late quaternary geological history of the dead sea area israel abstract a 34 5 m borehole which was drilled near the dead sea coast altitude 394 m in the southern part of the fan delta of wadi zeelim reveals the geological history of that area from the latest pleistocene to present the depositional time frame is based on six 14c dates and two u th dates an erosional or nondepositional period is implied by the hiatus between 21 100 yr b p u th age depth 33 m and 11 315 yr b p 14c age depth 32 m a subsequent arid phase is recorded by a 6 5 m thick layer of halite based on 14c dates this phase relates to the abrupt younger dryas cold period reported in temperate to polar regions the fragility of the environment in this region is indicated by the fact that the region experienced such a severe short aridification phase less than 1000 yr evidence of which is found widely in the desert fringes of the middle east and north africa the aragonite found in most of the holocene section indicates that the well site was covered by the lake for most of the holocene exceptions are the intervals at 0 3 and 10 14 m depths which represent low stands of the lake

x ray microanalysis of fluid inclusions and its application to the geochemical modeling of evaporite basins direct access to brines trapped in halite is possible by freezing and breaking halite crystals on a cooling stage inside a scanning electron microscope quantitative analyses of major solutes na mg k ca cl and so4 in natural brines were obtained by means of x ray microanalysis of the frozen fluid inclusions using frozen droplets of brines with known composition as standards precision errors were estimated to be lower than 10 and detection limits vary from below 0 02 mol l for ca k and so4 to 0 55 mol l for na analyses of several inclusions of sizes larger than 20 m were performed for each cross section of halite the composition of primary fluid inclusions in halites from a drill core in the messinian basin of lorca se spain were used to constrain the parameters of a geochemical model of the evolution of the basin a computer program to simulate evaporation paths was developed using thermodynamic equilibrium and mass balance as constraints the halite sequence was interpreted as resulting from the evaporation of initial seawater in a hydrologically open basin with seawater replacing the evaporated water and a small fraction of basinal brine leaking out in the middle of the sampled sequence the basin was closed to the sea and only continental water flowed into the basin reworking part of the halite deposited in the margins in contrast with these results only very poor information would have been obtained from the mineralogical record alone consisting mainly of halite and minor gypsum

will the dead sea die the level of the dead sea the lowest surface on earth is currently declining at a rate of 0 8 m yr and has dropped about 20 m since the beginning of the twentieth century it reached 410 m in 1997 we address the question of whether the level of the dead sea will continue to decline a numerical model developed in this study to determine the water balance accounts for the increase in salinity and the concomitant decrease in the rate of evaporation that accompanies reduction in the activity of the water simulations based on ranges of water withdrawal scenarios suggest that the dead sea will not die rather a new equilibrium is likely to be reached in about 400 yr after a water level decrease of 100 to 150 m

paleoclimate and location of the border between mediterranean climate region and the saharo arabian desert as revealed by speleothems from the northern negev desert israel speleothem bearing karstic caves of the northern negev desert southern israel provides an ideal site for reconstructing the paleoclimate and paleo location of the border between mediterranean climate region and the saharo arabian desert major periods of speleothem deposition representing humid periods were determined by high resolution 230 th u dating and corresponding studies of stableisotopecompositionwereusedtoidentifythesourceofrainfallduringhumidperiodsandthevegetationtype majorhumidintervals

evidence of potash salt formation in the pliocene sedom lagoon dead sea rift israel abstract the dead sea is a ca chloride evaporitic lake close to halite saturation carnallite kmgcl3 6h2o is the next mineral predicted to precipitate and is currently produced in solar ponds on the shores in israel and jordan the particular composition of the dead sea has been attributed to the contribution of pliocene residual brines formed during the deposition of the sedom formation that currently reappear as hydrothermal flows the chemical composition of these returning flows suggests that sedom brines reached the potash forming sylvite and or carnallite stage the sedom formation is a thick more than 2000 m evaporite succession made up of bedded salt rock accumulated during the pliocene when an arm of the mediterranean sea seeped through the dead sea rift forming the sedom lagoon the present study is focused on the upper part of the sedom formation mearat sedom member where detailed petrology bromine contents in salt cryo sem eds microanalysis of fluid inclusions in halite and isotopic compositions 34s and 18o in sulfates and 37cl in salt were investigated although halite is the main evaporite mineral minor sylvite and carnallite occurrences in the form of early diagenetic nodules cements and or authigenic crystals are commonly present the geochemical modeling of the primary fluid inclusion composition in halite points to the evaporation of seawater or mixtures of seawater and continental water with a very minor a cyclic evolution of the basinal brines can be deduced from the composition of fluid inclusions together with the bromine contents in halite and the sulfate isotopes thus stages of dilution involving fresh marine and or continental waters alternated with stages of high concentration when the saturation of the lagoon brine with respect to the potash salts was reached potash minerals could crystallize on the shores or in the marginal zones of the lagoon and could be dissolved and recycled during the subsequent dilution stages

insolation values for the climate of the last 10 million years new values for the astronomical parameters of the earth s orbit and rotation eccentricity obliquity and precession are proposed for paleoclimatic research related to the late miocene the pliocene and the quaternary they have been obtained from a numerical solution of the lagrangian system of the planetary point masses and from an analytical solution of the poisson equations of the earth moon system the analytical expansion allows the direct determination of the main frequencies with their phase and amplitude numerical and analytical comparisons with the former astronomical solution ber78 are performed so that the accuracy and the interval of time over which the new solution is valid can be estimated the corresponding insolation values have also been computed this analysis leads to the conclusion that the new values are expected to be reliable over the last 5 ma in the time domain and at least over the last 10 ma in the frequency domain

climatic controls on holocene lake level changes in europe sensitivity experiments with a simple water balance model were used to constrain the possible climatic causes of distinct holocene patterns of lake level variation in different regions of europe lakes in s sweden were low at 9 ka high around 6 5 ka low again around 4 ka and are high now lakes in estonia show similar but weaker trends lakes in s france were highest around 9 ka lowest around 4 ka intermediate now lakes in greece were also high around 9 ka but continued rising until 7 5 ka then fell gradually from 5 ka with a brief high phase around 3 ka and are low now the model was forced with insolation anomalies deduced from orbital variations temperature anomalies inferred from the pollen record and cloudiness anomalies derived from changes in the position of the subtropical anticyclone inferred from reconstructed changes in the equator to pole temperature gradient in order to evaluate the effects of resultant evaporation changes on catchment water balance the resulting simulated changes in runoff precipitation minus actual evapotranspiration were slight and frequently opposite to the observed trends larger changes in precipitation are plausible and are required to explain the data the required precipitation increase in n europe from 9 ka low to 6 ka high is suggested by gcm experiments to have been a consequence of interacting insolation and residual ice sheet effects on the atmospheric circulation over the north atlantic the explanation of other observed changes including the drying trend during the holocene in s europe has not been provided by gcm experiments to date explanations may lie in changes in mesoscale circulation sea surface temperature patterns and the coupling between these phenomena that may not follow orbital changes in any simple way

integrated multi site u th chronology of the last glacial lake lisan abstract we present a new integrated multi site chronology for lake lisan which occupied the dead sea basin and jordan valley during the last glacial period 70 14 kka marine isotope stages 4 3 2 the dead sea basin lacustrine deposits are unique among closed basin sediments in that they formed in a deep hypersaline water body that precipitated primary aragonite which is amenable to radiometric dating by u series providing a solid basis for studies of the relationship of middle east climate to other changes in the high latitudes or the tropics the application of u th dating for lacustrine carbonates requires corrections for detrital u and th and hydrogenous initial 230th here we followed an iterative approach in which we evaluate the composition of the detrital contamination independently for every set of coeval samples to determine the corrected ages these were further filtered and combined with lithological limnological considerations which were used to construct age height models for all studied stratigraphic sections finally the ages of stratigraphic tie points were used to integrate the individual age height models into a unified chronology the resulting chronological framework indicates that the ages of several primary gypsum units associated with catastrophic lake level drops correspond with the timing of heinrich events in the north atlantic thus a final iterative step involves refining the ages of lisan gypsum events based on the ages of heinrich events 6 5 5a 4 and 1 this approach yields an unprecedented basin wide unified event anchored chronology for the lisan formation with typical age uncertainties ca 1000 2000 years 95 confidence limit across the entire last glacial well below those typically related to individual u th and radiocarbon dating of dirty carbonates from similar time intervals the results can be further extrapolated to new sites and serve as a geochronometric reference for the reconstruction of the limnological history of lake lisan

late pleistocene rise of the sedom diapir on the backdrop of water level fluctuations of lake lisan dead sea basin abstract during the last glacial between 70 and 15 kyr b p large parts of the dead sea rift were inundated by lake lisan we use the established history of lake lisan water level fluctuations as a tool for determining the rates and styles of the salt tectonic uplift of the sedom salt diapir our reconstruction is based on new accurate mc icpms u th ages of lake lisan deposits overlying the top of mount sedom the surface expression of the sedom diapir these sediments range in age between 46 4 and 15 5 kyr b p comparison of the present elevations of the studied lisan sediments to the lake lisan level curve indicates that these sediments were uplifted to their present elevations due to the diapiric rise of mount sedom during the late pleistocene lisan sediments older than 46 4 kyr b p were not found yet on mount sedom suggesting that it was exposed prior to that time we correlate the exposure phase of mount sedom with the lowest stand of lake lisan between 48 and 43 kyr b p during which previously deposited sediments were eroded the age of the top of the lisan formation on mount sedom is 15 5 kyr b p and it has been uplifted by 75 m since then

sea rain lake relation in the last glacial east mediterranean revealed by δ18o δ13c in lake lisan aragonites we investigated the sea rain lake relation during the last glacial holocene in the east med iterranean region by comparing the 18 o and 13 c records of authigenic aragonite deposited in lake lisan the dead sea mediterranean foraminifera and speleothems the lisan formation data display long and short term variations of 18 o representing steady state conditions of the lake e g 5 6 0 5 and 4 5 1 in the upper and lower members of the lisan formation respectively and short term excursions reflecting large floods and droughts the long term steady state 18 o values of the lisan aragonites show similarity to the corresponding time equivalent records of the eastern mediterranean foraminifera and judea mountain speleothems the last glacial deposits are in all of them 2 3 heavier than the holocene ones we interpret this similarity as reflecting the significance of the source effect on the long term behavior of isotopic reservoirs speleothem 18 o is strongly influenced by the marine reservoir that contributes its vapor to rain formation the lake 18 o is dominated by the composition of the inflowing water short term variations in the isotopic composition of rainfall are dominated by the amount effect and the temperature and those of the lake s upper water mass by the lake s water balance 13 c values are more variable than 18 o in the same lisan sequences e g 13 c in the lower member is 1 0 1 7 whereas 18 o is 4 6 0 7 and are 1 to 1 5 higher in the upper member than in the lower and middle members of the lisan formation these variations reflect significant increase in primary productivity of the lake and algal bloom activity it appears that the hypersaline saline lakes were not as dead as the dead sea is and that algal activity had an important impact upon the geochemistry of lake lisan the 18 o data combined with independent geochemical and limnologic information e g level fluctuations indicate that lisan time was characterized by high precipitation high lake stands high atmospheric humidity whereas the holocene dead sea shows the opposite behavior this paleoclimatic reconstruction is consistent with independent evidence for significantly wetter conditions in the east mediterranean region during the last glacial period copyright 2005 elsevier ltd

last interglacial climates the last interglacial commonly understood as an interval with climate as warm or warmer than today is represented by marine isotope stage mis 5e which is a proxy record of low global ice volume and high sea level it is arbitrarily dated to begin at approximately 130 000 yr b p and end at 116 000 yr b p with the onset of the early glacial unit mis 5d the age of the stage is determined by correlation to uranium thorium dates of raised coral reefs the most detailed proxy record of interglacial climate is found in the vostok ice core where the temperature reached current levels 132 000 yr ago and continued rising for another two millennia approximately 127 000 yr ago the eemian mixed forests were established in europe they developed through a characteristic succession of tree species probably surviving well into the early glacial stage in southern parts of europe after ca 115 000 yr ago open vegetation replaced forests in northwestern europe and the proportion of conifers increased significantly farther south air temperature at vostok dropped sharply pulses of cold water affected the northern north atlantic already in late mis 5e but the central north atlantic remained warm throughout most of mis 5d model results show that the sea surface in the eastern tropical pacific warmed when the ice grew and sea level dropped the essentially interglacial conditions in southwestern europe remained unaffected by ice buildup until late mis 5d when the forests disappeared abruptly and cold water invaded the central north atlantic ca 107 000 yr ago

oscillatory climate modes in the eastern mediterranean and their synchronization with the north atlantic oscillation abstract oscillatory climatic modes over the north atlantic ethiopian plateau and eastern mediterranean were examined in instrumental and proxy records from these regions aside from the well known north atlantic oscillation nao index and the nile river water level records the authors study for the first time an instrumental rainfall record from jerusalem and a tree ring record from the golan heights the teleconnections between the regions were studied in terms of synchronization of chaotic oscillators standard methods for studying synchronization among such oscillators are modified by combining them with advanced spectral methods including singular spectrum analysis the resulting cross spectral analysis quantifies the strength of the coupling together with the degree of synchronization a prominent oscillatory mode with a 7 8 yr period is present in all the climatic indices studied here and is completely synchronized with the north atlantic oscillation an energy analysis of the synchronization

a coral oxygen isotope record from the northern red sea documenting nao enso and north pacific teleconnections on middle east climate variability since the year 1750 a 245 year coral oxygen isotope record from the northern red sea ras umm sidd egypt 28 n in bimonthly resolution is presented the mean annual coral 18o signal apparently reflects varying proportions of both sea surface temperature and 18oseawater variability in conjunction with instrumental observations of climate the coral record suggests for interannual and longer timescales that colder periods are accompanied by more arid conditions in the northern red sea but increased rainfall in the southeastern mediterranean whereas warmer periods are accompanied by decreased rainfall in the latter and less arid conditions in the northern red sea a 70 year oscillation of probably north atlantic origin dominates the coral time series interannual to interdecadal variability is correlated with instrumental indices of the north atlantic oscillation nao the el nino southern oscillation enso and north pacific climate variability the results suggest that these modes contributed consistently to middle east climate variability since at least 1750 preferentially at a period of 5 7 years

coherent pan asian climatic and isotopic response to orbital forcing of tropical insolation the oxygen 18 isotope composition of calcite in stalagmites across southern and eastern asia are highly correlated to one another on orbital time scales large negative excursions are coincident with maxima in summer insolation in the subtropics of the northern hemisphere nh these isotopic excursions reflect changes in the precipitation weighted isotopic composition of precipitation 18op we present results from two core experiments using an isotope enabled climate model the high insolation and low insolation experiments in which the model is forced by extrema in nh summer insolation compared to the low insolation experiment the high insolation climate features profound large scale changes in the pattern of monsoon precipitation spanning from africa to southeast asia that are due to changes in the relative contributions of temperature and moisture to the near surface equivalent potential temperature e under high insolation a more rapid increase in land surface temperature in early summer causes the greatest e and hence precipitation to shift from the oceans in low insolation such as today to be over land in high insolation such as the early holocene the model captures the general pattern of isotopic excursions seen in caves spanning from israel to western china including large drops in 18op over eastern tibet 7 the arabian peninsula and northeast africa 4 although there are large changes in precipitation over tibet the change in 18op is due to changes in the 18o of water vapor that is delivered and subsequently precipitated it does not inform on local precipitation amount or intensity

northward intrusions of low and mid latitude storms across the saharo arabian belt during past interglacials the rain regime of the levant during the late quaternary was controlled primarily by mediterranean cyclonic systems associated with north atlantic climate shifts lake levels in the dead sea basin have been robust recorders of the regional hydrology and generally indicate highstand wet conditions throughout glacial intervals and lowstands dry during interglacials however sporadic deposition of travertines and speleothems occurred in the negev desert and arava valley during past interglacials suggesting intrusions of humidity from southern sources probably in association with enhanced activity of mid latitude red sea synoptic troughs and or low latitude tropical plumes the southerly incursions of wetness were superimposed on the long term interglacial levantine arid conditions as refl ected by the current prevailing hyperaridity and could have had an important impact on human migration through the red sea dead sea corridor

ages of quaternary pluvial episodes determined by uranium series and radiocarbon dating of lacustrine deposits of eastern sahara abstract as documented by radiocarbon dating and geoarchaeological investigations the now hyperarid northwestern sudan and southwestern egypt experienced a period of greater effective moisture during early and middle holocene time about 10 5 ka we have used the uranium series technique to date lacustrine carbonates from bir tarfawi bir sahara east wadi hussein oyo depression and the great selima sand sheet localities results indicate five paleolakeforming episodes occurred at about 320 250 240 190 155 120 90 65 and 10 5 ka four of these five pluvial episodes may be correlated with major interglacial stages 9 7 5e and 1 the 90 65 ka episode may be correlated with substage 5c or 5a our results support the contention that past pluvial episodes in north africa corresponded to the interglacial periods farther north ages of lacustrine carbonates from existing oases and from the sand sheet fail to indicate pluvial conditions between about 60 and 30 ka age results and field relationships suggest that the oldest lake and ground water deposited carbonates were much more extensive than those of the younger period and that carbonate of the latest wet periods were geographically localized within depressions and buried channels

stratigraphy depositional environments and level reconstruction of the last interglacial lake samra in the dead sea basin in this paper we describe the stratigraphy and sediments deposited in lake samra that occupied the dead sea basin between 135 and 75 ka this information is combined with u th dating of primary aragonites in order to estimate a relative lake level curve that serves as a regional paleohydrological monitor the lake stood at an elevation of 340 m below mean sea level msl during most of the last interglacial this level is relatively higher than the average holocene dead sea 400 30 m below msl at 120 and 85 ka lake samra rose to 320 m below msl while it dropped to levels lower than 380 m below msl at 135 and 75 ka reflecting arid conditions in the drainage area lowstands are correlated with warm intervals in the northern hemisphere while minor lake rises are probably related to cold episodes during mis 5b and mis 5d similar climate relationships are documented for the last glacial highstand lake lisan and the lowstand holocene dead sea yet the dominance of detrital calcites and precipitation of travertines in the dead sea basin during the last interglacial interval suggest intense pluvial conditions and possible contribution of southern sources of wetness to the region

catastrophic arid episodes in the eastern mediterranean linked with the north atlantic heinrich events the response of continental climate to the well documented climate oscillations during the last glacial period has been a subject of intense interest yet much less is known about the influence on regional continental climates than in the marine or polar realms of earth the detailed lake level history of the closed lake lisan paleo dead sea in the middle east has been reconstructed from shoreline indications and high resolution u th and 1 4 c chronologies thus providing data on the response of the lake s catchment area to the climate changes during the corresponding period we present a correlation between the newly developed lake lisan level curve for the past 55 k y and the north atlantic heinrich events the correlation indicates a closely connected climate response between these north atlantic events and the hydrologic conditions that prevailed in the eastern mediterranean our findings show that although the generally cooler conditions that prevailed during the last glaciation favored high levels of the lake catastrophic events in the north atlantic which are associated with maximum cooling have been responsible for droughts in the eastern mediterranean we infer that cold water input to the mediterranean originating in the collapse of the north atlantic deep water circulation caused the reduction of evaporation and less precipitation in the eastern mediterranean

middle and late pleistocene humid periods recorded in palaeolake deposits of the nafud desert saudi arabia present climate in the nafud desert of northern saudi arabia is hyper arid and moisture brought by north westerly winds scarcely reaches the region the existence of abundant palaeolake sediments provides evidence for a considerably wetter climate in the past however the existing chronological framework of these deposits is solely based on radiocarbon dating of questionable reliability due to potential post depositional contamination with younger 14c by using luminescence dating we show that the lake deposits were not formed between 40 and 20 ka as suggested previously but approximately ca 410 ka 320 ka 200 ka 125 ka and 100 ka ago all of these humid phases are in good agreement with those recorded in lake sediments and speleothems from southern arabia surprisingly no holocene lake deposits were identified geological characteristics of the deposits and diatom analysis suggest that a single perennial lake covered the entire south western nafud ca 320 ka ago in contrast lakes of the 200 ka 125 ka and 100 ka humid intervals were smaller and restricted to interdune depressions of a pre existing dune relief the concurrent occurrence of humid phases in the nafud southern arabia and the eastern mediterranean suggests that moisture in northern arabia originated either from the mediterranean due to more frequent frontal depression systems or from stronger indian monsoon circulation respectively however based on previously published climate model simulations and palaecolimate evidence from central arabia and the negev desert we argue that humid climate conditions in the nafud were probably caused by a stronger african monsoon and a distinct change in zonal atmospheric circulation

relationships between lake level changes and water and salt budgets in the dead sea during extreme aridities in the eastern mediterranean abstract thick halite intervals recovered by the dead sea deep drilling project cores show evidence for severely arid climatic conditions in the eastern mediterranean during the last three interglacials in particular the core interval corresponding to the peak of the last interglacial marine isotope stage 5e or mis 5e contains 30 m of salt over 85 m of core length making this the driest known period in that region during the late quaternary this study reconstructs dead sea lake levels during the salt deposition intervals based on water and salt budgets derived from the dead sea brine composition and the amount of salt in the core modern water and salt budgets indicate that halite precipitates only during declining lake levels while the amount of dissolved na and cl accumulates during wetter intervals based on the compositions of dead sea brines from pore waters and halite fluid inclusions we estimate that 12 16 cm of halite precipitated per meter of lake level drop during periods of halite precipitation the mg2 concentration increases and the na cl ratio decreases in the lake our calculations indicate major lake level drops of 170 m from lake levels of 320 and 310 m below sea level mbsl down to lake levels of 490 and 480 mbsl during mis 5e and the holocene respectively these lake levels are much lower than typical interglacial lake levels of around 400 mbsl these lake level drops occurred as a result of major decreases in average fresh water runoff to 40 of the modern value pre 1964 before major fresh water diversions reflecting severe droughts during which annual precipitation in jerusalem was lower than 350 mm y compared to 600 mm y today nevertheless even during salt intervals the changes in halite facies and the occurrence of alternating periods of halite and detritus in the dead sea core stratigraphy reflect fluctuations between drier and wetter conditions around our estimated average the halite intervals include periods that are richer and poorer in halite indicating based on the sedimentation rate that severe dry conditions with water availability as low as 20 of the present day continued for periods of decades to centuries and fluctuated with wetter conditions that spanned centuries to millennia when water availability was 50 100 of the present day these conclusions have potential implications for the coming decades as climate models predict greater aridity in the region

late holocene lake levels of the dead sea this work presents a high resolution lake level record of the late holocene dead sea a hypersaline terminal lake whose drainage basin encompasses both mediterranean and hyperarid climatic zones the lake level curve reflects the regional hydrologic variations in the drainage basin which in turn represent the levant paleoclimates the curve is based on 46 radiocarbon ages of organic remains from well exposed sedimentary sequences along the dead sea shores these sequences record fluvial and lacustrine depositional environments the paleolakeshores are marked by shore ridges coarse sand units and aragonite crusts in the modern dead sea such features indicate the exact elevation of the shore the late holocene dead sea level fluctuated within the range of 390 to 415 m below sea level mbsl for most of the time the lake was below the topographic sill 402 mbsl separating the northern and southern basins of the dead sea and was confined to the deep northern basin nevertheless short term rises in the late holocene dead sea level caused the flooding of the shallow and flat southern basin highstands occurred in the second and first centuries b c and the fourth century a d during the roman and early byzan tine periods respectively in the eleventh and twelfth centuries a d during the crusader period and at the end of the nineteenth century a d the rises mark a significant change in the annual rainfall in the region which likely exceeded the instrumentally measured modern average the curve also indicates drastic drops that exposed the sedimentary sequences to erosion the oldest and probably deepest drop in the lake level culminated during the fifteenth and fourteenth centuries b c after a retreat from a higher lake stand the longest lowstand occurred after the byzantine period and continued at least until the ninth century a d this arid period coincided with the invasion of moslem arab tribes into the area during the seventh century a d the dramatic fall of the dead sea level during the twentieth century is primarily artificial and has been caused by the diversion of runoff water for the drainage basin but the magnitude is not considered exceptional for the late holocene although the past drops in the lake never exceeded the modern artificial drop rates they do represent extreme arid conditions that occurred frequently over the past several thousand years

elastic uplift in southeast greenland due to rapid ice mass loss this is the publisher s version also available electronically from http onlinelibrary wiley com

obscuring of long eccentricity cyclicity in pleistocene oceanic carbon isotope records abstract long eccentricity 400 kyr cycles in carbon isotope records from the pacific and atlantic oceans and the mediterranean sea of the past 5 0 ma are compared all records show maximum 13c values 13cmax at eccentricity minima during the pliocene but this relationship obscured in the pleistocene after 1 6 ma in particular for the open ocean deep water 13c records since a clear anti phase relationship was set up between oceanic 18o and 13c in the 100 kyr band from this time we attribute the obscured 400 kyr signal to a major change in the oceanic carbon reservoir probably associated with restructure of the southern ocean a similar change occurred in the miocene at 13 9 ma when the 400 kyr cyclicity in 13c records flattened out together with a drastic cooling and antarctic ice sheet expansion a remarkable exception is the mediterranean surface water 13c record which remained paced by the long term eccentricity cycle throughout the pliocene and pleistocene suggesting a low latitude climatic origin of the 400 kyr signal that is independent of glacial interglacial forcing since the earth is currently passing through an eccentricity minimum it is crucial to understand the nature of the 13cmax events

lithology of the long sediment record recovered by the icdp dead sea deep drilling project dsddp abstract the sedimentary sections that were deposited from the holocene dead sea and its pleistocene precursors are excellent archives of the climatic environmental and seismic history of the levant region yet most of the previous work has been carried out on sequences of lacustrine sediments exposed at the margins of the present day dead sea which were deposited only when the lake surface level rose above these terraces e g during the last glacial period and typically are discontinuous due to major lake level variations in the past continuous sedimentation can only be expected in the deepest part of the basin and therefore a deep drilling has been accomplished in the northern basin of the dead sea during winter of 2010 2011 within the dead sea deep drilling project dsddp in the framework of the icdp program approximately 720 m of sediment cores have been retrieved from two deep and several short boreholes the longest profile 5017 1 revealed at a water depth of 300 m reaches 455 m below the lake floor blf i e to 1175 m below global mean sea level and comprises approximately the last 220 240 ka the record covers the upper part of the amora penultimate glacial the last interglacial samra the last glacial lisan and the holocene ze elim formations and therewith two entire glacial interglacial cycles thereby for the first time consecutive sediments deposited during the mis 6 5 5 4 and 2 1 transitions were recovered from the dead sea basin which are not represented in sediments outcropping on the present day lake shores in this paper we present essential lithological data including continuous magnetic susceptibility and geochemical scanning data and the basic stratigraphy including first chronological data of the long profile 5017 1 from the deep basin the results presented here a focus on the correlation of the deep basin deposits with main on shore stratigraphic units thus providing a unique comprehensive stratigraphic framework for regional paleoenvironmental reconstruction and b highlight the outstanding potential of the dead sea deep sedimentary archive to record hydrological changes during interglacial glacial and transitional intervals

dead sea drawdown and monsoonal impacts in the levant during the last interglacial sediment cores recovered by the dead sea deep drilling project dsddp from the deepest basin of the hypersaline terminal dead sea lake floor at 725 m below mean sea level reveal the detailed climate history of the lake s watershed during the last interglacial period marine isotope stage 5 mis5 the results document both a more intense aridity during mis5 than during the holocene and the moderating impacts derived from the intense mis5e african monsoon early mis5e 133 128 ka was dominated by hyperarid conditions in the eastern mediterranean levant indicated by thick halite deposition triggered by a lake level drop halite deposition was interrupted however during the mis5e peak 128 122 ka by sequences of flood deposits which are coeval with the timing of the intense precession forced african monsoon that generated mediterranean sapropel s5 a subsequent weakening of this humidity source triggered extreme aridity in the dead sea watershed and resulting in the biggest known lake level drawdown in its history reflected by the deposition of thick salt layers and a capping pebble layer corresponding to a hiatus at 116 110 ka the dsddp core provides the first evidence for a direct association of the african monsoon with mid subtropical latitude climate systems effecting the dead sea watershed combined with coeval deposition of arabia and southern negev speleothems arava travertines and calcification of red sea corals the evidence points to a climatically wet corridor that could have facilitated homo sapiens migration out of africa during the mis5e peak the hyperaridity documented during mis5e may provide an important analogue for future warming of arid regions of the eastern mediterranean levant

summary of marine sedimentary shear modulus and acoustic speed profile results using a gravity wave inversion technique experimental techniques and inverse methods have been established to extract marine sediment shear modulus with depth profiles from measurements of wave induced seabed motion on the shallow continental shelf seabed sediments are modeled as a quasistatic incompressible layered elastic medium in response to wave induced pressures an iterative eigenvalue expansion technique is used to extract the inverse under typical continental shelf conditions this inversion method is found to have a depth resolution limit of approximately 3 m with a maximum penetration of 200 m using semiempirical sediment models it is possible to deduce sediment porosity bulk density and shear and compressional wave speeds from the shear modulus profile one representative result from the new jersey shelf is examined in detail and favorably compared with independent sediment profiling methods a summary of experimentally determined sediment profiles from four other sites on the eastern u s continental shelf is given

the mid cretaceous super plume carbon dioxide and global warming carbon dioxide releases associated with a mid cretaceous super plume and the emplacement of the ontong java plateau have been suggested as a principal cause of the mid cretaceous global warming the authors developed a carbonate silicate cycle model to quantify the possible climatic effects of these co sub 2 releases utilizing four different formulations for the rate of silicate rock weathering as a function of atmospheric co sub 2 they find that co sub 2 emissions resulting from super plume tectonics could have produced atmospheric co sub 2 levels from 3 7 to 14 7 times the modern pre industrial value of 285 ppm based on the temperature sensitivity to co sub 2 increases used in the weathering rate formulations this would cause a global warming of from 2 8 to 7 7c over today s global mean temperature altered continental positions and higher sea level may have been contributed about 4 8c to mid cretaceous warming thus the combined effects of paleogeographic changes and super plume related co sub 2 emissions could be in the range of 7 6 to 12 5c within the 6 to 14c range previously estimated for mid cretaceous warming co sub 2 releases from oceanic plateaus alone are unlikely to have been directly responsible for more than 20 of the mid cretaceous increase in atmospheric co sub 2

evidence from lake lisan of solar influence on decadal to centennial scale climate variability during marine oxygen isotope stage 2 documentation of short term climate variability during the glacial period has been limited by the availability of well dated high resolution archives here we present a paleoclimate reconstruction from varved lacustrine sediments of lake lisan dead sea rift for ca 26 2 17 7 calendar ka the age is based on a floating varve chronology anchored to radiometric dates our reconstruction indicates that small ice rafting events a b c and d as well as heinrich events in the north atlantic are associated with the eastern mediterranean arid intervals study of seasonal sublaminae yields evidence of several additional decadal to century scale arid events that correlate with cooler temperatures at higher latitudes analyses in the frequency domain indicate the presence of periodicities centered at 1500 yr 500 yr 192 yr 139 yr 90 yr and 50 60 yr suggesting a solar forcing on climate

strontium isotopic chemical and sedimentological evidence for the evolution of lake lisan and the dead sea precise strontium isotope ratios combined with chemical analyses and sedimentological information are used to monitor the water sources and the evolution of the dead sea and its late pleistocene precursor lake lisan 70 18 kyr b p the materials analyzed include bulk aragonite water leached soluble salts and residual aragonite and gypsum from the lisan formation in the perazim valley near the sw shore of the dead sea the residual aragonite and the associated soluble salts display systematic fluctuations in 17sr86sr ratios between 0 70803 and 0 70806 and from 0 70805 to 0 70807 respectively in individual soluble salt residual aragonite pairs the soluble salt displays a higher 87sr86sr ratio gypsum samples yield 17sr86sr ratios similar to the soluble salts from adjacent layers in the section this shows that in individual samples the source of sr in aragonite was distinct from that in soluble salts and the gypsum the sterility of the lisan sediments their strictly nonbioturbated fine lamination and their high content of chloride salts indicate that lake lisan was a saline or even hypersaline water body in the absence of alternative sources of hco3 and s042 the abundance of primary aragonite and gypsum in the lisan column reflects an import of very large volumes of freshwater into the otherwise saline lake resulting in a density stratification of this water body the history of the upper water layer and that of the lower brine is reflected in the chemical and strontium isotope composition of the aragonite and in that of the associated soluble salts and in the gypsum samples respectively whereas the bicarbonate and much of the ca2 required for aragonite crystallization were supplied by the freshwater the complementary ca2 and sr 2 were added by the lower brine the upper water layer of lake lisan acted as a so42 capacitor during the lake s rise periods it was removed therefrom as prominent gypsum beds upon climatic induced drier period mixing or even complete overturn of the lake the evolution of lake lisan took place between two distinct modes the first was characterized by an extensive supply of freshwater and resulted in a rise of the lake s level a density layered structure and precipitation of aragonite the second mode was marked by a diminishing freshwater input resulting in mixing or complete overturn of its water and precipitation of gypsum these two modes reflect the climatic evolution of the region in the late pleistocene which fluctuated between drier and wetter periods the transition to the holocene is accompanied by the dry up of lake lisan and its contraction to the present dead sea

the late quaternary limnological history of lake kinneret sea of galilee israel the freshwater lake kinneret sea of galilee and the hypersaline dead sea are remnant lakes evolved from ancient water bodies that filled the tectonic depressions along the dead sea transform dst during the neogene quartenary periods we reconstructed the limnological history level and composition of lake kinneret during the past 40 000 years and compared it with the history of the contemporaneous lake lisan from the aspect of the regional and global climate history the lake level reconstruction was achieved through a chronological and sedimentological investigation of exposed sedimentary sections in the kinnarot basin trenches and cores drilled at the ohalo ii archeological site shoreline chronology was established by radiocarbon dating of organic remains and of melanopsis shells the major changes in lake kinneret level were synchronous with those of the southern lake lisan both lakes dropped significantly 42 000 30 000 23 800 and 13 000 yr ago and rose 39 000 26 000 5000 and 1600 yr ago between 26 000 and 24 000 yr ago the lakes merged into a unified water body and lake level achieved its maximum stand of 170 m below mean sea level m bsl nevertheless the fresh and saline water properties of lake kinneret and lake lisan respectively have been preserved throughout the 40 000 years studied calcium carbonate was always deposited as calcite in lake kinneret and as aragonite in lake lisan dead sea indicating that the dead sea brine which supports aragonite production never reached or affected lake kinneret even during the period of lake high stand and convergence the synchronous level fluctuation of lakes kinneret lisan and the holocene dead sea is consistent with the dominance of the atlantic mediterranean rain system on the catchment of the basin and the regional hydrology the major drops in lake kinneret lisan levels coincide with the timing of cold spells in the north atlantic that caused a shut down of rains in the east mediterranean and the lakes drainage area d 2004 university of washington all rights reserved

the sources and evolution of sulfur in the hypersaline lake lisan paleo dead sea d 34 s values in gypsum are used to evaluate the fate of sulfur in the hypersaline lake lisan the late pleistocene precursor of the dead sea 70 14 ka bp and applied as a paleo limnological tracer the ca chloride lake lisan evolved through meromictic periods characterized by precipitation of authigenic aragonite and holomictic episodes characterized by enhanced gypsum precipitation the lake deposited two major gypsum units the blower gypsum unitq deposited at 56 ka showing d 34 s values of 18 20x and the bupper gypsum unitq deposited at 17 ka displaying significantly higher d 34 s values of 26 28x laminated and disseminated gypsum residing within the aragonite exhibit d 34 s values in the range of 26x to 1x the isotopic composition of the gypsum was dictated by freshwater sulfate input that replenished the upper layer of the lake the mixolimnion bacterial sulfate reduction bsr that occurred under the anoxic conditions of the lower brine the monimolimnion and mixing between these two layers during meromictic periods the sulfate reservoir in the lower brine was replenished by precipitation of gypsum from the upper layer and its subsequent dissolution due to sulfate deficiency induced by bsr activity this process describes a bsulfur pumpq mechanism and its effect on d 34 s in the water can be modeled by a modified rayleigh distillation equation steady state d 34 s values 40x were reached in the lower brine after long meromictic periods following overturn episodes induced by diminishing freshwater input and lake level decline large quantities of d 34 s enriched gypsum precipitated the negative d 34 s values in laminated and disseminated gypsum provide evidence for bsr activity in the lower brine that removed isotopically depleted sulfides from the water column causing significant isotopic enrichment of remaining sulfate following the lake desiccation the sediments were exposed and the latter sulfides oxidized and re crystallized as gypsum d 2005 elsevier b v all rights reserved

eemian tropical and subtropical african moisture transport an isotope modelling study during the last interglacial insolation maximum eemian mis 5e the tropical and subtropical african hydrological cycle was enhanced during boreal summer months the climate anomalies are examined with a general circulation model echam4 that is equipped with a module for the direct simulation of 18o and deuterium h218o and hdo respectively in all components of the hydrological cycle a mechanism is proposed to explain the physical processes that lead to the modelled anomalies differential surface heating due to anomalies in orbital insolation forcing induce a zonal flow which results in enhanced moisture advection and precipitation increased cloud cover reduces incoming short wave radiation and induces a cooling between 10 n and 20 n the isotopic composition of rainfall at these latitudes is therefore significantly altered increased amount of precipitation and stronger advection of moisture from the atlantic result in isotopically more depleted rainfall in the eemian east african subtropics compared to pre industrial climate the east west gradient of the isotopic rainfall composition reverses in the eemian simulation towards depleted values in the east compared to more depleted western african rainfall in the pre industrial simulation the modelled re distribution of 18o and d is the result of a change in the forcing of the zonal flow anomaly we conclude that the orbitally induced forcing for african monsoon maxima extends further eastward over the continent and leaves a distinct isotopic signal that can be tested against proxy archives such as lake sediment cores from the ethiopian region

ice volume and sea level during the last interglacial during the last interglacial period 125 000 years ago sea level was at least several meters higher than at present with substantial variability observed for peak sea level at geographically diverse sites speculation that the west antarctic ice sheet collapsed during the last interglacial period has drawn particular interest to understanding climate and ice sheet dynamics during this time interval we provide an internally consistent database of coral u th ages to assess last interglacial sea level observations in the context of isostatic modeling and stratigraphic evidence these data indicate that global eustatic sea level peaked 5 5 to 9 meters above present sea level requiring smaller ice sheets in both greenland and antarctica relative to today and indicating strong sea level sensitivity to small changes in radiative forcing

increased seasonality in middle east temperatures during the last interglacial period the last interglacial period about 125 000 years ago is thought to have been at least as warm as the present climate owing to changes in the earth s orbit around the sun it is thought that insolation in the northern hemisphere varied more strongly than today on seasonal timescales which would have led to corresponding changes in the seasonal temperature cycle here we present seasonally resolved proxy records using corals from the northernmost red sea which record climate during the last interglacial period the late holocene epoch and the present we find an increased seasonality in the temperature recorded in the last interglacial coral today climate in the northern red sea is sensitive to the north atlantic oscillation a climate oscillation that strongly influences winter temperatures and precipitation in the north atlantic region from our coral records and simulations with a coupled atmosphere ocean circulation model we conclude that a tendency towards the high index state of the north atlantic oscillation during the last interglacial period which is consistent with european proxy records contributed to the larger amplitude of the seasonal cycle in the middle east

quantitative assessment of glacial fluctuations in the level of lake lisan dead sea rift abstract a quantitative understanding of climatic variations in the levant during the last glacial cycle is needed to support archaeologists in assessing the drivers behind hominin migrations and cultural developments in this key region at the intersection between africa and europe it will also foster a better understanding of the region s natural variability as context to projections of modern climate change detailed documentation of variations in the level of lake lisan the lake that occupied the dead sea rift during the last glacial cycle provides crucial climatic information for this region existing reconstructions suggest that lake lisan highstands during cold intervals of the last glacial cycle represent relatively humid conditions in the region but these interpretations have remained predominantly qualitative here i evaluate realistic ranges of the key climatological parameters that controlled lake level based on the observed timing and amplitudes of lake level variability i infer that a mean precipitation rate over the wider catchment area of about 500 mm y 1 as proposed in the literature would be consistent with observed lake levels if there was a concomitant 15 50 increase in wind speed during cold glacial stadials this lends quantitative support to previous inferences of a notable increase in the intensity of mediterranean winter storms during glacial periods which tracked eastward into the levant in contrast to highstands during regular stadials lake level dropped during heinrich events i demonstrate that this likely indicates a further intensification of the winds during those times

thermodynamic constraints on dead sea evaporation can the dead sea dry up abstract the relation between climatic parameters relative air humidity and the water activity of the dead sea water determines the possible maximum evaporation of the lake using the pitzer thermodynamic approach the activity of the dead sea water during evaporation was calculated and compared to the present relative air humidity above the water long term 1992 1997 quasi continuous meteorological data acquired at sea provide detailed information on the patterns and trends of the relative humidity above the lake present climatic conditions allow the dead sea water to evaporate down to a water activity of 0 50 corresponding to the lowest air humidity measured over the lake this water activity falls in the range of halite precipitation while carnallite precipitation starts somewhat lower a h 2 o 0 49 our dynamic model predicts that for air humidity as low as 50 reflecting present climate conditions the dead sea level may drop to as low as 500 m i e 500 m below mean sea level at that point the lake will have a volume of 88 km 3 and a surface area of 526 km 2 for the sake of comparison at the beginning of 1977 after the southern basin of the dead sea was separated from the northern basin the level of the lake was 402 m its volume was 146 km 3 and its surface area was 815 km 2

abrupt aridities and salt deposition in the post glacial dead sea and their north atlantic connection abstract abrupt arid events in the post glacial 17 4 10 kyr bp dead sea basin dsb were recorded by significant lake level declines in lake lisan and massive deposition of gypsum and salt between 17 4 and 16 kyr cal bp the lake level dropped from its late mis2 stand of 260 m below mean sea level m bmsl to 330 m bmsl depositing a thick sequence of gypsum between 16 and 15 kyr cal bp the lake level recovered but dropped abruptly again at 14 kyr cal bp to below 465 m bmsl probably the lowest late pleistocene stand then between 13 and 11 kyr cal bp the younger dryas time interval the lake rose above 400 m bmsl and declined at 11 10 kyr cal bp depositing a thick sequence of salt the abrupt lake level drops and salt deposition coincided with times of ice and meltwater discharges into the north atlantic na heinrich event h1 and meltwater pulse mwp1a similar coincidence between ice and meltwater discharges in the na e g h events and arid episodes at the levant was recorded during the colder last glacial period demonstrating a persistent effect of the north atlantic hydrology and sea ice advances on the levant climate the climatically turmoil post glacial period was accompanied by significant developments in human culture the collapse of the natufian culture during the bolling allerod and the rise of the pre pottery neolithic cultures ppn a and b around the 11 10 kyr cal bp salt deposition interval marking the initiation of the neolithic revolution in the region

holocene climate variability and cultural evolution in the near east from the dead sea sedimentary record abstract a comprehensive record of lake level changes in the dead sea has been reconstructed using multiple well dated sediment cores recovered from the dead sea shore interpreting the lake level changes as monitors of precipitation in the dead sea drainage area and the regional eastern mediterranean palaeoclimate we document the presence of two major wet phases 10 8 6 and 5 6 3 5 cal kyr bp and multiple abrupt arid events during the holocene the arid events in the holocene dead sea appear to coincide with major breaks in the near east cultural evolution at 8 6 8 2 4 2 3 5 cal kyr bp wetter periods are marked by the enlargement of smaller settlements and growth of farming communities in desert regions suggesting a parallelism between climate and near east cultural development

constraints on hydrological and paleotemperature variations in the eastern mediterranean region in the last 140 ka given by the δd values of speleothem fluid inclusions abstract speleothem fluid inclusions potentially provide vital data on the paleohydrological conditions in glacial and interglacial periods we show here that d analyses of fluid inclusions from speleothems in three caves in the eastern mediterranean region israel provide a basis for understanding hydrological and temperature variations in the last 140 ka using measured d fluid inclusion values and temperature ranges constrained by the present day mediterranean meteoric water line mmwl and the global mwl we show a strong compatibility between the land and marine temperature records with the highest land temperatures occurring at 120 130 ka 17 22 c and the present 18 c and the lowest temperatures during the lgm about 10 c lower than present interglacial waters are constrained to follow the mmwl and most glacial waters also plot close to the mmwl with a slight shift towards the mwl however during two remarkable brief periods at the termination of the lgm the waters plot on the mwl suggesting that both sharp cooling and an increase in relative humidity above the em sea reduced d excess values to those of the global system

a 250 ka sedimentary record from a small karstic lake in the northern levant yammouneh lebanon paleoclimatic implications the levant influenced by both the mediterranean sea and the saharan arabian deserts is a key region for understanding climatic changes in response to glacial interglacial boundary conditions that have greatly affected regional hydrology here we present the first long term paleoenvironmental record from the northern levant presently much wetter than the southern levant our record derives from the multi proxy study of a sediment core 36 m long retrieved from the small intra mountainous tectonic basin of yammouneh lebanon which is mainly supplied by karstic springs sediments consist of a thick accumulation of brownish to greenish clayey silts interrupted by intervals of whitish marls composed of caco3 rich material the core chronology is based on radiometric dating 14c and u th and paleomagnetic techniques the sedimentary sequence spans approximately the last two glacial interglacial cycles 250 ka carbonate content is relatively high throughout the profile due to a perennial input of detrital calcite from the watershed but varies significantly the marls are mostly composed of authigenic and biogenic calcite and reflect lacustrine environments with high carbonate productivity during peaks of interglacial periods their occurrence suggests low physical erosion of the basin slopes which were covered by arboreal vegetation and intense karstic water circulation under warm and relatively wet conditions in agreement with pollen data the clayey silts are dominated by quartz and clay minerals and a few amounts of k feldspars and dolomite they are characterized by high concentration in magnetic particles and high relative concentrations of si al k and fe considered as strictly of detrital origin due to the carbonated nature of the watershed quartz and k feldspars are attributed to eolian origin from a distal source the clayey silt intervals generally suggest palustrine conditions with abrupt flows responsible for runoff derived material or subaerial environments and low local water availability in particular during the last glacial maximum high si al and k al ratios during interglacials are attributed to relatively high eolian dust contribution due to the decrease of local detrital inputs our study reveals significant differences between yammouneh and lake records from the dead sea basin southern levant the latter showing high low levels during glacial interglacial periods these hydrological differences might reflect either changes in the north south ns rainfall gradient in response to the development of the northern ice sheet and the southward migration of the westerly belt or local factors i e a decrease in efficient precipitation and water availability at yammouneh during the coldest glacial periods e g the last glacial maximum due to water storage by ice caps on the mount lebanon range and frozen soils in the yammouneh basin

recurrence pattern of holocene earthquakes along the dead sea transform revealed by varve counting and radiocarbon dating of lacustrine sediments abstract a high resolution holocene seismic history of the dead sea transform dst is established from laminated sedimentary cores recovered at the shores of the dead sea radiocarbon dating and annual laminae counting yield excellent agreement between disturbed sedimentary structures identified as seismites and the historical earthquake record all recent and historical strong events of the area were identified including the major earthquakes of a d 1927 1837 1212 1033 749 and 31 b c the total of 53 seismites recognized along the entire holocene profile indicate varying recurrence intervals of seismic activity between a few and 1000 years with a conspicuous minimum rate at 2100 31 b c and a noticeable maximum during the past six to eight centuries most of the epicenters of the correlated earthquakes are situated very close to the dead sea within 150 km or up to 400 km north of it along the dst between 1000 b c and a d 1063 and from a d 1600 to recent time the epicenters are all located on the northern segment of the dst whereas prior to 1000 b c and between a d 1000 and 1600 they appear to scatter along several segments of the dst we establish how the local intensity exerts a control on the formation of seismites at historically estimated intensities greater than vii all well documented earthquakes are correlated whereas at intensities smaller than vi none are matching the periods with enhanced earthquake rate along the dst correlate with those along the north anatolian fault as opposed to the intervening east anatolian fault this may indicate some elastic coupling on plate boundary scale that may also underlie escape and extrusion tectonics typical of continental collision

sources and transport routes of fine detritus material to the late quaternary dead sea basin abstract the sources and routes of transport of fine detritus material fdm to the lakes filling the late quaternary dead sea basin were studied by petrographic mineralogical grain size chemical and sr nd isotope analyses on sediments of the late quaternary lacustrine formations including river flood material dust and loess from the lake watershed the lacustrine formations comprise two sedimentary facies one that consists of alternating laminae of primary aragonite and silty detritus material aad facies and another that consists mainly of laminated detritus particles and generally lacks aragonite ld facies the aad facies characterizes the glacial intervals e g mis2 and 4 when lake levels were high while the ld facies characterizes interglacials e g mis1 5 and warmer glacial intervals e g mis3 when lake levels were low the detritus of both aad and ld facies show similar mineralogy mainly quartz and calcite grains with minor feldspars and clays but distinct grain sizes 8 10 m and 50 60 m respectively and distinct 87 sr 86 sr and end 0 711 0 712 and 7 to 8 versus 0 709 0 710 and 5 respectively the aad and ld fdm comprise desert dust of mixed granitic basaltic composition that was blown from the sahara desert and from the nile delta to the northern negev desert e g the loess deposits and the judean mountains bordering the dead sea basin mainly during glacial intervals along with enhanced mediterranean rain fronts the aad fdm reflects an enhanced transport of saharan granitic dust to the vicinity of the lake mainly during glacials the ld fdm was recycled from the loess surface cover of the negev desert mainly during interglacials and warm glacial intervals

unraveling rift margin evolution and escarpment development ages along the dead sea fault using cosmogenic burial ages abstract the dead sea fault dsf is one of the most active plate boundaries in the world understanding the quaternary history and sediments of the dsf requires investigation into the neogene development of this plate boundary dsf lateral motion preceded significant extension and rift morphology by 10 ma sediments of the sedom formation dated here between 5 0 0 5 ma and 6 2 2 1 inf ma yielded extremely low 10be concentrations and 26al is absent these reflect the antiquity of the sediments deposited in the sedom lagoon which evolved in a subdued landscape and was connected to the mediterranean sea the base of the overlying amora formation deposited in the terminal amora lake which developed under increasing relief that promoted escarpment incision was dated at 3 3 0 8 0 9 ma burial ages of fluvial sediments within caves 3 4 0 2 ma and 3 6 0 4 ma represent the timing of initial incision initial dsf topography coincides with the earliest red sea morb s and the east anatolian fault initiation these suggest a change in the relative arabian african plate motion this change introduced the rifting component to the dsf followed by a significant subsidence margin uplift and a reorganization of relief and drainage pattern in the region resulting in the topographic framework observed today