correlate well with the decrease in summer insolation and with the climatic instability recorded in north atlantic high latitudes

middle pleistocene magnetostratigraphy and susceptibility stratigraphy data from a carbonate aeolian system mallorca western mediterranean abstract this study shows that successions of pleistocene carbonate aeolian deposits can be placed successfully in a geochronologic framework using magnetostratigraphic and susceptibility stratigraphic analysis supplemented by luminescence dating studies of wave cut platforms and biostratigraphic evidence the investigated aeolian system covers a significant part of southernmost mallorca and is exposed in impressive coastal cliff sections at the study site at els bancals the aeolian system has a maximum thickness of 16 m and is composed of alternating dark red colluvial deposits and greyish red aeolian dune and sand sheet deposits forming seven cyclostratigraphic units each cyclostratigraphic unit represents landscape stabilisation colluviation and soil formation followed by dunefield development when marine carbonate sand was transported far inland by westerly or north westerly winds the aeolian system is located on top of a wave cut marine platform 12 14 m a s l this platform probably formed during a sea level highstand in marine isotope stage mis 11 427 364 ka and renewed marine activity probably later in mis 11 is indicated by the formation of beach deposits two sections at els bancals were sampled for a paleomagnetic study additional samples were taken to detect variations in magnetic susceptibility ms the characteristic remanent magnetisation has been recovered for the most part of the succession in spite of diagenetic overprinting there is evidence for two probably three reversal polarity excursions possible connected to the levantine cr1 and cr0 biwa iii episodes if this correlation is correct the sampled succession represents a time interval in the middle pleistocene between ca 410 and ca 260 ka this age estimate is supported by the ms study and by luminescence dates of 333 70 ka aeolianite from lower part of the succession and 275 23 ka aeolianite from the top of the succession the nature of the succession suggests deposition during alternating warm and moist colluvial deposition soil formation and cold dry and windy conditions dunefield formation the susceptibility signal can be correlated with the insolation signal at 65 n suggesting that environmental variation on mallorca was linked to orbitally forced climate change and it seems that aeolian activity and dunefield formation were linked to glacial or stadial periods

tyrrhenian coastal deposits from sardinia italy a petrographic record of high sea levels and shifting climate belts during the last interglacial isotopic substage 5e abstract detailed petrographic and sedimentological analysis of tyrrhenian coastal deposits from four sites in sardinia provides new data about climate and sea level changes during the early part of the last interglacial isotopic substage 5e and shows that facies analysis is not only useful for the identification of ancient depositional environments but also represents a powerful tool for evaluating past climatic conditions and sea level forcing mechanisms two shallowing upward sequences sensu ward w c brady m j 1979 strandline sedimentation of carbonate grainstones upper pleistocene yucatan peninsula mexico am assoc pet geol bull 63 362 369 commonly separated by an erosion surface and displaying complex geometric relationships occur above modern sea level at several locations along the shorelines of sardinia these sequences include upper shoreface to backshore deposits and were formed during separate sea level highstands attributed to isotopic substage 5e our recent revision of these deposits indicates that each sequence presents distinctive petrographic characteristics the older succession essentially contains mixed calcarenites rich in quartz grains and lithic fragments whereas the younger sediments are dominated by carbonate bioclasts such as red algae coral and mollusk fragments both units apparently accumulated in a similar depositional setting but during different climatic regimes the petrography of the lower unit reflects a temperate humid period characterized by increased weathering and continental erosion whereas the composition of the upper one suggests a dryer and possibly warmer climate favoring active carbonate production the disparity in petrographic composition between sequences probably records the migration of atmospheric circulation cells i e a shift of climate belts before and after the 128 ka insolation maximum our climatic data are coherent with the calculated insolation curves for isotopic substage 5e and thus support the milankovitch hypothesis for the origin of pleistocene climates in contrast our sedimentological data clearly show the occurrence of two distinctive highstands of sea level during this time period which does not agree with the hypothesis it follows that the relation between orbitally induced insolation variations climate and sea level is not necessarily straightforward

archean to recent aeolian sand systems and their sedimentary record current understanding and future prospects the sedimentary record of aeolian sand systems extends from the archean to the quaternary yet current understanding of aeolian sedimentary processes and product remains limited most preserved aeolian successions represent inland sand sea or dunefield erg deposits whereas coastal systems are primarily known from the cenozoic the complexity of aeolian sedimentary processes and facies variability are under represented and excessively simplified in current facies models which are not sufficiently refined to reliably account for the complexity inherent in bedform morphology and migratory behaviour and therefore cannot be used to consistently account for and predict the nature of the preserved sedimentary record in terms of formative processes archean and neoproterozoic aeolian successions remain poorly constrained palaeozoic ergs developed and accumulated in relation to the palaeogeographical location of land masses and desert belts during the triassic widespread desert conditions prevailed across much of europe during the jurassic extensive ergs developed in north america and gave rise to anomalously thick aeolian successions cretaceous aeolian successions are widespread in south america africa asia and locally in europe spain and the usa several eocene to pliocene successions represent the direct precursors to the present day systems quaternary systems include major sand seas ergs in low lattitude and mid latitude arid regions pleistocene carbonate and holocene modern siliciclastic coastal systems the sedimentary record of most modern aeolian systems remains largely unknown the majority of palaeoenvironmental reconstructions of aeolian systems envisage transverse dunes whereas successions representing linear and star dunes remain under recognized research questions that remain to be answered include i what factors control the preservation potential of different types of aeolian bedforms and what are the characteristics of the deposits of different bedform types that can be used for effective reconstruction of original bedform morphology ii what specific set of controlling conditions allow for sustained bedform climb versus episodic sequence accumulation and preservation iii can sophisticated four dimensional models be developed for complex patterns of spatial and temporal transition between different mechanisms of accumulation and preservation and iv is it reasonable to assume that the deposits of preserved aeolian successions necessarily represent an unbiased record of the conditions that prevailed during episodes of earth history when large scale aeolian systems were active or has the evidence to support the existence of other major desert basins been lost for many periods throughout earth history

rapid environmental changes in southern europe during the last glacial period oxygen isotope records from greenland ice cores1 2 indicate numerous rapid climate fluctuations during the last glacial period north atlantic marine sediment cores show comparable variability in sea surface temperature and the deposition of ice rafted debris3 4 5 in contrast very few continental records of this time period provide the temporal resolution and environmental sensitivity necessary to reveal the extent and effects of these environmental fluctuations on the continents here we present high resolution geochemical physical and pollen data from lake sediments in italy and from a mediterranean sediment core linked by a common tephrochronology our lacustrine sequence extends to the past 102 000 years many of its features correlate well with the greenland ice core records demonstrating that the closely coupled ocean atmosphere system of the northern hemisphere during the last glacial4 extended its influence at least as far as the central mediterranean region numerous vegetation changes were rapid frequently occurring in less than 200 years showing that the terrestrial biosphere participated fully in last glacial climate variability earlier than 65 000 years ago our record shows more climate fluctuations than are apparent in the greenland ice cores together the multi proxy data from the continental and marine records reveal differences in the seasonal character of climate during successive interstadials and provide a step towards determining the underlying mechanisms of the centennial millennial scale variability

multiphase late quaternary aeolian sediment accumulation in western south africa timing and relationship to palaeoclimatic changes inferred from the marine record abstract extensive aeolian deposits exist along the western margin of south africa from cape town through to the namib sand sea and represent a significant palaeoenvironmental archive recording millennial scale patterns of regional and hemispheric environmental change to establish the timing of dune development this study applies optically stimulated luminescence osl dating techniques to the aeolian features of the west coast in total 35 samples were obtained from six dune cores along a north south transect extending from elands bay 32 26 s 18 14 e to kleinsee 29 14 s 16 59 e ages from these dunes exhibit five distinct peaks suggesting phases of activity deposition at 4 5 16 24 30 33 43 49 and 63 73 ka the spatial and temporal extent of the data have allowed for correlations to be made with evidence from marine cores from the southeast atlantic and a more coherent regional environmental history to be developed results suggest that 1 environmental changes in this region are strongly linked to variations in wind strength and atmospheric circulation systems during the late quaternary and 2 luminescence ages from aeolian deposits cannot necessarily be equated with periods of increased aridity with other factors such as wind strength and sediment supply being of critical importance

aeolianite and barrier dune construction spanning the last two glacial interglacial cycles from the southern cape coast south africa the southern cape region of south africa has extensive coastal aeolianites and barrier dunes whilst previously reported limited knowledge of their age has precluded an understanding of their relationship with the climatic and sea level fluctuations that have taken place during the late quaternary sedimentological and geomorphological studies combined with an optical dating programme reveal aeolianite development and barrier dune construction spanning at least the last two glacial interglacial cycles aeolianite deposition has occurred on the southern cape coast at ca 67 80 88 90 104 128 160 189 and 200 ka before the present using this and other published data coupled with a better understanding of late quaternary sea level fluctuations and palaeocoastline configurations it is concluded that these depositional phases appear to be controlled by interglacial and subsequent interstadial sea level high stands these marine transgressions and regressions allowed onshore carbonate rich sediment movement and subsequent aeolian reworking to occur at similar points in the landscape on a number of occasions the lack of carbonates in more recent dunes oxygen isotope stages 1 2 and 4 5 is attributed not to leaching but to changes to carbonate production in the sediment source area caused by increased terrigenous material and or changes in the balance between the warm agulhas and nutrient rich benguela ocean currents

a reappraisal of the dwarfed mammoth mammuthus lamarmorai major 1883 from gonnesa south western sardinia italy the gonnesa quaternary deposits have been cited since the end of the 19th century due to the discovery during the construction of a railway of an incomplete postcranial skeleton belonging to an endemic dwarfed elephant afterward described by major as a new species elephas lamarmorae major 1883 although the remains have since been reported in the literature as coming from the aeolian deposits outcropping at funtana morimenta the precise provenance of the findings and their chronostratigraphical setting remained uncertain taking into account the route of the now disused railway the stratigraphical successions of the morimenta area and the fact that the elephant bones were actually collected during a number of excavations spanning several decades the location of the fossiliferous site is most likely on the northeast end slope of guardia pisano hill gonnesa where aeolianites correlate with the funtana morimenta formation fmf outcrop the fmf is supposed to predate the onset of the mis 5e climatic event and the tyrrhenian panchina overlies equivalent deposits cropping out along the gonnesa gulf coast therefore the hypothesis that the elephant remains found in the morimenta area were retrieved from late middle pleistocene deposits cannot be ruled out the anatomical features of the bones suggest they represent a single individual perhaps partially exposed and damaged before the discovery new evidence including a thus far unpublished tusk fragment from the guardia pisano hill gonnesa whose schreger angles fall within the range of mammuthus supports the systematic attribution of the incomplete morimenta skeleton to a dwarfed mammoth the size reduction of this sardinian dwarfed mammoth is discussed in light of body mass changes undergone by insular endemic elephants

pyroxene structures cathodoluminescence and the thermal history of the enstatite chondrites in order to explore the thermal history of enstatite chondrites we examined the cathodoluminescence cl and thermoluminescence tl properties of 15 eh chondrites and 21 el chondrites including all available petrographic types both textural types 3 6 and mineralogical types alpha delta the cl properties of el3 alpha and eh3 alpha chondrites are similar enstatite grains high in mn and other transition metals display red cl while enstatite with low concentrations of these elements show blue cl a few enstatite grains with greater than 5 wt feo display no cl in contrast the luminescent properties of the metamorphosed eh chondrites are very different from those of metamorphosed el chondrites while the enstatites in metamorphosed eh chondrites display predominantly blue cl the enstatites in metamorphosed el chondrites display a distinctive magenta cl with blue and red peaks of approximately equal intensity in their spectra the tl sensitivities of the enstatite chondrites correlate with the intensity of the blue cl and unlike other meteorite classes are not simply related to metamorphism the different luminescent properties of metamorphosed eh and el chondrites cannot readily be attributed to compositional differences but x ray diffraction data suggests that the enstatite in eh5 gamma delta chondrites is predominantly disordered orthopyroxene while enstatite in el6 beta chondrites is predominantly ordered orthopyroxene the difference in thermal history of metamorphosed el and eh chondrites is so marked that the use of single petrographic types is misleading and separate textural and mineralogical types are preferable our data confirm earlier suggestions that metamorphosed eh chondrites underwent relatively rapid cooling and the metamorphosed el chondrites cooled more slowly and experienced prolonged heating in the orthopyroxene field

buried palaeosols of nw sardinia italy as archives of the late quaternary climatic fluctuations abstract a multi disciplinary approach was performed to investigate two compound geosols included between wind blown deposits at the top and interglacial mis 5 beach sediments at the bottom located along the alghero coast north western sardinia italy a sedimentological and morphological study was carried out on the profile in the field and samples collected on the main pedomembers were subjected to several laboratory analyses consisting of physical and chemical determinations on bulk samples mineralogy xrd micromorphology on undisturbed samples thin section sem and edax micro probe analyses dating was performed by means of optically stimulated luminescence osl the studied geosols show the evidence of a complex pedosedimentary evolution around 80 to 70 ka the lower geosol underwent weathering and clay illuviation wet and warm conditions followed by calcification recalcification processes dry contrasted and finally by strong bioturbation around 70 ka the onset of the glacial period mis 4 is marked by the deposition of a sand dune capping the lower geosol these results indicate that the coastal area of the central mediterranean kept the relatively warm conditions typical of the interglacial climate for most of the early wurm and reached cold conditions only at about 70 ka possibly in relation to the rapid cooling of the heinrich event h7 the upper geosol developed on colluvial material including abundant pedorelicts and reddish earth material deposited around 50 ka before being buried by aeolian sand around 43 ka this deposit underwent pedogenesis phases possibly associated to middle wurm interstadial events indicating that in the study area these events were intense enough to influence pedogenesis

luminescence dating of interglacial coastal depositional systems recent developments and future avenues of research abstract luminescence dating offers new opportunities to explore the evolution of quaternary marine coastal facies and landforms this review highlights the main advances in luminescence geochronology of interglacial coastal sediments through the analysis of 547 luminescence ages most of which were published during the last decade the majority of these reported luminescence investigations have been carried out along passive margin coasts since the turn of the century the discovery of a normalization procedure known as single aliquot regeneration sar has drastically reduced data scatter and improved precision with the consequence that quartz sar optically stimulated luminescence osl has become the dating protocol of choice for the last interglacial lig period a more complex technique known as thermally transferred osl tt osl is presumably proposed for dating older interglacials of the mid pleistocene and beyond feldspar luminescence is increasingly being applied to dating pleistocene sea level high stands due to a much higher dose saturation level than quartz osl the use of feldspar irsl infrared stimulated luminescence is limited by the occurrence of variable but ubiquitous anomalous fading af following the advent of af correction methods several middle pleistocene sites have been amenable to dating albeit with significant related uncertainties recently new protocols involving the measurement of post ir irsl at elevated temperatures have yielded relatively coherent ages for interglacial sediments up to ca 300 ka quartz osl tt osl af corrected irsl and post ir irsl ages are generally correlated with periods of sea level high stands a few ages are reported from the early and middle part of the middle pleistocene as mis11 9 and more commonly mis7 high stands are documented in strongly uplifting active margin coasts however by far the most obvious age peak corresponds to the end of the lig the mis5e shoreline is probably the most studied and luminescence dated coastal feature of all as the chronology of the sea level markers is crucial to assess global eustatic sea level variations through the course of the last interglacial nevertheless the observed abundance of young 100 120 ka luminescence ages for presumed mis5e sediments may underline methodological issues and or reflect the higher preservation potential of late regressive sequences on the other hand the occurrence of geographically distant reports of mis5a high stand might reflect a true eustatic origin for this event age analysis supports the impression of general reliability of luminescence for the timing of former sea level high stands there is a clear need to address issues in dose rate variability in the phenomenology of fading in feldspar and in the behaviour of luminescence growth with dose both in laboratory and natural conditions these could be addressed and properly evaluated by dating different minerals as multiple or single grains with consequent variable internal dose rates more robust practices in the application of luminescence dating techniques could eventually constrain the age uncertainties to no better than 2 3 therefore the strength of luminescence as a dating tool is more in terms of its extended age range and the ubiquity of datable material

the significance of cryoturbation phenomena in environmental reconstruction cryoturbation results mainly from differential heave related to 1 drainage and thermal conditions and 2 frost susceptibility loadcasting and cryostatic pressures are restricted to wet soils such as pure silt or silty sand the translocation of fine particles resulting from repeated freezing and thawing can promote frost susceptibility in a previously non susceptible material as well as a loss in stability of the surface horizons liquefaction small and metric scale cryoturbations can be explained by this process large scale deformations and injections may be related to abnormal liquefaction not necessarily associated with frost regular patterns are associated with fissure nets upturned injections in a downslope direction attest to cryoturbation and frost creep a lowering of the water table promotes the formation of drop like cryoturbations most of which can be related to seasonal frost in imperfectly to poorly drained soils they are not indicative of permafrost except in well drained situations or in the case of flat bottomed involutions

sand deposition during the last millennium at aberffraw anglesey north wales as determined by osl dating of quartz abstract ground penetrating radar gpr was used to identify sediment units at the terminus of a small dune field at aberffraw nine samples were taken from boreholes sample locations were based on the stratigraphy established by gpr quartz grains were dated using a single aliquot regenerative dose protocol that allows for sensitivity changes sand deposition at llyn coron aberffraw occurred three times in the last 700 years with initial sand movement occurring around 1331 ad when historical documents record sand being mobilised in a strong storm

pleistocene raised marine terraces of the spanish mediterranean and atlantic coasts records of coastal uplift sea level highstands and climate changes detailed geological mapping morphostratigraphic palaeontological and geochronological uranium series analyses were undertaken on the raised marine terraces and interbedded terrestrial deposits along the spanish peninsular and insular atlantic and mediterranean coasts several sets of pleistocene shallow marine to coastal deposits exposed in a staircase arrangement are interpreted as being emplaced during sea level highstands coeval with interglacials or interstadials correlating with marine oxygen isotopic stages ois 5a 5c 5e 7 9 11 and older up to three highstands have been identified in deposits formed during ois 5e close to the end of ois 5e there is a record of sudden changes in sea surface conditions and climate marked by the disappearance of a major proportion of the warm senegalese fauna switches from oolitic to non oolitic facies and accumulation of boulder beaches dating of the coral cladocora caespitosa found in a layer that also contains strombus bubonius confirms the occurrence of warm fauna in the mediterranean basin during ois 7 as previously suggested by hillaire marcel et al 1986 goy et al 1986a b zazo and goy 1989 also the occurrence of warm faunas in deposits corresponding to an older interglacial probably ois 9 or 11 in the balearic islands suggests similar oceanographic conditions sea surface temperature assuming constant salinity during the last interglacial and at least two interglacials of the middle pleistocene in the western mediterranean a 2002 elsevier science b v all rights reserved

mis 5a and mis 3 relatively high sea level stands on the hatay samandag coast eastern mediterranean turkey abstract the coastal belt of hatay samandag in the east mediterranean is marked by the intersection of the african arabian and eurasian anatolian platelet plates where several quaternary shorelines related to relative sea level changes can be seen above the current sea level in this study the most common and best preserved high sea level markers of the marine isotope stage mis 5 and mis 3 shorelines were dated for the first time using the mollusc based electron spin resonance esr method as a result of this research the age of the late mis 5 and mis 3 sea level highstands in the eastern mediterranean the elevation of the corresponding shoreline at samandag coast and the vertical component of the late quaternary tectonic movements which has an impact on shoreline were determined the shorelines at 48 43 m elevations between cevlik and samandag at 58 6 m in tekebasi and at 21 m at keldag have been dated to approximately 72 ka and therefore are correlated with mis 5a the shoreline at 40 39 m elevations between cevlik and samandag has been dated to approximately 53 ka and therefore is correlated with mis 3 according to the position of the mis 5a shorelines the uplift rate over the last 72 ka was 0 88 mm y between cevlik and samandag 1 08 mm y in tekebasi and 0 56 mm y in keldag yielding a 0 84 mm y average this rather fast uplift appears to be related to the vertical component of the strike slip active faults in the samandag antakya fault zone

age and significance of late pleistocene lithophyllum byssoides intertidal algal ridge nw sardinia italy abstract intertidal coralline red algal build ups lithophyllum byssoides rims or ridges are considered precise sea level markers and mostly used for holocene sea level history several well preserved patches of relict red algal ridges crop out along the north west sardinian coast mediterranean sea italy and have great potential in reconstructing the late pleistocene sea level history of the western mediterranean the aim of this paper is to determine the sedimentary characteristics of the relict lithophyllum byssoides build ups cropping out along the sardinian nw coast and to demonstrate how these can be used as past sea level indicators to establish a chronological framework for these deposits luminescence dating both quartz osl and k feldspar pirir290 has been applied and allows for the lithophyllum byssoides ridge formation to be assigned to marine isotopic stage mis 5e 132 112 ka the studied relict ridges confirmed that mis 5e sea level was at least at 4 m above present well matching the widely accepted last interglacial global sea level curves hence fossil lithophyllum byssoides ridges can be used as stratigraphic and chronologic indicators of late pleistocene sea level moreover the study has underlined that lithophyllum byssoides may grow 1 in sheltered places along high cliffy coasts forming bench like structures and 2 in high energy environments on wave cut platforms around fallen blocks or potholes first as isolated mounds and then merging to form reef like structures

first evidence for onshore marine isotope stage 3 aeolianite formation on the southern cape coastline of south africa abstract the southern cape coast of south africa boasts an impressive suite of plio pleistocene aeolian dune deposits aeolianite previous research has shown that in this region onshore dune accumulation was generally focused around interglacial sea level highstands with the locus of coastal dune accumulation shifting onto the adjacent continental shelf during glacial sea level lowstands here using new luminescence dating results we present the first evidence for preserved onshore glacial age dunes specifically on the robberg peninsula a rocky headland 28 km east of knysna two phases of aeolianite formation are identified corresponding to early 45 60 ka and late 35 30 ka marine isotope stage mis 3 subsequently during the holocene all substantive dune accumulation occurred between 10 2 and 7 0 ka forming cliff fronting dunes and filling the limited accommodation space on the headland including an archaeological rock shelter combining these ages with bathymetric data we infer that this distinct onshore glacial age aeolianite record reflects 1 restricted accommodation space during sea level highstands 2 a regional narrowing of the continental shelf and 3 liberation of sediments lying on a prominent 45 to 60 m offshore terrace which would have been exposed during mis 3 this demonstrates that despite broad regional scale trends in the timing of coastal aeolian activity driven by commonalities in relative sea level trends and climate distinct local variations in late quaternary coastal evolution can be identified this is ascribed to local controls on preservation accommodation space and sediment supply shoreline position and antecedent offshore sediment supplies such findings may have wider implications for interpretations of site context resource availability at several notable coastal archaeological sites and more broadly suggest that local offshore or onshore geologic contexts can at times assume greater influence on a preserved coastal aeolianite record than the regional scale trends in sea level and climate

new data on the pleistocene of mallorca abstract stratigraphic geomorphologic and isoleucine epimerization studies at 15 sites in mallorca define four aminozones a c e and f g of increasing age that are related to transgressive regressive marine cycles from the holocene to the mid pleistocene calibration of aminozone e glycymeris aile ile mean from all sites 0 41 0 03 n 38 is provided by a 129 7 ka u series coral age on cladocora caespitosa from son grauet of the younger aminozones a relates to the holocene transgression and aminozone c to a mid to late isotopic stage 5 event 90 15 ka revealed only by supralittoral eolianites assigning an age to the older poorly resolved aminozones f and g called f g in this case is uncertain without supporting radiometric data but an age of 180 ka can be assigned to these aminozone s f g based on a kinetic model and other examples in the mediterranean several deposits previously dated u series molluscs between 75 and 300 ka appear to belong to the last interglacial complex stage 5 and aminozone e a proposed revision of the positive sea level history of mallorca shows multiple minor oscillations during the major last interglacial cycle stage 5 and two mid pleistocene sea levels one lower than present and the other at about 14 m a s l

seasonal control on coastal dune morphostratigraphy under a monsoon climate mui ne dunefield se vietnam abstract having developed in the later quaternary period the mui ne dunefield representing the upper most portion of a major coastal barrier complex in se vietnam formed by wind regimes associated with the asian monsoon climate the barrier complex is 100 km long and higher than 150 m in elevation but despite its large dimensions research on its geomorphological and geological characterization is limited several active dune fields extend 2 10 km landwards from the coast while the rest of the barrier surface is stabilized we applied ground penetrating radar gpr and quartz optically stimulated luminescence osl dating to the transverse dunes of the mui ne dunefield to characterize the morphostratigraphy and recent aeolian sedimentation history currently the dunes have a relief of typically 5 10 m and a wavelength of 50 100 m they are driven by the northeasterly winter monsoon winds and reversed with minor relief in response to the southwesterly summer monsoon gpr profiles and osl ages define three morphostratigraphic units the modern holocene and pleistocene dune units the gpr data of the modern dune unit is dominated by a series of steep reflections that dip exclusively towards the west reflecting the winter monsoon and is punctuated by reactivation surfaces evidence for the wind reversal is not preserved in the sediment successions but is represented by reactivation surfaces thus a subunit bounded by the reactivation surfaces defines annual deposition the preservation potential of a subunit varies with the migration rate of the transverse dune and in the fastest migrating dunes approximately one subunit was preserved every year 1 1 0 6 subunit yr the modern dunes are generally younger than 100 years and have migrated wsw at net rates of 0 6 2 5 m yr the holocene dune unit is as thick as the modern unit although it spans a period ten times longer reflecting the lower preservation potential of the transverse dunes as sedimentary records due to erosion associated with their migration the rate of dune migration suggests that an aeolian contribution of coastal sands has occurred following the sea level highstand of the middle holocene accounting for the extent of the active dunefields this mode of the barrier accumulation is considered as an analogue for earlier highstand events however the dunefields only cover a fraction of the entire barrier it is thus inferred that barrier formation occurred over a long period probably encompassing several glacial interglacial cycles sand accumulation during the lowstand either by transport of sand from the subaerially exposed shelf and or reworking of sand emplaced during the prior highstand may contribute significantly to the barrier development

luminescence chronology of aeolianites from the section at givat olga coastal plain of israel abstract the eastern mediterranean coastal plain of israel is composed mainly of loam sand and gravel of pleistocene to holocene age indicating an alternation of marine coastal and continental environments owing to the complexity of the numerous exposures of aeolianites kurkar and soils hamra in the elongated ridges along the coastal plain it is difficult to set up a reliable stratigraphy a systematic luminescence dating study was carried out on loose sand kurkar and hamra deposits in the coastal plain between netanya and haifa sixteen samples were taken and investigated from the section at givat olga the chronological results show excellent agreement between the infrared optically stimulated luminescence irsl and thermoluminescence tl techniques indicating that the former sand dunes were well bleached prior to deposition the irsl and tl age estimates range from about 75 3 ka for the aeolianites indicating that this kurkar ridge formed during an older period of the last glaciation likely before 50 ka

abrupt temperature changes in the western mediterranean over the past 250 000 years a continuous high resolution western mediterranean sea surface temperature sst alkenone record spanning the past 250 000 years shows that abrupt changes were more common at warming than at cooling during marine isotope stage mis 6 sst oscillated following a stadial interstadial pattern but at lower intensities and rates of change than in the dansgaard oeschger events of mis 3 some of the most prominent events occurred over miss 5 and 7 after prolonged warm periods of high stability climate during the whole period was predominantly maintained in interglacial interstadial conditions whereas the duration of stadials was much shorter

quaternary sea level history and the origin of the northernmost coastal aeolianites in the americas channel islands national park california usa abstract along most of the pacific coast of north america sand dunes are dominantly silicate rich on the california channel islands however dunes are carbonate rich due to high productivity offshore and a lack of dilution by silicate minerals older sands on the channel islands contain enough carbonate to be cemented into aeolianite several generations of carbonate aeolianites are present on the california channel islands and represent the northernmost quaternary coastal aeolianites on the pacific coast of north america the oldest aeolianites on the islands may date to the early pleistocene and thus far have only been found on santa cruz island aeolianites with well developed soils are found on both san miguel island and santa rosa island and likely date to the middle pleistocene the youngest and best dated aeolianites are located on san miguel island and santa rosa island these sediments were deposited during the late pleistocene following the emergence of marine terraces that date to the last interglacial complex 120 000 yr to 80 000 yr based on radiocarbon and luminescence dating the ages of these units correspond in time with marine isotope stages mis 4 3 and 2 sea level was significantly lower than present during all three time periods reconstruction of insular paleogeography indicates that large areas to the north and northwest of the islands would have been exposed at these times providing a ready source of carbonate rich skeletal sands these findings differ from a previously held concept that carbonate aeolianites are dominantly an interglacial phenomenon forming during high stands of sea in contrast our results are consistent with the findings of other investigators of the past decade who have reported evidence of glacial age and interstadial age aeolianites on coastlines of australia and south africa they are also consistent with observations made by darwin regarding the origin of aeolianites on the island of st helena in the south atlantic ocean more than a century and a half ago

the role of african dust in the formation of quaternary soils on mallorca spain and implications for the genesis of red mediterranean soils abstract african dust additions explain the origin of terra rossa soils that are common on the carbonate platform island of mallorca spain mineralogical and geochemical analyses indicate that quaternary carbonate eolianites on mallorca have a very high purity usually composed of more than 90 carbonate minerals calcite dolomite and aragonite in contrast terra rossa soils developed on these eolianites have lower carbonate contents and contain higher concentrations of quartz and other silicates analyses of immobile trace elements indicate that the non carbonate fractions of the eolianites have distinctive zr hf la yb cr sc and th ta values that differ from the superjacent terra rossa soils these observations indicate that even if sufficient dissolution of the eolianite had taken place to create the soils by residual accumulation immobile element ratios in the soils require an external source however zr hf la yb cr sc and th ta values in the soils fall within the range of values for these element ratios in african dust collected on barbados and mainland spain we conclude that the silicate fractions of terra rossa soils on mallorca are derived mainly though not wholly from far traveled african dust and this process may explain the origin of other terra rossa soils found in southern europe

a radiometric calibration of the specmap timescale the astronomical theory of climate change asserts that earth s climate is affected by changes in its orbit which vary the seasonal and latitudinal distribution of solar radiation this theory is the basis of the orbitally tuned specmap timescale a key constraint for this important chronology was the mid point of the penultimate deglaciation initially dated to 127 000 years ago recent work suggests this event may be considerably older casting doubt on the astronomical theory the specmap timescale and the accuracy of orbitally tuned chronologies difficulties with u th coral dating of sea level events have impeded progress on this problem because most corals are not closed systems here we use a new approach to u th dating that corrects for open system behavior and produces a sea level curve of sufficient resolution to confidently correlate with specmap over the last 240 000 years permitting a reassessment of both this critical chronology and a central tenet of climate change theory high precision ages for 24 oxygen isotope events provide a 240 000 year chronology for marine 18o records that is independent of orbital tuning assumptions although there appear to be significant differences between the radiometric and orbitally tuned timescales near the lastglacial maximum and at the marine isotope stage 7 6 boundary a comparison of radiometric and specmap ages for identical isotope events suggest that the specmap timescale is quite accurate and that its errors were in general overestimated despite suborbital complexity orbital cyclicity is clearly evident in our record high amplitude sea level oscillations at periods greater than 20 000 years are very close in phase to summer insolation in the northern hemisphere although sea level changes cannot be uniquely tied to a specific season or latitude of insolation forcing the simplest explanation is that long period high amplitude sea level change is linked to northern hemisphere insolation forcing these results validate the principles of orbital tuning and suggest such timescales are generally robust

rates of aeolian transport on a beach in a temperate humid climate short term field measurements of aeolian transport using a saltiphone indicate that actual rates of transport deviate considerably from the potential rates predicted by transport equations when examined in detail however potential rates are approached during special conditions mostly when the wind blows offshore parallel or slightly oblique to the beach and relative humidity is below 85 also the potential rates of transport may be approached when wind speeds considerably exceed threshold speed even during showers the main cause of the large deviation of actual from potential rates is in the absence of transport during very wet conditions prolonged rainfall regardless of wind speed and the variation of threshold velocity with time the threshold velocity increases during wet conditions with onshore winds or because of the presence of algae therefore potential transport is defined as the transport optimum to predict the actual rates of transport accurately insight into the variation of the threshold velocity is essential aeolian transport of sand seems to be related to moderate events and not to extreme events conforming to the principle of magnitude and frequency

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

preserving the palaeoenvironmental record in drylands bioturbation and its significance for luminescence derived chronologies luminescence osl dating has revolutionised the understanding of late pleistocene dryland activity however one of the key assumptions for this sort of palaeoenvironmental work is that sedimentary sequences have been preserved intact enabling their use as proxy indicators of past changes this relies on stabilisation or burial soon after deposition and a mechanism to prevent any subsequent re mobilisation as well as a dating technique osl especially at the single grain level can be used to gain an insight into post depositional processes that may distort or invalidate the palaeoenvironmental record of geological sediment sequences this paper explores the possible impact of bioturbation the movement of sediment by flora and fauna on luminescence derived chronologies from quaternary sedimentary deposits in texas and florida usa which have both independent radiocarbon chronologies and archaeological evidence these sites clearly illustrate the ability of bioturbation to rejuvenate ancient weathered sandy bedrock and or to alter depositional stratigraphies through the processes of exhumation and sub surface mixing of sediment the use of multiple osl replicate measurements is advocated as a strategy for checking for bioturbated sediment where significant osl heterogeneity is found caution should be taken with the derived osl ages and further measurements at the single grain level are recommended observations from the linear dunes of the kalahari show them to have no bedding structure and to have osl heterogeneity similar to that shown from the bioturbated texan and florida sites the kalahari linear dunes could have therefore undergone hitherto undetected post depositional sediment disturbance which would have implications for the established osl chronology for the region

pleistocene alluvial and aeolian deposits with tephra on the island of lopud eastern mid adriatic croatia provenance wind regime and climate controls abstract pleistocene alluvial and aeolian sediments occur as small patches in many places in the area of the eastern adriatic coast and on the islands on the southeasternmost mid adriatic island of lopud they were studied along two lateral sections in sunj bay where a lense of reworked tephra is intercalated within the alluvial deposits the interpretation of the depositional mechanism the sand source the wind regime and the volcanic activity was based on facies analysis sedimentological characteristics and mineralogical and geochemical composition alluvial deposits represent recycled aeolian sand accumulated in a small scale alluvial plain during a relatively long lasting humid phase while overlying aeolian sands were deposited under the influence of the sea ward blowing nnw wind during more arid and windy periods sporadically occurring breccia lenses composed of limestone fragments from the cretaceous basement strata are the result of occasional high sediment concentration flows and deposition in shallow stream channels alluvial sand is composed of siliciclastic detritus derived from different metamorphic magmatic and older sedimentary rocks of the inner dinarides while the aeolian sand represents a mixture of siliciclastic detritus of the same provenance and carbonate clastic detritus sourced from the karst dinarides the lack of carbonate detritus in the alluvial deposits is probably a consequence of dissolution due to the humid climate the tephra lense represents pyroclastic material that was reworked by water and pedogenically altered the tephra belongs to the high k calc alcaline and shoshonite series with a trachyte trachydacite composition indicating an origin from the campanian province in southern italy as the most probable source area the similar composition of clastic material on lopud to the composition of aeolian and alluvial deposits on the neighbouring eastern mid adriatic localities islands of mljet korcula and lastovo and peljesac peninsula suggests their common source while the tephra lense documents pleistocene volcanic activity and suggests the influence of a southern wind during the humid phase

the chronostratigraphy of late pleistocene glacial and periglacial aeolian activity in the tuktoyaktuk coastlands nwt canada aeolian periglacial sand deposits are common in the tuktoyaktuk coastlands of western arctic canada regionally extensive and thick aeolian sand sheet deposits have been observed in two major stratigraphic settings within a sand unit characterized by large aeolian dune deposits and interbedded with glaciofluvial outwash from the laurentide ice sheet lis small localized sand sheets have also been observed along the tops of sandy bluffs within sequences of drained thermokarst lakes deposits and as an involuted veneer above buried basal ice of the lis on the basis of radiocarbon and optically stimulated luminescence osl dates from preserved periglacial aeolian sand sheets and dunes a regional chronostratigraphy is presented which indicates that both extensive dunes and sand sheets accumulated mainly between ca 30 and 13 ka a switch to dominantly sand sheet aggradation at ca 14 13 ka with sand sheets forming widely until ca 8 ka is attributed to a surface armouring by glacial deposits associated with the advance of the lis and b amelioration of the climate from cold aridity an absence of osl dates between ca 8 and 1 ka suggests that sand sheets stabilized during much of the holocene local sand sheet aggradation during recent centuries has occurred near sandy bluffs and on the floors of drained thermokarst lakes the osl dates constrain the maximum extent of the lis in the tuktoyaktuk coastlands to marine isotope stage 2

aeolian beach ridges and their significance for climate and sea level concept and insight from the levant coast east mediterranean abstract relict beach ridges of aeolian origin and associated soils are often used for inferring relative sea level and climate with contrasting results most studies link the aeolian coastal deposits to regressive phases some to high sea level stands and a few to intermediate relative sea level positions we interpret the apparent contradictions as indicating the lack of an over arching concept and the inconsistent usage of sea level related terms in this paper we present an integrated morpho sedimentological concept for a microtidal mid latitudinal coast and review existing data from the levant east mediterranean coast to evaluate the concept and to eliminate nomenclatural confusion a coastal depositional environment in a semi arid environment consists of shallow marine aeolian and alluvial facies which together form an aeolian beach ridge complex as a package of strata which respond simultaneously to sea level change a transgressive complex forms through reworking or overstepping of the coastal foredune and a regressive complex forms by downstepping under transgression the aeolian beach ridge represents the highstand deposit and its adjacent shallow marine sediment is the transgressive deposit under regression the complex represents the falling stage and the associated downdip surface marks the lowstand on the levant coast we find chronologically well constrained offlapping aeolian beach ridges as parts of six downstepping beach ridge complexes formed between 200 ka and 10 ka the complexes represent the falling stage systems tract fsst of a short lived 5th order depositional sequence when the shoreline shifted from a position close to the modern coastline to the shelf or below the shelf edge three of these fssts and their up dip and down dip super bounding surface together form the 4th order 100 ka sequence of the last interglacial glacial cycle the absence of transgressive highstand and lowstand systems tract is explained by the poor preservation potential due to the small sediment budget of the complex the falling stage complex has a high preservation potential because sediment source area increases while the sand drift potential remains above the local threshold on the levant coast sand delivery to the backshore continued during relative sea level falls for distances of up to 10 km between dune and coastline which is unprecedented in most modern analogues the significance of the dune soil succession for climate is limited because the dunes are governed by relative sea level change the vegetation response to changes in precipitation is non linear and the dune dynamics are characterised by low resilience and hysteresis

late pleistocene records of littoral processes at the tyrrhenian coast central italy depositional environments and luminescence chronology two cliff sites on the tyrrhenian coast of central italy have been investigated in order to investigate late pleistocene depositional environments by microfacies analysis and chronostratigraphy by luminescence age estimations both sections cover the period from the last interglacial to the end of the last glaciation in the buca dei corvi site an increasing rate of uplift is recognised which is responsible for significant environmental change and formation of the modern coastal fault scarp at around 9 ka in the golfo di baratti site the vertical succession of three marine horizons previously recognised by cortemiglia et al 1983 is attributed to the ois stages 5c 5a and 3 respectively this cliff section is affected by nne ssw orientated normal faults confirming that extentional structural processes are still active the coastal deposit of stage 3 today located at 7 m a s l suggests abnormal high uplift rate if the position of the palaeo shoreline was assumed at 40 to 50 m both central mediterranean coastal records strongly suggest that the eustatic sea level has dropped to a smaller amount than that of the open oceans

optically stimulated luminescence dating of young sediments a review optically stimulated luminescence osl dating of young 1000 years sediments is used increasingly in a wide variety of late holocene studies as a mean of establishing contemporary sedimentation rates or the timing of sediment deposition this paper provides a summary of the basic principles of osl dating outlines the problems specific to the dating of young material and then uses recent applications to young sediments to illustrate the greatly increased scope and potential of the method in geomorphology and the geology of recent deposits the overall reliability of this new generation of osl ages is examined by comparing where possible osl ages with independent age control it is concluded that the osl ages are accurate in that there is no evidence for systematic over or under estimation it is our conclusion that osl dating should be regarded as a reliable chronological tool for determining the time of deposition of water lain sediments from the coastal zone and aeolian deposits from both coastal and inland environments our conclusion is supported by the growing popularity of osl dating in geomorphology and geology

geomorphology stratigraphy and facies analysis of some late pleistocene and holocene key deposits along the coast of sardinia italy abstract two major synthems have been recognised along the coasts of sardinia the older one is composed of two sub synthems the oldest of which was formed in high energy boulder beaches and is a thin condensed transgressive sequence usually located at the foot of a marine cliff the overlying sub synthem was generated by aeolian slope interdunal ponds and alluvial depositional environments it is widespread and terraces and relict dune fields are usually deeply dissected its deposition is associated with a cold and arid climate the aeolian and alluvial deposition was interrupted by the evolution of steppe prairie soils a more evolved reddish brown bt paleosol is locally found at the top of the sequence the younger synthem is made of beach and coastal lagoon and swamps it is more variable in thickness rests unconformably over the older one and has no sedimentary cover it is laterally correlated to the present day depositional environments such as alluvial plains and beaches unfortunately because beach deposits of this synthem are found up to 6 m asl and a marine notch is present at 5 6 m capo san marco the widespread idea that sardinia is a stable area and that marine sea level during the holocene was never higher than nowadays led to their previous attribution to mis 5e however all the stratigraphic geomorphic and pedological evidence indicates that only the older sub synthem can be correlated with the mis 5e high stand the younger sub synthems made of aeolian lacustrine and alluvial deposits at cala gonone santa reparata capo s marco and s giovanni di sinis were deposited during the rest of the late pleistocene the younger synthem evolved during the holocene and this is the chronological setting of the beach deposits at is arenas scala e croccas santa reparata and capo san marco radiocarbon dating confirms these attributions unfortunately osl dating suggests an older chronology for these deposits and therefore it seems that further investigations are needed

palaeoclimate and palaeoenvironmental responses in the western mediterranean over the last 140 ka evidence from mallorca spain climatic change in the western mediterranean basin over the last 140 ka has been investigated from sediment and soil sequences along the coast of the northeastern part of mallorca spain palaeoclimate and palaeoenvironments are reconstructed from sediment and soil structures marine and terrestrial molluscan fauna grain size distributions mineral magnetics sediment and soil chemistry sem and oxygen isotope values dating is by osl and amino acid geochronometry along with marine molluscan faunal assemblages all oxygen isotope stages and substages from ois 6 to 1 are recorded mean annual temperatures m a t of c 19 2 c for the climatic optimum of the last interglacial compare with c 17 3 c for the present and are associated with high sea level extensive woodland and stable soils although wide temperature ranges are detected during this stage with values as low as c 10 3 c through ois 5d to 5a m a t fluctuated from 8 2 c to 17 9 c low sea level open vegetation effective river activity and aeolian sand and dust deposition characterize 5d and 5b while relatively high sea level and soil development on stable landscapes dominate ois 5c and 5a ois 4 is represented by m a t of c 4 9 c with aeolian sand and loess deposition limited river activity and weak soil development loess deposition persisted into ois 3 but at this time the m a t was c 13 c and with higher humidity and vegetation growth during the lgm ois 2 m a t was c 8 1 c and effective river slope and aeolian processes along with associated with limited vegetation cover were responsible for the most extensive changes in the landscape major rates of change occur during periods of climatic deterioration when the high levels of geomorphic energy were imposed on a landscape undergoing a breakdown of vegetation cover

middle to late pleistocene dunefields in rocky coast settings at cala xuclar eivissa western mediterranean recognition architecture and luminescence chronology abstract this study focuses on cliff front anchored and sand ramp aeolian dune accumulations in cala xuclar eivissa ibiza western mediterranean during different sea level falling stages from middle to late pleistocene times stratigraphic mapping conventional lithostratigraphic logging and osl datings are used to reconstruct dune formation and evolution facies analyses result in the identification of six sedimentary units three of which correspond to dune deposits formed at mis 6 145 ka mis 5d c 100 ka and mis 4 77 73 ka respectively additionally there is a beach deposit at 2 m above present msl which resembles the mis 5a this study concludes that each dune system corresponds to a relatively low sea level stand that exposed enormous amounts of marine carbonate sands that was transported inland by migrating dunes under strong north westerly winds therefore sea level fall and the related sediment supply owe likely to be key factors in the formation of these aeolianites systems

beach deposits of mis 5e high sea stand as indicators for tectonic stability of the carmel coastal plain israel abstract ten beach deposits mainly beachrock on the carmel coastal plain northern israel are discussed six are reported for the first time the deposits are situated within or close to the following seasonal stream locally termed nahal channels nahal ahuza amiram ovadia galim megadim bir ibdawiya me arot and kebara the morphology and lithology of most of the deposits are similar their uppermost altitude varies from 0 to 9 m above the present sea level most of the deposits are composed mainly of fine quartz sand and marine mollusk shells carbonate cemented the dominant mollusk families are glycymerididae cardiidae and donacidae most of the beach deposits are situated between cemented aeolian sandstones locally termed kurkar layers on the carmel coast ridge in the nahal ahuza deposit a marine gastropod lentigo latus an index fossil for the mis 5e high sea stand in the mediterranean area was discovered according to lithology and chronostratigraphy the presence of lentigo latus th u aar and rtl dating and flint artifacts the beach deposits were related to the last interglacial maximum about 125 ka bp i e the mis 5e high sea stand these beach deposits are used to identify the palaeo sea levels and coastlines and to study the tectonics along the carmel coastal plain by comparing the elevations and characteristics of the beach deposits to known mis 5e deposits elsewhere and by analyzing archaeological data it is concluded that during the last 125 ka the maximum possible vertical displacement was less than 48 mm ka and the carmel coastal plain was relatively tectonically stable

pleistocene calcareous aeolian alluvial deposition in a steep relief karstic coastal belt island of hvar eastern adriatic croatia abstract pleistocene aeolian and alluvial deposits occur on the island of hvar belonging to the eastern adriatic karstic coastal belt along the north eastern mediterranean margin the depositional mechanism of the aeolian alluvial and talus sediments are interpreted based on facies analysis and mineralogical composition aeolian deposits are represented by cross bedded cross laminated and sub horizontally laminated fine to medium grained calcareous sands the cross bedded units form tabular sets stacked into cosets sets and cosets are separated by distinct low angle bounding surfaces which mostly dip towards the east interpreted as the upwind direction cross laminated units form isolated sets within the cross bedded and sub horizontally laminated units cross bedded and cross laminated units represent dunes dominated by grain fall and wind ripple deposition respectively dunes produced by sand flow also occur but are less common the cross bedding is truncated by reactivation surfaces transverse dunes and some small dome shaped dunes were also present sub horizontally laminated sandy units represent aeolian sand sheets developed by wind ripple migration in the interdune area a few wind rippled dune apron deposits also occur trace fossils are locally very abundant within the aeolian deposits mostly produced by plants soft sediment deformation such as contorted cross bedding and pocket structures occur scattered and rare reddish horizons show pedogenesis unlikely most quaternary coastal aeolian sands these sands do not include marine bioclasts in composition the sands are composed of extraclasts dominated by limestone with subordinate chert quartz sericite schist quartzite and quartz amphiboles pyroxene and epidote are the most abundant translucent heavy minerals the mineralogical composition and palaeoflow directions indicate that the dinarides were the main provenance of the sand transported by primary easterly and northerly continental winds causing migration of dunes towards the palaeo adriatic sea alluvial deposits are intercalated with the aeolian sands they are composed of breccia derived from a nearby steep hill ridge and by resedimented aeolian sand deposited by traction currents during flash floods talus fragments reached the aeolian sands only sporadically climate strongly affected aeolian alluvial and talus depositions during arid conditions dunes migrated forming a dune field whilst more humid climate triggered heavy rains and generated erosion of aeolian deposits alluvial sedimentation colonisation of plants and pedogenesis deposition was in a topographic basin and was controlled by capacity of source area and wind however local orography characterised by developed and steep karstic relief strongly affected wind directions and in that way had specific controls on the dune field evolution dominating winds caused seaward dune migration differing from most mediterranean quaternary coastal aeolian dune localities characterised by landward migration