sequence stratigraphy in a mixed carbonate silicilastic depositional system middle miocene styrian basin austria the mixed carbonate siliciclastic weisenegg allo formation records three depositional sequences corresponding approximately to the tb 2 3 tb 2 4 and tb 2 5 global cycles sea level fluctuations were of the order of at least 30 m siliciclastic lowstand systems tracts comprise lignite deposits reworked basement and tidal siltstones above a tectonically enhanced sequence boundary as well as coastal sand bars coastal sands of the transgressive systems tract contain distinct layers of well cemented nodules they are interpreted as the first stage in hardground formation and record superimposed minor sea level fluctuations coral patch reefs and rhodolith platforms developed during transgressive phases and were subsequently drowned and or suffocated by siliciclastics during early highstand shallowing upwards siliciclastic parasequences each terminated by a bank of rhodolith limestone form the late highstand systems tract the limestone beds record superimposed fourth order transgressive pulses occasionally a carbonate highstand wedge developed lowstand carbonate shedding occurred where the top of a platform which suffered incipient drowning during highstand was near sealevel again during the following lowstand late highstand delta progradation is common

middle miocene ocean climate transition high resolution oxygen and carbon isotopic records from deep sea drilling project site 588a southwest pacific high resolution stable isotopic records are presented for the epi benthic foraminifer cibicidoides the inferred shallow dwelling planktonic globigerinoides quadrilobatus and the inferred deep dwelling planktonic globoquadrina dehiscens from the middle miocene 16 12 ma of deep sea drilling project site 588a lord howe rise southwest pacific high resolution multiple species oxygen and carbon isotopic data define the timing and character of the well known middle miocene climatic oceanographic transition with a resolution comparable to quaternary records the benthic foraminiferal 18o record is marked by several large fluctuations from 16 to 14 8 ma followed by a series of rapid 50 kyr 18o increases that suggest a new state of the ocean climate system after 14 8 ma the total middle miocene benthic oxygen isotopic increase of 1 2 is largely incorporated in two steps an increase of 0 8 from 14 5 to 14 0 ma and a second increase of 0 7 from 13 45 to 12 45 ma each step is comprised of a series of marked 18o increases indicative of rapid east antarctic ice sheet growth and contemporaneous deepwater cooling a strong covariance of 0 7 between the benthic and deep dwelling planktonic species from 14 5 to 14 0 ma including a rapid increase from 14 1 to 14 05 ma suggests a 0 7 increase in the 18o composition of seawater 18osw because of east antarctic ice sheet growth comparison of the 18o record of gs quadrilobatus suggests that surface waters warmed at this site by 3 c from 14 1 to 13 6 ma carbon isotopic time series for each species generally covary throughout the early to middle miocene interval 16 12 ma confirming that 13c variations in this interval largely represent reservoir changes high resolution 13c data allow improved resolution of the latter five of six 13c maxima within the well known early to middle miocene carbon isotopic excursion the monterey carbon isotopic excursion from 17 0 to 13 5 ma this is useful for global correlation the last of these maxima ends with a 1 decrease centered from 13 9 to 13 7 ma 300 kyr after the 18o increase considered to reflect east antarctic ice growth covariance between benthic 18o and 13c from 16 to 13 8 ma suggests a sensitive relation between global carbon cycling and the ocean climate system prior to 13 8 ma episodic increases in organic carbon burial may have contributed to deep sea benthic 13c maxima and synchronous global cooling the positive relationship ended at 13 8 ma indicative of changing relations between global carbon cycling and the ocean climate system brought on by the increased stability of the east antarctic ice sheet after a major growth phase from 14 5 to 14 0 ma

aturia from the miocene paratethys an exceptional window on nautilid habitat and lifestyle many examples of drifted aturia shells in shallow littoral deposits have been reported worldwide suggesting that the paleobiogeographic distribution of this cenozoic nautilid could be a mere post mortem artifact an exceptional lower miocene deposit from the central paratethys yields abundant about 500 specimens and very well preserved newly hatched as well as adult shells associated with upper and lower jaws representing the first unequivocal case of autochthonous aturia and one of the most exceptional nautilid deposits reported so far oxygen isotope ratios show that aturia lived like nautilus being nektobenthic at all stages of its development but unlike nautilus both newly hatched and adult aturia lived at the same water depth and temperature about 240 330 m and 13 17 6 degrees c in which the eggs were laid the dysoxic paleoenvironmental setting in which aturia occurs in abundance may be interpreted in light of both the capacity of nautilus to exploit tolerate oxygen depleted waters and the molecular phylogenetic tree of cephalopods suggesting plesiomorphic physiological traits associated with hypoxia tolerance since the last common ancestor of aturia and nautilus may be traced back at least into the jurassic this sheds new light onto the relative scarcity of mesozoic and cenozoic nautilids in well oxygenated epicontinental shelf deposits c 2011 elsevier b v all rights reserved

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

middle miocene southern ocean cooling and antarctic cryosphere expansion magnesium calcium data from southern ocean planktonic foraminifera demonstrate that high latitude similar to55degreess southwest pacific sea surface temperatures ssts cooled 6degrees to 7degreesc during the middle miocene climate transition 14 2 to 13 8 million years ago stepwise surface cooling is paced by eccentricity forcing and precedes antarctic cryosphere expansion by similar to60 thousand years suggesting the involvement of additional feedbacks during this interval of inferred low atmospheric partial pressure of co2 pco 2 comparing ssts and global carbon cycling proxies challenges the notion that episodic pco2 drawdown drove this major cenozoic climate transition sst salinity and ice volume trends suggest instead that orbitally paced ocean circulation changes altered meridional heat vapor transport triggering ice growth and global cooling

unusual braarudosphaera bigelowii and micrantholithus vesper enrichment in the early miocene sediments from the slovenian corridor a seaway linking the central paratethys and the mediterranean abstract during a stratigraphic survey of an early miocene sedimentary sequence outcropping in se slovenia an unusual enrichment of the calcareous nannoplankton assemblage with pentaliths pentagonal nannoliths consisting of five crystal units and showing radial symmetry was detected pentaliths were only abundant in a short interval which was sampled in detail the lithological composition of this interval was indistinguishable from that of the underlying and the overlying strata the composition of nannoplankton assemblages and distribution patterns of different taxa were studied mineral composition total calcite content and 13c values of chosen sediment samples were analysed as well the pentalith enriched strata were deposited in the lower early miocene corresponding to the egerian stage of the central paratethys and the aquitanian of the mediterranean in the slovenian corridor a seaway linking the central paratethys and the mediterranean the presence of rare specimens of discoaster druggii and helicosphaera carteri allows stratigraphic correlation with the transition of nn1 triquetrorhabdulus carinatus zone and nn2 discoaster druggii zone of martini martini e 1971 standard tertiary and quarternary calcareous nannoplankton zonation in farinacci a ed proceedings of the ii planctonic conference roma 1970 ed technoscienza pp 739 785 pentaliths belong to two species braarudosphaera bigelowii and micrantholithus vesper both species display a wide range of morphological variation and most likely represent a group of sibling species the pattern of distribution of both species displays obvious similarities throughout most of the studied interval in the upper part of the studied interval b bigelowii reaches maximum abundance while m vesper disappears since the ability of b bigelowii to thrive in hyposaline water is well known it appears that m vesper tolerates reduced water salinity as well but to a lesser extent than b bigelowii no significant paleoclimatic and paleogeographical changes are known in this particular region during the early miocene however the onset of far reaching extensional tectonic processes took place during this time the enrichment of nannoplankton assemblage with pentaliths may represent a reflection of a short lived episode of hyposaline conditions enhanced influx of freshwater and terrigenous material is indicated by a drop in 13c values a rise in nannoplankton productivity and the presence of sand in some samples from the pentalith enriched strata the most likely causes of this episode are regional tectonic changes associated with the onset of intensive tectonic activity in the western part of the central paratethys

characterisation of ottnangian middle burdigalian palaeoenvironments in the north alpine foreland basin using benthic foraminifera a review of the upper marine molasse of southern germany abstract considerable facies changes and varying foraminiferal assemblages have been described from the lower miocene sediments of the upper marine molasse in the north alpine foreland basin of southern germany and have resulted in the distinction of a western molasse and eastern molasse however the causes and processes leading to these local differences have largely remained unexplored to date the aim of this study is to explore possible explanations in order to better understand the palaeogeographic stratigraphic and environmental setting the study focuses on the ottnangian middle burdigalian segment of the upper marine molasse in southern germany and includes a review of previously published data together with new data from the borehole stockhausen which is located between the areas of the eastern and western molasse methods include quantitative analysis of benthic foraminiferal assemblages qualitative studies of planktonic foraminifera and calcareous nannoplankton as well as palaeoenvironmental considerations based on the actualistic approach the results of these studies demonstrate that the lower and middle ottnangian upper marine molasse include a single transgressive regressive sedimentary cycle with gradual changes of foraminiferal assemblages in the eastern molasse on the other hand two sedimentation cycles are recognizable in the western molasse and in the borehole stockhausen where the lower and middle ottnangian sediments are separated from one another by an unconformity and display an abrupt change in lithofacies and foraminiferal content the benthic foraminiferal assemblages from the area of the western molasse are indicative of a rather shallow sea but indicative of a much deeper facies in the basin area of the eastern molasse it can therefore be concluded that the shallow sea to the west was more sensitive to minor changes in sea level than the area of the eastern molasse either because of global sea level variation or as a result of regional tectonics this means that the occurrence of two sedimentary cycles in the western molasse and absence of the second cycle in the eastern molasse may be the result of shallower water depths and a lower subsidence rate in the area of the western molasse another interesting result from our studies relates to the sea level highstand and maximum extension of the upper marine molasse sea that based on our studies has occurred during the early ottnangian rather than during the middle ottnangian as suggested previously during this highstand the area of the eastern molasse displays a differentiation into a deep neritic basin facies characterised by high organic flux and moderate oxygen depletion at times and a marginal marine facies with well oxygenated environments the latter facies remained poorly understood until recently the entire region of the south german molasse basin was affected by a regression during the middle ottnangian this phase is characterised by unstable environmental conditions in the eastern molasse i e salinity fluctuations and temporarily strong oxygen depletion of bottom waters in the western molasse life conditions became even worse and as a result a drastic decline in marine life is observable

miocene facies associations and sedimentary evolution of the southern transylvanian basin romania implications for hydrocarbon exploration abstract the transylvanian basin is a mature hydrocarbon province of romania characterized by two petroleum systems mesozoic thermogenic and miocene biogenic an extensive outcrop based sedimentological and micropaleontological study correlated to seismic and well data discusses the elements of the miocene petroleum system the facies associations are indicative of alluvial fandelta shallow and deep marine settings these are grouped into four different depositional systems evaporite mud carbonate sand mud and sand gravel their evolution in time and space shows large differences between various parts of the basin that have important consequences for exploration the transylvanian gas is formed by more than 99 methane of bacterial origin this is sourced by low quality the largest traps typically have multistory up to 20 pay zones with a total of 100 bcf to 1 tcf reserves exploration to date has focused on structural traps but most of the obvious structures have been drilled it is argued that significant exploration potential lies in stratigraphic plays including confined submarine fans slope channels detached lowstand prograding wedges incised valleys diapir flanks salt tectonics related unconformities and various sub volcanic plays risks of the petroleum system elements associated to these plays in different areas of the basin are discussed

paleoenvironmental reconstruction of the early to middle miocene central paratethys using stable isotopes from bryozoan skeletons stable carbon and oxygen isotope values from single bryozoan colonies were used to reconstruct the paleoenvironments of the early to middle miocene ottnangian to badenian sediments of the central paratethys this approach utilizes a locally abundant allochem while avoiding matrix and multiple allochem contamination from bulk rock samples bryozoan colonies and a few foraminifera and rock matrix samples from 14 localities yielded 399 carbon and oxygen isotope values data from six of the localities 15 of the total number of samples were interpreted as having been diagenetically altered and were rejected the remaining data indicate a primarily localized upwelling signal with lesser variation caused by global climatic and regional tectonic forcing of sea level salinity and temperature paleotemperatures were calculated to range from 12 to 21 c despite potential taxonomic and diagenetic problems bryozoan colonies are a powerful underutilized source of paleoenvironmental carbon and oxygen isotope data

palaeoenvironment palaeoclimate and age of the brassington formation miocene of derbyshire uk the brassington formation is the most extensive miocene sedimentary succession onshore in the uk because of its unique position at the margin of nw europe the pollen from this lithostratigraphical unit provides evidence on the development of vegetation affected by north atlantic currents and hypothesized atmospheric circulation changes during the middle to late miocene climate cooling palynostratigraphy suggests that the uppermost kenslow member of the brassington formation is not coeval previously all occurrences of the kenslow member were assumed to be contemporary the oldest pollen assemblage is from the more southern bees nest pit which represents a subtropical conifer dominated forest of late serravallian age c 12 ma a younger assemblage was observed from the more northern kenslow top pit this indicates that a subtropical mixed forest was present during the early tortonian 11 6 9 ma the shift from a conifer dominated to a mixed forest was related to precipitation although the total precipitation did not change between the two assemblages the younger assemblage had more uniform rainfall throughout the year the diachronous nature of the kenslow member means that the depositional model of the brassington formation needs revising and this will have implications for neogene to recent uplift of the southern pennines supplementary material all valid formally defined palynomorph taxa below the generic level that are mentioned in this paper with full author citations are available at http www geolsoc org uk sup18889

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

early middle miocene topographic growth of the northern tibetan plateau stable isotope and sedimentation evidence from the southwestern qaidam basin abstract this study presents facies analysis and carbonate stable isotopic records of a 4435 m thick oligocene middle miocene 30 to 11 ma stratigraphic section from the southwestern qaidam basin which place constraints on the interplay between topographic growth and climatic hydrologic changes in the northern tibetan plateau three types of carbonate including marl limestone pedogenic carbonate and carbonate cement were collected and went through detailed screening for diagenesis carbonate cements are primary early diagenetic carbonates formed in shallow ground water setting the majority of marls limestones and pedogenic carbonates are primary micritic carbonates whereas a few of them showing alterations were sub sampled to avoid diagenetic phases a negative shift in the 18o values of marls limestones and depositional environment change from palustrine to shallow lacustrine associated with paleohydrological change at 20 ma are likely caused by tectonic activity in adjacent ranges around 15 14 ma a decrease of 1 5 in the most negative 18o values of carbonate cements is interpreted to reflect the topographic growth of surrounding mountain ranges i e altun shan east kunlun range this inference is supported by the sedimentary facies change from marginal lacustrine to fluvial that was accompanied by an abrupt increase in sedimentation rate finally a 1 5 positive shift in the most negative 18o values of carbonate cements and pedogenic carbonates enriched 13c values of pedogenic carbonates as well as sedimentary environment change from fluvial to braided river alluvial fan at 13 12 ma most likely reflect a regional aridification event observed over a large area of the central asia this aridification event may have been associated with continued topographic growth of the northern tibetan plateau to a critical elevation to block moisture e g westerlies from penetrating the interior of central asia

use of tidal circulation modeling in paleogeographical studies an example from the tertiary of the alpine perimeter tidal conditions in ancient shallow marine basins as revealed by preserved sedimentary deposits reflect the strong influence of the paleobathymetry use of a tidal circulation model can test existing paleobathymetric reconstructions meso and macrotidal conditions are believed to have existed throughout most of the miocene molasse france and switzerland seaway tidal simulations using external tidal ranges of 2 and 4 m entering from the south mediterranean fail to generate mesotidal conditions in the majority of the seaway because of a narrow constriction in the present alpes du dauphine and drome areas meso tidal conditions are simulated in the rhone alp part of the seaway only after the postulated paleobathymetry is widened in the alpes du dauphine area this change allows tidal penetration from the mediterranean despite this widening the new simulations fail to generate mesotidal conditions in the swiss part of the seaway mesotidal conditions are simulated in switzerland with the addition of a second tidal input from eastern switzerland favoring an interpretation that the swiss part of the seaway was connected with either the eastern mediterranean or the indo pacific ocean the revised paleobathymetry brackets uplift events that affected the basin margin

impact of carbonate producing biota on platform architecture insights from miocene examples of the mediterranean region abstract different types of carbonate platforms formed in the mediterranean during the miocene low angle homoclinal types of ramp distally steepened ramps flat topped platforms and reef rimmed shelves the critical differences between these platforms result from differences in the capacities of the carbonate systems to accumulate sediments above hydrodynamic base level ecologically controlled accommodation the various depositional profiles and facies belt distributions resulted from the interplay between different sediment production and redistribution processes and the internal architectures resulted from the response of each type of platform to changes in accommodation heterogeneities driven by high frequency sea level cycles are maximized in platforms ruled by shallow water euphotic framework dominated production and minimized in low angle ramps where sediment resulted from aphotic and oligophotic carbonate production in the mediterranean region there is no direct relationship between type of platform and global temperature as shown by the coeval occurrence of different platforms in similar latitudinal settings although temperature is a key limiting factor other paleoceanographic factors such as trophic resources may have also been along with biological evolution important factors influencing different types of carbonate producing biotas

three dimensional geological modeling supports a revised burdigalian chronostratigraphy in the north alpine foreland basin precise age data are a basic prerequisite for the correlation of a sedimentary succession with the global time scale which in turn allows one to place its biotic and other data in a global context in the north alpine foreland basin nafb a patchy distribution of outcrops and uncertainties in the correlation of strata have led to conflicting age models in particular for deposits of lower miocene burdigalian age here we present a new three dimensional geological model of the se german sector of the nafb covering an area of 13 200 km2 which helps to resolve the discrepancies the dataset comprises lithostratigraphic information from 150 boreholes supplemented by magnetostratigraphic data from six outcrops computer based 3d modeling was conducted with the open source software qgis for a 500 m thick succession comprising units of the upper marine molasse the brackish oncophora fm and the upper freshwater molasse the results provide new insights pertaining to 1 the isochrony of strata 2 subsidence and 3 synsedimentary tectonics the new data permit us to reliably place the outcrops within the regional lithostratigraphic scheme thus enabling a new correlation of their magnetic polarities with the global time scale on this basis we propose a revised age model for the middle and upper burdigalian strata in the eastern part of the nafb which is supported by previously reported 87sr 86sr age data the model indicates that the succession is substantially up to 0 8 ma younger than earlier publications have suggested furthermore it implies that the two synsedimentary tectonic events discerned may both be related to the large scale tectonic movements that affected the nafb during the late burdigalian

middle miocene seasonal temperature changes in the styrian basin austria as recorded by the isotopic composition of pectinid and brachiopod shells abstract using the isotope record on pectinid and brachiopod shells we reconstructed middle miocene palaeotemperatures for a shelf environment in the styrian basin austria bivalve shells of macrochlamys sp collected from different horizons of the lower badenian leitha limestone show 18 o values in the range of 3 to 0 peedee belemnite the large intrashell variability of 3 indicates significant seawater temperature fluctuation the results suggest that despite the high geographical latitude ca 40 n the climate in southern austria was warm subtropical with a pronounced seasonality at that time in contrast the 18 o isotopic composition of a pectinid flabellipecten sp and an indeterminate terebratulid brachiopod from the siliciclastic deposits overlying the leitha limestone ranges between 0 and 1 this indicates cooler mean annual temperatures and reduced seasonal variations a 39 ar 40 ar age on fresh volcanic biotites shows a value of 14 2 0 1 ma the tuffs containing the biotites are located below the layer containing the terebratulid and the flabellipecten sp the stable isotope and radiogenic data suggest that the drop in temperature is in direct relationship with the east antarctic ice sheet expansion which started at ca 14 ma due to the variation in temperature the subtropical fauna in the retznei quarry disappeared during the early miocene and the biogenic limestones were replaced by clastic sediments the 18 o isotopic profiles from three pectinids collected from the leitha limestone indicate that these grew within ca 1 5 years growth interruptions occurred during the warm season because during this period the pectinids very likely used their energy for the growth and maturation of gonads carbon isotopic compositions vary between 0 and 2 statistical tests show that for some of the analyzed shells the cyclicity of the 13 c profiles may be explained by the temperature dependent fractionation between air co 2 and dissolved bicarbonate

age of the badenian salinity crisis impact of miocene climate variability on the circum mediterranean region massive evaporites were deposited in the central european paratethys sea during the badenian salinity crisis bsc the scarcity of absolute age data has hampered a thorough understanding of these salt deposits here we present a robust chronology for this catastrophic event by 40 ar 39 ar dating of volcanic tuffs below and within the badenian salts in southern poland the onset of bsc evaporite deposition is dated at 13 81 0 08 ma and the entire event is estimated to have lasted 200 600 k y correlation to oxygen isotope records shows that the bsc evaporites were just preceded by glacial event mi 3b suggesting a causal relationship the corresponding sea level fall most likely restricted the open marine connection to the mediterranean thereby trapping the salt in the deep paratethys basins

time calibration of sedimentary sections based on insolation cycles using combined cross correlation dating the gone badenian stratotype middle miocene paratethys vienna basin austria as an example cross correlation between insolation intensities and a combination of sedimentary characters is introduced to obtain precise time calibration of sedimentary cycles the first step is to transfer the section scale into ages using power spectra comparing the main periods with orbital cycles while in the second step the standardized values of sedimentary signals are cross correlated with the standardized insolation curve as an example for the applicability of the method we investigated calcium carbonate organic carbon in a 9 m sampled section from the historical badenian stratotype at baden sooss lower austria comparing courses of geochemical parameters between the historical stratotype and a nearby drilled 102 m scientific core resulted in continuation of the core section into the stratotype cross correlation between magnetic susceptibility ms combined with the negatively correlated calcium carbonate content of the drilled section on the one side and summer solar insolation at 65 northern latitude on the other resulted in an extremely significant correlation between 14 221 and 13 982 ma this is younger than the before estimated time frame 14 379 to 14 142 ma based on cross correlation between ms and the orbital 100 kyr eccentricity and 41 kyr obliquity cycles the direct continuation of the drilled section by the stratotype covering a time span of 17 7 kyr consequently dates the badenian stratotype between 13 982 and 13 964 ma therefore the upper limit of the stratotype assigned to the early badenian puts it close to the langhian seravallian boundary at 13 82 ma demonstrating the need for revising the badenian stratigraphic subdivision based on orbital cycles especially the middle badenian wielician substage

changing seas in the early middle miocene of central europe a mediterranean approach to paratethyan stratigraphy the miocene palaeogeographic evolution of the paratethys sea is still poorly constrained here we use modern mediterranean biochronology to provide an up to date overview of changing seas in central europe instead of a paratethys sea that waxed and waned with fluctuating global sea level we show that the evolution of different seas was mainly controlled by tectonic phases the early miocene ottnangian sea 18 ma was connected to the mediterranean via the rhone valley while the karpatian sea 16 5 ma was initiated by a tectonically induced marine transgression through the trans tethyan gateway in most central european basins the establishment of the badenian sea 15 2 ma triggered by subduction related processes in the pannonian and carpathian domain is significantly younger by 1 myr than usually estimated the updated palaeogeographic reconstructions provide a better understanding of the concepts of basin dynamics land sea distribution and palaeoenvironmental change in the miocene of central europe this article is protected by copyright all rights reserved

paleogeographic evolution of the late miocene lake pannon in central europe abstract the paleogeographic evolution of lake pannon within the pannonian basin is reconstructed with eight maps ranging from the middle miocene to the early pliocene the maps are based on the distribution of selected biozones and specific fossils and on complementary sedimentological and seismic information our reconstruction shows that the history of lake pannon can be divided into three distinct intervals an initial stage with low water level which resulted in isolation from the sea at about 12 ma and might have led to temporary fragmentation of the lake an interval of gradual transgression lasting until ca 9 5 ma and a long late interval of shrinkage and infilling of sediments that persisted into the early pliocene the deep subbasins of the lake formed during the transgressive interval in more basinward locations than the deep basins of the preceding sarmatian age the southern shoreline running parallel with the sava and danube rivers along the northern foot of the dinarides changed very little during the lifetime of the lake while the northern shoreline underwent profound changes

millennial scale vegetation dynamics in an estuary at the onset of the miocene climate optimum article i nfo pollen analyses have been proven to possess the possibility to decipher rapid vegetational and climate shifts in neogene sedimentary records herein a c 21 kyr long transgression regression cycle from the lower austrian locality stetten is analysed in detail to evaluate climatic benchmarks for the early phase of the middle miocene climate optimum and to estimate the pace of environmental change based on the coexistence approach a very clear signal of seasonality can be reconstructed a warm and wet summer season with c 204 236 mm precipitation during the wettest month was opposed by a rather dry winter season with precipitation of c 9 24 mm during the driest month the mean annual temperature ranged between 15 7 and 20 8 c with about 9 6 13 3 c during the cold season and 24 7 27 9 c during the warmest month in contrast today s climate of this area with an annual temperature of 9 8 c and 660 mm rainfall is characterized by the winter season mean temperature 1 4 c mean precipitation 39 mm and a summer mean temperature of 19 9 c mean precipitation 84 mm different modes of environmental shifts shaped the composition of the vegetation within few millennia marshes and salt marshes with abundant cyperaceae rapidly graded into taxodiaceae swamps this quick but gradual process was interrupted by swift marine ingressions which took place on a decadal to centennial scale the transgression is accompanied by blooms of dinoflagellates and of the green alga prasinophyta and an increase in abies and picea afterwards the retreat of the sea and the progradation of estuarine and wetland settings were a gradual progress again despite a clear sedimentological cyclicity which is related to the 21 kyr precessional forcing the climate data show little variation this missing pattern might be due to the buffering of the precessional related climate signal by the subtropical vegetation another explanation could be the method inherent broad range of climate parameter estimates that could cover small scale climatic changes

late early miocene palaeoenvironmental changes in the north alpine foreland basin abstract the north alpine foreland basin nafb experienced rapidly changing palaeoenvironmental conditions at the end of the early miocene middle to late burdigalian paratethys stages ottnangian and karpatian with transformation of fully marine settings into brackish and eventually freshwater environments these changes were related to global sea level fluctuations climate oscillations and tectonic processes associated with the uplift of the alps this study presents a new and comprehensive data set derived from 13 boreholes and 491 core samples from the molasse basin of southwest germany that provides a significantly better understanding of late early miocene palaeoenvironments in the nafb based on lithostratigraphy biostratigraphy and palaeoecological interpretation of rich fauna and flora assemblages we show that the upper burdigalian sediments comprise a regressive lower segment grimmelfingen formation and equivalents as indicated by the occurrence of the bivalve rzehakia and a transgressive upper component kirchberg formation and equivalents characterized by the advent of new fish and mollusc assemblages furthermore we present a new lithostratigraphic concept for the kirchberg formation which forms an important part of the upper brackish molasse obm based on biostratigraphic constraints and recently published magnetostratigraphic data it appears that the regressive segment of the upper burdigalian obm sediments correlates with the end of the global third order sea level cycle bur 3 while the transgressive component reflects the karpatian transgression at the beginning of sea level cycle bur 4 this implies that the karpatian transgression actually affected the molasse basin of southern germany and upper austria whereas previous studies had considered this part of the nafb as terrestrial during that time span the new results are depicted in three palaeogeographic maps for the nafb at 18 ma 17 5 17 1 ma and 17 ma respectively

the pannonian c hipparions from the vienna basin abstract the hipparion datum has been recognized as being a key geochronologic marker for early late miocene eurasian and african horizons the vienna basin pannonian c hipparions are the stratigraphically oldest basal mn9 ca 11 4 11 0 ma and we contend herein the most primitive of all old world hipparions we evaluate the stratigraphic context cheek tooth morphological characters paleodietary and paleoenvironmental context of the three pannonian c hipparion assemblages from gaiselberg atzelsdorf and mariathal austria we find that the gaiselberg and atzelsdorf are slightly more primitive than the mariathal hipparion assemblage and refer the first two assemblages to hippotherium sp while the mariathal assemblage is referred to hippotherium aff primigenium exhibiting some advanced characters that presage austrian and german later vallesian age we review the chronology and biogeography of the old world hipparion datum and evolutionary relationships of first occurring european west and south asian and north african hipparion to north american cormohipparion we evaluate and expand upon earlier paleodietary studies of pannonian c hipparions and determine that they were browser dominant mixed opportunistic feeders

cenozoic exhumation of the internal zagros first constraints from low temperature thermochronology and implications for the build up of the iranian plateau the iranian plateau is a flat 1 5 2 km high plateau thought to result from the collision between the arabian and eurasian plates since 30 5 ma and may represent a young analogue to the so far better studied tibetan plateau in order to constrain the exhumation history of the internal zagros and of the iranian plateau we herein present apatite u th he ahe and apatite aft and zircon fission track zft data on plutonic rocks from the sanandaj sirjan zone ssz urumieh dokhtar magmatic arc udma central iran and kopet dagh thermochronologic data show that the ssz was exhumed early in the collision process essentially before 25 20 ma with a likely acceleration of cooling during the late eocene from 0 04 to 0 3 mm year results suggest that cooling of the internal zagros migrated from the ssz to the udma during a more mature stage of the continental collision after 17 ma i e coeval with the outward propagation of deformation and topography fronts in the external zagros constant exhumation rates in the udma 0 3 mm year suggest that no significant variation of erosion rates occurred since the onset of continental collision in central iran the overlap of zft aft and ahe ages from gneissic samples points to rapid cooling during the late eocene 42 c myr which is consistent with previous reports on the formation of eocene metamorphic core complexes

badenian sarmatian chronostratigraphy in the polish carpathian foredeep abstract the miocene of the northern part of the polish carpathian foredeep contains a record of events particularly important in the evolution of the central paratethys basin there the paratethyan badenian salinity crisis resulted in the deposition of evaporite gypsum deposits of the krzyzanowice formation the ensuing post evaporite marine badenian deposition is recorded by the marly pecten beds the transition to the overlying clays of the syndesmya beds represents the initial deterioration of normal marine conditions within the basin and is associated with the disappearance of typical stenohaline faunal components during the badenian sarmatian extinction event and the subsequent appearance of endemic sarmatian taxa the history of these paratethyan events has hitherto been only poorly dated new 40ar 39ar dating of biotite and volcanic glass from a rhyolite tuff within the pecten beds babczyn 2 core constrains its depositional age to 13 06 0 11 ma this age suggests that the faunal extinction presumably took place after 13 06 0 11 ma and that the salinity crisis ended before then this result is consistent with other reliable radiometric age constraints that collectively suggest that the crisis began shortly after 13 81 0 08 ma de leeuw et al 2010 and that evaporite deposition took place ca 13 60 0 07 ma de leeuw et al 2010 both the badenian evaporites and the pecten beds in carpathian foredeep are thus serravallian in age and represent the lower part of neogene nannoplankton zone 6 nn 6

climate changes in the early to middle miocene of the central paratethys and the origin of its echinoderm fauna abstract this study uses echinoderm diversity to assess climatic changes in the early to middle miocene of the central paratethys it is based mainly on a taxonomically standardised dataset of central paratethys echinoids supplemented by data on asteroid ophiuroid crinoid and holothuroid distributions potential constraints of the raw diversity data are explored and possible biases are identified these include a heterogeneous rock record in terms of outcrop area and facies of the preserved sedimentary rocks stage duration and sampling bias the latter was overcome by utilising rarefaction analysis to investigate species richness these analyses show that the patterns observed in the raw data are robust and not severely biased by sampling intensity the potential influence of a heterogeneous rock record was assessed by comparing surface outcrop areas of the various stages to standing diversity a second bias involving a heterogeneous rock record the non preservation of distinct habitats was overcome by carrying out within habitat comparison of standing diversity and faunal composition the observed patterns were therefore established as true signals rather than artefacts produced by various biases consequently echinoderm diversity is used to evaluate climate changes during the neogene of the central paratethys as well as to interpret minimum winter and summer sea surface temperatures in the badenian middle miocene climatic conditions during the deposition of the badenian leitha limestone were addressed along with the presence of n s gradients within the central paratethys the presently available data suggest warm temperate conditions for the late eggenburgian early burdigalian followed by a brief temperature drop in the ottnangian early late burdigalian temperatures increased again in the karpatian and a climatic optimum was reached in the early badenian a slight cooling during the middle badenian was reflected by the southwards shift of predominantly temperate genera from the northern fringes of the central paratethys in the early badenian to the central parts in the late badenian the faunal gradients observed in the early badenian of the central paratethys suggest that the boundary between the warm temperate and tropical zone lay somewhere within the paratethys at that time considering the more southerly position of the study area about 34 palaeolatitude in the early middle miocene this implies that the tropical climate zone was much wider during the early middle miocene than today biogeographic investigations of the central paratethyan echinoid faunas show that the overwhelming part of the central paratethys echinoid species are immigrants from the mediterranean area immigration occurred in three distinct waves during the late eggenburgian the karpatian and early badenian while no common echinoid species were identified between the boreal region and the central paratethys two species of asteroids from the northern most fringes of the central paratethys also occur in the north sea basin endemism is low in most of the stages except for the ottnangian when geodynamic processes and global cooling resulted in a large scale re organisation of central paratethyan faunas

pleistocene environmental dynamics recorded in the loess of the middle and lower danube basin abstract the substantial loess deposits of the middle and lower danube basin in southeastern europe represent one of the thickest and most comprehensive terrestrial palaeoenvironmental records on the continent yet are also the least well understood environmental conditions over the last million years have resulted in relatively continuous deposits uninterrupted by glaciation and tundra conditions which nevertheless reflect oscillations between relatively warm humid interglacial and cold dry glacial intervals this relative environmental stability may have proven important for hominins migrating into and through the region the loess stratigraphy comprises distinct loess paleosol sequences reflecting glacial interglacial phases which can be quantified for intensity using environmental magnetism and geochemistry these phases are emphasised by variations in vegetation and malacofauna which respond to climatic change the loess deposits demonstrate broadly similar sedimentological characteristics across the basin danubian loess deposits initiated in response to the tectonic formation of the pannonian basin retreat of the large palaeolakes and increased sediment supply from the danube the period from 1 ma 500 ka mis 27 13 was characterised by alternating loess deposition and pedogenesis during glacial and interglacial periods respectively in response to relatively humid forested conditions this period represents the opening of the danube corridor and provides the backdrop for initial hominin arrival into europe after 500 ka and particularly after mis 9 loess accumulation rates increased in response to relatively more steppic arid environments mis 9 and 13 15 were the most humid phases of the last 600 ky the mis 5 interglacial period was the warmest and relatively most humid period preceding the holocene and was followed by substantially increased loess accumulation during mis 4 which may be linked to north atlantic circulation the complexity of the mis 3 interstadial paleosol suggests that conditions were not uniformly warm and wet during this time mis 3 corresponds with the first arrival of anatomically modern humans to europe the last glacial maximum and younger dryas of mis 2 were characterised by substantially increased loess accumulation indicating cold steppe environments most likely influenced by the north atlantic although conditions were sufficiently mild that the region acted as a refugium for thermophilic biota as may also have been the case for most of the pleistocene glacial cycles the holocene soil represents relatively wamer and more humid conditions corresponding to the current interglacial

coralline algae corallinales rhodophyta in western and central mediterranean messinian reefs abstract coralline algae are common components in messinian reefs in the sorbas basin in se spain and in the salento peninsula southern italy they occur encrusting coral skeletons and other bioclasts forming rhodoliths and as fragments in back reef reef framework and proximal to middle slope facies corallines also occur in halimeda boundstones associated to coral reefs in contrast no coralline algae have been recorded in the fine grained distal slope deposits in both areas and in lagoonal marly limestones in salento the relative abundance of corallines in reefs and their species richness is significantly higher in the salento platform than in the intermontane sorbas basin which was affected by terrigenous influx neogoniolithon brassica florida and spongites fruticulosus dominate the shallow water assemblages lithophyllum records peak at the base of reef core and upper slope deposits around 20 m palaeodepth and phymatolithon calcareum and species of lithothamnion are most abundant in deeper slope facies the main components of the messinian mediterranean reef coralline assemblages are extant species common in the mediterranean and along the north atlantic coast from morocco and the canary islands to the british islands a few such as spongites fruticulosus and phymatolithon calcareum have been living in the mediterranean region for more than 25 ma four species still live in the indo pacific but disappeared from the mediterranean during the messinian salinity crisis the typical components of present day indo pacific coral reefs do not occur in the mediterranean messinian reefs the mediterranean atlantic character of the messinian reef corallines reflects the decrease in tropical biotas in the mediterranean throughout the miocene probably related to global cooling and isolation of the mediterranean from the indian ocean since the middle miocene

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

graphite and quartz petrofabrics examples from the ediacaran black quartzites of the ossa morena zone sw iberia abstract we study with the electron back scattered diffraction ebsd technique the fabric of metamorphosed and ductilely deformed phtanites or graphitic cherts a common lithotype in ediacaran supracrustals of the west european cadomian orogen currently they are black quartzites with a planolinear tectonite structure microscopically they present a sub mm scale alternation of coarse and fine grained dynamically recrystallized quartz bands we attribute intracrystalline plasticity partitioning to variations in graphite inclusion concentration constraining quartz grain boundary mobility during dynamic recrystallization under non coaxial strain regimes and moderate to elevated temperatures 400 650 c lattice preferred orientations of quartz c and axes are geometrically related to the external reference frame provided by foliations and lineations we also identify the involvement of 0001 r m and m c quartz intracrystalline slip systems deformation modes operated simultaneously and under identical temperatures in interleaved parallel domains mm to cm thick in adjacent coarse and fine grained bands medium to high t plasticity is congruent with the syntectonic temperature gradients associated with the amphibolite facies metamorphism of the country rocks we also present the first specific study published so far on natural deformation graphite lattice preferred orientation graphite inclusions as well as those of mica exhibit mineral shape fabrics that suggest operation of 0001 slip however ebsd measurements also record fabrics suggestive of m slip in spite of a rather small volumetric proportion graphite spatial organization at increased shear strains facilitated ductile deformation if a graphite network is established in the rock it can potentially increase rock electrical conductivity thus accounting for mid and lower crust anomalous electric conductivity

biotic and abiotic response to palaeoenvironmental changes at lake pannons western margin central europe late miocene a multidisciplinary study was performed on a c 30 m thick limnic deltaic sequence in the styrian basin austria geophysical gamma ray activity rock magnetism geochemical organic carbon sulphur and sedimentological observations were combined with palaeontological information mainly ostracods on this base several ecological factors were deduced terrigenous influx salinity water depth and oxygenation based on integrated stratigraphy as well as on palaeomagnetic results the whole section is set to chron c5r 2r 1n 11 308 11 263 ma and covers a period of less than 45 kyr in addition to the long term record we analysed short term changes by high resolution sampling 5 mm sample interval ostracods magnetic susceptibility this 2 3 m thick interval spans in total 3500 yr with an individual sample resolution of a few years only the combination of these data permit the description of the palaeoenvironmental evolution of the section in detail at the base of the section the development of a conifer swamp on the lakeside of lake pannon is documented this almost freshwater swamp existed for some centuries before it became extinct within a few decades due to a rise of the water table the drowning is related to a transgression of lake pannon which triggered the establishment of a brackish water fauna as well as greigite formation in the lake sediments in general the ongoing transgression favoured benthic life due to increased salinity up to mesohaline conditions the high resolution ostracod and magnetic susceptibility record reflect short term fluctuations in bottom water ventilation these oscillations probably range in the order of centuries and decades and are possibly related to climatic shifts later the successive deepening of the lake resulted in a significant faunal turnover a meromictic system with a well established oxygen depleted hypolimnion developed finally the limnic phase was replaced by a prograding deltaic system where the amplified input of coarse grained material and freshwater also affected benthic life periodic changes in clay illite content were detected by the gamma ray log throughout the entire section the observed cycles 5 12 kyr of the gamma ray log may reflect a super ordinate modulation of the sedimentary record by climatically forced changes in precipitation or run off

intracontinental miocene reconstruction of hydrology and paleoclimate change in the forez basin france part ii sedimentary successions of palustrine deposits from the forez graben recorded changes in depositional and hydrological conditions throughout the middle to late miocene of france paleontological mineralogical and geochemical data combined with mass balance calculation allowed the identification of modern diagenetic and eogenetic stages of authigenic precipitation within the sedimentary pile stratigraphic log contains six clay and sand rich sequences some associated with freshwater ostracods delta c 13 delta o 18 values and sr isotopic ratios of whole rock samples and ostracods indicate that the montrond les bains upper sequence 8 to 175 mbs is a continental lake system that recorded continental weather condition 15 to 25 degrees c during the upper miocene time geochemical changes permit the estimation of variations of evaporation inflow changes e i 8 to 75 and delta o 18 rainfall 6 to 8 parts per thousand associated with two sequences delta o 18 and e i progressive changes were related to runoff to colder climate conditions large e i values in below 100 mbs are associated with the appearance of authigenic calcite and dolomite precipitation euhedral dolomite seems to be related to desiccation period that induced capillary pumping of water undersaturated with respect to calcite but saturated for dolomite the lower part of the middle miocene sedimentary series 175 to 300 mbs hosts continental deposits with scarce fossil a larger proportion of dolomite and massive pyrite levels related to mixed eogenetic and diagenetic precipitation scarce preserved eogenetic levels with unrealistic e i ratios suggest either delta o 18 values similar to the upper section but with temperature lower than 15 c or a similar temperature but very low delta o 18 rainfall calculated delta o 18 h2o values have to be as low as 15 parts per thousand delta o 18 h2o values are similar to present day melted snow this stable isotope suggests episodes of regional warming melting surrounding snow and able to mobilize as well as deposit thick sand levels eogenetic to diagenetic calcite dolomite and pyrite precipitation involves sand mg fluid influxes associated with methanogenic process eogenesis mixed with recrystallized pyrite and dolomite with diagenetic fluid circulation

the interplay between eustacy tectonics and surface processes during the growth of a fault related structure as derived from sequence stratigraphy the govora ocnele mari antiform south carpathians abstract orogenic collision represents a moment when typical rules of thin skinned development are at odds with the generalized interaction between the upper and buoyant lower plate deriving the kinematics of these collisional features is usually difficult because of the large amounts of subsequent erosion study areas such as those that exist along the south carpathians foredeep where the syn and post collisional sediments are still preserved are important places to identify record and quantify out of sequence deformation here sequence stratigraphic techniques may be used in order to detect tectonic movements which are an order of magnitude higher resolution than those routinely identified by either standard structural analysis or isotope geochronology this study proves that what has been previously interpreted as a one stage growing anticline situated at the contact with the core of the orogen is in fact a gradually evolving antiform structure with at least four quantifiable pulses of vertical movements associated with various amounts of orogenic uplift during collision the interplay between the orogenic core and the anticline uplift controls the depositional area the effects of sea level variations being subordinated transversal shear zones such as strike slip faults are used as transport corridors by the progressive infill of large quantities of sediments from the source area towards the larger basins situated more to the foreland

upper bathyal trace fossils document palaeoclimate changes introductionichnofossils are good indicators ofenvironmental conditions in the geo logical past especially in the marinerealm bromley 1996 the oxygencontent and food availability areimportant for the burrowing organ isms and their uctuations in uencevertical distribution of trace fossilsalong sedimentary pro les savrdaand bottjer 1986 1994 wetzel anduchman 1998 2001 savrda 2007 bottom conditions in the oceans arein uenced by the climate trace fossils fig 1 exceedingly preserve informa tion about environmental conditionsat the time when they were produced but trace fossils of burrowing organ isms re ect environmental conditionsat a younger time compared with thehorizon where the burrows occur thetime interval burrowed by a de nedtrace fossil producer thus depends onthe sedimentation rate and penetra tion depth of the burrower with respect to the usefulness oftrace fossils for interpreting marinepalaeoenvironments the questionarises about the in uence of thepalaeoclimate on deep water tracefossil assemblages and how theseassemblages preserve this signal thisidea was already applied to latecretaceous erba and premoli silva 1994 savrda 1995 and eocene sed iments heard et al 2008 ndingcorrelations of trace fossils with orbi tal cycles stratigraphical andpalaeoenvironmental frameworka 102 m long section of predomi nantly middle miocene langhian sediments from a core in the southernvienna basin austria geographicalcoordinates utm wgs84 e016 13 44 n47 59 24 was investi gated using a multidisciplinaryapproach leading to the reconstruc tion of palaeoenvironmental condi tions ba ldi and hohenegger 2008 c oric and hohenegger 2008 hohe negger et al 2008b pervesler et al 2008 rupp and hohenegger 2008 wagreich et al 2008 according tothese investigations the sediments ofthis section represent sea oor condi tions of the upper bathyal in thewestern part of the paratethys sea harzhauser and piller 2007 pilleret al 2007 during the early middlemiocene the sedimentary successionconsists of more than 95 bioturbat ed marly shales wagreich et al 2008 whereby the upper part 6 40 m is condensed by tectonic distur bance hohenegger et al 2008a thedeeper section 40 102 m shows con tinuous sedimentation fig 2 thewhole section can be astronomicallytuned from 14 379 to 14 142 ma ago fig 2 based on the strong coinci dence of periods in anisotropicmagnetic susceptibility ams the calcium carbonate and organiccarbon content measured in the lower tectonically undisturbed section andon the correlation of these periodswith orbital cycles this dating ho henegger et al 2008a b is con rmedby the biostratigraphic tie points or bulina suturalis and the lack of heli cosphaera waltrans abdul aziz et al 2008 the average sedimentation rateis 470 mm ka

shifts in oxygen and carbon isotope signals in marine molluscs from the central paratethys europe around the lower middle miocene transition abstract stable isotope data of mollusc shells from two adjacent time slices karpatian badenian from the central paratethys were investigated to detect differences in environmental parameters and to depict shifts in the isotope signature of the paratethyan seawater around the early middle miocene transition altogether seventeen different gastropod species and one bivalve species from the karpatian korneuburg basin and the badenian northern alpine foreland basin were selected representatives of various ecological guilds yielded different isotope patterns especially in 13c reflecting different original habitats or nutrition although molluscs precipitate their shells in oxygen isotopic equilibrium we preferred to compare isotope data of shells of the same genus of the family turritellidae from the karpatian and badenian the badenian turritella shells from the northern alpine foreland basin yielded distinctly higher 18o and 13c values than the respective karpatian shells from the korneuburg basin as the main factors controlling 18o values in gastropod shells are temperature and 18o of the water during precipitation the differences between the oxygen isotope data of the two time slices can only be explained by these factors good independent palaeotemperature proxies exist for the early to middle miocene of central europe they do not indicate a significant temperature variation therefore different 18o values of the seawater in the different basins of the central paratethys must be responsible for the contrasting 18o values when calculated with commonly assumed 18o seawater values for the miocene badenian turritella shells indicate too cold temperatures these data clearly document the danger of palaeotemperature interpretations based solely on stable isotopes as smaller and marginal marine settings such as the paratethys sea can be seriously influenced by regional differences in the isotope composition of the seawater only a thorough consistent control by other climate proxies e g palaeoecology of molluscs as in this study allows a sensible interpretation

palaeogeographic significance of tidal deposits an example from an early miocene paratethys embayment northern hungary abstract tide influenced deposits can be used in palaeogeographic reconstructions because they are good indicators of open marine connections an example is presented from the eggenburgian late aquitanian early burdigalian of the north hungarian bay this bay was part of an inland sea the paratethys tide influenced deposits prove that tidal motions in the north hungarian bay were locally amplified this required a free propagation of tidal waves from the open ocean through the paratethys into this embayment since all seaways towards the mediterranean were closed during the early eggenburgian the only connection between the north hungarian bay and open marine waters which allowed the transmission of tidal waves was the outlet towards the east slovakian basin in the northeast the presence of tide influenced deposits in the north hungarian bay implies that tidal waves entered the eastern paratethys from the east through a wide passage other examples of lower miocene tide influenced deposits in the mediterranean and paratethian regions are reported from different periods in these cases amplification of tidal motions in various embayments and straits also occurred because of the local basin morphology it is demonstrated that significant palaeogeographic changes during the early miocene resulted in changes of current pathways and related shifts of loci of tide influenced deposition

early diagenetic greigite as an indicator of paleosalinity changes in the middle miocene paratethys sea of central europe the miocene epicontinental paratethys sea of central eurasia has experienced multiple restriction and reconnection events to the open ocean magnetostratigraphy is an important dating tool to better understand the temporal and spatial paleoenvironmental variations associated with these changes magnetostratigraphy in the paratethys domain however is complicated by the presence of greigite fe3s4 here we report rock magnetic and x ray fluorescence data of the tisa section romania which was previously magnetostratigraphically dated at the middle miocene base at 12 8 ma and top at 12 2 ma this section comprises the badenian sarmatian extinction event bsee which is marked by a major salinity change from marine to brackish environments related to the opening of the connection between the central and the eastern paratethys basins in the marine badenian sediments below the bsee the pyritization process is shown to be complete because of abundant sulfate supply in the brackish sarmatian deposits four intervals with early diagenetic greigite are observed and linked to insufficient sulfate in the water column these four greigite intervals appear to correspond to maxima in the 100 kyr eccentricity cycle we propose that increased fresh water from the eastern paratethys basin during eccentricity maxima restricted the sulfate availability in the tisa area leading to a reduced hs production and enhanced greigite preservation the early diagenetic formation of greigite enables a quasi syn depositional recording of the paleomagnetic field which allows reliable paleomagnetic dating in this section our results further suggest greigite as a potential indicator for salinity changes during marine brackish transitions

early miocene climate and biomes of turkey evidence from leaf fossils dispersed pollen and petrified wood abstract the early miocene was a period of major palaeogeographic reorganization in the eastern mediterranean region during which time the anatolian plateau became subaerial and several intracontinental basins intermittently became connected to the paratethys and mediterranean seas in this paper we analyse early miocene vegetation and climate using leaf records palynological assemblages and fossil wood at 36 localities from western and central turkey most of which have precise age control based on radiometric dating and mammal faunal ages using the leaf flora of guvem bes konak kesekoy climate leaf analysis multivariate program clamp analyses and koppen signatures were employed to infer a palaeoclimate typical of modern laurel forest regions based on the palynological records abundance of various pollen taxa was used as a measure of openness of vegetation and regional presence of major tree taxa most pollen floras are dominated by tree pollen ranging from 85 to 98 and indicated widespread afforestation in the pollen diagrams shifts in dominance from swamp forest elements taxodioideae to well drained forests pinaceae indicate changes in lake levels or phases of basin development such shifts may have been associated with the development of more xeric forest vegetation wood anatomical features such as false tree rings further may indicate seasonal climate pollen diagrams and macrofossils reflect zonal and azonal broadleaf and needleleaf forest and extrazonal open vegetation the latter occurred in areas with shallow soils on volcanic rocks or limestone e g cycads dracaena or coastal areas herb dominance taxonomic composition and biogeographic affinities suggest laurel forest as a major forest biome on well drained soils and ecotones between laurel forest and broadleaf deciduous forest biomes a comparison with younger floras shows that these are neither more diverse nor more warmth loving despite an increase in global temperature mid miocene climatic optimum suggesting bottlenecks during previous oligocene cooler times for warmth loving taxa

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

early miocene european loess a new record of aridity in southern europe the intercalation of silty units and coarse grained units represented by conglomerates and breccia characterizes a lower miocene terrestrial sedimentary sequence in the north croatian basin a part of the southwestern pannonian basin system these sediments were previously interpreted as alluvial sediments where the silty units would reflect deposition on a floodplain however in this study we show new results that support a different interpretation of the genesis of the silty units the units which vary in thickness between 6 and 180 cm are mostly composed of structureless loose silt they are brownish yellow to yellowish brown in color and do not contain fossils scanning electron microscopy indicated that quartz grains show fracture faces conchoidal fractures v shaped percussion marks linear steps and conchoidal crushing features such microtextures together with the macroscopic characteristics of the silt units indicate that they were deposited by wind therefore this study reports the first occurrence of miocene loess outside of china silt sized particles were probably produced by salt weathering processes on salina type lake flats during long arid periods alluvial deposition was controlled by a more humid climate so the intercalation of eolian silty units with alluvial conglomerates and breccias reflects alternation of arid and more humid periods in the early miocene this agrees with regional paleoclimate studies that show cyclicity in the climate with a dry cycle and orbital scale climate variability controlling paleoenvironmental and sedimentary changes in the area during the early miocene

palaeomagnetic evidence for tertiary counterclockwise rotation of adria abstract with the aim of obtaining tertiary palaeomagnetic directions for the adriatic foreland of the dinaric nappe system we carried out a palaeomagnetic study on platform carbonates from stable istria from the northwestern and the central dalmatia segment of imbricated adria despite the weak to very weak natural remanences of these rocks we obtained tectonically useful palaeomagnetic directions for 25 sites from 20 localities all exhibit westerly declinations both before and after tilt correction concerning the age of the magnetizations we conclude that five subhorizontal and magnetite bearing eocene localities from stable istria are likely to carry primary remanence whereas three tilted and hematite bearing ones were remagnetized in the northwestern segment of imbricated adria the cluster of the mean directions improved after tectonic correction indicating pre tilting magnetization in contrast maastrichtian eocene platform carbonates from central dalmatian were remagnetized in connection with the late eocene oligocene deformation or miocene hydrocarbon migration based on the appropriate site locality means we calculate mean palaeomagnetic directions for the above three areas and suggest an alternative interpretation of the data of kissel et al j geophys res 100 1995 14999 for the flysch of central dalmatia the four area mean direction define a regional palaeomagnetic direction of dec 336 inc 52 k 107 95 9 from these data we conclude that stable istria in close coordination with imbricated adria must have rotated by 30 counterclockwise in the tertiary relative to africa and stable europe we suggest that the latest miocene early pliocene counterclockwise rotations observed in northwestern croatia and northeastern slovenia were driven by that of the adriatic foreland i e the rotation of the latter took place between 6 and 4 ma

foraminifera from the borehole altdorf se germany proxies for ottnangian early miocene palaeoenvironments of the central paratethys abstract during the ottnangian early miocene the shallow epicontinental sea of the upper marine molasse in the western and central paratethys realm experienced major sea level fluctuation leading to significant environmental changes however the effects of these changes remain largely unexplored because detailed palaeoenvironmental analyses of the respective time interval are scarce we here present a thorough analysis of the benthic foraminiferal composition 36 samples 5616 individuals and 90 taxa from a 105 25 m thick marine ottnangian succession of the borehole altdorf and from two coeval outcrops neuhofen oberschwarzenbach all located in the western central paratethys studies on the planktonic foraminifera and calcareous nannoplankton were conducted as well we show that benthic foraminiferal assemblages clearly differ with regard to species composition diversity indexes relative abundances of infauna epifauna and oxygen indicators we introduce five foraminiferal biofacies which together are suggestive of a transgressive regressive development and several distinct environmental changes from the early to middle ottnangian the planktonic foraminiferal assemblages from altdorf and the central paratethys suggest cold temperate surface water however high nutrient availability and taphonomic factors such as selective dissolution could also have affected the planktonic assemblages in most samples the relative abundance of infaunal epifaunal benthic foraminifera planktonic foraminifera and calcareous nannoplankton clearly indicates nutrient rich waters we did not find indicators for upwelling as a possible source for the nutrient flux and therefore assume that the high nutrient levels indicate large scale river influx in a humid climate based on our foraminiferal biofacies we postulate the presence of a particularly high fluviatile runoff and high organic matter supply resulting in a moderate oxygen depletion of marine bottom waters for the period of relative sea level highstand in the early ottnangian strong oxygen depletion of bottom waters occurs in the middle ottnangian and is mainly caused by salinity stratification and a reduced water exchange to the open ocean during that time moreover our data demonstrate that p b ratios for early and middle ottnangian samples only partially support the palaeobathymetric reconstructions based on the benthic foraminifera we suggest that fluviatile input and estuarine circulation strongly affected the relative abundances of planktonic foraminifera besides tidal and other marine currents

active volcanism on io as seen by galileo ssi abstract active volcanism on io has been monitored during the nominal galileo satellite tour from mid 1996 through late 1997 the solid state imaging ssi experiment was able to observe many manifestations of this active volcanism including 1 changes in the color and albedo of the surface 2 active airborne plumes and 3 glowing vents seen in eclipse about 30 large scale tens of kilometers surface changes are obvious from comparison of the ssi images to those acquired by voyager in 1979 these include new pyroclastic deposits of several colors bright and dark flows and caldera floor materials there have also been significant surface changes on io during the galileo mission itself such as a new 400 km diameter dark pyroclastic deposit around pillan patera while these surface changes are impressive the number of large scale changes observed in the four months between the voyager 1 and voyager 2 flybys in 1979 suggested that over 17 years the cumulative changes would have been much more impressive there are two reasons why this was not actually the case first it appears that the most widespread plume deposits are ephemeral and seem to disappear within a few years second it appears that a large fraction of the volcanic activity is confined to repeated resurfacing of dark calderas and flow fields that cover only a few percent of io s surface the plume monitoring has revealed 10 active plumes comparable to the 9 plumes observed by voyager one of these plumes was visible only in the first orbit and three became active in the later orbits only the prometheus plume has been consistently active and easy to detect observations of the pele plume have been particularly intriguing since it was detected only once by ssi despite repeated attempts but has been detected several times by the hubble space telescope at 255 nm pele s plume is much taller 460 km than during voyager 1 300 km and much fainter at visible wavelengths prometheus type plumes 50 150 km high long lived associated with high temperature hot spots may result from silicate lava flows or shallow intrusions interacting with near surface so2 a major and surprising result is that 30 of io s volcanic vents glow in the dark at the short wavelengths of ssi these are probably due to thermal emission from surfaces hotter than 700 k with most hotter than 1000 k well above the temperature of pure sulfur volcanism active silicate volcanism appears ubiquitous there are also widespread diffuse glows seen in eclipse related to the interaction of energetic particles with the atmosphere these diffuse glows are closely associated with the most active volcanic vents supporting suggestions that io s atmopshere is dominated by volcanic outgassing globally volcanic centers are rather evenly distributed however 14 of the 15 active plumes seen by voyager and or galileo are within 30 of the equator and there are concentrations of glows seen in eclipse at both the sub and antijovian points these patterns might be related to asthenospheric tidal heating or tidal stresses io will continue to be observed during the galileo europa mission which will climax with two close flybys of io in late 1999

climate impact of high northern vegetation late miocene and present the late miocene belongs to the late phase of the cenozoic climate at that time was still warmer and more humid as compared to today especially in the high latitudes corresponding to the climate situation palaeobotanical evidences support that vegetation in the high northern latitudes changed significantly from the late miocene until today to quantify the climate impact of this vegetation change we analyse how vegetation in the high northern latitudes contribute to climate evolution for that we perform climate modelling sensitivity experiments for the present and for the late miocene tortonian 11 7 ma for our present day sensitivity experiment we introduce the tortonian vegetation in the high northern latitudes for our tortonian sensitivity experiment we introduce the modern vegetation on the same grid cells in the tortonian and in the present the modern vegetation leads to a strong cooling of the northern extratropics up to 4 c nevertheless the meridional heat transports remain nearly unchanged in both cases in general the vegetation impact on climate is similar in the tortonian and in the present however some exceptions occur due to the tethys ocean in the tortonian temperatures decline only weakly in eastern europe and western asia in the tortonian climate temperatures on the sahara realm rise up to 1 5 c while the temperatures do not change remarkably in the present day climate this different behaviour is caused by a stronger and more sensitive hydrological cycle on the sahara region during the tortonian

miocene connectivity between the central and eastern paratethys constraints from the western dacian basin abstract the dacian basin formed an important link between the central and eastern parts of the paratethys a chain of late tertiary inland seas and lakes this study presents constraints on miocene sea and lake level fluctuations in the dacian basin and on the connectivity between it and other paratethys basins based on the interpretation of seismic lines a micropalaeontological study and lithofacies analysis of a large number of outcrops it is shown that relative sea level fluctuations in the western part of the dacian basin during the middle miocene were primarily driven by tectonic activity in the nearby carpathian mountains from the maeotian late miocene onwards however tectonic activity was minor and relative sea level fluctuations were primarily driven by changes in basin connectivity and climate the connection between the central and eastern paratethys was broken at the end of the middle miocene leading to the development of an endemic fauna in the former but new data presented here suggest that isolation was not sustained completely as central paratethys species appeared in the dacian basin during the maeotian late miocene besides the isolation two falls in water level occurred in the basin during the latest miocene of these the intra pontian sea level drop is the best known we show however that this drop was preceded by a larger sea or lake level drop in the late sarmatian maeotian this latter event may have affected much larger parts of the paratethys and we recommend more study of the bordering basins the hypothesis that the connection between the dacian and central paratethys basins was located in the region where the danube river presently crosses the carpathians was tested but no supporting evidence was found

circum mediterranean oligo miocene biogeographic evolution the gastropods point of view based on studies in iran qom basin esfahan sirjan basin zagros mountains in turkey mut and sivas basins in the mesohellenic basin and in northeastern egypt a new palaeobiogeographic concept for the oligocene and miocene in the circum mediterranean area with special emphasis on the distribution patterns of gastropod faunas is presented a very strict biogeographic terminology is proposed to avoid the common fusion of geographic faunistic and geodynamic terms in the palaeontologists jargon our main interest focuses on the affinities and the faunistic interactions between the early mediterranean and the early indo pacific regions during the oligo miocene especially the role of the early indo pacific faunas as the mythic centre of origination of early neogene european mollusc faunas as often vaguely indicated in the literature is critically evaluated this leads to the establishment of a mediterranean iranian province and a western indian eastern african province as palaeobiogeographic subunits of the western tethys region during the oligocene due to major geodynamic and related biogeographic changes in the early miocene the western tethys region no longer existed and was replaced by the proto mediterranean atlantic region for the area of the paratethys the palaeobiogeographic unit danubian province which includes the protocaspian subprovince is proposed furthermore the underrated transatlantic communication of the oligo miocene nearshore mollusc faunas is demonstrated altogether this paper is a contribution to the discussion on the biogeographic concepts classification and nomenclature in palaeontology as initiated by westermann palaeogeogr palaeoclimatol palaeobiogeogr 158 2000 1 13 163 2000 49 68 2002 elsevier science b v all rights reserved

the muddy bottom of lake pannon a challenge for dreissenid settlement late miocene bivalvia abstract the late miocene dreissenids of lake pannon a long existing eastern central european lake bear witness to two very different modes of life which allowed these bivalves to successfully settle in what appears to be an inhospitable environment one guild is restricted to the genera mytilopsis conrad 1858 and sinucongeria lorenthey 1894 these representatives are extreme r strategists which tend to produce temporal boom and bust populations during time windows of improved ecological conditions these opportunities are interpreted here to correlate with cyclic shifts in the epilimnion hypolimnion relation and the corresponding oxygenation of bottom waters events which are probably triggered by low frequency orbital forcing the second guild is composed solely of congeria partsch 1836 the paradox of the proliferation of a single species characterised by extreme size and weight in a muddy oxygen deficient lake environment avoided by nearly all other molluscs points to a hidden mechanism not accessible to other species we tentatively link this mechanism with chemosymbiosis functional morphology in interplay with a highly sulphidic over saturated interstitial water support an interpretation of the large congeria subglobosa as a successful h2s pump model

marine faunal realms of the mesozoic review and revision under the new guidelines for biogeographic classification and nomenclature consensus among the friends of paleobiogeography produced tentative guidelines to the classification and nomenclature of marine biogeographic units i e biochores based on these loose rules the present paper is a critical review of all published mesozoic marine realms subrealms and superrealms formerly called climatic belts biochores are defined by the overall endemism within geographic and time envelopes that include choro and chrono types without consideration of facies or climate the hierarchy of ranks or tiers is superrealm realm subrealm province subprovince only ranks in italics are obligatory region is informal these ranks scale with endemism geographic range and persistence in time biochores are named geographically following nomenclatural guidelines not strict rules of synonymy and homonymy with priority beginning with uhlig s paper of 1911 uhlig s two climatic belts are tentatively accepted as optional top ranking superrealms for times of exceptional global endemism available names for them are euroboreal or panboreal new and tethys panthalassa the validity of the 29 existing names for realm group biochores realms subrealms and superrealms in the marine mesozoic is discussed 19 names are rejected for a variety of reasons including synonymy homonymy and usefulness the most important realm group biochores are arctic and boreal atlantic in the boreal euroboreal realm or superrealm and tethyan mediterran caucasian indo pacific jurassic early cretaceous and austral middle late cretaceous in the tethys panthalassa superrealm

on the formation and evolution of the pannonian basin constraints derived from the structure of the junction area between the carpathians and dinarides 1 the large number and distribution of rollback systems in mediterranean orogens infer the possibility of interacting extensional back arc deformation driven by different slabs the formation of the pannonian back arc basin is generally related to the rapid miocene rollback of a slab attached to the european continent a key area of the entire system that is neglected by kinematic studies is the connection between the south carpathians and dinarides in order to derive an evolutionary model we interpreted regional seismic lines traversing the entire serbian part of the pannonian basin the observed deformation is dominantly expressed by the formation of miocene extensional detachments and half grabens the extensional geometries and associated synkinematic sedimentation that migrated in time and space allow the definition of a continuous and essentially asymmetric early to late miocene extensional evolution this evolution was followed by the formation of few uplifted areas during the subsequent latest miocene quaternary inversion the present day extensional geometry changing the strike across the basin is an effect of the clockwise rotation of the south carpathians and apuseni mountains in respect to the dinarides our study infers that the carpathian rollback is not the only mechanism responsible for the formation of the pannonian basin an additional middle miocene rollback of a dinaridic slab is required to explain the observed structures furthermore the study provides constraints for the pre neogene orogenic evolution of this junction zone including the affinity of major crustal blocks obducted ophiolitic sequences and the sava suture zone

evidence of cenozoic environmental and ecological change from stable isotope analysis of sirenian remains from the tethys mediterranean region sirenians sea cows manatees and dugongs have been primary consumers in tropical and subtropical shallow water marine ecosystems for more than 50 m y though fossils of the earliest sirenians have been recovered from the caribbean sirenians are thought to have originated in the tethys mediterranean region which underwent significant climate change over the course of the cenozoic application of stable isotope analysis can provide new insight into how diet and habitat preferences were affected by climate change and how these ecological changes correlate with diversity patterns for this region tooth enamel was sampled from 57 specimens of sirenians from the tethys mediterranean and adjacent seas spanning the eocene to pliocene enamel 13c values across this time interval were consistently high and indicative of diets composed mostly of marine seagrasses in contrast enamel 18o values showed significant change over time and across the region sirenians from southern sites i e egypt libya had significantly higher mean 18o values than specimens from most european locations suggesting variation in salinity within the tethys mediterranean the range in enamel 18o values increased from the paleogene through the neogene but enamel 13c values remained steady indicating that changes in environmental conditions did not necessarily coincide with major changes in dietary preferences declines in sirenian taxonomic diversity in the late miocene were likely due to the rapid climate and oceanographic changes during the latter half of the cenozoic and their impacts on available dietary resources elevated 13c and 18o values in mediterranean sirenians during the messinian salinity crisis corroborate the hypothesis of ecophenotypic dwarfing in these animals

heterozoan carbonates when where and why a synthesis on parameters controlling carbonate production and occurrences abstract in modern and phanerozoic times heterozoan carbonates group a large array of depositional environments from the poles to the tropics this global assessment reviews the critical parameters and controlling factors of heterozoan carbonates i stratigraphic and global distributional trends ii oceanographic and trophic relationships and iii biological and sedimentary processes well documented case studies n 129 have been investigated when facies and stratigraphic attributes were available and when environmental settings such as oceanography climate and paleogeography were clearly identified these case studies occur during specific periods of time in the sedimentary record e g late ordovician early carboniferous early permian and neogene while they are absent during others e g triassic and jurassic periods during greenhouse to icehouse transitions and those with active thermohaline circulation are particularly conducive for heterozoan carbonates based on global oceanographic patterns and existing ecological and hydrodynamic regime classifications hallock 2001 pedley and carannante 2006 james and jones 2015 a process based classification scheme is proposed that distinguishes two main heterozoan carbonate systems i a highly productive system characterized by suspension feeding biota and ii an oligo mesotrophic warm temperate system characterized by red algal and seagrass derived biota eight depositional models are proposed that combine i the source of energy for metabolic activities that allow the carbonate producing biota to thrive and ii hydrodynamics and physiography of the depositional system that control the sediment accumulation the local and platform scale based profiles can be used to complement the facies approach of james and jones 2015

computer based mollusc stratigraphy a case study from the eggenburgian lower miocene type region ne austria abstract the eggenburg group comprises the type deposits of the lower miocene central paratethys regional stage eggenburgian in ne austria these marine to estuarine deposits transgress in northwestern direction either on palaeozoic rocks of the bohemian massif or on oligocene to lower miocene fluviomarine sediments they are known from three palaeo geographic units situated on the southeastern margin of the bohemian massif these are 1 the southern marginal zone 2 the northwestern n s striking horn basin and 3 the northeastern crystalline plateau termed the eggenburg bay the present study investigates distribution patterns of the exceptionally diverse mollusc fauna composed of 321 taxa species and subspecies within and between those units hierarchical cluster analysis is employed using ward s method and squared euclidean distance calculation a comprehensive database with 1900 sets based on field museum and literature investigations allows compilation of 50 taxonomic lists samples for 30 different localities and six lithostratigraphic units four marine and two brackish formations the resulting grouping pattern implies the existence of four groups three corresponding with palaeo geography and one including low diversity taxon poor samples the analysis of the diversity distribution supports the interpretation that the lower diversity of samples from marine formations stems from secondary distortions such as diagenesis or insufficient sampling hence the samples characterised by a species richness value lower than half of the maximum species richness value of the corresponding formation were excluded from analysis the resulting grouping pattern verified the secondary distortion premise the pattern remained the same except that the low diversity cluster became restricted to samples of brackish origin among the marine samples palaeoecological differences between two fully marine formations from the eggenburg bay were of minor importance as they could not be clearly separated in contrast the individual palaeogeographic regions were shown to be taxonomically coherent but inconsistent with one other as palaeobiogeographic processes were implausible in such a small geographic area the explanation of these differences is based on the time factor including speciation extinction and faunal migration processes the relative stratigraphic position of the horn basin between the marginal zone and the eggenburg bay is implied by hierarchically ordered similarities in order to also indicate their chronological ordinance the index fossil distribution was analysed the chronological pattern is unequivocally provided by the abundant presence of the lower eggenburgian pectinid chlamys gigas schlotheim which is restricted to the marginal zone and the horn basin and by the abundant upper eggenburgian to lower ottnangian pectinids flexopecten palmatus lamarck and chlamys holgeri geinitz which are restricted to the eggenburg bay this refinement of the regional stratigraphic pattern shed light on the eggenburgian marine flooding progression early in the transgression the southern marginal zone was first marine flooded at the same time the horn basin developed an estuarine environment the next phase installed the fully marine environment in the horn basin at the same time the eggenburg bay still a mainland represented a southward pointing cape it first became flooded at the beginning of the upper eggenburgian

glacioeustatic fluctuations the mechanism linking stable isotope events and sequence stratigraphy from the early oligocene to middle miocene one of the most difficult challenges of sequence stratigraphy is the establishment of synchronism between events observed in widely separated basins problems arise because the resolution of the best stratigraphic methods is not good enough to establish the synchronism of similar aged events on a global scale unless a common mechanism affecting global eustasy is assumed such as variations in the ice volume there is no a priori reason to expect that sequences of similar age in widely separated basins are indeed synchronous the stable oxygen isotope composition of marine carbonates is a proxy for sea level which has been underutilized in sequence stratigraphy identification of isotope events is based on d sup 18 o data from dsdp and odp sites 522 529 563 608 and 747 drilled in the atlantic and indian oceans these records were used to define oligocene and miocene oxygen isotope zones in addition we present isotope data from petrobras well a drilled in the campos basin brazil ages of isotope events correspond well with the ages of sequence boundaries and maximum flooding surfaces because of the good correlation between the isotope and sequence stratigraphic records we reconfirm that ice volume change is the common mechanism driving sea level fluctuations from the oligocenemore to present less

u th pb geochronology of zircon and monazite from syenite and pincinite xenoliths in pliocene alkali basalts of the intra carpathian back arc basin abstract phreatomagmatic eruptions in the lucenec basin in slovakia ejected fragments of igneous rocks of unknown age and ranging in composition from gabbro to syenite and orthopyroxene granodiorite pincinite two kinds of syenites with different fe3 contents composed of anorthoclase and interstitial metaluminous trachyte to alkali rhyolite glass represent the final products of alkali basalt differentiation at depths of 10 and 15 18 km pincinite composed of plagioclase quartz orthopyroxene ilmenite and interstitial peraluminous dacite glass is a quenched supersolidus anatectic melt formed at the depth of 17 20 km by high temperature dehydration melting of biotite bearing gneissic protolith zircon from pincinite and syenite and monazite from syenite were dated using excimer laser ablation icp ms the obtained ages cluster at 5 8 0 1 and 5 4 0 1 ma thus corroborating the genetic link between the two rock types and constraining the residence time of at least 300 100 ka of the parental basalt in the deep crustal magma storage zones the inferred ages overlap the upper miocene pliocene boundary and are considerably younger than spatially associated basaltic lava flows dated using the k ar method consequently the fluviolacustrine poltar formation overlying the maar structure must have sedimented during the pliocene and not during the upper miocene pontian as previously assumed

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

strong interannual variation of the indian summer monsoon in the late miocene the modern asian monsoon system exhibits strong interannual variation which has profound environmental and economical impacts it has been well documented that the mean asian monsoon state underwent significant changes in the late miocene 11 5 ma ago but how the interannual variability of the monsoon climate evolved during this period is still largely unknown in this study a long term simulation of the late miocene with a fully coupled atmosphere ocean general circulation model echam5 mpi om at t31l19 resolution is used to explore the interannual variation of the indian summer monsoon ism in the late miocene the regional climate model cosmo clm with a higher spatial resolution 1 1 is further employed to better characterize the spatial patterns of these variations our results show that although the mean ism circulation is weaker in the late miocene runs its interannual variation is as strong as or even stronger than at present and the dominant periods 2 6 2 7 years are shorter than at present 3 4 8 4 years it is noticed that while the extratropical influence on the ism variability is weaker than present a persistent el nino southern oscillation with stronger than present interannual variability is observed in our late miocene run this may have maintained a strong interannual variation of the ism with a shorter period in the late miocene our findings do not only improve our understanding of the asian monsoon evolution in the late miocene but also shed light on the future changes in the interannual variability of the ism

biostratigraphy and paleoenvironments of the late oligocene in the north western transylvanian basin revealed by the foraminifera assemblages abstract the paleoenvironmental evolution and biostratigraphy of the oligocene vima formation from the north western transylvanian basin maramure county romania is presented based on planktonic and benthic foraminiferal assemblages the deposits were assigned to late rupelian early chattian ages more precisely the globigerina angulisuturalis chiloguembelina cubensis crz o4 and paragloborotalia opima hoz o5 biozones the ecological preference of benthic foraminifera and statistical treatment of the raw data set were used to identify relationships between assemblages and reconstruct the ancient environments paleobathymetrical estimates indicate a deposition of the sediments in outer shelf to upper bathyal settings the shelf is characterized by alternating well oxygenated bottom waters and poor oxygen content indicated by low oxygen tolerant taxa the upper bathyal assemblages dominated by tubular agglutinated foraminifera suggest oligotrophic environments periodically disturbed by turbidite currents while the whole agglutinated communities suggest undersaturated bottom waters in respect to calcium carbonate and possible depletion in oxygen content due to water column stratification paleoclimatic reconstructions based on planktonic foraminifera suggest cool to temperate surface water temperatures with boreal influences the younger deposits of the f nt nele section indicate a warming trend at the surface waters the aggradational to progradational stacking pattern of the identified high frequency sequences suggest a high stand systems tract under the control of the regional tectonics

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

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

foraminiferal record of marine transgression during deposition of the middle miocene badenian evaporites in central paratethys borkow section polish carpathian foredeep benthic and planktonic foraminifera from a marly clay intercalation sandwiched between mid badenian middle miocene gypsum deposited in an environment of an evaporitic shoal 1 m deep at borkow southern poland indicate a major marine flooding event in the previously isolated carpathian foredeep basin central paratethys after this very short term environmental change benthic foraminifers started to colonize a new niche which was previously defaunated and the pattern of benthic foraminiferal colonization is similar to that related to the reflooding which terminated the badenian evaporite deposition the benthic foraminifer assemblages are composed of pioneer opportunistic r selected species dominated by elphidiids the connection of the carpathian foredeep basin with the marine reservoir was short lived the marly clay intercalations in evaporite sequences originating in bared basins can thus register major environmental changes