the spread of grass dominated habitats in turkey and surrounding areas during the cenozoic phytolith evidence abstract the arrival of hipparionine horses in the eastern mediterranean region around 11 ma was traditionally thought to mark the simultaneous westward expansion of savanna vegetation across eurasia however recent paleoecological reconstructions based on tooth wear carbon isotopes and functional morphology indicate that grasses played a minor role in late miocene ecosystems of the eastern mediterranean which were more likely dry woodlands or forests the scarcity of grass macrofossils and pollen in miocene floras of europe and asia minor has been used to support this interpretation based on the combined evidence it has therefore been suggested that late miocene ungulate faunal change in the eastern mediterranean signals increased aridity and landscape openness but not necessarily the development of grass dominated habitats to shed new light on the miocene evolution of eastern mediterranean ecosystems we used phytolith assemblages preserved in direct association with faunas as a proxy for paleovegetation structure grassland vs forest we extracted phytoliths and other biogenic silica from sediment samples from well known early to late miocene 20 7 ma faunal localities in greece turkey and iran in addition a middle eocene sample from turkey yielded phytoliths and served as a baseline comparison for vegetation inference phytolith analysis showed that the middle eocene assemblage consists of abundant grass phytoliths grass silica short cells interpreted as deriving from bambusoid grasses as well as diverse forest indicator phytoliths from dicotyledonous angiosperms and palms pointing to the presence of a woodland or forest with abundant bamboos in contrast the miocene assemblages are dominated by diverse silica short cells typical of pooid open habitat grasses forest indicator phytoliths are also present but are rare in the late miocene 9 7 ma assemblages our analysis of the miocene grass community composition is consistent with evidence from stable carbon isotopes from paleosols and ungulate tooth enamel showing that c4 grasses were rare in the mediterranean throughout the miocene these data indicate that relatively open habitats had become common in turkey and surrounding areas by at least the early miocene 20 ma 7 million years before hipparionine horses reached europe and arid conditions ensued as judged by faunal data

the history of danube loess research the loess paleosol sequences of the danube basin contain the longest and most complete terrestrial records of middle and late pleistocene paleoclimates in europe consequently it is no surprise that scientific research into european loess began in this region and has a long and distinguished history european loess research was initiated by count marsigli in the serbian vojvodina in the late 17th century formed the focus of the international loess commission which straddled both sides of the iron curtain from 1961 and culminated with george kukla s seminal studies in the 1970s correlating the loess archives with deep sea sediments the rise in popularity of the longer chinese loess sequences in the early 1980s shifted the international research focus away from europe and it was not until the change of century that scientific investigation intensified in the region this time with much more sophisticated tools for analysis despite its potential as one of europe s most valuable quaternary archives scientific research into danube loess has until recently been hindered both by landscape heterogeneity and the large number of countries it covers these have presented a major limiting factor in developing a unified research approach for decades regional national loess stratigraphic models were defined separately difficulties in correlating such schemes persist especially since these often change significantly with advances in dating methodologies a cooperative effort is necessary to synthesize the available data which requires not only the insights from but also the perspective provided by an appreciation of the history of the research in this study we present a critical historical overview of loess research in the danube region we classify the major research phases throughout the long tradition of danube loess investigations into five categories 1 the early period late 17th century until 1920 extending from marsigli to penck 2 the classic period 1920 1961 encompassing the contributions of milankovic and the development of pedostratigraphy 3 the modern period 1961 present which oversaw czech innovations and developments in geochronologic methods in particular amino acid racemisation aar and luminescence dating and 4 contemporary research from bronger s unified pedostratigraphy to orbitally tuned timescales finally 5 we present a vision of future danube loess research

plant and micromammal based paleoprecipitation proxies comparing results of the coexistence and climate diversity approach abstract both plant and vertebrate communities have been used to reconstruct paleoprecipitation however direct stratigraphic comparisons between the two types of proxies have hardly been performed which is due to the fact that plant and vertebrate fossils usually do not occur together in single geological beds here we focus on a series of 18 sites from the neogene of europe and anatolia that contain both types of fossils and compare paleoprecipitation predictions produced by the coexistence approach plants and the climate diversity approach micromammals most of the sites have overlapping uncertainty intervals for mean annual precipitation as generated by the two methods pointing to a common precipitation related signal in flora and fauna nevertheless a systematic difference appears to characterize drier sites for which micromammal richness based estimates for annual precipitation tend to be lower than plant based coexistence based estimates driest month precipitations are in agreement for drier sites but strongly differ for wetter sites with micromammal richness based estimates being higher overlap is poor for estimates of wettest month precipitation which are higher when based on plant based coexistence possible sources for a bias towards higher annual values in plants are related to the inclusion of local wetland elements in the analysis and or to a lower taxonomic resolution for pollen and spores compared to macroflora micromammal based annual estimates could be biased towards drier values when smaller samples lack rare species that could be preferentially wet adapted several of the higher driest and lower wettest month micromammal based estimates could result from over extrapolation beyond the calibration domain for arboreality as currently existing in the modern western old world on the other hand the use of several se asian reference taxa could add a high precipitation monsoonal component to the plant based predictions in addition wettest month estimates for both plants and micromammals probably suffer from the poor performance of water excess as a limiting factor an attempt to further increase the predictive power of the micromammal based prediction equations was performed by incorporating non linear terms and by using an extended calibration set including selected plant based precipitation estimates for micromammal assemblages without modern analogue in the western old world proxy inter calibration

the capillary fringe and its effect on water table response abstract shallow water tables are often observed to respond in a highly disproportionate manner to precipitation events that is the magnitude of the response is often much greater than would be predicted on the basis of the specific yield of the geologic material and the amount of rainfall physical arguments are presented to show that if the capillary fringe the zone of tension saturation extends to ground surface then the addition of a very small amount of water can result in an immediate and large rise in the water table the arguments are supported by a field experiment in which the addition of 0 3 cm of water caused the water table to rise 30 cm in 0 25 min thus demonstrating the large and highly transient influence of the capillary fringe on the position of the water table the evidence in this study as well as recent work of others suggests that the capillary fringe effect could have a major influence on the process of stream flow generation contaminant transport to surface waters and contaminant transport in hydrogeologic regimes having shallow water tables it is further shown that calculations of groundwater recharge and consumptive use based on water table response and an assumed specific yield could be substantially in error

late miocene to early pliocene vegetation of southern europe 7 4ma as reflected in the megafossil plant record abstract assemblages of plant megafossils from the late miocene to early pliocene sites in southern europe have been re evaluated in order to get data for reconstructing the development of vegetation and climate during this time interval 7 4 ma main areas of the survey are centred in greece and adjacent countries italy southern france and spain as a product of this study maps of the studied area for the late miocene have been produced showing main physiognomic features of the forests expressed in the proportions of broad leaved deciduous broad leaved evergreen legume type and sclerophyllous components respectively

on late oligocene to pliocene depocentre migrations and the evolution of the carpathian pannonian system abstract the late oligocene to pliocene evolution of foredeep basins of the eastern alps carpathians fold and thrust belt is marked by pronounced internal to external and lateral depocentre shifts the latter shifts covering a present along arc distance of 1700 km portray accelerating rates of foredeep depocentre migration particularly so in the late early and in the middle miocene from about 7 to about 45 cm yr lateral depocentre migration came to a close at the beginning of the late miocene the subsequent late miocene to pliocene foredeep infill history was characterized by exponentially increasing accumulation rates in the intersection area of the east european ukrainian and moesian platforms successive steps in the evolution of the foredeep basins had pronounced counterparts in the intra carpathian area the beginning of acceleration of foredeep depocentre migration in latest early miocene times was coeval with the inception of intra carpathian extensional tectonics the extremely rapid middle miocene depocentre shift coupled with a change in direction of foredeep depocentre migration corresponded with maximum extension in the intra carpathian area the ensuing end of foredeep depocentre migration around the middle late miocene transition was coeval with the end of extension of the intra carpathian area which in turn was followed by the inception of overall thermal subsidence at about 11 5 ma the timing of and spatial relationships between discrete coeval events in arc and intra arc evolution put unambiguous geological constraints on geodynamic modelling of the evolution of the carpathian pannonian system it is speculated that the geological observations may best be understood in terms of the surficial effects of lateral migration of slab detachment such effects would mirror the dominant role of a concentrating slab pull taken to result in e g a time progressive acceleration of foredeep depocentre migration

tertiary palaeogeography and tectonostratigraphic evolution of the northern and southern peri tethys platforms and the intermediate domains of the african eurasian convergent plate boundary zone abstract the increasing effects of african eurasian convergence during the tertiary resulted in the uplift and emergence of the northern and southern peri tethys platforms palaeogeographic maps covering six selected time slices including the middle eocene late early oligocene late early miocene early middle miocene early late miocene and middle to late pliocene illustrate that environmental and depositional differentiations on the northern platform and along the bordering domains of the convergence zone were more pronounced than on the southern platform and its adjacent areas the tectonic evolution of the northern platform included an overall eastward directed trend in the onset of basin uplift and emergence which started at about the eocene oligocene transition at 34 ma tectonostratigraphic analyses indicate a striking contemporaneity of the events which defined the temporal and spatial development of both the domains of the convergent plate boundary zone and the bordering platforms five episodes of major regional change in palaeogeographic and tectonic setting are distinguished they occurred in the late eocene 37 34 ma early late oligocene 30 27 ma latest early to earliest middle miocene 17 15 ma early late miocene 9 8 ma and late early to early middle pliocene 4 3 ma these episodes encompassed changes which were most probably induced by geodynamic events primarily related to the relative motions of the african arabian and eurasian plates in turn the plate motions are assumed to have triggered discrete steps in the regional kinematics and geodynamics that governed the palaeogeographic evolution of the peri tethys platforms and the intermediate domains of the african eurasian plate boundary zone

orbitally driven mid burdigalian coastal sabkha cycles from the sivas basin sedimentological paleontological and geochemical data abstract the early to middle miocene period in the sivas basin is represented by a thick deposition of mud dominated marine sediments karacaoren formation in an overall bay like paleogeographic setting previous studies have suggested that halokinesis induced local tectonics and orbital climatic fluctuations have been the primary controls on depositional evolution in the present study we investigated a 60 m thick karaman gypsum member kgm located at the base of the karacaoren formation in terms of its sedimentological paleontological both palynology and nannofossil biostratigraphy and geochemical mineralogical aspects to better characterize climatic controls on its deposition nannofossil assemblages indicate that the studied member is confined within the sphenolithus belemnos zone nn3 18 92 17 97 ma and is mainly composed of rhythmic alternations of supratidal evaporites and lagoonal marine mudstones the palynological data demonstrate a minor yet consistent occurrence of megathermic taxa and numerous dinoflagellate cysts in mudstone intervals the high chemical proxy of alteration cpa values and occurrence of kaolinites in the same mudstone intervals further prove deposition under warm and humid subtropical conditions the perfect match between the environmental cyclicities in the kgm with a benthic 18o curve justifies a strong control of obliquity short eccentricity of a 40 100 kyr duration and hints at radical precipitation changes throughout the individual orbital cycles these precipitation changes are explained by extreme latitudinal precipitation gradients during relatively hot periods before the mid miocene climatic optimum

calcareous nannofossil biostratigraphy and magnetostratigraphy of the upper miocene and lower pliocene of the northern aegean orphanic gulf strimon basin areas greece abstract the transitional position of the northern aegean makes it an important area for studying the relation between the mediterranean and the eastern paratethys a chronostratigraphic framework has been obtained for the late neogene deposits along the orphanic gulf and in the strimon basin of northern greece by analysing calcareous nannofossil data and paleomagnetic results from eight sections the local formations and major lithological units have been correlated with the upper miocene and lower pliocene stages furthermore the obtained framework has facilitated a more detailed reconstruction of the effects of the messinian salinity crisis on the sedimentary record magnetostratigraphic data from the strimon basin result in an age estimate of 6 3 ma for the dafni choumnikon formation transition between normal polarity subchrons c3an 2n and c3an 1n since this late miocene age estimate corresponds closely to estimates of the maeotian pontian boundary in the eastern paratethys dacic basin we believe this transition from marine to brackish conditions corresponds to this latter boundary the gypsiferous unit in the basal part of the choumnikon equivalent beds along the orphanic gulf can then be correlated with the evaporites in the northern aegean and the lower evaporites of the mediterranean basin consequently we assume that these northern aegean evaporites have been deposited between 5 96 and 5 59 ma freshwater deposits above the evaporites are easily traceable across the orphanic gulf area as a gravel or sandstone unit topped by a travertine marker bed and have a wide lateral continuation since their position is intermediate between the shallow marine gypsum anhydrite and the more open marine clastics of the pliocene we argue that these beds correlate with the desiccation phase of the mediterranean and black sea basins this intra messinian event probably occurred between 5 59 and 5 50 ma thus predating the upper evaporites or lago mare of the mediterranean a clear recognition of the miocene pliocene boundary remains problematic in the orphanic gulf area nannofossil assemblages in the sections suggest a higher position of the local base of the pliocene than indicated by the level with the first appearance of planktonic and benthic foraminifera discontinuous occurrences of levels containing nannofossil assemblages of zone mnn11b c are found between the travertine unit and the lowermost pliocene beds representing brief marine ingressions the latter show that in the latest messinian presumably temporary connections of atlantic mediterranean waters with the northern aegean basin existed these marine ingressions likely extended further into the eastern paratethys as demonstrated by the presence of nannofossil assemblages in the middle and upper pontian of the dacic and euxinic basins the events around the miocene pliocene transition resulted in a fairly abrupt change from brackish to open marine conditions in a relative deep basin which was subject to increased rates of subsidence from the onset of evaporite deposition in the late messinian onward

late oligocene and miocene climate and vegetation in the eastern paratethys area northeast bulgaria based on pollen data abstract the results of palynological studies of the oligo miocene in the western part of the euxinian basin eastern paratethys are based on the analysis of 57 samples from core c 136a drilled near the town of balchik varna district some samples were barren or contained very little pollen and were not included in the analysis quantitative data are thus confined to 26 polleniferous samples we present results for the upper oligocene as well as the tarkhanian karaganian bessarabian and chersonian stages of the middle to upper miocene mixed deciduous forests were widespread during the time period studied swamp forests are also recorded with distribution maxima observed in the oligocene and in the bessarabian the widest extent of herbaceous vegetation is recorded in the late bessarabian and chersonian when it occupied open landscapes after a marine regressional phase the climatic data reconstructed by the coexistence approach indicate mean annual temperatures mats of ca 15 17 c and mean annual precipitation maps of 800 1300 mm for the upper oligocene the narrowest coexistence intervals of the tarkhanian and karaganian display mats of 14 17 c and maps of 800 1300 mm the most substantial data are for the bessarabian in which the lower part is characterized by mats of 15 6 16 6 c and maps from 800 1200 1300 mm the results for the upper part of the bessarabian are more variable especially with respect to precipitation that is generally lower 700 800 mm the same is true for the chersonian where besides lower precipitation lower annual temperature and temperature of coldest month are observed these results correlate with previous vegetation and palaeoclimate data from the forecarpathian basin nw bulgaria

middle miocene langhian sapropel formation in the easternmost mediterranean deep water basin evidence from northern cyprus abstract mid miocene langhian 15 4 ma sapropels formed within the easternmost mediterranean basin now uplifted in northern cyprus these sapropels represent the oldest known sapropels in a predominantly marl succession six well developed sapropels were studied strontium isotope dating of twelve samples gave a preferred age of 15 4 ma langhian i e during the final phases of the middle miocene climatic optimum mco the age of the best preserved nannofossil assemblage langhian is close to the strontium ages the langhian strontium ages are preferred over an alternative early serravallian age for less well preserved nannofossil assemblages total organic carbon contents in the sapropels reach maximum values of 3 9 wt relative to the host marls the sapropels show enrichments in terrigenous derived minerals and related major and trace elements sedimentological evidence indicates that the terrigenous sediments were eroded from the northern borderlands of the deep water basin under warm humid conditions high fresh water run off from surrounding landmasses is likely to have promoted a low salinity lid to the eastern mediterranean deep water basin this in turn would have restricted deep water ventilation and promoted widespread anoxia exceptionally high concentrations of chalcophile elements e g cu ni and zn are consistent with anoxic conditions abundant nutrient rich fresh water input is also likely to have stimulated siliceous productivity although any siliceous microfossils did not survive diagenesis a significant role for diagenesis in sapropel formation is indicated by the mobilisation of ba from sapropels to marl directly beneath orbitally induced dry wet oscillation the mechanism invoked to explain the pliocene to holocene sapropels apparently was already in place during the latest stages of the mco when the langhian sapropels accumulated these sapropels accumulated immediately after the middle miocene closure of the southern neotethys when the eastern mediterranean sea apparently became more sensitive to orbital cyclicity the development of a semi enclosed deep water basin was therefore a prerequisite for sapropel formation

the neogene of eurasia spatial gradients and temporal trends the second synthesis of neclime article i nfo this volume represents the second synthesis of the international open research network neclime neogene climate evolution in eurasia that was established in 2000 to study climate change in eurasia during the neogene and its impact on ecosystems the main objectives of neclime research are 1 proxy data based quantitative reconstructions of neogene climate in eurasia by means of standardised techniques 2 the modelling of atmospheric and oceanic circulation and of biomes using neogene boundary conditions and 3 the analysis of the interaction between palaeogeography vegetation and climate presently 94 scientists from 34 countries are neclime members contributing with their published data to a collective data base integrating proxies from various sources such as palaeobotany vertebrate palaeontology and geology the following core topics are addressed in the volume precipitation patterns and landscape opening the asian monsoon systems the potential of past climates for the evaluation of future climate change scenarios as well as short term change and variability of climate highlights of the single contributions are summarised in a proxy data section and in a modelling section respectively it is shown that the integrative approach presented in this volume brings about a much better and much more detailed understanding of neogene climate dynamics in eurasia than previously achieved even though neogene climate changes may have regional aspects differing considerably from each other and from the general global trend the results from the various proxy and modelling studies consistently show that later neogene cooling implicated more pronounced latitudinal and longitudinal gradients on the other hand the issue reveals a number of problems and questions resulting from the contrary nature of palaeozoological and palaeobotanical palaeoclimate proxies and modelling results mainly at a more regional level the models can not yet explain the relatively warm high latitudes during the neogene and we still do not sufficiently understand the role of the various boundary conditions such as co2 palaeogeography and palaeovegetation in the observed neogene climate change and its regional differentiation these apparent uncertainties underline the importance of the study of palaeo scenarios in order to enhance the reliability of future climate projections

miocene vegetation and climate dynamics in eastern and central paratethys southeastern europe abstract from the cretaceous to modern time the earth s climate system has changed repeatedly from a greenhouse to an icehouse the miocene appeared as the last warm episode in earth history prior to the establishment of large northern hemisphere ice sheets furthermore the miocene was characterized by both large scale marine transgressions and pronounced episodes of regressions e g opening and closure of marine corridors as well as appearance and disappearance of lakes and swamps the sea level changes and instability of the climate system strongly influenced not only marine ecosystems but also the terrestrial biota to throw new light on the miocene evolution of european ecosystems and climate dynamics we compared plant assemblages from southeastern europe palaeogeographically this area is a transitional belt between tethyan and paratethyan realms and it thus constitutes a crucial geographical position when one tries to comprehend the exchange pathways of various floristic elements appearance and evolution of steppe vegetation interaction between forest and steppe vegetation and of course the corresponding climates influencing the vegetation dynamics both macro and microfloristic plant associations were considered in our analysis large palaeofloristic and palaeocoenotic transformations occurred during the miocene the early to middle miocene flora is rich and diverse in thermophilous elements which formed polydominant mesophytic to hygromesophytic forests early miocene climate was warm and humid with mean annual temperatures mainly above 16 c and annual rainfalls over 1000 mm the middle miocene was the warmest period of the whole miocene with annual temperatures ranging from 17 c to 19 c and winter temperatures from 7 c to 12 5 c climatic changes after the miocene climatic optimum caused changes in floristic composition and vegetation structure the vegetation shows a decreasing trend in abundance of palaeotropic and thermophilous elements reduction of macrothermic elements and disappearance of evergreen laurel forests together with these changes is a corresponding increase in the role of arctotertiary species in plant communities and they became dominants in mesophytic forests the available data indicate that major vegetation changes occur in the late miocene this period is characterized by more diverse climatic conditions which were directed by global climatic changes and probably complicated by regional palaeogeographic reorganizations and tectonic processes slight cooling and some drying is recorded for the beginning of the late miocene followed by fluctuations of palaeoclimate parameters observed which display cycling change of humid dryer and warmer cooler conditions our study provides a new insights on the miocene vegetation and climate dynamics and evolution in southeastern europe

arabia eurasia collision and the forcing of mid cenozoic global cooling the end of the eocene greenhouse world was the most dramatic phase in the long term cooling trend of the cenozoic era here we show that the arabia eurasia collision and the closure of the tethys ocean gateway began in the late eocene at 35 ma up to 25 million years earlier than in many reconstructions we suggest that global cooling was forced by processes associated with the initial collision that reduced atmospheric co2 these are 1 waning volcanism across southwest asia 2 increased organic carbon storage in paratethyan basins e g black sea and south caspian 3 increased silicate weathering in the collision zone and 4 a shift towards modern patterns of ocean currents associated with increased vigour in circulation and organic productivity

straight thinking about groundwater recession while in catchment and hillslope hydrology a more nuanced approach is now taken to streamflow recession analysis in the context of major aquifers it is commonly still assumed that the groundwater head recession rate will take exponential form an idea originally proposed in the 19th century however it is shown here that in early times the groundwater head recession in a major aquifer should take an almost straight line form with a rate approximately equal to the long term recharge rate divided by the aquifer storage coefficient the length of this phase can be estimated from an analytical expression derived in the paper which depends on the aquifer diffusivity length scale and the position of the monitoring point a transitional phase then leads to an exponential phase after some critical time which is independent of the position of the monitoring point major aquifers in a state of periodic quasi steady state are expected to have rates of groundwater flux recession which deviate little from the average rate of groundwater recharge where quasi exponential groundwater declines are observed in nature their form may be diagnostic of particular types of aquifer properties and or boundary effects such as proximity to drainage boundaries variations in transmissivity with hydraulic head storage changes due to pumping nonequilibrium flow at a range of spatial and temporal scales and variations in specific yield with depth recession analysis has applicability to a range of groundwater problems and is powerful way of gaining insight into the hydrologic functioning of an aquifer

cyclic climate and vegetation change in the late miocene of western bulgaria abstract a late miocene paludal to lacustrine sequence from a carbonate basin in nw bulgaria staniantsi basin is analysed displaying up to 27 rhythmically bedded sedimentary cycles in the lower part of the sequence the cycles consist of alternating autochthonous brown coal and marls containing diverse mollusc assemblages the upper part of the sequence is characterized by alternating dark to light grey clays and calcareous silts a palynomorph record comprising 163 samples is analysed by statistical means to reconstruct vegetation changes the coexistence approach is used to calculate quantitative palaeoclimate records for 6 parameters the studied section displays hierarchical cyclicity patterns longer term cycles possibly related to eccentricity period 100 kyr are present in the palynomorph record and show climate changes of warmer wetter and cooler drier periods in combination with frequency oscillations of thermophilous elements short term cycles most probably related to precession period 21 7 kyr are expressed by alternations of brown coal and marl shell beds and show cyclic change in peat forming vegetation related to oscillations of the groundwater level as a triggering mechanism wetter warmer and drier cooler climate phases related to orbital precession are probable in addition sections sampled at high resolution display small scale climate and vegetational variability as is shown by the analysis ferns were an important component of the peat forming vegetation while outside the mire a wetland vegetation consisting of pioneers and a mixed mesophytic forest with evergreen shrubs existed an oligo to mesotrophic slightly alkaline lake became repeatedly established with a diverse mollusc fauna and a dense hydrophytic vegetation with characean meadows in the upper part of the section a spreading of herbaceous vegetation is observed also known from other contemporaneaous palynomorph records in bulgaria and surrounding areas the increase of asteraceae in the upper part of the section combined with a marked decrease in woody taxa points to an opening of habitats and a decrease in mean annual precipitation this trend is paralleled by the mollusc fauna which yields several terrestrial partly xerophilous taxa

mio pliocene magnetostratigraphy in the southern carpathian foredeep and mediterranean paratethys correlations a full understanding of the mio pliocene palaeogeographical and palaeoenvironmental changes in the circum mediterranean region during the messinian salinity crisis msc is at present hampered by the lack of reliable chronostratigraphic correlations between the mediterranean and paratethys regions here we present magnetostratigraphic ages for the upper miocene to pliocene deposits of the southern carpathian foredeep in romania these ages are in good agreement with those recently obtained from the eastern carpathian foredeep and define a new chronology for the eastern paratethys the meotian pontian boundary is not biostratigraphically

early pliocene vegetation changes forced by eccentricity precession example from southwestern romania repetitive changes in early pliocene marine and continental sediments were forced by astronomical cycles eccentricity precession and related to low amplitude climatic fluctuations as demonstrated at capo rossello and monte san nicola sicily this work aims to establish if such climatic fluctuations have also controlled changes in the vegetation during the warm early pliocene high resolution pollen analysis of the lupoaia section sw romania provides evidence of a clear response owing to its location within a delta system which constitutes a reliable area for pollen deposition near the carpathians i e capable of registering all the vegetation ecosystems from edaphic coastal associations up to the highest altitudinal belts and owing to its southeastern european longitude probably where warm humid air masses arrived regularly making the region a highly favourable refuge for thermophilous plants eccentricity appears to have controlled fluctuations in temperature development of thermophilous elements during eccentricity minima and descent of altitudinal trees during eccentricity maxima while precession appears to have forced changes in humidity expansion of cypress swamps related to precession maxima and spread of herbaceous marshes requiring more humidity related to precession minima with respect to increased precipitation and run off

petrographical and organic geochemical study of the kovin lignite deposit serbia abstract the origin of the organic matter om and the characteristics of the depositional environment of lignites from the upper miocene kovin deposit hosting three coal seams of serbia were evaluated based on petrographic data bulk organic geochemical parameters biomarker analysis and stable isotope geochemistry 13c of individual biomarkers samples were collected from four boreholes gd 601 and gd 603 the a field and kb 79 and kb 91 the b field representing different parts of coal seams i ii and iii investigated lignites are typical humic coals the om of lignites is derived from woody vegetation and herbaceous peat forming plants with prevalence of the former in most samples peat forming vegetation is characterized by abundant decay resistant gymnosperm coniferous plants followed by a low amount of angiosperms lignite forming plants mostly belonged to the gymnosperm families cupressaceae taxodiaceae phyllocladaceae and pinaceae slight input of ferns fungi and aquatic macrophyta to lignite om is also evident distributions of hopanoids and isotopic compositions of these biomarkers reflect the activity of various microbial populations represented by methanotrophic chemoautotrophic and heterotrophic bacteria during diagenesis prominent c28 28 30 bisnorneohop 13 18 ene was observed for the first time in the lignite extracts according to the 13c value it was probably derived from chemoautotrophic bacteria c28 28 30 bisnorneohop 13 18 ene could be one of the possible precursors of a series of orphan aromatic hopanoids bearing an ethyl group at c 21 via progressive aromatization peatification proceeded in a fresh water environment under variable redox conditions from anoxic to slightly oxic all three coal seams are heterogeneous the lower parts of the coal seams represent a topogenous fresh water peat mire with open water areas which was subjected to inundations the upper parts of coal seams represent a wet forest swamp with relatively stable conditions despite the observed variations in all three coal seams the mean values of petrographic and organic geochemical parameters suggest general increasing of wetness and establishment of more stable conditions from seam iii to seam i maceral and biomarker data indicate that rapid flooding of the bogs stopped peat growth in all three coal seams relatively frequent variations in all three coal seams followed by repetition of lignite characteristics depict well the pronounced seasonality e g short term cycles of the climate during late miocene in investigated area

tree diversity in the miocene forests of western eurasia abstract in the present study published miocene mega and microfloral records compiled from a total of 92 localities in western eurasia are analysed with respect to diversity of different plant functional types pfts to study spatial diversity patterns and their evolution three time intervals are selected corresponding to the langhian 16 3 13 6 ma the serravallian 13 6 11 6 and the earlier part of the tortonian 11 6 8 5 ma first all arboreal species occurring in the floras are classified using a total of 13 different pfts functional types of trees and climatically defined subtypes in a next step diversity spectra with respect to these pfts are generated for each site cluster analysis is then performed in order to obtain groups of floras with similar spectra that are interpreted in terms of vegetation type their spatial distribution in each time interval is shown in maps according to these results zonally arranged patterns are obtained broadleaved deciduous forests are most important in the higher latitudes while mixed mesophytic forests dominate the mid latitudes in western eurasia broadleaved evergreen forests are of minor importance in the area of interest the observed diversity patterns and their changes in time are correlated with spatial climate patterns and the continental palaeoclimate evolution during the late miocene cooling broadleaved evergreen forests completely disappear from the mid latitudes of western eurasia and mixed mesophytic forests of the mid latitudes are mostly replaced by broadleaved deciduous vegetation types in the context of this cooling a drier season became established in western europe during the tortonian as is evident from reconstructed arboreal diversity data and precipitation data in central europe vegetation types indicating permanently humid conditions persisted throughout all the three time intervals analysed

neogene lake systems of central and south eastern europe faunal diversity gradients and interrelations abstract the gastropod diversity of 12 neogene lake systems is evaluated in total 1184 gastropod taxa from 119 localities are recorded deriving from the early miocene rzehakia lake system the early to middle miocene dinarid lake system lake skopje the paratethyan sarmatian lakes and the south german lakes the late miocene lake pannon the pliocene lakes dacia transylvania slavonia kosovo and sostanj as well as the holocene lake petea each lake system is characterised according to its faunistic inventory and endemism according to their gastropod faunas the lakes may be divided into pyrgulid hydrobiid viviparid and planorbid dominated ones the generally high endemism rate is between 60 and 98 species diversity and generic diversity are strongly correlated in contrast neither endemism nor lake size are tightly linked with diversity outstandingly high diversities such as observed for lake pannon are rather a result of the combined effect of autochthonous evolution in a long lived system and accumulation of inherited elements examples of parallel evolution in lymnaeids and planorbids are presented

late miocene and pliocene large land mammals and climatic changes in eurasia the fossil teeth of land mammals offer a powerful tool to map the regional details of past climate change in the terrestrial realm we use meanplant eaterhypsodonty molarcrownheight oflateneogenemammallocalitiestomaplatemioceneandpliocenepalaeoprecipitation on the eurasian continent and with higher temporal resolution in europe the results show that the mid latitude drying in eurasia affected thecentral parts ofthecontinentfirst and thatthedrying of western europeafter about7 8maseemstohavecoincidedroughlyintimewith a return to more humid conditions in eastern asia with a return to a drier east and more humid west in the pliocene within europe the hypsodonty based palaeoprecipitation maps suggest that the sequence from mn 9 to mn 12 ca 11 1 6 8 ma was dominated by an east west continental marine humidity gradient which gradually intensified and with a shift of dryer conditions eastwards in mn 12 ca 7 5ma thiswaspartlyoverlainfrommn13onwardsbyanorth southorientedgradient whichpersistedatleasttotheendofthepliocene the maps for both the earliest late miocene mn 9 ca 11 1 9 7 ma and the earliest pliocene mn 14 ca 4 9 4 2 ma show very low regional differentiation possibly suggesting perturbed phases in the evolution of the mammal communities analysis of hypsodonty and dietary structure of the mammalian plant eater community in europe during the entire interval shows that the miocene pliocene boundary was marked by a strong decrease in mesodont species and mixed feeders and an increase in brachydont species and omnivores in this view the shift in the latest miocene from east west to partly north south polarised hypsodonty patterns corresponds mainly to an increase in hypsodont species and grazers it seems probable that the east west gradient was primarily driven by precipitation while the north south gradient would also have been strongly influenced by temperature related effects of humidity

the miocene climatic optimum evidence from ectothermic vertebrates of central europe abstract data sets of central european temporal distributions of thermophilic ectothermic vertebrates channidae varanidae chamaeleonidae cordylidae tomistomidae alligatoridae giant turtles and of north alpine foreland basin nafb distributions of ectothermic vertebrates adapted to dryer habitats albanerpeton inexpectatum salamandra sansaniensis bufo cf viridis chamaeleo caroliquarti gekkonidae varanus hofmanni bransateryx sp are analysed two main migration events of thermophilic ectotherms at 20 ma and 18 ma in the lower miocene are discerned they indicate the beginning of the miocene climatic optimum in central europe 42 45 n palaeolatitude with a lower limit of the mean annual temperature mat of 17 4 c derived from the minimal mat of their extant relatives furthermore additional palaeobotanical data and records of bauxite point to a mat of 22 c this warm and humid optimum peaked at 18 16 5 ma ottnangian karpatian and is confirmed by the coexistence of all investigated thermophilic taxa the following period early badenian is characterised by probably unchanged temperatures but a seasonality in precipitation with dry periods up to six months two major seasonal phases between 16 3 and 15 7 ma earliest early badenian and between 14 7 and 14 5 ma early middle badenian transition are indicated by an immigration of dry adapted taxa from the surrounding karst plateau to the nafb it is presumed that the tectonical reorganisation of the central paratethys realm had considerable influence on this regional humidity pattern the warm period ended abruptly between 14 0 and 13 5 ma middle late badenian transition with major regional extinction events of most of the thermophilic groups in central europe and a drop of the mat of probably more than 7 c to temperatures around 14 8 15 7 c this drop can be attributed predominantly to a decrease of more than 11 c of the minimum cold months temperature this temperature decrease marked the beginning of a climatic zonation of the european continent and is also evidenced by a progressively southward disappearance of the crocodile diplocynodon from 38 45 n palaeolatitude to 30 37 n during the middle and earliest late miocene the results correlate well with palaeobotanical data from the mid latitudes of europe and north america and the deep sea temperature curve generated from oxygen isotope ratios

a short term cooling event 4 205 million years ago in the ptolemais basin northern greece abstract a distinct clay rich layer in the otherwise regular succession of alternating lignites and marls of the early pliocene ptolemais formation reveals an equally distinct palynomorph assemblage only in this layer fresh water dinoflagellate cysts spiniferites cruciformis and gonyaulax apiculata are encountered these co occurring dinoflagellate species may be taken to indicate that surface water temperatures must have been remarkably low for early pliocene mid latitudes contrasting other indications that overall warm humid climates prevailed at this time a multi component study of this so called dinolayer with an astrochronologically derived age of 4 205 0 01 ma was undertaken to further investigate the apparently contrasting climatic signals integrated sedimentological micropaleontological palynological and geochemical data indicate that the dinolayer was deposited in a shallow fresh water lake the pollen record points to slightly cooler conditions during deposition of the dinolayer in comparison with conditions just below and above an anomalously low winter temperature is proposed as a possible cause for the recorded phenomena

vegetation response during the lead up to the middle miocene warming event in the northern rocky mountains usa abstract the mid miocene climatic optimum mmco initial warming beginning ca 18 ma and with peak warming ca 17 14 75 ma constitutes the earth s most recent greenhouse episode characterized by a transient shift to higher global atmospheric co 2 levels and warmer possibly wetter climatic conditions combined with the spread of grass dominated habitats it has been suggested that the mmco lead to significant turnover and modernization of fauna and flora however records documenting local vegetation change during the mmco are rare hence this hypothesis remains largely untested herein we combine phytolith assemblages and 13 c records from paleosol organic matter from the railroad canyon section rcs eastern idaho to provide the first direct detailed and continuous long term record of vegetation composition and structure in a single basin during the lead up to the mmco 22 9 15 2 ma late arikareean early barstovian phytolith assemblage analysis indicates that grasses primarily c 3 pooids dominated early middle miocene vegetation potential c 4 pacmad grasses were present by ca 21 6 20 7 ma late arikareean and vary in abundance 0 4 17 2 of diagnostic phytoliths through the section although relatively rare overall pacmad grasses decrease significantly through time in parallel with declining diatom abundances and an increase in pooid grasses in contrast paleosol 13 c org indicates 0 29 1 c 4 vegetation but no consistent temporal change where both phytolith and isotope based estimates are made from the same paleosol they are within error most 82 of the time thus the apparent discrepancy in temporal trends could either be due to differences in the resolution of the two records or could be explained if many pacmads were not c 4 grasses but instead water loving c 3 species overall these data suggest that open habitat mosaic vegetation with grass dominated grasslands and open woodlands occurred in the north rocky mountains usa by at least the early miocene more comparable to the timing for the spread of grass dominated habitats in the great plains than previously thought additionally phytolith data suggest that overall vegetation structure remained relatively stable throughout the rcs inconsistent with published paleosol morphology data this points to regionally unique floral patterns decoupled from global climate change leading into the mmco

a new analytical expression for ultimate specific yield and shallow groundwater drainage the ultimate specific yield i e the specific yield under steady state condition is generally dependent on the water table depth in the shallow groundwater systems this paper presents a new expression to describe this relationship the expression is based on the relationship between soil water content soil depths below ground surface near the saturation zone i e water content profile which can be fitted by the van genuchten model because this model is highly nonlinear a taylor series expansion was used to solve the integral equation for specific yield in our study the new expression was verified by a drainage experiment and the results demonstrated that the new expression is reliable for eolian sand when the range of water table fluctuation is less than 30 cm the expression is easily applicable because knowledge of the water content profile near the saturation zone is the only requirement compared with the expression obtained from the brooks corey model the new expression can be used for a variety of aquifer and soil media the improved accuracy of the specific yield provides a better estimate of discharge rates in shallow groundwater systems with water table fluctuations copyright 2014 john wiley sons ltd

pollen record and integrated high resolution chronology of the early pliocene dacic basin southwestern romania an integrated stratigraphic study has been performed on four early pliocene fssections in the western dacic basin including the long reference section of lupoaia based on the integration of mediterranean nannoplankton assemblages the regional lignite stratigraphy records of large and small mammals large climatic fluctuations according to pollen grains and climatostratigraphic relationships at the european scale it has been possible to establish a magnetostratigraphic correlation of the different sections to the geomagnetic polarity time scale gpts this correlation suggests that all normal episodes of the early pliocene from thvera to cochiti chrons are recorded hence the complete pollen record covers an almost continuous time span from about 5 33 to 4 30 ma in addition the regional dacian romanian stage boundary in the dacic basin is located in the nunivak c3n 3n episode with an age of 4 55 0 05 ma our chronologic calibration combined with high resolution pollen data results in a detailed record of paleoclimate in which the 100 kyrs and 400 kyrs eccentricity cycles are clearly identified

monsoon variability over peninsular india during late pleistocene signatures of vegetation shift recorded in terrestrial archive from the corridors of western ghats abstract the fossil flora recovered from the kangvai well ratnagiri district maharashtra 17 53 41 n 73 12 23 e has been used to reconstruct the monsoon variations and seasonal rainfall pattern during the late pleistocene 44 020 390 years bp by using the coexistence approach the reconstruction suggests that the southwest sw and northeast monsoons ne contributed 64 and 18 of the total rainfall respectively moreover the pre monsoon showers were responsible for about 15 of the annual rainfall as both sw and ne monsoons were very active along with the pre monsoonal rainfall the length of rainy season increased and extended up to 9 months in a year favouring the evergreen continuum and prevalence of wet evergreen forests until the late glacial maximum or slightly prior to it however due to the weakening of ne and pre monsoon rainfall later in the late pleistocene and early holocene the area experiences only four months of rainy season now on account of the present day sw monsoon these changes resulted in the extinction of wet evergreen taxa which are now endemic to the wetter parts of western ghats from the fossil locality our reconstruction agrees with the previous studies from the western ghats suggesting that the wet evergreen taxa require

the coexistence approach theoretical background and practical considerations of using plant fossils for climate quantification the coexistence approach was established by mosbrugger and utescher 1997 as a plant based method to reconstruct palaeoclimate by considering recent climatic distribution ranges of the nearest living relatives of each fossil taxon during its existence for over more than 15 years its basics have been tested and reviewed in comparison with other terrestrial and marine climate reconstruction techniques and climate modelling data however some controversies remain about its underlying data or its applicability in general in view of these controversies this paper discusses the power and limitations of the coexistence approach by summarising past results and new developments we give insights into the details and problems of each step of the application from the assignment of the fossil plant to the most suitable nearest living relative the crucial consideration of the usefulness of specific taxa towards their climatic values and the correct interpretation of the software based suggested palaeoclimatic intervals furthermore we reflect on the fundamental data integrated in the coexistence approach by explaining different concepts and usages of plant distribution information and the advantages and disadvantages of modern climatic maps additionally we elaborate on the importance of continually updating the information incorporated in the database due to new findings in e g palaeo botany meteorology and computer technology finally for a transparent and appropriate use we give certain guidelines for future applications and emphasize to users how to carefully consider and discuss their results we show the coexistence approach to be an adaptive method capable of yielding palaeoclimatic and palaeoenvironmental information through rime and space c 2014 elsevier b v all rights reserved

modelling late miocene vegetation in europe results of the caraib model and comparison with palaeovegetation data abstract the caraib carbon assimilation in the biosphere model is used to study the vegetation distribution during the late miocene tortonian in this version the plant classification is specifically adapted to best represent miocene european vegetation compared to other plant classifications used in global models this adapted classification is more refined since it is specifically developed for european vegetation and it includes various thermophylous tree types which were present in europe during the miocene the corresponding climatic tolerance parameters are based on the study of laurent et al journal of vegetation science 15 739 746 2004 for the tree types currently present in europe and on the distribution of analogue species in southeastern asia and north central america for the thermophylous sub tropical trees the same classification is used to characterize the palaeoflora at the available late miocene localities allowing a model data comparison at the plant functional type level rather than at the biome level the climatic inputs to caraib are obtained from the cosmos atmosphere ocean general circulation model the climatic anomalies tortonian minus present derived from cosmos are interpolated to a higher spatial resolution before being used in the vegetation model these anomalies are combined with a modern climatology to produce climatic fields with high spatial resolution 10 10 this procedure has the advantage of making apparent relief features smaller than the grid cells of the climate model and hence makes easier the comparison with local vegetation data although it does not really improve the quality of the tortonian climate reconstruction the new version of caraib was run over europe at this higher spatial resolution it calculates the potential distribution of 13 different classes of trees including cold cool warm temperate sub tropical and tropical types together with their cover fractions net primary productivities and biomasses the resulting model vegetation distribution reconstructed for the tortonian is compared to available palaeovegetation and pollen data before performing this comparison the tree taxa present at the various data sites are assigned to one or several model classes depending on the identification level of the taxa if several classes are possible for a taxon only those that can co exist with the other tree classes identified at the site are retained this methodology is similar to the co existence approach used in palaeoclimatic reconstructions based on vegetation data it narrows the range of tree types present at the various sites by suppressing in the data the extreme types such as the cold boreal temperate and tropical trees the method allows a comparison with the model simulation on a presence absence basis this comparison provides an overall agreement of 53 between the model and the data when all sites and tree types are considered the agreement is high 85 for needle leaved summergreen boreal temperate cold trees larix sp and for tropical trees intermediate 40 for other boreal temperate cold trees and for needle leaved evergreen temperate cool trees broadleaved summergreen temperate cool trees and broadleaved evergreen warm temperate trees and poor

euro north african sirenia biodiversity as a response to climate variations abstract earth has a latitudinal biodiversity gradient in which more species inhabit tropical than polar regions frequently attributed to seasonality this ecological pattern is applied to the evolution of the euro north african sirenians and its relation to cenozoic climate change climate disruption changes in seasonality and geological processes such as sea level variations are statistically tested as primary drivers to explain sirenian evolution and regional amphi mediterranean sirenian speciation and biodiversity

comparative study of serbian miocene coals insights from biomarker composition abstract the origin of the organic matter om and the characteristics of the paleoenvironment of serbian brown coals covering a time span from the lower to the upper miocene were evaluated and compared based on comprehensive petrological and biomarker analyses investigated coals are typical humic coals peat forming vegetation is characterized by abundant decay resistant gymnosperm coniferous plants followed by variable amount of angiosperms coal forming plants belonged to the gymnosperm families taxodiaceae podocarpaceae cupressaceae araucariaceae phyllocladaceae and pinaceae peatification proceeded in fresh water environment under variable eh settings from anoxic to slightly oxic condition upper miocene lignites were formed in neutral to slightly acidic environment whereas lower and middle miocene coals were deposited under neutral to slightly alkaline and more reductive conditions which is the result of calcium rich surface waters derived from the surrounding jurassic to cretaceous calcareous country rock and higher water column level diagenetic changes of the om were governed by bacterial activity rather than thermal alteration biomarker pattern does not significantly differ in serbian coals of different ages the main differences between upper middle and lower miocene coals are expressed by higher gelification index gi proxy ratio p aq n c 23 n c 27 n c 31 and pimarane 16 h phyllocladane ratio as well as lower relative abundance of c 31 r hopane of the latter one om of lower miocene coals is more mature corresponding to immature early mature stage huminite vitrinite reflectance 0 45 whereas om of upper miocene lignites is in immature diagenetic phase huminite reflectance 0 3 consequently higher gelification of lower miocene coals is probably an effect of higher rank however high humidity wet climate and low acidity within the mire could not be excluded a good correlation between biomarker parameters and paleoclimate data is observed indicating that biomarker patterns represent a valuable tool that reflect even slight paleoclimate changes in serbia during miocene

estimating recharge based on long term groundwater table fluctuation monitoring in a shallow aquifer of malaysian tropical rainforest catchment a practical and reliable approach was applied to investigate the groundwater dynamics and obtain natural direct recharge based on the time series of water table fluctuation in moderately flat coastal area with a shallow water table and tropical rainforest weather drainage rate was about 0 034 m day in the study area as estimated by falling groundwater table in period of no rainfall and specific yield values ranged between 0 11 and 0 23 by calculating depth dependent specific yield based on soil water storage for layering soils the method was applied to the monthly data of shallow aquifer at eight field sites in north kelantan river catchment in the period of 1991 2011 the cross correlation and partial cross correlation reveal the acceptable correlation between the water table fluctuation and the rainfall data assuming the time lag from precipitation to water table response is negligible due to shallow water table recharge rates vary with the field sites and mainly depend on soil type and rainfall rather than surface geology although computer simulation with mrcr code was implemented with limited data two series still results are just slightly greater than the field data which indicated the method successfully employed and can be applied in areas with similar conditions in future

the cenozoic cooling continental signals from the atlantic and pacific side of eurasia a b s t r a c t the evolution of cenozoic continental climate signals from the atlantic and pacific side of eurasia can be assessed for the first time by comparing climate records obtained for two mid latitudinal regions for the west a detailed climate record over the past 45 ma based on palaeofloras from two northern german cenozoic basins mosbrugger et al 2005 r evealed major trends and shorter term events throughout the cenozoic cooling thus testifying the close correlation of continental and marine temperature evolution as derived from oxygen isotopes zachos et al 2008 using the same methodology we analyze a total of 14 floral horizons originating from continental strata of southern primory e russia in order to study the evolution at the eastern side of the continent the primory e record spans the middle eocene to early pleistocene as the coeval record for the atlantic side it reflects major global signals of cenozoic climate change such as the temperature decline throughout the late eocene coinciding with the growth of antarctic ice sheets warming during the mid miocene climatic optimum and step wise cooling throughout the later neogene the comparison of both records reveals differing regional patterns the considerable longitudinal temperature gradient currently existing between both study areas already began to evolve during the aquitanian and was very significant during the mid miocene climatic optimum the temperature offset between east and west is likely attributable to an effective north atlantic current already operational from the late early miocene onwards bringing about mild winters and low seasonality in western europe while in primory e seasonality steadily increased from the late oligocene on the strong late pliocene decline of cold month mean temperatures recorded in primory e is supposed to coincide with the establishment of the siberian high as semi permanent structure of the northern hemisphere circulation pattern when comparing the precipitation records obtained for both study areas an unexpected co variability at the longer term in the order of 5 20 ma is noted pointing to continent wide hydrological changes the steady decline of mean annual precipitation in the primory e record beginning in the bartonian and culminating in the aquitanian coincides with an aridity increase reported from coeval chinese inland localities of the mid latitudes the seasonality patterns of rainfall point to progressive intensification of the east asian summer monsoon in primory e since the later tortonian while the post zanclean decline of the precipitation of the dry season can be related to an increasing impact of the winter monsoon 2015 elsevier b v all rights reserved

analytical expressions for drainable and fillable porosity of phreatic aquifers under vertical fluxes from evapotranspiration and recharge 1 in shallow unconfined aquifers the response of the water table wt to input and output water fluxes is controlled by two distinct storage parameters drainable and fillable porosity which are applicable for wt drawdown and rise respectively however only the drainable porosity estimated from the hydrostatic soil moisture profile is in common use in this study we show that under conditions of evapotranspiration and or recharge from or to a shallow water table drainable and fillable porosity have different values separate analytical expressions are developed for drainable and fillable porosity accounting for dynamic soil moisture conditions through the assumption of successive steady state fluxes in the unsaturated zone the equations are expressed in terms of soil hydraulic parameters and matric suction at the soil surface parametric evapotranspiration and recharge functions are used to estimate the suction at the soil surface the final expressions are independent of evapotranspiration or recharge function thus allowing the use of any appropriate function to estimate the storage parameters it is shown that the occurrence of unsaturated zone fluxes can result in significantly different values of drainable and fillable porosity even when hysteresis is neglected application of the two parameters in a boussinesq type groundwater model resulted in significantly improved estimates of field measured water table dynamics compared to the hydrostatic single parameter model

vegetation and palaeoclimate in the miocene of ukraine miocene deposits marine and terrestrial distributed throughout the whole territory of ukraine contain numerous palaeontological remains including plant macro and microfossils there are well known occurrences of fossil leaves as well as fruits and seeds the miocene strata of ukraine belong to the central and the eastern paratethys and deposits from these regions have been studied palynologically for the reconstruction of the vegetation of lowland and mountain areas in ukraine palynological data have been complemented with data obtained from carpological and foliar studies to obtain quantitative climate data microfloral records from the ukraine plain and the ukrainian carpathians are analyzed using the coexistence approach the main trends of floral changes were directed by the global climate evolution complicated by regional tectonic processes major vegetation change occurred during the late miocene cooling in southern ukraine the cooling was accompanied by a gradual drying and partial replacement of forest vegetation by herbaceous communities that increased in richness and expanded from east to west

late miocene climate in the circum alpine realm a quantitative analysis of terrestrial palaeofloras abstract selected mega and microfloras from central and southern europe have been analysed for the time interval tortonian pannonian mn 9 12 with the coexistence approach to obtain quantitative palaeoclimate data the results give a geographically differentiated picture of the late miocene climate in the circum alpine area spatial patterns are presented in maps for mean annual temperature temperature of the coldest month temperature of the warmest month mean annual precipitation and mean annual range of temperature the obtained data show an overall warm humid and homogenous climate with very low latitudinal and longitudinal gradients there is no indication of a mediterranean type of climate palaeogeographic influences on climate patterns are evident the pannonian lake caused mild winters and a lower seasonality of temperature in the pannonian basin

middle miocene latitudinal climatic gradient in western europe evidence from pollen records abstract pollen analysis of sections spanning the middle miocene langhian and serravallian from southern spain to switzerland has been carried out with the aim of reconstructing the existing latitudinal environmental gradient floral assemblages indicate a tropical subtropical to warm temperate climate for the entire area during the middle miocene the presence in all pollen spectra of taxa with high temperature requirements demonstrates that the latitudinal gradient in temperature was relatively low the development of a diverse subarid flora in southern spain including neurada lygeum prosopis calligonum nitraria caesalpiniaceae etc points to a very dry climate with a marked seasonality these features clearly indicate that a very warm and dry climate i e a steppe environment was already present during the langhian in the northwestern mediterranean area on the other hand milder conditions are progressively inferred towards the north as subdesertic elements gradually disappeared and taxa with higher water requirements increased the latter dominates the pollen assemblages in the eastern central part of france and switzerland thus precipitations would have been evenly distributed throughout the year we interpret this gradient from subdesertic vegetation in the south to humidity adapted plant environments in the north as the result of a latitudinal gradient in precipitation

variational estimation of the wind stress drag coefficient and the oceanic eddy viscosity profile abstract a variational optimal control technique is used to assimilate both meteorological and oceanographic observations into an oceanic ekman layer model an identical twin experiment is discussed first in which the observations are created by the dynamic model the field measurements from the lotus 3 long term upper ocean study 3 buoy are then analysed by fitting the model results to the data the unknown boundary condition the wind stress drag coefficient and the unknown vertical eddy viscosity distribution are deduced simultaneously from the data and an optimal estimate of the current field is obtained though the model is simple the results show that the variational assimilation technique is capable of extracting from the available observations a reasonable wind stress drag coefficient and vertical eddy viscosity distribution

sedimentology and stratigraphy of cenozoic deposits in the kagizman tuzluca basin northeastern turkey the kagizman tuzluca basin is located in the northeastern anatolia to the east of the intersection point near karliova of the major north and east anatolian fault systems this intermontane basin displays a thick sequence over 2000 m of mostly terrestrial deposits represented by repetitive alternations of the lake and fluvial environments ranging from late eocene oligocene to middle late miocene a marine incursion only mappable in the southeastern margin of the basin deposited limestones and sandy limestones rich in marine mollusks and nummulites in particular n fichteli that constrain an early oligocene age for this marine unit kagan fm the terrestrial basin fill deposits show different thicknesses throughout the basin due to irregular bottom topography and tectonic configuration of the basin margins the thickest deposits were accumulated along the different margins of the basin which received high quantities of siliciclastics from meandering river alluvial and coastal fans fan delta gilbert type delta and wave worked fluvial delta climate changes have also driven the development of lake environments during distinct depositional periods siliciclastic dominated overfilled lakes halikislak and kizilkaya formations and chemical dominated underfilled lakes turabi and tuzluca formations were formed they have been also classified as newark type and fundy type lakes respectively fluvial systems evolved from high energy meandering rivers deposited under humid climate gungoren formation to low energy meandering rivers resulted from arid and semiarid climates cincavat formation the transitional intervals from ephemeral river dry mudflat cincavat formation to saline pan lake tuzluca formation indicate wadi sand flat playa fluvial systems the chronostratigraphic constrains of the entire sequence remain poor and so far solely based on vertebrate fossil assemblages the evaporitic tuzluca formation would be middle miocene in age due to its stratigraphic position over the cincavat formation

analytical expressions for transient specific yield and shallow water table drainage 1 new closed form expressions are introduced to capture the dependence of specific yield on time and depth to water table the expressions allow the user to convert observations of water table fluctuations to volumes of water released from storage in a shallow water table aquifer whereas a linear relationship between water table fluctuations and released volumes holds for a deep water table aquifer this relationship is nonlinear for shallow water table aquifers the dependence of specific yield on time stems from the slow drainage of soil water from pores above the water table the new expressions allow determination of transient specific yield and time to drain the soil water profile for a given water table fluctuation if the time step in a numerical groundwater model is longer than the time for limiting specific yield then a constant time independent specific yield can be justifiably adopted the new expressions are easy to use and require knowledge of soil hydraulic properties which are readily available from soil water retention data and surveys

late miocene to pliocene palaeogeography of the paratethys and its relation to the mediterranean abstract the palaeogeographic evolution of the paratethyan and mediterranean realms are reconstructed with three maps ranging from the late miocene to the middle late pliocene the maps are based on the facial analysis of selected deposits clastic input slope slide process analyses as well as biogeographic data of the planktic benthic and terrestrial biota characteristic fossil assemblages are used for palaeobathymetric and palaeohydrologic interpretations restoration of palaeogeographic connections the palaeogeographic reconstructions are palinspastically restored after dercourt j ricou l e vrielynck b eds 1993 atlas tethys palaeoenvironmental maps gauthier villars paris pp 1 307 14 maps the paleogeographic atlas of northern eurasia 1997 inst tectonics lithospheric plates moscow 26 maps with modifications maps have been prepared for the terminal tortonian early messinian late pannonian early maeotian late messinian pontian salinity crisis time and piacenzian gelasian akchagilian they illustrate the neogene palaeogeographic evolution during and after the attic orogenesis though the emerging mountain system of the alpine foldbelt increasingly separated the paratethys from the mediterranean tethys paratethys connections remained extant and sufficiently effective for limited communication between both basins they governed many features of the cyclic depositional history and biogeographic evolution of the eastern paratethys

present day climatic equivalents of european cenozoic climates abstract recently continental climate evolution in central europe over the last 45 ma has been reconstructed from the palaeobotanical record using a nearest living relative methodology coexistence approach ca the reconstructed climate curves document in detail the transition from almost tropical conditions in the mid eocene to a temperate climate at the pliocene pleistocene transition the observed climatic shifts are primarily expressed as non proportional changes of the different variables taken into account in the present study a published palaeoclimate data set for a total of 42 macrofloras complemented by new calculations is used as base to analyse the climatic space in which a fossil flora existed to define these spaces ca intervals calculated for 3 temperature mean annual temperature cold and warm month mean and 3 precipitation variables mean annual precipitation mean monthly precipitation of the driest and of the wettest month are combined using a global gridded climatology 10 resolution this climate space is then utilized to identify recent climate analogues with respect to the variables regarded for 18 macrofloras climatic analogue regions with respect to 6 variables are identified on the globe for 16 macrofloras analogues exist when three temperature parameters and mean annual precipitation are regarded no recent equivalents are found in 8 cases this corroborates the assumption of the temporary existence of non analogue climates in the cenozoic as shown by multivariate statistics the observed anomalies with respect to present day conditions basically refer to high winter temperatures deploying a gis the recent climate analogues can be presented as sets of grid cells for each flora that can be mapped on a globe once identified these regions can be merged with adequate thematic layers to assess additional proxy data for the palaeofloras to exemplify the procedure koeppen climate type numbers of days with ground frost as well as matthews biome classes are reconstructed the resulting koeppen types ranging from a to c are largely consistent with data previously published the ground frost record shows almost frost free conditions for the mid eocene greenhouse and for the mid miocene climatic optimum for the chattian up to 7 days with ground frost result during the late miocene cooling the number of days with ground frost significantly increased the inferred matthews biomes reveal changing patterns of evergreen and deciduous forest cover when recent climate analogues are found for a fossil flora present climate can be used to calibrate the original ca data it is shown that calibration considerably improves the resolution of the continental climate records

global vegetation dynamics and latitudinal temperature gradients during the mid to late miocene 15 97 5 33 ma a 617 site palaeobotanical dataset for the mid to late miocene is presented this dataset is internally consistent and provides a comprehensive overview of vegetational change from 15 97 to 5 33 ma the palaeobotanical dataset has been translated into the biome4 classification scheme to enable direct comparison with climate model outputs the vegetation change throughout the langhian seravallian tortonian and messinian is discussed the data shows that the langhian which includes the end of the mid miocene climatic optimum represents a world significantly warmer than today the high northern latitudes were characterised by cool temperate forests the mid latitudes by warm temperate mixed forests the tropics by tropical evergreen broadleaf forests and antarctica by tundra shrub vegetation cool temperate mixed forest existed during the seravallian in the high northern latitudes a reduction in warm temperate mixed forests in the mid latitudes and a loss of tundra on antarctica was noted tortonian vegetation distribution indicates that further cooling had occurred since the seravallian the major changes in vegetation include the first evidence for cold taiga forest in the high northern latitudes and a further reduction of warm temperate mixed forests by the messinian this cooling trend had eliminated warm temperate mixed forests from the western usa and australia and had formed mid latitude deserts despite the cooling trend throughout the mid to late miocene the vegetation distribution of all four reconstructed stages reflect the vegetation of a world warmer than the pre industrial conditions the latitudinal distribution of bioclimatic zones suggests that the latitudinal temperature gradient for the langhian would have been significantly shallower than at present and has gradually but asymmetrically become more modern towards the end of the miocene first the southern hemisphere distribution of bioclimatic zones became more modern probably due to the climatic effects of a fully glaciated antarctica the northern hemisphere bioclimatic zone gradient continued to be shallower than modern throughout the miocene and slowly became more modern by the messinian

paleoenvironmental settings of the sofia lignite basin insights from coal petrography and molecular indicators abstract compositions of balsha lignite sofia coal bearing basin bulgaria and carbonaceous shales are studied by petrological and geochemical proxies the macropetrographic characteristic of profiles is relatively constant the lignite is generally composed of dull matrix coal containing significant amounts of xylite fragments the typical microscopic constituents of the lignite are the ulminite and less frequently textinite lenses scattered within attrinitic groundmass the maceral composition of the organic matter in carbonaceous shales does not differ significantly from that of the lignite samples biomarker assemblages of the extractable portions are determined by gas chromatography mass spectrometry additional information for the compositions of residues after extractions is obtained by tmah thermally assisted hydrolysis methylation petrographic contents lipid assemblage and tmah thermally assisted hydrolysis methylation data imply that the original peat bog is formed in fresh water forest swamp preferably composed by gymnosperms polar diterpenoids argue for cupressaceae s l taxodiaceae as the most probable vegetation for one of the profiles appreciable angiosperm rich herbaceous type flora contribution is assumed polar oleanane triterepenoids and their aromatized derivatives argue for angiosperm input the relevance of a norfriedel 8 en 10 one friedelin ratio for groundwater level appraisal is discussed it admits long period of high water level in the paleomire high content of vanillyl structures and subordinated presence of syringyl units in products of tmah thermally assisted hydrolysis methylation are hint for gymnospermae input in the paleoswamp and angiospermae contribution to one of the profiles cinnamyl phenolic units indicating non woody angiosperm vegetation presence are registered as well flavonoids in products are considered as taxonomic markers of cupressaceae plants in the paleoswamp

the coexistence approach a method for quantitative reconstructions of tertiary terrestrial palaeoclimate data using plant fossils abstract the coexistence approach is introduced as a method for quantitative terrestrial palaeoclimate reconstructions in the tertiary it is based on the assumption that tertiary plant taxa have similar climatic requirements to their nearest living relatives the aim of the coexistence approach is to find for a given fossil flora and a given climate parameter the climatic interval in which all nearest living relatives of the fossil flora can coexist for this purpose we have developed a data base climbot containing for over 800 tertiary plant taxa the nearest living relatives and their climatic requirements and an algorithm for analysis climst for all types of fossil floras the coexistence approach thus allows the rapid quantitative reconstruction of 10 different climate parameters including the mean annual temperature temperature of the warmest month temperature of the coldest month mean annual precipitation maximum monthly precipitation minimum monthly precipitation precipitation of the warmest month relative humidity potential evaporation as well as the ratio of mean annual precipitation over potential evaporation the reliability and resolution of the coexistence approach are tested with various techniques and proved to be reasonably good for instance the resolution with respect to the mean annual temperature can be up to 1 c applications to various modern and fossil floras are illustrated and the advantages and disadvantages of the coexistence approach are discussed

towards an astrochronological framework for the eastern paratethys mio pliocene sedimentary sequences of the focsani basin romania abstract a reliable geological timescale for the neogene sedimentary deposits of the romanian carpathian foredeep did not exist so far due to the lack of accurate isotopic datings and straightforward magnetostratigraphic correlations here we present a new chronology for the upper miocene to pliocene deposits of the westernmost part of the eastern paratethys based on high resolution magnetostratigraphic data from the focsani basin the thick and continuous river sections of putna 2 35 km and rimnicu s rat 7 32 km yield excellent magnetostratigraphic results and allow an unambiguous correlation to the polarity timescale for the interval between 7 and 2 5 ma the new age control permits the calculation of accumulation rates for each polarity zone which shows a significant increase at approximately 5 8 6 my the upper miocene to pliocene sedimentary rocks of the focsani basin display cyclic alternations of sandy units and finer intervals the calculated values for the average duration of the observed sedimentary cycles are very close to the average duration of precession 21 7 ky which indicates that the sedimentary cycles from the eastern carpathian foredeep deposits are astronomically forced we show that the usage of the unambiguous time control offered by magnetic polarity stratigraphy would give a more realistic picture of the processes that have taken place in this tectonically active region

palynological evidence for miocene climate change in the forecarpathian basin central paratethys nw bulgaria abstract we reconstruct quantitatively the middle to upper miocene climate evolution in the southern forecarpathian basin central paratethys area northwest bulgaria by applying the coexistence approach to 101 well dated palynofloras isolated from three cores the climatic evolution is compared with changes in vegetation and palaeogeography the middle miocene was a period of a subtropical warm temperate humid climate with mean annual temperature mat between 16 and 18 c and mean annual precipitation map between 1100 and 1300 mm thereby during the entire middle miocene a trend of slightly decreasing temperatures is observed and only small climate fluctuations occur which are presumably related to palaeogeographic reorganisations the vegetation shows a corresponding trend with a decrease in abundance of palaeotropic and thermophilous elements the upper miocene is characterised by more diverse climatic conditions probably depending on palaeogeographic and global climatic transformations the beginning of this period is marked by a slight cooling and a significant drying of the climate with mat 13 3 17 c and map 652 759 mm after that fluctuations of all palaeoclimate parameters occur displaying cycles of humid dryer and warmer cooler conditions which are again well reflected in the vegetation our study provides a first quantitative model of the middle upper miocene palaeoclimate evolution in southeastern europe and is characterised by a relatively high precision and resolution with respect to the climate data and stratigraphy

reproduction of estuarine bathymetry by means of a process based model western scheldt case study the netherlands abstract the current study aims to investigate the processes governing the evolution of major morphological features in alluvial estuaries as well as their morphodynamic interaction with the geometry by means of a 3d morphodynamic process based numerical model delft3d the main hypothesis is that channel shoal patterns evolve through the interaction between tidal movement the available sediments and the tidal basins geometry once such a system is not disturbed too much by extreme events stable morphological patterns will emerge that compare well with observed features starting from a flat bed and imposing the western scheldt geometry model results show two distinct time scales i e channel shoal pattern formation within decades and a slow longitudinal profile development continuing for centuries the developing channel shoal patterns reflect major morphological features observed in the western scheldt estuary using the 1998 bathymetry as a reference we applied different indicators and techniques to evaluate the model performance over time namely visual comparison hypsometries brier skill score bss mean basin depth and longitudinal profiles sensitivity analysis shows that trends in development are similar for different model parameter settings like introducing salt fresh water density differences or variations in sediment grain size and sediment transport formulation varying river discharge and including non erodible layers dredging and dumping activities and 3d hydrodynamics led to occasional improvements the geometry is an important governing factor for pattern development applying an erodible geometry reveals a timescale for geometric adaptation that is much longer than the pattern development timescale within the basin model runs including highly schematized extreme conditions suggest that extreme events play a limited role the main conclusion of the study is that the interaction between tidal forcing and basin geometry plays a major role in the development of morphological features in an alluvial tidal basin such as the western scheldt a process based model taking into account these major forcing mechanisms can predict such features with significant skill the bathymetries generated in this study may form the basis for further studies considering for example the impact of sea level rise on estuarine morphodynamic development or a rapid assessment of estuarine bathymetry in the absence of measured data

late miocene intensification of continentality in the black sea region the black sea basin is the sink for some of the largest european rivers and has acted as such since it was part of the eastern paratethys the late miocene to pliocene sedimentary record of the black sea documents several phases of strongly evaporitic conditions associated with extreme changes in regional hydrology here we present the first combined record of continental temperature soil type and biomass burning in the circum black sea region from the late miocene to the transition into pliocene 10 0 to 5 0 ma we use branched glycerol dialkyl glycerol tetraethers brgdgt to reconstruct mean annual air temperature mat and soil ph within the catchment of the black sea basin and complement these data with evidence from charcoal morphology as a proxy for burned biomass the brgdgt data reveal generally decreasing temperatures and acidic soils between 10 and 8 5 ma overlapping with increase in herbaceous cover in the black sea region the pontian flooding at 6 12 ma is characterized by large quantities of organic debris and charcoal fragments in the basin and is followed by cooling starting at 5 97 ma event that is superimposed on the tg 20 and tg 22 glacial peaks at 5 8 ma between 5 8 and 5 0 ma the brgdgts seem to be primarily derived from a cold steppe environment enhanced fire activity coinciding with generally cooler temperatures and a higher proportion of herbaceous plants are indicative of increased continentality between 5 8 and 5 0 ma in the black sea region

suspended sediment transport under estuarine tidal channel conditions abstract a modified version of the geoprobe tripod has been used to monitor flow conditions and suspended sediment distribution in the bottom boundary layer of a tidal channel within san francisco bay california measurements were made every 15 minutes over three successive tidal cycles they included mean velocity profiles from four electromagnetic current meters within 1 m of the seabed mean suspended sediment concentration profiles from seven miniature nephelometers operated within 1 m of the seabed near bottom pressure fluctuations vertical temperature gradient and bottom photographs additionally suspended sediment was sampled from four levels within 1 m of the seabed three times during each successive flood and ebb cycle while the instrument was deployed std nephelometer measurements were made throughout the water column water samples were collected each 1 2 hours and bottom sediment was sampled at the deployment site from these measurements estimates were made of particle settling velocity ws from size distributions of the suspended sediment friction velocity u from the velocity profiles and reference concentration ca was measured at z 20 cm these parameters were used in the suspended sediment distribution equations to evaluate their ability to predict the observed suspended sediment profiles three suspended sediment particle conditions were evaluated 1 individual particle size in the 4 11 62 5 0 5 m range with the reference concentration ca at z 20 cm c 2 individual particle size in the 4 6 size range flocs representing the 7 11 size range with the reference concentration ca at z 20 cm cf and 3 individual particle size in the 4 6 size range flocs representing the 7 11 size range with the reference concentration predicted as a function of the bed sediment size distribution and the square of the excess shear stress in addition computations of particle flux were made in order to show vertical variations in horizontal mass flux for varying flow conditions

palaeogeographic environment during the desiccation of the black sea abstract during the latest chersonian about 10 3 m y ago tectonic movements took place leading to an elevation of the crimean caucasian chain and to an isolation of the fore caucasian part of the black sea basin this part of the basin had been draining the rivers of the russian platform and after the isolation it became desalinized while the main part of the black sea basin was almost desiccated and evaporites mainly dolomites formed in it due to the predominant calcium magnesium carbonate composition of the chersonian sea waters these dolomites are found in the drillings of dsdp leg 42b and are confirmed geophysically the tectonic movements during the latest chersonian led to the formation of a series of grabens along which the mediterranean sea invaded the north aegean area and a little later during the early maeotian the black sea

aquifer response to stream stage and recharge variations ii convolution method and applications abstract in this second of two papers analytical step response functions developed in the companion paper for several cases of transient hydraulic interaction between a fully penetrating stream and a confined leaky or water table aquifer are used in the convolution integral to calculate aquifer heads streambank seepage rates and bank storage that occur in response to stream stage fluctuations and basinwide recharge or evapotranspiration two computer programs developed on the basis of these step response functions and the convolution integral are applied to the analysis of hydraulic interaction of two alluvial stream aquifer systems in the northeastern and central united states these applications demonstrate the utility of the analytical functions and computer programs for estimating aquifer and streambank hydraulic properties recharge rates streambank seepage rates and bank storage analysis of the water table aquifer adjacent to the blackstone river in massachusetts suggests that the very shallow depth of water table and associated thin unsaturated zone at the site cause the aquifer to behave like a confined aquifer negligible specific yield this finding is consistent with previous studies that have shown that the effective specific yield of an unconfined aquifer approaches zero when the capillary fringe where sediment pores are saturated by tension extends to land surface under this condition the aquifer s response is determined by elastic storage only estimates of horizontal and vertical hydraulic conductivity specific yield specific storage and recharge for a water table aquifer adjacent to the cedar river in eastern iowa determined by the use of analytical methods are in close agreement with those estimated by use of a more complex multilayer numerical model of the aquifer streambank leakance of the semipervious streambank materials also was estimated for the site the streambank leakance parameter may be considered to be a general or lumped parameter that accounts not only for the resistance of flow at the river aquifer boundary but also for the effects of partial penetration of the river and other near stream flow phenomena not included in the theoretical development of the step response functions

a critical reevaluation of palaeoclimate proxy records from loess in the carpathian basin abstract in the carpathian basin loess is the most important archive of quaternary palaeoclimate evolution but only in the past two decades systematic and high resolution investigations were conducted those studies remarkably improved our knowledge of the regional past environmental change palaeoclimate inferences based on the magnetic susceptibility and grain size distribution as the most commonly used palaeoenvironmental proxies for the carpathian basin loess indicate colder and drier climatic conditions during glacials when compared to interglacials with an increasing number of studies using novel proxies in loess research such a traditional understanding of dry and cold glacials and humid and warm interglacials in the carpathian basin has been questioned as an illustrative example mollusc based climate reconstructions suggest generally warm and very dry summer conditions with mean july temperatures up to 21 c for the southern carpathian basin during the last glacial results based on stable carbon isotopes strongly oppose such high summer temperatures but studies based on n alkanes are in general agreement with the mollusc data when it comes to the vegetation reconstruction indicating mostly steppic conditions however n alkanes studies contradict warm and dry glacial conditions as indicated by mollusc based reconstructions pointing instead to cold and relatively humid glacials in addition there is an ongoing debate whether or not millennial scale climatic oscillations can be observed in the carpathian basin loess as well as whether this area was an important northern hemisphere dust source or rather a sink of far distance dust transport consequently the current state of the art of the palaeoclimate reconstructions from loess in the carpathian basin is rather inconsistent in order to make sense of the existing palaeoclimate data from the carpathian basin loess we have reevaluated and reinterpreted the available data we discuss and propose a coherent interpretation of rock magnetic grain size malacological stable carbon and nitrogen isotope n alkane and bacterial membrane lipid data for the last glacial cycle loess archives from the carpathian basin we show that glacial conditions in the carpathian basin led to a notable increasing north south gradient in temperature and an even stronger expressed decreasing trend in humidity and that most of the biomarker proxy data conducted in loess for the very dry southern part of the carpathian basin show a strong bias towards arid conditions in particular palaeotemperature reconstructions seem to be misleading glacial conditions were drier and colder than previously proposed summer temperatures likely under 15 c during glacials but notably warmer than in other parts of western central and eastern europe the vegetation consisted mostly of steppic environments during both glacials and interglacials we indicate that the carpathian basin has a potential to be a major dust source of the northern hemisphere during glacials although it was at the same time exposed to the deposition of fine far distance travelled dust moreover the main issues in the regional and continental correlation of loess are highlighted as well as the sensitivity of the carpathian basin loess to the millennial scale climate variability recorded in other northern hemisphere records finally we suggest that the onset of loess formation in the investigated area occurred during the middle pleistocene transition and it was probably related to intensive silt production related to glacier dynamics in the alpine ice cap

swash aquifer interaction in the vicinity of the water table exit point on a sandy beach the coupling of sandy beach aquifers with the swash zone in the vicinity of the water table exit point is investigated through simultaneous measurements of the instantaneous shoreline swash front location pore pressures and the water table exit point the field observations reveal new insights into swash aquifer coupling not previously gleaned from measurements of pore pressure only in particular for the case where the exit point is seaward of the observation point the pore pressure response is correlated with the distance between the exit point and the shoreline in that when the distance is large the rate of pressure drop is fast and when the distance is small the rate decreases the observations expose limitations in a simple model describing exit point dynamics which is based only on the force balance on a particle of water at the sand surface and neglects subsurface pressures a new modified form of the model is shown to significantly improve the model data comparison through a parameterization of the effects of capillarity into the aquifer storage coefficient the model enables sufficiently accurate predictions of the exit point to determine when the swash uprush propagates over a saturated or a partially saturated sand surface potentially an important factor in the morphological evolution of the beach face observations of the shoreward propagation of the swash induced pore pressure waves ahead of the runup limit shows that the magnitude of the pressure fluctuation decays exponentially and that there is a linear increase in time lags behavior similar to that of tidally induced water table waves the location of the exit point and the intermittency of wave runup events is also shown to be significant in terms of the shore normal energy distribution seaward of the mean exit point location peak energies are small because of the saturated sand surface within the seepage face acting as a rigid lid and limiting pressure fluctuations landward of the mean exit point the peak energies grow before decreasing landward of the maximum shoreline position

what controlled mid late miocene long term aridification in central asia global cooling or tibetan plateau uplift a review abstract debate continues over whether global cooling or uplift of the tibetan plateau provided the first order driver for the aridification moisture levels of central asia throughout the mid late miocene between about 17 and 5 ma this review attempts to throw new light on the relations between the aridification and these two key factors this paper examines the evolution of miocene climate both moisture and temperature within five separate regions of eurasia to help understand the large scale controls of long term moisture in central asia the five regions include 1 europe 2 high latitude asia 3 the east asian monsoon region 4 the south asian monsoon region and 5 central asia itself because moisture reaching central asia has to firstly cross at least one of the other four regions temperature proxy data compiled from these five regions correlate with ocean temperatures from the global deep sea oxygen isotope records furthermore compiled moisture proxy data from the four regions surrounding central asia co vary and correlate with each other this can be explained by positive feedbacks between drying and cooling and supports the assumption that global cooling provides a dominant driving factor for the drying of eurasia global cooling reduces the amount of water vapor held in the atmosphere and thereby can cause terrestrial drying however in central asia the moisture evolution shows less similarity with its surroundings the uplift of the tibetan plateau including the tianshan mountains could provide a possible explanation for this difference the changing topography resulting from uplift events over time and space strongly influenced the moisture patterns in central asia during miocene times future research on the spatial timing and amplitude of tibetan plateau uplift should be useful to understand the moisture processes in central asia during the miocene

middle miocene badenian vegetation and climate dynamics in bulgaria and poland based on pollen data abstract the miocene represents a time in eurasia when evergreen and thermophilous dominated paleogene vegetation was replaced by deciduous and temperate plants climatically it is the transition from a greenhouse to an icehouse world with the middle miocene climatic optimum as the last warm episode of earth history processes of plant evolution transformation of vegetation and coenotic structure were significantly forced by both changes in the global climate system and also by significant palaeogeographic reorganizations to give new insight in the middle miocene evolution of european ecosystems and climate dynamics we compared plant assemblages from northern bulgaria and southern poland southern paratethyan and polish lowlands realms based on palaeoecological analysis the main palaeocommunities are distinguished in hygro hydrophytic herbaceous palaeocoenoses reed marshes hygrophytic forest palaeocoenoses swamp forest and bush swamp riparian forests and mixed mesophytic forests despite some differences in taxonomic composition of these fossil floras and the proportion of individual taxa the vegetation shows similar composition and trends through time the main trend in the vegetation dynamics is a general decrease in the abundance of palaeotropic and thermophilous elements of semi evergreen forests together with these changes is a corresponding increase in the role of arctotertiary species in plant communities and these plants became dominant in the mesophytic forests changes in swamp vegetation are climatically related too but these reflect mainly local environmental dynamics and changes in inundation of the basin climate data from bulgaria and poland lack significant latitudinal climate gradient thus confirming more or less homogenous climatic conditions within europe in the middle miocene

petrological and geochemical composition of lignite from the d field kolubara basin serbia abstract the upper miocene lignite from the main coal seam in the d field kolubara basin is a typical humic coal with huminite liptinite and inertinite concentrations of up to 83 7 vol 17 2 vol and 15 5 vol respectively in the huminite group textinite and ulminite are the most abundant macerals with variable amounts of densinite and attrinite liptodetrinite and sporinite are the most common macerals of the liptinite group while inertodetrinite is the most abundant maceral of the inertinite group the mineral matter consists mostly of clay minerals the main sources of organic matter were gymnosperms conifers and microbial biomass followed by angiosperms based on composition of saturated and aromatic diterpenoids it has been established that coal forming plants belonged to the gymnosperm families taxodiaceae podocarpaceae cupressaceae araucariaceae phyllocladaceae and pinaceae peatification occurred in neutral to slightly acidic fresh water environment composition and distribution of biomarkers show that diagenetic changes of the organic matter were mainly governed by bacterial activity in a suboxic to oxic environment based on distribution of aromatic diterpenoids a novel diagenetic pathway for transformation of abietane type precursors under suboxic to oxic conditions is proposed variations in compositions of macerals and biomarkers are in concordance with pronounced seasonality during pontian which caused changes in the water level redox conditions during peatification and to some extent vegetation differences in the paleo plant communities

variational inverse parameter estimation in a cohesive sediment transport model an adjoint approach 1 parameter estimation in the sediment deposition and resuspension process is an important issue in numerical modeling of suspended sediment transport the sediment settling velocity and resuspension rate are two critical parameters controlling the sediment exchange process between the water column and sediment bed in this paper a variational inverse data assimilation scheme for estimation of the sediment settling velocity and resuspension rate is developed and tested with a three dimensional cohesive sediment transport model the sediment settling velocity and resuspension rate are treated as poorly known parameters in the model and are estimated by the variational inverse scheme using an adjoint approach a limited memory quasi newtonian conjugate gradient algorithm is used in the minimization process the variational inverse model is tested in the james river estuary in virginia by identical twin experiments numerical experimental results show that variational inverse data assimilation is a useful tool for retrieving poorly known parameters in a cohesive sediment transport model

stable isotope compositions of herbivore teeth indicate climatic stability leading into the mid miocene climatic optimum in idaho u s a abstract the effects of global climate change are manifested at the regional level consequently evaluation of links between palaeoenvironmental change and turnover of past biotas must use regional scale climate data here we test whether climate change influenced faunal and floral patterns leading up to and during the mid miocene climatic optimum mmco based on datasets collected in the railroad canyon section rcs central eastern idaho u s a specifically we use isotope compositions of herbivore tooth enamel to investigate how mean annual precipitation map mean annual temperature mat cold month mean temperature cmmt and temperature seasonality varied through the rcs and how this local record compares to global climate reconstructions isotope compositions of teeth from the fossil equid merychippus and rhinocerotid diceratherium were compared across five time bins from c 23 to c 15 ma bulk 18o values of both taxa indicate that meteoric water compositions were unchanged through the study interval consistently c 15 6 but were c 1 9 higher than current regional meteoric water this difference points to warmer climates in central eastern idaho during the miocene post middle miocene topographic uplift in western north america and or shifts to air mass trajectories serial sampling of enamel shows seasonal fluctuations in water compositions and temperature bulk 13c values indicate an average map of 190 range 10 510 mm yr 1 with no significant change through the study interval comparable to today s map 236 mm yr 1 the reconstructed semi arid seasonal warm climate for the rcs agrees with phytolith assemblage data from the same strata indicating dominantly open grassy habitats however it is inconsistent with previously held ideas of warm wet mid miocene climates in the northern rocky mountains nrm based on paleosol analyses our inferred stable climate conditions for the mmco of the nrm contrast with coeval records from europe and asia indicating sustained or enhanced warm and wet climates these differences point to a decoupling of regional climate from global trends and highlight the necessity of studying regional variation to understand the biotic impacts of global climate change

millennial scale climatic cycles in the early pliocene pollen record of ptolemais northern greece early pliocene lacustrine sediments from the ptolemais basin northern greece exhibit a climatically induced cyclicity which can be correlated with the orbital cycle of precession superimposed on precession controlled cycles palynological time series data reveal a higher order climatic cyclicity with periodicities of 10 2 5 and 1 5 ka these millennial scale vegetation changes are likely to reflect changes of the soil moisture gradient on mountain slopes caused by fluctuations in orographic winter precipitation such fluctuations corroborate the concept of a nao like north atlantic climatic teleconnection during early pliocene times the periodicities are similar to those of climate oscillations inferred from quaternary records the occurrence of millennial scale cyclicity in a time interval when the northern hemisphere was essentially ice free implies an ultimate forcing mechanism that operated independently of changes in the thermohaline circulation in the atlantic ocean the cycles are likely to be related to long period variations in solar activity

miocene depositional environment and climate in western europe the lignite deposits of the lower rhine basin germany abstract miocene lignites representing a depositional history of about 7 million years 18 11 ma before present have been studied by organic petrological and organic geochemical methods including analysis of stable carbon and oxygen isotopes the three lignite seams investigated morken frimmersdorf garzweiler developed from peats which grew in a nutrient depleted paralic environment situated close to the sea all seams have low ash mineral matter contents but seam frimmersdorf is richer in sulfur as compared to seams morken and garzweiler sulfur richness and distribution in seam frimmersdorf might be due to the diagenetic effect of sulfate reduction and pyrite precipitation following flooding by the sea and deposition of the marine neurath sands on top of seam frimmersdorf geochemical palaeotemperature analysis gdgt revealed a warm climate during deposition of the peats representing lignite seams morken and frimmersdorf which shifted towards lower temperatures 2 3 c during deposition of the uppermost seam garzweiler i e at about 13 11 ma before present this trend is basically supported by cellulose oxygen isotope values which show a significant scatter however carbon isotope values are less variable indicating predominance of angiosperms in the peat vegetation and rather stable environmental conditions as well as floral assemblage organic petrological studies reveal predominance of small plants and a nutrient depleted environment a modified groundwater index gwiac was applied suggesting deposition above the general groundwater level

benchmark data of a changing sea palaeogeography palaeobiogeography and events in the central paratethys during the miocene abstract the reconstruction and interpretation of terrestrial ecosystems and vegetational patterns in the central european miocene have to take into account the influence of a vast landlocked water body namely the paratethys sea as a northern appendage of the early mediterranean sea it spanned a north south gradient of at least 4 latitude and has been suggested to represent some kind of palaeothermometer which reflected slight expansions or restrictions of climatic belts due to its vulnerable marine connections it was also highly susceptible to major global sea level fluctuations which are reflected in phases of endemism hence a fairly continuous record of marine nearshore assemblages throughout the miocene reflects an extraordinary interplay of sea level fluctuations changes in climate immigrations and blooms in autochthonous elements whilst biostratigraphic implications of these patterns were recognised early in palaeontology a biogeographic model is still lacking the intermingling of palaeogeographic terms with those restricted to biogeography is still commonly used a situation which can be overcome by integrating data from different biota into a new palaeobiogeographic scheme herein a data set of 1809 species level taxa gastropoda and foraminifera serves as the base for interpretations gastropods in particular turned out to be of greatest value for the differentiation of palaeobiogeographic units due to sensitive reactions to all environmental parameters and occupying a wide range of ecological niches based on the excellent gastropod record the proto danubian province early danubian p danubian p balatonian p and a proto caspian subprovince are defined the biogeographic reorganisations are associated with five major biotic events within the gastropod faunas these big five comprise four extinctions the late ottnangian extinction event loee the mid badenian extinction event mbee the badenian sarmatian extinction event bsee the sarmatian pannonian extinction event spee and one exceptional immigration origination event termed the early badenian build up event ebbe foraminifera are less valuable for palaeobiogeographic purposes in the area and time slice studied endemisms are generally lower and turn over rates less dramatic they are however very useful for stratigraphic correlations with the mediterranean and atlantic areas this fairly well calibrated marine biostratigraphy of the central paratethys serves as stratigraphic backbone and control for continental stratigraphy

late miocene climatic and environmental variations in northern greece inferred from stable isotope compositions δ18o δ13c of equid teeth apatite abstract during the late miocene vallesian turolian transition an important faunal turnover affected continental vertebrate faunas and particularly primates with the replacement of hominids by cercopithecid monkeys in europe in order to better understand this turnover from a climatic perspective stable oxygen and carbon isotope compositions of fossil equid tooth enamel contemporaneous with either hominids or cercopithecids have been analyzed hipparion teeth recovered from seven greek localities spanning from the late vallesian to the end of turolian have 18op values of apatite phosphate suggesting an increase in mean air temperatures from 13 3 c at the beginning of the vallesian to 17 2 c during the late turolian 13c values of local plants have been estimated using the carbon isotope compositions of apatite carbonate by applying to our data the relationship established between the 13c value of modern c3 plants and mean annual precipitations estimated average precipitations slightly decreased from 890 109 100 mm a 1 to 471 58 54 mm a 1 during this time span according to koppen s classification of climates northern greece was submitted to modern like mediterranean climates during the late miocene the change in climatic conditions which took place during the late vallesian early turolian transition remained within the range of mediterranean climate modes thus being unlikely at the origin of a dramatic modification in local vegetation this study strongly suggests that climate might not be the key factor of the vallesian turolian major faunal turnover at least in the eastern mediterranean basin

stable isotope ecology of hippotherium from the late miocene pannonian basin system abstract the retreat of the paratethys sea in the middle to late miocene left behind a series of intermontane lakes across central europe ancient lake pannon which existed in present day hungary and surrounding countries was gradually filled in by fluvial sedimentation from 10 to 4 ma this infilling allowed for the migration of mammals such as the horse hippotherium into the pannonian basin system pbs stable carbon and oxygen isotope records from hippotherium are used here to reconstruct changing environmental conditions of the late miocene in this region our emphasis is on understanding the vegetation and surface water of the basin because these in turn affected the isotopic composition of lake pannon we analyzed the enamel of 68 hippotherium teeth from 23 localities in the pbs for carbon and oxygen isotope composition carbon isotope records indicate that hippotherium in the central regions of the basin were feeding in more open habitats than those in the northwest we find no evidence of the expansion of c4 grasses into the pbs oxygen and carbon isotope values from the vienna basin nw part of the pbs generally covary whereas those from more central regions do not the oxygen values of the central pbs are generally lower than those of the vienna basin these data suggest that the interior of the pbs was generally dry which forced hippotherium to use water sources that were not strongly evaporated such as rivers originating from outside the basin the dry interior was likely caused by a rain shadow east of the alps and north of the dinarides consequently much of the surface inflow into lake pannon would have been influenced by runoff from high elevations around or outside the basin by understanding the terrestrial environment better constraints can be placed on lake conditions in future work

palaeoclimate and vegetation change in serbia during the last 30 ma abstract in the present study 14 published megafloras from the serbian cenozoic are analyzed with respect to vegetation type palaeoclimate and palaeogeographic settings the floras cover a time span from the oligocene to the late miocene the results obtained are compared with continental climate records from other parts of europe and discussed in the context of global climate change to obtain a quantitative palaeoclimate record a total of seven different climate variables is calculated for each of the floras using the coexistence approach it is shown that basic patterns of vegetation change such as the immigration of arcto tertiary deciduous floristic elements during the early miocene and the decreasing diversity of laurophyllous taxa during the late miocene are ruled by climate change and a changing palaeogeography the serbian cenozoic climate record shows a steep cooling gradient during the oligocene that is most probably is connected to a northward movement of tectonic plates the globally observed middle miocene climate optimum and the late miocene cooling are well reflected according to the palaeotemperatures calculated a warm temperate climate existed in serbia throughout the time span examined the late miocene cooling is most pronounced in winter temperatures and is connected to increasing seasonality precipitation rates obtained for the serbian cenozoic especially those of the warmest and wettest months tend to be lower when compared to the central european cenozoic according to climate analysis and the interpretation of vegetational data there is evidence for regionally drier conditions and increased seasonality of precipitation in the time span from the late badenian to the early sarmatian

cohesive sediment transport model a mathematical model has been developed which simulates the transport of cohesive sediment the model solves the complete three dimensional version of the diffusion advection equation using a splitting method in conjunction with a characteristics technique and a mixed explicit implicit finite difference approach the effects of the flocculation deposition consolidation erosion and slump of the sediment are incorporated in the model which can also handle irregular layouts application of the model to a harbor siltation problem indicated that the large input data requirements can be satisfied economically and that the scheme yields realistic results the application also provided an insight into possible ways of operating the model for different field situations

geographic and temporal patterns in the late neogene 12 3 ma aridification of europe the use of small mammals as paleoprecipitation proxies abstract present day relations between small mammal community structure and rainfall are used to predict late neogene 12 3 ma precipitation patterns in europe and anatolia new proxy methods are developed which include regressions of mean annual and minimum monthly precipitation on diet invertivory index and locomotion habitat arboreality index a series of precipitation maps and a set of regional precipitation curves through time at 1 myr resolution are presented precipitation curves at a higher temporal resolution are constructed for the region of central spain the miocene results show the existence between 12 and 9 ma of a large wet 800 1200 mm yr zone extending from northern spain to the ukraine and characterized by the whole year penetration of large amounts of moisture far into the continent between 10 9 and 5 ma this european temperate wet zone etwz shrinks and or moves northward resulting in diachronous aridification a coeval northward migration of the subtropical high pressure zone shpz is hypothesized which is also consistent with the predicted onset of seasonal summer dryness between 10 and 8 ma the maximum extension of the etwz at 12 9 ma temporally correlates with northern hemisphere cooling suggesting that climate zonation rather than the global amount of atmospheric moisture controlled european climate at this time the main aridification at 9 8 ma could best be explained by a northward extension shifting of the subtropical high pressure zone and a transition towards less zonal circulation processes which ultimately could have been triggered by uplift of the tibetan plateau a temporary increase of precipitation at 7 6 ma is associated with renewed global cooling the lowest precipitation values less than 400 mm yr occur during the pliocene in southern and eastern europe uplift in eastern europe carpathians shrinking of the paratethys could well explain the aridification in this area and the associated sharpening of east west precipitation gradients across the continent

late miocene vegetation of the pannonian basin abstract the pannonian basin system provides sufficient data to study local and regional vegetation in the context of palaeoclimate and palaeogeography the present study attempts to make use of the latest results in stratigraphy and track vegetation change throughout the late miocene vegetation layers are reconstructed for five time slices from 10 8 ma to 6 5 ma and placed in a palaeogeographic context plant functional types and their distribution frequently applied in ecological studies and biome modelling serve as a tool for reconstructing palaeovegetation units a classification system is introduced considering non zonal elements as well in order to represent the neogene floral record the pft spectra obtained from fossil leaf assemblages indicate the presence of mainly broadleaved deciduous vegetation throughout the regarded time span with variable diversities of conifers and broadleaved evergreen vegetation components during the late miocene the lowland vegetation of the pannonian realm seemed to be more homogeneous than reported in other reconstructions which is in line with the persistence of overall warm and humid climate conditions the existence of distinctly dry periods as partly suggested by other proxies is not supported at the same time data suggest the coeval declining trend of the broadleaved evergreen component in the study area and its final complete disappearance from the north of the pannonian basin in the younger time slices constantly humid conditions might have existed along the northern border of the lake possibly connected to uplift pulses of the alps and carpathians

cenozoic climate gradients in eurasia a palaeo perspective on future climate change abstract recent studies in the frame of the neclime neogene climate evolution in eurasia network provide a comprehensive inventory of continental palaeoclimate data for various time slices reconstructed from the palaeobotanical record the integrative analysis of spatial gradients and patterns observed from the proxy data together with data obtained from numeric modelling studies considerably improved our knowledge about the functioning of the climate system in the cenozoic when compared to the present an overall warmer more humid climate existed cenozoic climates are characterized by warm high latitudes shallow latitudinal and longitudinal gradients and wet continental interiors while concentration of greenhouse gases was about at the present day level or considerably higher thus these past climates potentially are valuable to better understand future climate change because they allow empirical access to climate situations that do not or not yet exist today in the present study continental climate data calculated from micro and macrofloras using the coexistence approach are analysed in order to compare past gradients and patterns and their anomalies relative to present day conditions with future climate change scenarios for the case study three time intervals are selected the mid eocene represents a very warm period of the cenozoic exemplifying greenhouse conditions with high atmospheric co 2 of over 1 100 ppmv the mid miocene is known as outstanding warm time interval as well the concentration of greenhouse gases is still controversially discussed but was certainly below the eocene level a third interval selected the tortonian represents a time span of subsequent cooling with the beginning of arctic glaciation for this period a pre industrial co 2 level is assumed it is shown that the study of past climate patterns provides important clues when evaluating modelling results for future scenarios anomalies predicted under global warming partly coincide with the palaeoclimate data sets as an example for greenhouse conditions the mid eocene data also show a strong warming of the high latitudes and a significant positive anomaly of winter temperatures in the continental interior as in the model study for the future scenario however for the tortonian where a pre industrial co 2 can be assumed data show the best agreement with predicted patterns

late miocene to early pliocene chronostratigraphic framework for the dacic basin romania abstract new magnetostratigraphic results and calcareous nannofossil data of seven sections in the dacic basin of southern romania covering the latest maeotian to early romanian time span 6 4 4 0 ma allow a correlation with the current astronomical polarity time scale this establishes a chronological framework for the pontian and dacian stages of the paratethys and facilitates to correlate the paratethys stages with those of the mediterranean the maeotian pontian boundary is estimated at 6 15 0 11 ma within subchron c3an 1n while the age of the pontian dacian boundary is 5 30 0 1 ma within subchron c3r the odessian portaferrian and portaferrian bosphorian substage boundaries can be placed at about 6 0 and 5 6 ma at the base and near the end of chron c3r respectively consequently the pontian stage has a duration of approximately 0 85 myr and is coeval with the upper half of the messinian stage the base of the dacian stage corresponds to the onset of the pliocene and is coeval with the pontian kimmerian boundary of the euxinic black sea basin the dacian romanian boundary is recorded either at 4 58 0 05 ma in subchron c3n 2n nunivak or at 4 25 0 05 ma in subchron c3n 1n cochiti the length of the dacian stage is therefore about 0 7 myr or approximately 1 ma the transition of the getian into the parscovian substage can be dated at 4 83 ma within subchron c3n 3n sidufjall or at 4 55 ma within subchron c3n 2n nunivak the occurrence of calcareous nannofossil assemblages in the lower portaferrian and near the portaferrian bosphorian transition belonging to the upper part of the discoaster quinqueramus nn11 zone and in the middle bosphorian belonging to the amaurolithus tricorniculatus nn12 zone indicates the presence of ephemeral marine connections between the paratethys basin and the mediterranean during the late messinian another marine influx inferred from nannofossil species characteristic of the nn12 zone and found in lower dacian sediments near the top of subchron c3n 4n thvera post dates the basal pliocene transgression of the mediterranean basin

growth of subtropical forests in miocene europe the roles of carbon dioxide and antarctic ice volume the middle miocene is a crucial period for the evolution of apes and it corresponds to their appearance in europe the dispersion of apes was made possible by tectonic changes and the expansion of their habitat sub tropical forest in europe the context in which the middle miocene climatic optimum occurred still lacks constraints in terms of atmospheric p co 2 and ice sheet volume and extent using a coupled atmosphere ocean general circulation model gcm and dynamic vegetation model we investigated the sensitivity of miocene climate and vegetation to p co 2 levels and antarctic ice sheet configurations our results indicate that higher than present p co 2 is necessary to simulate subtropical forest in western and central europe during the middle miocene but that a threshold at high p co 2 makes subtropical forest partly collapse moreover removing ice over antarctica modifies oceanic circulation and induces warmer and slightly wetter conditions in europe which are consistent with the expansion of subtropical forest these results suggest that a small east antarctic ice sheet 25 of present day ice volume together with higher than present p co 2 values are in better agreement with available european middle miocene data

surface subsurface flow modeling with path based runoff routing boundary condition based coupling and assimilation of multisource observation data received 21 october 2008 revised 2 september 2009 accepted 16 september 2009 published 13 february 2010 1 a distributed physically based model incorporating novel approaches for the representation of surface subsurface processes and interactions is presented a path based description of surface flow across the drainage basin is used with several options for identifying flow directions for separating channel cells from hillslope cells and for representing stream channel hydraulic geometry lakes and other topographic depressions are identified and specially treated as part of the preprocessing procedures applied to the digital elevation data for the catchment threshold based boundary condition switching is used to partition potential atmospheric fluxes into actual fluxes across the land surface and changes in surface storage thus resolving the exchange fluxes or coupling between the surface and subsurface modules nested time stepping allows smaller steps to be taken for typically faster and explicitly solved surface runoff routing while a mesh coarsening option allows larger grid elements to be used for typically slower and more compute intensive subsurface flow sequential data assimilation schemes allow the model predictions to be updated with spatiotemporal observation data of surface and subsurface variables these approaches are discussed in detail and the physical and numerical behavior of the model is illustrated over catchment scales ranging from 0 0027 to 356 km 2 addressing different hydrological processes and highlighting the importance of describing coupled surfacesubsurface flow

centennial to decadal scale environmental shifts in and around lake pannon vienna basin related to a major late miocene lake level rise a detailed ultra high resolution analysis of a 37 cm long core of upper miocene lake sediments of the long lived lake pannon has been performed despite a general stable climate at c 11 9 ma several high frequency oscillations of the paleoenvironments and depositional environments are revealed by the analysis over a short time span of less than 1000 years shifts of the lake level associated with one major 3rd order flooding are reflected by all organisms by a cascade of environmental changes on a decadal scale within a few decades the pollen record documents shifting vegetation zones due to the landward migration of the coast the dinoflagellate assemblages switch towards offshore type due to the increasing distance to the shore the benthos is affected by low oxygen conditions due to the deepening this general trend is interrupted by smaller scale cycles which lack this tight interconnection especially the pollen data document a clear cyclicity that is expressed by iterative low pollen concentration events these negative cycles are partly reflected by dinoflagellate blooms suggesting a common trigger mechanism and a connection between terrestrial environments and surface waters of lake pannon the benthic fauna of the core however does not reflect these surface water cycles this forcing mechanism is not understood yet but periodic climatic fluctuations are favoured as hypothesis instead of further lake level changes short phases of low precipitation reducing pollen production and suppressing effective transport by local streams might be a plausible mechanism this study is the first hint towards solar activity related high frequency climate changes during the vallesian late miocene around lake pannon and should encourage further ultra high resolution analyses in the area

determining the mean large scale circulation of the atlantic with the adjoint method abstract a new model approach based on the adjoint formalism and aimed at assimilating large sets of hydrographic data is presented the goal of the model calculations is to obtain the mean large scale ocean circulation together with coefficients of iso and diapycnal mixing and air sea heat and freshwater fluxes the final optimal solution is required to be consistent with the principle of geostrophy and must predict realistic distributions of temperature and salinity the model covers the entire atlantic and has realistic topography model resolution is nonuniform and ranges from 2 5 to 10 horizontally and from 60 m to 500 m in the vertical model velocities are initialized with geostrophic flows calculated from original hydrographic station data initial air sea heat fluxes and mixing coefficients are taken from the literature mass heat and salt budgets are satisfied exactly and for given boundary conditions and model flows the model temperature and salinity distributions are calculated then h

dynamic coupling of a three dimensional hydrodynamic model with a laterally averaged two dimensional hydrodynamic model 1 an efficient method to dynamically couple a three dimensional 3d hydrodynamic model with a laterally averaged two dimensional 2dv hydrodynamic model is described the method is a useful tool to incorporate narrow tributaries that have vertically 2d flow patterns into a three dimensional hydrodynamic simulation for a shallow and large water body that has a 3d flow pattern the coupling of the two models is facilitated with a free surface correction fsc method that is unconditionally stable with respect to gravity waves wind and bottom shear stresses and vertical eddy viscosity terms the coupled model solves laterally averaged 2dv reynolds averaged navier stokes rans equations for the narrow tributaries and three dimensional rans equations for the larger water body the coupled 3d 2dv model was used to simulate hydrodynamics and salinity transport processes in an idealized estuary with a large water body and two narrow tributaries in the 3d 2dv simulation the entire simulation domain was split into one 3d subdomain and two 2dv subdomains to illustrate the efficiency of the coupled 3d 2dv model a 3d simulation was also conducted for the entire simulation domain it was found that the coupled 3d 2dv model can generate the same model results as those by the 3d model but uses less than half of the computer time of the 3d simulation for this particular case an application of the coupled 3d 2dv model to the lower peace river upper charlotte harbor lpr uch system in southwest florida usa shows that the dynamically coupled model retains the efficiency of both the 3d model and the 2dv model

delineation of recharge rate from a hybrid water table fluctuation method 1 the concept of the hybrid water table fluctuation wtf method for recharge rate estimation was revisited to estimate the recharge rate a physically based wtf equation was established the concept of transient fillable porosity was proposed and computed with unsaturated hydraulics models the developed model is tested by applying to the water table fluctuation data from hongcheon korea in the applications the recharge and fillable porosity estimates were found to be most sensitive to nonlinearity in the unsaturated water content profile and permeability also the water table level drift which does not originate from precipitation serves as a major source of estimation error

estuarine flocs their size settling velocity and density the size and settling velocity of flocs of suspended sediments from the chesapeake bay were measured in laboratory experiments and in the field the curves between floc diameter and settling velocity showed a non stoke s relationship that was best described by the following settling velocity cm s 1 73 floc diameter cm 0 78 furthermore the relationship between floc diameter and settling velocity indicated that the floe density decreased as the floes increased in size in addition to changing density a cylinder shape was found to be the best shape factor