on the wave number spectrum of oceanic mesoscale variability observed by the seasat altimeter variations of sea surface height measured by the seasat altimeter in nearly repeat orbits during the last 24 days of the mission are used to compute the wave number spectrum of mesoscale variability in various parts of the oceans the instrument noise level 150 cm2 cycles km has limited the resulting oceanic spectrum to wavelengths longer than 100 km we found that the characteristics of the oceanic spectrum are dependent on the energy level of the mesoscale variability in the high energy areas close to major current systems most of the energy is contained at wavelengths longer than 250 km at wavelengths shorter than 250 km the spectrum basically follows a k 5 k is wave number dependence in the low energy areas remote from major current systems the spectrum follows a k 1 dependence at wave lengths from 100 to 1000 km based on the assumption of horizontal isotropy of mesoscale variability scalar wave number spectra of sea surface height and geostrophic kinetic energy are also presented dynamical implications of these spectra are discussed the effects of residual geoid and atmospheric water vapor on the computed oceanic spectra have been rigorously examined it was found that the general characteristics of the oceanic spectra were not significantly affected by them

dating the quaternary progress in luminescence dating of sediments abstract luminescence dating comprises a collection of numerical age techniques that are among the most significant chronological tools currently used in quaternary research this paper briefly reviews the key historical developments in luminescence dating from its roots in thermoluminescence dating of heated minerals to the development of optical dating methods for sunlight exposed sediments we describe the principles and practicalities of the various techniques commonly used in luminescence dating including multiple aliquot single aliquot and single grain procedures and we discuss some of the latest approaches to recognising and minimising potential errors in age estimation e g by means of component analysis and dose distribution methods in optical dating the overview also introduces the other papers in this special issue of quaternary science reviews which address a selection of important issues in basic research technique development and application of luminescence dating to critical questions in the geological and archaeological sciences illustrated with examples from around the world and the last million years of earth history

changes in mobility patterns as a factor for site density variation in the recent epigravettian of northern italy and southeastern france abstract this paper critically considers the use of radiocarbon dates as a demographic proxy for past population our goal is not to reject or valid this approach we even did not focus on the various bias of this approach or on the several correction methods used to reduce them we rather argue that when trying to interpret 14c dates in a demographic perspective it is essential to analyze socio economic parameters studying the case of the lateglacial upper palaeolithic of southeastern france and northern italy we demonstrate that the use of techno economic approaches allows discussing this way to interpret the radiocarbon data from this analysis we argue that a change in the density of dates cannot be simply interpreted in term of demography we demonstrate that these variations can be the result of changes in the way people organize themselves in a territory in other word we argue that mobility patterns are somehow responsible for the density of dates and sites

pottery versus sediment optically stimulated luminescence dating of the neolithic vinca culture serbia optically stimulated luminescence osl dating was applied to the neolithic vinca culture s type site vinca belo brdo to establish best protocols for routine luminescence dating of similar holoce

quaternary sediments in the dien bien phu fault zone nw vietnam a record of young tectonic processes in the light of osl sar dating results abstract the dien bien phu fault zone dbp orientated nne to n is one of the most seismically active zones in indochina in nw vietnam this zone is 160 km long and 6 10 km wide cutting sedimentary and metamorphic rocks of the late proterozoic palaeozoic and mesozoic age as well as palaeozoic and late triassic granitoids along the dbp relatively small narrow pull apart basins occur the three largest of which chan nua lai chau and dien bien phu have been studied in detail all of them are bounded by sinistral and sinistral normal faults responsible for offset and deflected drainage presence of numerous shutter ridges and displaced terraces and alluvial fans the normal component of motion is testified to by well preserved triangular facets on fault scarps highly elevated straths in river watergaps overhanging tributary valleys as well as high and uneven river bed gradients our observations indicate a minimum recent sinistral offset ranging from 6 8 to 150 m for holocene valleys to 1 2 9 75 km for middle late pleistocene valleys in different fault segments the thickness of quaternary sediments varies from 5 25 m in the lai chau area to some 130 m in the dien bien phu basin in the lai chau basin the middle terrace 23 m alluvia of nam na river at muong te bridge have been optically stimulated luminescence single aliquot regenerative dose technique osl sar dated at 23 40 to 13 ka these sediments were normal faulted by some 11 m after 13 ka and mantled by vari coloured slope loams 8 12 m thick containing colluvial wedges composed of angular debris these wedges were probably formed due to at least three palaeoseismic events postdating 6 ka in the dien bien phu basin in turn alluvium of the upper holocene terraces has been osl sar dated to 6 5 7 and 1 7 1 0 ka whereas the younger sub recent terrace sediments give ages of 0 5 0 2 ka displaced terraces and alluvial fans allow us to suppose that the sinistral and sinistral normal faults bounding narrow pull apart basins in the southern portion of the dbp fault reveal minimum rates of left lateral strike slip ranging from 0 6 to 2 mm year in holocene and 0 5 3 8 mm year in pleistocene times whereas rates of holocene uplift tend to attain 1 mm year north of lai chau and 0 4 0 6 mm year west of dien bien phu more precise estimations however are difficult to obtain due to poor age control of the displaced drainage rates of quaternary strike slip are comparable with those of the red river fault the sense of movement being however opposite taking into account the presence of two phases of late cenozoic strike slip of contrasting sense of motion as well as the geometry of the two fault zones we hypothesize that the red river and dien bien phu faults are conjugate faults capable of generating relatively strong earthquakes in the future

testing optically stimulated luminescence dating of sand sized quartz and feldspar from fluvial deposits abstract we apply single aliquot optically stimulated luminescence osl dating to quartz and feldspar rich extracts from fluvial channel deposits of the rhine meuse system in the netherlands the time of deposition of these deposits is tightly constrained by radiocarbon dating or historical sources this allows us to compare osl ages obtained on quartz and infrared osl ir osl ages obtained on potassium rich feldspar with independent ages over the range of 0 3 13 ka we show that the quartz osl ages are in good agreement with the expected age using ir osl dating of feldspar we find a slight age overestimate for the youngest sample whereas for older samples the age is significantly underestimated we also apply osl dating to older fluvial and estuarine channel deposits with limited independent chronological constraints comparison of feldspar ir osl ages with the quartz osl ages up to 200 ka shows a clear trend where the former severely underestimates the latter this trend is similar to that found for the samples with independent age control indicating that the feldspar ir osl ages are erroneously young for the entire age range in the youngest samples incomplete resetting of the ir osl signal prior to deposition probably masks the age underestimation we show that the ir osl age underestimation is partly caused by changes in trapping probability due to preheating correction for this phenomenon improves the ir osl ages slightly but does not provide a complete solution to the discrepancy we suggest that in the light of the problems encountered in the ir osl dating of feldspar quartz is the mineral of choice for osl dating of these deposits however feldspar dating should continue to be investigated because it has potential application to longer time scales

holocene environmental reconstruction from deltaic deposits in northeast greenland terraces of different age in the zackenberg delta located at 74 n in northeast greenland have provided the opportunity for an interdisciplinary approach to the investigation of holocene glacial periglacial pedological biological and archaeological conditions that existed during and after delta deposition the raised zackenberg delta accumulated mainly during the holocene climatic optimum starting slightly prior to 9500 cal yr bp 30 m a s l and continued until at least 6300 cal yr bp 0 5 m a s l evidence of sea level change is based on conventional 14c dates of shells from the marine delta bottomsets 14c ams dating of macroscopic plant material from the foresets and of fluvial deposits arthropod and plant remains from 7960 cal yr bp in the delta foresets include the oldest evidence of the arctic hare in greenland and evidence of a rich herb flora slightly different from the modern flora empetrum nigrum and salix herbacea remains indicate a summer temperature at least as high as today during delta deposition post depositional nivation activity dated by luminescence lichenometry and schmidt hammer measurements indicate mainly late holocene activity at least since 2900 yr bp including little ice age lia avalanche activity pedological analyses of fossil podsols in the zackenberg delta including 14c ams dating of selected organic rich b horizons show continued podsol development during the holocene climatic optimum and into the subsequent colder period of the late holocene until 3000 2400 yr bp a neo eskimo house ruin found on the lower part of the delta presently being eroded by the sea is dated to ad 1800 it presumably was abandoned prior to ad 1869 and suggests that some of the last eskimos that lived in northeast greenland might have occupied the zackenberg delta copyright 2002 john wiley sons ltd

luminescence dating of late pleistocene eruptions in the eifel volcanic field germany robust chronologies of late pleistocene and holocene volcanic eruptions are vital for hazard analysis but accurate and precise dating of these events is often difficult here we apply various luminescence techniques to quartz and polymineral extracts from heated crustal xenoliths enclosed in scoria and volcanically heated bedrock in the quaternary eifel volcanic field evf germany consistent results from red thermoluminescence rtl and optically stimulated luminescence osl of quartz and from post infrared infrared stimulated luminescence of polymineral material demonstrate complete luminescence signal resetting during lava emplacement and sufficient signal stability rtl and osl age underestimation of one sample with independently known age from the lava contact zone could be eliminated by annealing before laboratory regenerative irradiation the average luminescence age of 33 6 2 4 ka for the wartgesberg eruption is in good agreement with independent age control while the average age of 15 5 1 1 ka for the facher hohe scoria cone is much younger than previously assumed this result represents the third youngest known eruption in the evf our new data are in line with the hypothesized climate controlled triggering of eifel volcanism and confirm that active volcanism related to asthenosphere upwelling migrates from nw to se in the evf

the gravity field in the central pacific from satellite to satellite tracking satellite to satellite doppler tracking between the ats 6 and the geos 3 spacecraft is used to measure the high degree and order gravity field over an 80 area in the central pacific ocean doppler tracking provides velocity measurements of geos 3 as a function of time which are easily converted to line of sight accelerations since the low degree and order gravity field is known well each geos 3 revolution is reduced relative to a twelfth degree and order field model the method is then capable of measuring wavelengths in the range from about 3500 to 1000 km accelerations computed along 40 revolutions roughly half of them descending and the others ascending can be contoured into a map of the gravity field at the geos 3 altitude of 840 km the dominant wavelength of the map is about 2000 km a comparison of this field with an altimeter derived geoid and the gem 10b gravity field shows good agreement since each map is essentially independent of the others this comparison is critical in establishing the validity of any of the maps each map shows virtually the same areas of positive and negative anomalies these areas are essentially the same in the central pacific as those found in our earlier study compared with surface amplitudes these anomalies are only one tenth as large at the geos 3 altitude this observation and the correlation of gravity with residual depth anomalies imply that the cause of some of these anomalies may be due to bumps in the upper surface of the lithosphere that are compensated at depths of about 30 100 km some of the anomalies apparently do not correlate with residual depth anomalies

ice dammed lakes and rerouting of the drainage of northern eurasia during the last glaciation during the quaternary period ice sheets centred over the barents and kara seas expanded several times onto mainland russia and blocked northflowing rivers such as the yenissei ob pechora and mezen large ice dammed lakes with reversed outlets e g toward the caspian sea formed south of these ice sheets some lakes are reconstructed from shorelines and lacustrine sediments others mainly from ice sheet configuration ice dammed lakes considerably larger than any lake on earth today are reconstructed for the periods 90 80 and 60 50 ka the ages are based on numerous optically stimulated luminescence osl dates during the global last glacial maximum lgm about 20 ka the barents kara ice sheet was too small to block these eastern rivers although in contrast to the 90 80 and 60 50 ka maxima the scandinavian ice sheet grew large enough to divert rivers and meltwater across the drainage divide from the baltic basin to the river volga and that way to the caspian sea climate modelling shows that the lakes caused lower summer temperatures on the continent and on the lower parts of the ice sheet the final drainage of the best mapped lake is modelled and it is concluded that it probably emptied within few months we predict that this catastrophic outburst had considerable impact on sea ice formation in the arctic ocean and on the climate of a much larger area c 2003 elsevier ltd all rights reserved less

how radial orbit errors are mapped in altimetric surfaces in the radar altimeter measurement of the satellite height above the instantaneous sea surface radial orbit errors are mapped on the earth with the spacecraft motion in many geophysical and oceanographical applications of satellite altimetry a precise knowledge of the mapped error features is necessary to estimate sea or ice sheet surface topographies and to assess their absolute accuracies so we derive a general formulation to infer from any a priori time spectrum of orbit errors the characteristic wavelengths of the mapped error biasing the recovery of a sea surface topography because of commensurability between the satellite motion and earth rotation radial orbit errors at the nodal or orbital periods and their harmonics are mapped into smooth long wavelength surfaces and fully aliased in the steady surface topography as this phenomenon presents a close relationship with the resonance of the orbit perturbations we suggest naming it the mapped orbit error resonance our formulation also provides an explicit account of both time and space sampling effects on the correlation of the mean sea surface oceanic tides and orbit errors for instance the typical wavelength of a resonant mapped error is scattered by the land gaps in all the near wavelengths of an oceanic surface the derived mapping function also seems to indicate that the statistics of the crossover differences are unable to estimate the absolute precision of altimetric surfaces because a nonnegligible portion of radial orbit errors falls into the steady component of the sea surface

the distribution of apparent dose as determined by optically stimulated luminescence in small aliquots of fluvial quartz implications for dating young sediments abstract we noted recently murray et al 1995 that quartz samples taken from in channel fluvial deposits have apparent doses ranging over several orders of magnitude we suggested that these dose distributions are best explained by a mixture of a small number of poorly bleached grains and a larger number of well bleached grains in this paper we examine the distribution of apparent dose in small aliquots each composed of 2000 grains of different particle size fractions 63 90 m 90 125 m 125 180 m 180 212 m 212 250 m diameter from two samples collected from the murrumbidgee river new south wales australia the samples are of known burial age the first being 70 years old and the second being its modern equivalent 0 2 gy the difference in the lowest apparent dose in the two samples is considered to be the result of their different burial times we suggest a method for dating recently deposited

luminescence dating of archaeometallurgical slag use of the sar technique for determination of the burial dose abstract the potential of using luminescence techniques to date metallurgical slag of archaeological origin has been investigated slag is an important residue from the metal smelting process and there is no technique currently available to directly date it an attempt has been made to apply an optically stimulated luminescence osl single aliquot technique using quartz extracted from the slag matrix a single aliquot regeneration technique was used and preliminary results are encouraging in spite of problems encountered in the determination of the equivalent dose d e and apparent underestimation of the preliminary dates obtained the results presented here were obtained from measurements on copper and iron slag from archaeological sites in britain and greece

measurement of equivalent doses in quartz from contemporary water lain sediments using optically stimulated luminescence the single aliquot technique and its derivatives are very attractive for the measurement of the very small doses found in young materials because they inherently avoid concerns about low dose non linearity and can offer high precisions a modification is outlined to the single aliquot regeneration and added dose sara protocol mejdahl and botter jensen 1994 quaternary geochronology quaternary science reviews 13 551 5541 to permit its application to sedimentary quartz using the optically stimulated luminescence signal this revised protocol is then used to determine the doses found in several contemporary fluvial sediments and one coastal beach sand thought to be deposi ted by recent wave action two over bank river deposits were both homogeneously well bleached with doses of 0 4 gy although most of the grains in three channel deposits from a range of catchment sizes were also well bleached contamination by a small proportion of very poorly bleached quartz grains prevented the measurement of the dose in the majority the beach deposit was homogeneously bleached and contained a dose of about 0 02 gy it is concluded that over bank sites may provide accurate dates for samples older than a few hundred years but that the heterogeneity of the channel sites limits the accuracy of dates less than a few thousand years

gravity model improvement for seasat analysis of the data from the seasat altimeter a 10 cm precision instrument requires accurate knowledge of the radial position of the spacecraft for oceanographic applications such as the study of tides and ocean circulation as well as for geodetic applications initial orbit determinations using the best available geodetic and force models gave radial errors approaching 5 m the dominant source of this radial error was the gravity field model improvements in the gravity modeling were made by successively incorporating the seasat laser and unified s band ground tracking data the geos 3 altimeter data and finally the seasat altimeter data with the most recent model a set of spherical harmonic coefficients complete to degree and order 36 seasat ephemerides have been computed for an orbital arc length of 12 days with an rms radial accuracy of about 70 cm

radial variations of a satellite orbit due to gravitational errors implications for satellite altimetry the linear perturbations of the radius of a satellite orbit due to the geopotential are derived from these estimates are made of the radial orbit error due just to geopotential errors from current models employing only conventional satellite tracking data the estimates show that about an order of magnitude improvement in the satellite geopotential will be necessary to utilize the full accuracy of independent satellite altimeter measurements the linear perturbations are used to show that 1 a substantial improvement in the low degree geopotential is possible from the indirect use of seasat altimetry at track crossovers and 2 a separation of permanent sea topography and geoid may be possible from direct use of the heights along the track

luminescence dating of archaeological materials using a new technique based on single aliquot measurements abstract a dating method based on single aliquot luminescence dose determination was applied to quartz and feldspars from heated archaeological materials the problem of changes of sensitivity to radiation resulting from signal erasure in regeneration measurements was studied in some detail and a new method based on single aliquot regeneration measurements within an added dose framework which appears to eliminate the problem of sensitivity change is proposed preliminary dating results mainly using quartz obtained with the new method are presented

between atlantic and mediterranean changes in technology during the late glacial in western europe and the climate hypothesis abstract during the second half of the upper paleolithic europe seems to have been divided in two vast techno cultural entities with their particular chronological sequence the western europe classical sequence and the epigravettian sequence in the south essentially because of an imbalance of data and differences in methodologies between these two regions their upper paleolithic sequences have rarely been compared thanks to the development of lithic technology in europe and a recent active research about the late glacial it is today possible to attempt such a challenging exercise of comparing these two long sequences in this paper we solely focus on the late glacial if the rare existing attempts of comparison focused on typology of lithic assemblages our paper aims for a more global approach of lithic industries based on recent technological studies this approach allows highlighting key elements in term of human behaviors our data suggest a similar process of change between western europe and the epigravettian during gi 1 bolling allerod all the criteria of the so called azilianization process are actually present in the epigravettian evolution sequence this similar trend within both evolution sequences stopped abruptly during the gs 1 younger dryas during this period and the very beginning of the holocene preboreal a massive return of blades and bladelets with high qualitative standards occurred in western europe while the simplification process is still in course in the epigravettian region in this paper we attempt to compare the various responses of vegetation to the major climatic instability of the late glacial across europe using a critical survey of the available environmental data considering the boundary that could have represented the alps between epigravettian and the western europe sequence two high resolution environmental sequences from north and south of the alps are especially examined are the differences in terms of environmental changes between these two areas significant did they play a role in human behaviors and motivate technological changes the comparison of palaeoenvironmental data with archaeological results tends to comfort some hypothesis of environmental determinism proposed by scholars but also provide new elements moderating regional models that cannot really be applied at a continental scale climatic correlations with socioeconomic changes highlighted in this paper are no more than one possible way of investigation that will need to be tested and discussed in further research

interglacial and glacial climate oscillations in a marine shelf sequence from northern denmark a multidisciplinary study abstract a 22 5 m long marine shelf sequence in northern denmark covers the climatic shifts from glacial environments through interglacial and into early glacial conditions the interglacial was interrupted by two cool intervals also the early glacial succession experienced oscillations of the climate and a period with ameliorated temperature conditions has been separated as an interstadial these results are based on a multidisciplinary high resolution study of lithology foraminifera ostracods macrofauna diatoms and stable isotopes in a silty clay sequence from a borehole at norre lyngby 70 5 48 0 m depth the lithostratigraphy and the variations in depositional environment in the area is supported by a reflection seismic profile across the core site the chronostratigraphy is discussed on the basis of biostratigraphical correlation and seismostratigraphy as well as optically stimulated luminescence osl dating and amino acid measurements the biostratigraphy and the osl dates suggest an eemian age for the interglacial while amino acid results point to an older age if the interglacial is confirmed as eemian we believe that the succeeding interstadial period is likely to be correlated with the brorup interstadial the climatic changes in this eastern part of the north sea region are closely linked with changes in the north atlantic circulation pattern and the environmental fluctuations at norre lyngby are therefore believed to reflect fluctuations in the past regional climatic and oceanic system

a contribution to late middle paleolithic chronology of the levant new luminescence ages for the atlit railway bridge site coastal plain israel abstract the atlit railway bridge arb prehistoric site is located on the northern coastal plain of israel within natural caves which formed in calcareous aeolianites kurkar perhaps during a high sea stand flint artifacts belonging to the levantine later mousterian tradition and faunal remains were found embedded in the kurkar infill of two caves the aeolianites in which the caves had developed were previously constrained by irsl 50 dating of feldspars to be older than the last interglacial highest sea stand frechen m et al 2004 chronology of pleistocene sedimentary cycles in the carmel coastal plain of israel quaternary international 121 1 52 providing a maximum age for the artifacts samples for luminescence dating were collected from the infill of the two caves ii and iii from the same deposits as the archaeological finds both quartz and alkali feldspars kf were extracted and measured using four different luminescence signals optically stimulated luminescence blue osl and violet stimulated luminescence vsl on quartz and the infrared stimulated luminescence irsl post ir ir 290 signal and the ir 50 signal corrected for anomalous fading on kf the ages obtained from analyses of the different minerals and signals mostly agree within errors the new luminescence ages date the sediment infill in caves iii and ii to 90 ka and 70 ka respectively indicating that hominin occupation of this locality is coeval with the nearby skhul cave and layer b in tabun cave

developments in optically stimulated luminescence and photo transferred thermoluminescence dating of young sediments application to a 2000 year sequence of flood deposits this paper demonstrates how optically stimulated luminescence osl and photo transferred thermoluminescence pttl can be used to date young 0 2000 year old flood deposits on the bank of a major river in the southern tablelands of southeastern australia quartz grains extracted from these deposits do not show a detectable dose dependent sensitivity change following optical stimulation this allows a recently proposed regeneration based protocol sara to be used to estimate the equivalent dose de acquired since burial for the oldest sample a dependence of de on pre heat temperature is removed by heating to at least 180 c for 10 s before stimulation values of de are reported for six samples using both osl and pttl values ranged between 0 4 and 6 5 gy with overall uncertainties usually 7 the values of de obtained using osl and pttl are in agreement dose rates are calculated from detailed analyses of environmental radionuclide concentrations and the resulting luminescence dates range from 100 13 to 1920 130 years before present the uncertainties include systematic effects for two layers where there is age control by 14c dates the luminescence dates are in good agreement unfortunately the limitations of the 14c data preclude firm conclusions about the size of any effective age residual at deposition for the luminescence samples although this is likely to be 50 100 years it is concluded that luminescence dating offers a considerable improvement over other techniques including 14c for recently transported fluvial sediments

esr dating of tephra with dose recovery test for impurity centers in quartz abstract the multiple aliquot regenerative additive method of esr electron spin resonance dating was applied to numazawa shibahara nm sb tephra from fukushima japan with dose recovery tests for impurity centers in quartz the age obtained from ti h center is consistent with the rtl red thermoluminescence and fission track ages while the ones from al and ti li center are overestimates the dose recovery test indicates that the equivalent dose estimate based on the ti h center agrees within 6 of the expected dose 370 gy the dose recovery test is a useful procedure for choosing the signal appropriate for dating

an alternative method of orbit improvement for a doppler tracked satellite a step toward earth gravity model refinement an alternative method of orbit and gravity field improvement for doppler tracked satellites is presented here in view of the prospect of future geodetic and altimetric missions doppler orbitography and radiopositioning integrated by satellite doris spot 2 the ocean topography experiment topex poseidon ers 1 owing to a refined analysis of the doppler residuals generated by a classical orbit computation it is successively possible 1 to improve the computed spacecraft orbit with interesting by products such as improved tracking station coordinates and doppler reference frequencies 2 to recover the disturbing forces due to a mismodeling of the geopptential model i e regional gravity anomalies above the stations in line of sight direction and at satellite altitude and 3 to globally refine the mismodeled gravity field from a dense set of this regional information the paper deals with the first two steps with emphasis on step 1 the more classical geodetic problem of step 3 will be the subject of a future paper simulation results for seasat and doris are presented and discussed with a simulated random noise of 0 3 cm s orbit error is recovered with an accuracy of a few decimeters with a noise level of 0 3 mm s orbit and force errors are recovered with an rms accuracy better than 0 2m and 0 2 mgal at 800 km altitude this is very encouraging for future doppler positioning systems like doris

an estimate of global absolute dynamic topography abstract we estimate the absolute dynamic topography of the world ocean from the largest scales to a short wavelength cutoff of about 6700 km for the period july through september 1978 the data base consisted of the time averaged sea surface topography determined by seasat and geoid estimates made at the goddard space flight center the issues are those of accuracy and resolution use of the altimetric surface as a geoid estimate beyond the short wavelength cutoff reduces the spectral 1eakage in the estimated dynamic topography from erroneous small scale geoid estimates without contaminating the low wavenumbers comparison of the result with a similarly filtered version of levitus historical average dynamic topography shows good qualitative agreement there is quantitative disagreement but it is within the estimated errors of both methods of calculation

on crossover adjustment in satellite altimetry and its oceanographic implications it is argued that to remove the satellite orbital errors the crossover adjustment method that represents orbital errors in terms of fourier series is preferable to the conventional bias and tilt crossover adjustment method however no matter what technique is used in the crossover adjustment orbital errors will introduce a geographically dependent error mostly a large scale slope which in terms of spherical harmonics is represented by the degree 1 terms into the derived sea surface topography this is because the responsible orbital errors have left no traces in crossover differences and therefore can never be removed however it is possible to reduce this fundamental uncertainty substantially if the record length is long enough its implications on observing the basin scale ocean circulation by satellite altimetry are discussed we also propose new methods for observing the large scale oceanic variability the conventional approach limited us to observing the mesoscale variability

attempt at using the single aliquot regenerative dose procedure for the determination of equivalent doses of upper palaeolithic burnt stones the equivalent dose of upper palaeolithic quartzite pebbles burnt in prehistoric hearths was determined using the optically stimulated luminescence osl signal and the single aliquot regenerative dose sar procedure since previously published thermoluminescence tl dates for these samples were in agreement with the archaeological record and other chronological data the tl equivalent doses were used as a reference the observed discrepancies between some tl and osl sar equivalent doses are probably due to accidental bleaching before the stones reached the laboratory instead of reflecting a deficiency of the sar procedure this hypothesis is confirmed by experiments which indicate that bleaching could reach considerable depths in quartzite specimens and significantly deplete the osl signal

first chronometric dates tl and osl for the aurignacian open air site of românesti dumbrăviţa i romania abstract currently absolute dates for the emergence of the early upper paleolithic and the timing of the earliest dispersal of anatomically modern humans amh into europe are sparse this is especially true for regions adjoining the eastern mediterranean and central europe with its dense clusters of sites along the austrian and german danube valley this article makes a first step toward filling this gap and for the first time presents absolute ages for the open air site of rom nesti dumbr vi a i banat sw romania located close to the oase cave where some of the oldest amh fossils were found a set of heated artefacts recently excavated from the aurignacian layer gh3 was dated by thermoluminescence tl and gives early chronometric dates for this technocomplex in romania the luminescence behavior of artefact samples required the use of different multiple and single aliquot measurement protocols to obtain reliable age information in addition analyses of glow curves and the performance during regenerative dose measurements allowed us to distinguish two types of samples since one group is characterized by poor dose reproducibility only samples showing reliable luminescence behavior were considered for final age interpretations as a result we could determine that the last heating of artefacts from gh3 happened most likely between 39 ka single aliquot age estimate and 45 ka multiple aliquot age estimate ago with a weighted average age of the gh3 finds of 40 6 1 5 ka including all data these dates were confirmed by osl dating of sediments of the find layer such an early age fits well to technological and typological features which place the dated lithic assemblage at the very beginning of the development of the aurignacian technocomplex usually seen as a proxy for the earliest wide spread presence of amh in europe

signature of the last shelf centered glaciation at a key section in the pechora basin arctic russia the vastiansky kon is the largest exposure of quaternary deposits in the pechora lowland northern russia morphologically the site belongs to the so called markhida moraine a complex east west trending zone of ice marginal landforms deposited by the kara sea ice sheet during the last glaciation the site exhibits a succession of sediments more than 100 m thick that according to previous studies covers the interval from the end of the elsterian to the beginning of the holocene unfortunately both the strong glaciotectonic deformation of the sedimentary succession and few absolute dates have made the chronological interpretation of the section difficult the present paper reviews previous studies of the site published in russian and presents the results of a reinvestigation focusing on the post eemian stratigraphy a marine eemian clay more than 8 m thick is overlain erosionally by 20 m of fluvial deposits of late eemain or early weichselian age the fluvial succession is overlain by a till and a marine clay which according to one interpretation may represent an early or middle weichselian advance of the kara ice sheet followed by a transgression the clay shows a transition into 15 m of estuarine and fluvial sediments overlain by more than 12 m of tundra floodplain deposits the whole succession has been upthrusted glaciotectonically by the last ice advance which deposited a more than 12 m thick till on top of the section based on a number of subtill radiocarbon age estimates from the site in the range 25 32 ka bp the youngest ice advance is considered to be of late weichselian age although a middle weichselian age cannot be excluded 1998 john wiley sons ltd

relict nebkhas pimple mounds record prolonged late holocene drought in the forested region of south central united states the origin and significance of pimple mounds low elliptical to circular dune like features found across much of the south central united states have been debated for nearly two centuries we cored pimple mounds at four sites spanning the ozark plateau arkansas river valley and gulf of mexico coastal plain and found that these mounds have a regionally consistent textural asymmetry such that there is a significant excess of coarse grained sediment within their northwest flanks we interpret this asymmetry as evidence of an eolian depositional origin of these mounds and conclude they are relict nebkhas coppice dunes deposited during protracted middle to late holocene droughts these four mounds yield optically stimulated luminescence ages between 2400 and 700 yr that correlate with well documented periods of eolian activity and droughts on the southern great plains including the medieval climate anomaly we conclude vegetation loss during extended droughts led to local eolian deflation and pimple mound deposition these mounds reflect landscape response to multi decadal droughts for the south central u s the spatial extent of pimple mounds across this region further underscores the severity and duration of late holocene droughts which were significantly greater than historic droughts

marmota marmota the most common prey species at grotta del clusantin insights from an unusual case study in the italian alps archaeozoological investigations carried out at grotta del clusantin in the italian north eastern alps suggest that this late upper palaeolithic site hosted small groups of marmot hunters taxonomic data describe an alpine grassland environment with arboreal and shrubby vegetation in proximity the bone assemblage is extremely fragmented as a result of anthropic activities and post depositional agents the presence of percussion cones butchering cutmarks burnt bones and the almost total absence of carnivore traces and animal lairs suggests that humans are responsible for faunal accumulation experimental approaches on marmot specimens supported archaeological evidence demonstrating elements of systematics and or explaining anatomical absences from field evidence lithic and functional data it has been inferred that this site was a specialized camp used for exploiting and consuming several rodent carcasses in the context of the first human occupations of the highlands at the onset of the lateglacial interstadial