a record of late quaternary continental weathering in the sediment of the caspian sea evidence from u th sr isotopes trace element and palynological data abstract this study presents combined mineralogical chemical isotopic 87sr 86sr and u th disequilibria series and palynological analyses on bulk sediments and on distinct mineral phases carbonates and clays from a 10 m long core drilled in the southern caspian sea and containing a late pleistocene and early holocene record the data allowed identifying 1 the main variations in sedimentation 2 the processes causing these variations 3 the modification of erosion vs weathering and 4 the influence of climatic and or caspian sea level changes in the region since the late pleistocene the chemical and mineralogical results allowed the division of the sedimentary sequence into three main units and a transition zone the lower unit unit u1 primarily consists of silicate and carbonate rich detritus sedimentation characteristics including observation of detritus in secular equilibrium are relatively constant within this unit and reflect mechanical erosion in a cold climate unit u1 probably corresponds to a glacial period when the vegetation cover was sparse and wind and river transport of pollen were strong subsequently global increase in temperatures has greatly modified the sedimentation in the caspian sea south basin biogenic sedimentation is higher in units u2 and u3 and detrital inputs varied from unit u1 variations in detrital input are likely to be caused by decreasing aeolian contribution and by relative changes in river volumes and origins the study of the bulk sediments clays and carbonates reflects an increase in chemical weathering since about 10 14c ka bp ago base of unit u2 in line with an increase in the vegetation cover our results suggest an evolution of continental weathering conditions in the catchment area of the caspian sea from dominantly mechanical physical erosion during the cold period to a continuous increase in weathering since the lateglacial period as climate improved which illustrates the strong relation between climate vegetation cover and weathering processes this paper also highlights how the u th disequilibrium series proxy combined with other geochemical and palynological studies could be a useful tool to record and constrain the modification of weathering regime in response to climatic and environmental changes at regional scale

late little ice age palaeoenvironmental records from the anzali and amirkola lagoons south caspian sea vegetation and sea level changes abstract two internationally important ramsar lagoons on the south coast of the caspian sea cs have been studied by palynology on short sediment cores for palaeoenvironmental and palaeoclimatic investigations the sites lie within a small area of very high precipitation in a region that is otherwise dry vegetation surveys and geomorphological investigations have been used to provide a background to a multidisciplinary interpretation of the two sequences covering the last four centuries in the small lagoon of amirkola the dense alder forested wetland has been briefly disturbed by fire followed by the expansion of rice paddies from ad1720 to 1800 on the contrary the terrestrial vegetation reflecting the diversity of the hyrcanian vegetation around the lagoon of anzali remained fairly complacent over time the dinocyst and non pollen palynomorph assemblages revealing changes that have occurred in water salinity and water levels indicate a high stand during the late little ice age lia from ad

superrotation of venus atmosphere analyzed with a full general circulation model 1 a general circulation model gcm has been developed for the venus atmosphere from the surface up to 100 km altitude based on the gcm developed for earth at our laboratory key features of this new gcm include topography diurnal cycle dependence of the specific heat on temperature and a consistent radiative transfer module based on net exchange rate matrices this allows a consistent computation of the temperature field in contrast to previous gcms of venus atmosphere that used simplified temperature forcing the circulation is analyzed after 350 venus days 111 earth years superrotation is obtained above roughly 40 km altitude below the zonal wind remains very small compared to observed values which is a major pending question the meridional circulation consists of equator to pole cells the dominant one being located within the cloud layers the modeled temperature structure is globally consistent with observations though discrepancies persist in the stability of the lowest layers and equator pole temperature contrast within the clouds 10 k in the model compared to the observed 40 k in agreement with observational data a convective layer is found between the base of the clouds around 47 km and the middle of the clouds 55 60 km altitude the transport of angular momentum is analyzed and comparison between the reference simulation and a simulation without diurnal cycle illustrates the role played by thermal tides in the equatorial region without diurnal cycle the gierasch rossow williams mechanism controls angular momentum transport the diurnal tides add a significant downward transport of momentum in the equatorial region causing low latitude momentum accumulation

recent coastal evolution of the caspian sea as a natural model for coastal responses to the possible acceleration of global sea level rise abstract the caspian sea serves as an excellent natural laboratory for studies of coastal response patterns as it is highly variable in its water level over decadal and secular time scales coastal morphology presumably nearshore bottom slope and profiles of depositional coastal bodies or erosional scarps as well as rates and amplitudes of water level changes appear to be the most important factors of coastal response rates and patterns nearshore bottom slope determines not only shoreline retreat values according to the bruun rule but also the very patterns of coastal evolution for various morphological types of depositional coasts including deltaic coasts strict analytical prediction of coastal response to the accelerated sea level rise is yet to be solved analysis of every response pattern of depositional coasts to sea level changes requires a specific modification of the bruun rule however these equations should be regarded only as the means to estimate an order of magnitude of shoreline retreat or advance in many cases equations based on the bruun rule cannot be applied at all boundary conditions for each quantitative model should be thoroughly studied where possible longshore sediment drift sediment washover on to the landward slope of depositional coastal features and possible onshore or offshore aeolian sediment movement should be taken into account moreover applicability of the bruun rule based equilibrium approach will possibly diminish under the possible future acceleration of sea level rise

evidence for late holocene highstands in central guilan east mazanderan south caspian coast iran abstract the iranian caspian coast in the central guilan and east mazanderan were investigated using the analysis of samples retrieved from outcrops cores and through geophysical campaign the analysis of particle size organic matter calcium carbonate and fossil content as well as radiometric dating extends the caspian sea level records through the latest holocene ca 2500 years ground penetrating radar provides information about the internal stratigraphy of exposures along the central guilan coast lagoonal sediments that contained caspian mollusc shells have been dated at 2500 900 and 500 bp their dated horizons are located at altitudes of 22 24 and 25 m respectively which indicate higher sea levels during the late holocene the internal architecture and morphology of the coastal areas demonstrate spit lagoon development through littoral drift on the central guilan and east mazanderan coasts these structures also indicate lagoon formation due to rapid sea level rise a wide shallow lagoon in the central guilan sefidrud area was formed due to the last sea level rise 500 bp this lagoon then dried up as the result of falling sea level and infilled due to diversion of the sefidrud course these coastal developments show three highstands during the last 2500 years

late pleistocene and holocene sea level change and coastal paleoenvironment evolution along the iranian caspian shore the authors published by elsevier b v this is an open access article under the cc by nc nd license http creativecommons org licenses by nc nd 4 0

biostratigraphy of the marine holocene on the iranian coasts of the caspian sea abstract marine holocene deposits of the coast of iran are represented by the upper khvalinian and new caspian beds upper khvalinian sediments are faunistically barren whereas the new caspian beds contain abundant fossil molluscs that allow subdivision into the daghestan new caspian and modern layers the only fossil species found in the daghestan layer is didacna cristata the new caspian sediment layer is characterized by a taxonomically diverse molluscan assemblage dominated by cerastoderma glaucum it is subdivided into the upper and lower new caspian sub layers modern sediments are lithologically diverse besides the new caspian fauna they also contain the valves of the species mytilaster lineautus which is known to have immigrated from the black sea

surface brightness variations seen by virtis on venus express and implications for the evolution of the lada terra region venus 1 venus express is since april 11 2006 in orbit around venus virtis visible and infrared thermal imaging spectrometer has started only hours after orbit insertion to collect an immense and unique data set of special interest is the wavelength range from 1 1 5 microns which includes the atmospheric windows by averaging several hundred multi spectral images obtained during the mission we have been able to map the surface temperatures for almost the whole southern hemisphere of venus blurring in the clouds limits the spatial resolution to approximately 100 km globally the most exciting and at the same time the most complex task is to retrieve compositional information for the surface of venus from the hyperspectral data obtained by virtis we report here about indication for variations in the surface composition in the lada terra region based on brightness variations mapped from virtis measurements and present some tentative links to the evolution of this region

felsic highland crust on venus suggested by galileo near infrared mapping spectrometer data received 2 march 2008 revised 29 july 2008 accepted 18 september 2008 published 31 december 2008 1 we evaluated the spatial variation of venusian surface emissivity at 1 18 mm wavelength and that of near surface atmospheric temperature using multispectral images obtained by the near infrared mapping spectrometer nims on board the galileo spacecraft the galileo nims observed the nightside thermal emission from the surface and the deep atmosphere of venus which is attenuated by scattering from the overlying clouds to analyze the nims data we used a radiative transfer model based on the adding method although there is still an uncertainty in the results owing to the not well known parameters of the atmosphere our analysis revealed that the horizontal temperature variation in the near surface atmosphere is no more than 2 k on the venusian nightside and also suggests that the majority of lowlands likely has higher emissivity compared to the majority of highlands one interpretation for the latter result is that highland materials are generally composed of felsic rocks since formation of a large body of granitic magmas requires water the presence of granitic terrains would imply that venus may have had an ocean and a mechanism to recycle water into the mantle in the past

lithospheric 3 d flexure modelling of the oceanic plate seaward of the trench using variable elastic thickness summary whendescribingthemechanicalbehaviourofthelithospheremodelledasathinplate themost important parameter corresponds to itsflexural rigidity which is commonly expressed through the effective elastic thickness te this parameter is a measure of the stiffness of the plate and defines the maximum magnitude and wavelength of those surface loads that can be supported without suffering unelastic deformation realistic 3 d models of the flexural response of the lithosphere near the trench are scarce because of the mathematical and computational complexity we present a method for determining the flexure of the lithosphere caused by the combined effect of 3 d seamount loading and bending of the lithosphere near the trench our method consists on solving numerically the flexure equations of the reissner mindlin thin plate theory including variable thickness using the finite element method with mesh adaptation the method was applied to study the flexure of the oceanic nazca lithosphere beneath the o higgins seamount group which lies 70km seaward of the chile trench the results show that an elastic thickness te of 5km under the seamounts a te of 15km far from the trench and a te of 13km near the trench can explain both the down deflection of the oceanic moho and bending of the oceanic lithosphere observed in seismic and gravity profiles in order to study the impact of high trench curvature on the morphology of the outer rise we apply the same methodology to study and model the flexure of the lithosphere in the arica bend region 14 s 23 s results indicate that the te values are overestimated if the 3 d trench curvature is not included in the modelling

the geology and geomorphology of the venus surface as revealed by the radar images obtained by veneras 15 and 16 a region by region condensed description of almost all of the area that was radar photographed by veneras 15 and 16 is presented using some generalizations the diversity of terrain was reduced to a discrete set from which a geological morphological map was constructed the predominant type of terrain of the studied area is a plain that was tentatively subdivided into five morphological types ridge and band patchy rolling plain dome and butte plain smooth plain and high smooth plain stratigraphically the ridge and band plains are the oldest and the smooth plains are the youngest the stratigraphic position of the other types is yet to be determined large sections of the plains show similarities to the mare type basaltic plains of the moon mercury and mars other types of terrain are combinations of ridges and grooves in various patterns linear parallel orthogonal diagonal or chevron like and chaotic in some places the ridge and groove terrain is stratigraphically below the plain material but in other places it appears to be plain material that has been subsequently deformed near the eastern and western boundaries of ishtar terra large several hundred kilometers in diameter ring like features can be seen that are named coronae or ovoids evidence of tectonic deformation and the presence of flow like patterns support their designation as volcano tectonic features beta regio seems to be an uplifted plain showing evidence of rifting and volcanism all types of terrain are sparesely peppered with craters of obvious impact morphology their average density gives the plain an age range of 0 5 to 1 109 years the fact that many impact craters are still in the pristine state indicates a very low rate of surface reworking at least for the last 0 5 to 1 109 years no evidence for water erosion sedimentation processes has been found the tectonic activity of venus has no equivalent on the moon mercury or even mars and can be compared only with that of the earth intensive horizontal deformation previously known only on earth occurs on venus but in a characteristic venusian style

the late pleistocene holocene history of the caspian sea abstract repeated fluctuations of the caspian sea are correlated with climate fluctuations with transgressions associated with climatic warming and regressions characteristic of cooler periods during the late pleistocene and holocene transgressions are associated with the early khvalynian 32 24 ka and late khvalynian 16 8 ka corresponding to the bryansk interstaidal and final deglaciation respectively regressions occured during the yenotavian event 24 17 ka corresponding to the last glacial maximum valdai and from 8 ka until the present corresponding to the waning of the holocene climatic optimum in the region variations in meltwater supply appear to be the primary factor controlling the caspian sea levels throughout the late quaternary

evidence for active hotspots on venus from analysis of magellan gravity data abstract the 500 myr average crater retention age for venus has raised questions about the present day level of tectonic activity in this study we examine the relationship between the gravity and topography of four large volcanic swells beta atla bell and western eistla regiones for clues about their stage of evolution the magellan line of sight gravity data are inverted using a point mass model of the anomalous mass to solve for the local vertical gravity field spectral admittance calculated from both the local gravity inversions and a spherical harmonic model is compared to three models of compensation local compensation a flexural model with local and regional compensation of surface and subsurface loads and a hotspot model of compensation that includes top loading by volcanoes and subsurface loading due to a deep low density mass anomaly the coherence is also calculated in each region but yields an elastic thickness estimate only at bell regio in all models the long wavelengths are compensated locally the long wavelength estimates of the deep compensation depth for bell atla western eistla and beta regiones are 125 175 200 and 225 km respectively with an error of approximately 35 km the flexural model is rejected primarily because it gives values of effective elastic thickness of approximately 100 km which is at least a factor of two larger than estimates of effective elastic thickness obtained from the coherence spectra at bell regio and from other studies that model the topographic expression of flexure at bell regio and in other tectonic settings globally assuming a crustal thickness of 30 km the fit to the hotspot model at atla regio gives an effective elastic thickness of 30 5 km atla regio is interpreted as an active hotspot because of the deep compensation depth and a strong subsurface loading signature at bell regio effective elastic thickness is 30 5 km at short wavelengths and 50 5 km at long wavelengths using a crustal thickness of 10 km the 30 km value is interpreted as the effective elastic thickness at the time when the volcanoes are emplaced the 50 km value is believed to reflect the present day effective elastic thickness bell regio has a relatively shallow compensation depth 125 km and a weak bottom to top loading ratio determined from the coherence spectra these results may indicate a relatively old possibly inactive plume the data at beta and western eistla regiones are of relatively poor quality and do not permit detailed interpretations these areas are interpreted as active hotspots because of their large compensation depths greater than typical of the rest of the planet

evolutionary trend of the gorgan bay southeastern caspian sea during and post the last caspian sea level rise abstract the gorgan bay gb is a semi confined sedimentary environment at the southeastern corner of the caspian sea cs high sensitivity to eustatic sea level variations resulted in changes in the sedimentary facies and patterns of erosion sedimentation for the gb in the last caspian sea level cycle 1977 1995 therefore the evolutionary trend in coastal sedimentary environments was studied to determine the pattern of erosion and sedimentation related to sea level fluctuation cycles the sedimentology of the bay basin was studied in 500 km2 of the study area in 2001 in addition coastal changes over the two past and post periods of sea level rise were studied using satellite images landsat 7 with a resolution of 30 m and arcgis 10 1 software waves wave induced currents and sediment transport were simulated using the mike 21 software package mixed sediments particularly at the western and southern areas of the bay basin were detected through reworking of coarser barrier island sediments into deeper areas well sorted 0 35 0 5 sediments with 98 31 2 8 sand size particles were identified as the common texture along the wave dominated coasts sea progradation destruction of the beach profile and an increase in sea coverage of approximately 15 600 ha around the gb were other impacts of the cs level rise additional impacts included severe erosion and submergence of a 9000 ha area of the flat coastal plains slope 0 035 the results demonstrate that water level rise has strengthened the sediment accumulation in the bay inlet and basin at a mean rate of 0 430 mcm and 12 7 mcm respectively both field measurements and simulation results revealed the notable shoaling of the bay entrance at a mean rate of 0 2 m simulations concluded that annual longshore transport toward the bay inlet has occurred at a net rate of 80 000 m3 during the last cs level rise natural events after the eustatic cycle in the southeastern corner of the cs resulted in severe shoaling of the gb inlet and basin and restriction in the water exchange between the bay and open sea therefore comprehensive management practices to restore the gb capacity and its natural habitats are critically needed

venus surface thermal emission at 1 μm in virtis imaging observations evidence for variation of crust and mantle differentiation conditions 1 the venus express spacecraft images the nightside thermal emissions using the visible and infrared thermal imaging spectrometer virtis at 1 02 1 10 and 1 18 m thermal emission from the surface is observed the signal is attenuated by scattering and absorption in the dense atmosphere the measured flux at the top of the atmosphere is positively correlated with surface temperature and surface emissivity the surface temperature of venus is relatively well constrained as being mainly a function of altitude with a gradient lesser or equal to the adiabatic lapse rate this study examines the correlation of virtis images showing a signal of the surface at 1 02 m with viewing geometry stray sunlight cloud opacity and topography and applies semiempirical relations to remove their influence the remaining contrast can be either ascribed to surface emissivity or unexpected temperature variations temperature variations due to active volcanism are unlikely to be persistent over the time of observations therefore the mosaic of all processed images is here interpreted in terms of surface emissivity variation the emissivity variation found is correlated with geomorphological features established from magellan synthetic aperture radar images it is generally lower at tessera terrain some but not all volcanic edifices show increased emissivity large lava flows in the lada terra lavinia planitia region also show an increased thermal emission this might indicate a more felsic surface composition of tessera highlands and large scale extrusive volcanism of ultramafic composition

rotation period of venus estimated from venus express virtis images and magellan altimetry abstract the 1 02 m wavelength thermal emission of the nightside of venus is strongly anti correlated to the elevation of the surface the virtis instrument on venus express has mapped this emission and therefore gives evidence for the orientation of venus between 2006 and 2008 the magellan mission provided a global altimetry data set recorded between 1990 and 1992 comparison of these two data sets reveals a deviation in longitude indicating that the rotation of the planet is not fully described by the orientation model recommended by the iau this deviation is sufficiently large to affect estimates of surface emissivity from infrared imaging a revised period of rotation of venus of 243 023 0 002 d aligns the two data sets this period of rotation agrees with pre magellan estimates but is significantly different from the commonly accepted value of 243 0185 0 0001 d estimated from magellan radar images it is possible that this discrepancy stems from a length of day variation with the value of 243 023 0 002 d representing the average of the rotation period over 16 years

elucidating the rate of volcanism on venus detection of lava eruptions using near infrared observations abstract lava eruptions can be observed remotely on venus nightside using a near infrared window at a 1 0 micrometer wavelength i e radiation at this wavelength emitted from the planetary surface traverses through the thick venus atmosphere and clouds due to the strong dependence of the intensity of thermal emission on temperature a hot surface produced by a lava eruption emits intense radiation with the intensity of the excess radiation depending on the surface area and temperature of the lava flow the excess emission from the hot surface is blurred by clouds yet a 1 km2 1500 k basaltic lava lake and a 50 km2 1000 k lava flow are readily detected using this technique rapid cooling of exposed lava results in excess surface radiation that is detectable for just one earth day after the end of an eruption hence short term eruptions are only detectable on the side of the planet where night is occurring eruptions lasting more than half a venus day i e more than about 60 earth days however are detectable across the globe as nighttime occurs sometime during this period for every such event due to limited observational geometries a complete global survey of active volcanos cannot be achieved from earth and in fact only about 10 of short lived major volcanic eruptions are observable alternatively a satellite orbiting high above venus 6 venus radii could detect virtually all short lived nighttime volcanic events or about half the events expected to occur across the globe

geomorphic response and 14c chronology of base level changes induced by late quaternary caspian sea mobility middle kura valley azerbaijan abstract recent geomorphological studies in azerbaijan reveal the importance of climato eustatic influences on landscape changes in the caspian sea basin during the last 40 ka radiocarbon dated fluvial landforms show that the paleohydrosystem of the middle kura valley and tributaries responded to regressive and transgressive phases of the caspian sea chrono sequences and landforms secured by 32 radiocarbon ages show strong correspondence between fluvial sediment accumulation and oscillations of base level in the caspian sea six phases of valley floor aggradation e g 27 000 13 000 11 000 3200 2900 2100 1600 1000 400 150 cal yr bp and seven phases of fluvial incision 37 000 37 000 27 000 13 000 11 000 3200 2900 2100 1600 1000 400 150 0 cal yr bp are recorded morphodynamics of the fluvial landscape show a strong correspondence with fluctuation in sea levels in the caspian sea the major upper pleistocene late glacial khvalynian c a 26 000 to 12 400 cal yr bp and various holocene transgressions as well as the mangyshlak c a 12 000 cal yr bp and derbent 6th 12th century ad regressions these data contribute to refining the caspian relative sea level curve for the last 30 ka using the chronology of changes in the aggradation or incision in the connected fluvial system

the wandering of the volga delta a response to rapid caspian sea level change due to its very low gradient and absence of tide and surf the volga delta is an even more extreme example of the fluvially dominated type than the mississippi delta however it differs from all other large delta systems in that it borders a closed basin the caspian sea now at 26 m below global sea level caspian sea level is much more dynamic than that of the world oceans and rises at present about 1 5 cm yr a hundred time the eustatic rate within the quatemary sea level oscillations of at least 5 orders of magnitudes have been distinguished which seem grossly out of phase with eustatic sea level between the weichselian early khvalyn highstand of 50 m and the early holocene mangyshlak lowstand at 80 m the apex of the volga delta has wandered over 700 km alongstream the present day volga delta is not a highstand deposit but probably represents a minor transgression in a major regressional stage the delta does not show a coarsening upwards sedimentary sequence but consists of a weichselian transgressional fining upwards sequence topped by eolian deposits in which the delta distributary channels have been incised present day sedimentation is limited to a narrow fringe along the delta front and to deeper waters over 200 km offshore sea level changes outpaced aggradation to such an extent that volga sediment is spread over the whole north caspian plain sequence stratigraphical principles are difficult to apply because sea level cycles of five orders of magnitude are superimposed and because there is not enough sediment loading or tectonic subsidence to create sufficient accommodation space

rapid holocene sea level changes along the iranian caspian coast abstract the caspian sea is well known for its rapid sea level change during 1929 1995 a full sea level cycle was observed first the sea level dropped 3 m with a lowstand in 1977 followed by a 3 m rise to 1995 after which the sea level has been relatively stable these oscillations are a specific feature of the caspian sea and its sedimentary record the main purpose of this study is to reconstruct the sea level curve in the holocene by using sedimentological and biostratigraphic analysis and radiocarbon dating along the iranian part of the caspian shore remote sensing images and historical maps show that two lagoons totally emerged and the gorgan delta prograded rapidly at a rate of around 160 m y 1 until the 1975 lowstand gorgan bay was reduced in size considerably and the connection to the sea was blocked due to growth of a spit and change in base level when sea level started to rise again the coastal morphology rapidly changed and the gorgan delta retrograded at the rate of around 140 m y 1 these sedimentary dynamics can be recognized in the preserved deposits in addition to the recent dynamics core data from the southeastern lowlands show four earlier highstands using characteristic barrier lagoon deposits early holocene sea level rose until a highstand was reached of ca 34 m this phase was followed by fluvial deposition in the gorgan delta associated with a base level fall there is also an evidence of sea level rise between 5000 and 2300 bp at ca 27 7 m on top of these deposits there is evidence of a highstand between 2700 and 2300 bp at ca 23 5 m the fourth highstand from the core data is dated to the little ice age at ca 24 m data from these last two highstands correspond well with other observations from the caspian region

development of spit lagoon complexes in response to little ice age rapid sea level changes in the central guilan coast south caspian sea iran the central guilan coast along the iranian caspian coastline is characterized by sandy beaches and the development of spit lagoon complexes which are prone to preserve past sea level fluctuations the morphology of three spit lagoon complexes along the central guilan coast was studied using ground penetrating radar gpr and sediment sequences to understand the effects of past sea level changes on spit lagoon development the results showed the prominent role of coastal setting in conditioning the development of spit lagoon formation in response to sea level change when the caspian sea experienced a highstand in the little ice age the coast of central guilan recorded fluctuations in sedimentation which are reflected for example by river avulsion and beach ridge formation depending on physical setting in the western half of the central guilan eastward longshore currents and strong wave action on a w e coastline coupled with sea level changes shaped the anzali spit lagoon complex while in the eastern part of the studied area river avulsion and changing the coastline orientation are responsible for development of the amirkola and kiashahr spit lagoon complexes under the same sea level fluctuations although sea level change has a major role in spit lagoon development an increase in the frequency of storms changes in sediment supply due to more precipitation and river avulsion are other players in spit lagoon development in the central guilan during the little ice age and more recent times

holocene vegetation history and sea level changes in the se corner of the caspian sea relevance to sw asia climate the palynological investigation of core tm 27 7 m long taken in a dried out lagoon reveals both holocene vegetation history in the north eastern foothills of the alborz mountains and past water level changes of the caspian sea cs the delay in woodland expansion at the beginning of the holocene which is typical of eastern turkey the iranian plateau and recorded in the cs south basin is only weakly felt as the region is close to glacial refugia of trees the succession of the main trees out of their refugia has been established as deciduous quercus carpinus betulus parrotia persica and fagus orientalis pterocarya fraxinifolia presenting therefore close affinities to south european interglacials of the early pleistocene this suggests a similarity in climate a pterocarya decline is observed after ad 495 the studied region is close to the easternmost tree distribution this could explain why it has been affected earlier than elsewhere in the northern alborz and the caucasus in addition human activities during the sasanian empire and the subsequent drying of the climate contributed to weakening the spread of this tree a maximal sea level occurs in the first part of the holocene from 10 6 to 7 2 cal ka it is suggested that the cs levels were significantly influenced by the monsoon precipitations over the western himalayas via the uzboy inflow this is followed by low levels from 7 2 to 3 5 cal ka with a minimum at 3 9 cal ka the neocaspian period should be considered a biozone rather than a chronozone as the environmental conditions reconstructed from dinocyst assemblages are different in shallow shelf waters and in the deep basins