structure and hydrocarbon habitats of the polish carpathian province geological geophysical and geochemical studies have been integrated to explain the structural evolution of the polish carpathians to describe their main hydrocarbon habitats and to propose a coherent scenario for the history of their petroleum systems the western carpathians form a classic fold and thrust belt that is largely overthrust toward the northeast over the mesozoic platform sequences or even the crystalline basement of the european foreland neogene synorogenic deposits in the foredeep lie unconformably on early inverted laramian structures of the autochthon in poland the allochthonous units of the western carpathians comprise two distinct assemblages south of the pieniny klippen belt the inner carpathians are made up of crystalline basement and mesozoic platform sequences that underwent mid cretaceous deformations in the north the outer carpathian flysch units are made up of cretaceous and paleogene terrigenous sequences with interbedded organic rich albian blackshale and oligocene menilite sequences pre eocene lateral thickness and facies changes in the flysch result from the highly differentiated paleogeography generated by the laramian episode of inversion flexural subsidence developed later and was followed by neogene episodes of thrusting effectively oil is found either in the mesozoic carbonates or sandstones of the autochthon central european platform in the foreland or beneath themore allochthon or in paleogene sandstone reservoirs of the allochthon recent results of biomarkers analyses suggest a common source rock e g the oligocene menilite sequence for the oils found in the allochthon outer carpathian flysch units and a number of oils in the autochthonous european platform toward the flexural bulge these structural and geochemical results allow a new approach to discuss the carpathian petroleum generation and migration problems less

life cycle of the east carpathian orogen erosion history of a doubly vergent critical wedge assessed by fission track thermochronology apatite fission track b t thermochronology applied to the east carpathian fold and thrust belt in romania constrains the interaction between the erosion history and the tectonic evo lution of the orogen the long lived constant asymmetric topography of the orogen and the erosion pattern as inferred from apatite ft data are in agreement with the style of evolution predicted by doubly vergent critical coulomb wedge models during the miocene up to 4 km of erosion took place over the actively deforming orogen and the erosion patterns forms a mirrored image of the subsurface deforming wedge the erosion products are deposited in flanking molasse basins which subsided contemporaneously due to the growing topographic weight of the wedge deformation of the wedge was presumably active from the early to late miocene but apatite ft ages between 14 and 9 ma and track length modeling predict an acceleration of erosion rates 0 5 0 3 mm yr ini tially in the middle to late miocene 3 2 ma the onset of erosion coincides with the last phase of convergence and a climax in the deformation history these features are interpreted to have been caused by underplating of the european continental margin convergence ceased before the pliocene according to the activity of thrust faults during the pliocene and quaternary up to 2 km of overburden was removed by erosion leading to isostatic rock uplift of the entire region the use of apatite fission track minimum ages supports the general idea that the orogen has a di achronous evolution from north to south the orogen in the southern bend zone has a more juve nile tectonic character and the main erosion phase took place during the pliocene and quaternary 5 0 ma the integrated approach of large scale morphology and fission track analysis confirms the applicability of the theoretical coulomb wedge mechanics to a natural compressive fold and thrust belt the study complements the geometric features of the orogenic wedge with quantified erosion histories and illustrates the effects of orogen evolution on vertical movements in the entire convergent setting

new discoveries at the middle pleistocene acheulian site of gesher benot ya aqov israel abstract the gesher benot ya aqov archaeological site in the northern dead sea rift of israel contains acheulian artifacts and middle pleistocene fossils initial results of a new interdisciplinary study have shown that fluviolacustrine sediments of the benot ya aqov formation which contains several archaeological occupations were deposited in an embayment of the hula basin they were subsequently deformed by tectonic activity associated with the dead sea rift biostratigraphy magnetostratigraphy and k ar dating serve to constrain the age of the benot ya aqov formation to between 240 000 and 730 000 yr b p archaeological excavation of three areas and two trenches at the new study area have produced abundant basalt flint and limestone artifacts mammalian and avian fossils and considerable plant material the lithic materials provide an excellent opportunity to study large assemblages of in situ acheulian artifacts a rare phenomenon in the middle pleistocene levantine record in addition the organic materials will facilitate paleoenvironmental reconstructions from an ecological floral perspective

geochronology paleogeography and archaeology of the acheulian locality of evron landfill in the western galilee israel a multidisciplinary study was conducted in a newly discovered paleolithic locality named evron landfill this locality is a part of the lower paleolithic complex of evron located at the western galilee israel examination of artifacts has enabled the cultural attribution of evron landfill to the early acheulian while detailed paleomagnetic stratigraphy places the hominin occupations near the brunhes matuyama transition 0 77 ma this age is constrained by cosmogenic isotope burial dating of the sediments overlying the paleolithic finds providing a minimum age of 0 66 0 11 ma for hominin activity at the site these results are further supported by the biochronological information derived from the faunal assemblage comparative analyses of faunal remains and lithic artifacts from evron landfill demonstrate similarities to the assemblages from the early acheulian site of evron quarry located 300 m to the south pedo sedimentological analyses indicate that hominin activity took place in a marsh environment in proximity to the mediterranean coast which probably fluctuated in both space and time with a fluvial environment in addition this study provides important data about ancient coastal activity during the early to middle pleistocene

slab break off abrupt cut or gradual detachment new insights from the vrancea region se carpathians romania slab break off is a plate tectonic process which does not only return lithospheric material into the deeper mantle but also has severe effects on surface movements and seismic hazard slab pull induced seismicity is reduced when the subducted slab decouples from the overlying crust in the vrancea region se carpathians strong earthquakes frequently occur at intermediate depths 70 180 km in a laterally small volume while the crust shows low but distributed seismicity the stress pattern shows similar partitioning with vertical extension in the slab and no preferred orientation in the overlying crust both features indicate a decoupling between slab and overlying crust either by slab break off or delamination however the strong vertical elongation of the slab requires that the upper end of the slab is fixed vertically thus a soft coupling is assumed that is strong enough to enable elongation of the slab but weak enough to inhibit quasi static stress transfer to the overlying crust

the biface assemblage from gesher benot ya aqov israel illuminating patterns in out of africa dispersal abstract this article presents the main characteristics of a lithic assemblage in particular its biface component from the acheulean site of gesher benot ya aqov israel we endeavor to demonstrate that this tradition did not evolve locally within the levant but was rather a result of a diffusion of ideas and or population from africa into the levant during the end of the lower beginning of the middle pleistocene the fact that other acheulean industries present in the northern dead sea rift resemble corresponding african traditions rather than each other may indicate that the gesher benot ya aqov occurrence was not an isolated event this phenomenon may be interpreted as representing a dynamic system in which populations and or ideas dispersed out of africa during the lower and middle pleistocene in repetitive distinct and separate waves

high resolution seismic traveltime tomography incorporating static corrections applied to a till covered bedrock environment a major obstacle in tomographic inversion is near surface velocity variations such shallow velocity variations need to be known and correctly accounted for to obtain images of deeper structures with high resolution and quality bedrock cover in many areas consists of unconsolidated sediments and glacial till to handle the problems associated with this cover we present a tomographic method that solves for the 3d velocity structure and receiver static corrections simultaneously we test the method on first arrival picks from deep seismic reflection data acquired in the mid late to 1980s in the siljan ring area central sweden to use this data set successfully one needs to handle a number of problems including time varying near surface velocities from data recorded in winter and summer several sources and receivers within each inversion cell varying thickness of the cover layer in each inversion cell and complex 3d geology simultaneous inversion for static corrections and velocity produces a much better image than standard tomography without statics the velocity model from the simultaneous inversion is superior to the velocity model produced using refraction statics obtained from standard reflection seismic processing prior to inversion best results using the simultaneous inversion are obtained when the initial top velocity layer is set to the near surface bedrock velocity rather than the velocity of the cover the resulting static calculations may in the future be compared to refraction static corrections in standard reflection seismic processing the preferred final model shows a good correlation with the mapped geology and the airborne magnetic map

using adv for cohesive sediment settling velocity measurements using an acoustic doppler velocimeter adv to simultaneously measure the turbulent diffusivities and suspended sediment concentrations ssc at one point in the water column provides an in situ approach to measure the settling velocity of cohesive sediments this approach does not alter the ambient turbulence ssc salinity and biological constituents that are the major factors affecting floc density and size and thus the settling velocity the settling velocity measured using this technique is much higher than that obtained from the traditional owen tube method which eliminates the effects of ambient turbulence using the settling velocities measured from this new approach and the erosion rates from in situ measurements in a numerical study of the dynamics of turbidity maximum in the york river the simulated results were quite reasonable this is encouraging because it was the first time that a modeling study used in situ measured settling velocities and erosion rates together and correctly predicted the formation of turbidity maximum although this is a promising approach there are improvements that should be included to establish the procedures of using an adv for measuring the settling velocity of cohesive sediments

structural evolution of the eastern balkans bulgaria abstract the balkans are an e w trending thrust belt mainly of palaeogene age generated by a left lateral transpression with maximum stress oriented n30 e the transpressive nature of the balkans may be deduced from the en echelon pattern of folds and thrusts which is due to oblique shortening with respect to pre existing mesozoic e w trending crustal anisotropies between the moesia platform and the balkans basin the front of the eastern balkans is marked by the chudnite skali ajtos thrust during the neogene and quaternary the balkans were inverted by right lateral transtensional tectonics which cross cut and dismembered the thrust belt the main transtensional segment is the southern margin of the balkans e g the emine line the steep transtensional faults disconnected the thrust planes of the balkans from the thrusts of the srednogorie to the south grabens are in general asymmetrical with master faults dipping 80 40 south westward and probably flattening into the middle crust the structural evolution of the balkans may also be traced into the black sea but the structural trends gradually change from the e w trend to a nw se strike indicating pure palaeogene compression and more recent neogene extension inverting and cross cutting the compressive features it is also interesting to note that the neogene tensional or transtensional inversion is not cylindrical it exhibits undulations of graben and transfer faults controlled by the pre existing compressive fabric the eastern balkans and their continuation in the black sea are morphologically and structurally deeper and they plunge eastward and south eastward towards the black sea this is due both to the deeper position of the balkans de collement planes in the black sea and to the thermal subsidence along the black sea continental margin

thermo mechanical controls on the mode of continental collision in the se carpathians romania abstract the carpathians orogenic system with its along arc variations in topography developed in the aftermath of continental collision is associated with unusual foredeep basins large scale strain and seismicity concentration and high velocity mantle bodies the east carpathians continental collision was non cylindrical leading to large scale variations in thrust nappe kinematics orogenic uplift patterns and foredeep subsidence controlled by the mechanics and geometry of the lower plate thermo mechanical modelling demonstrates that in this low rate convergence regime the subducted lithosphere had enough time to interact with the mantle to advance towards a thermal resettlement this is favored by the low degree of metamorphism mechanical weakness of the lower plate and the lack of active surface processes at the contact with and in the upper plate in contrast low buoyant thick lower crust and active surface processes keep the continuity of the slab intact and promote the development of typical foredeep basins the model explains in a self consistent manner the unusual geometry of the vrancea seismogenic slab in the bend zone of the romanian carpathians the model is also consistent with the presence of two high velocity bodies inferred from seismic tomography studies and explains the depth zonation of seismicity in the vrancea area differences between the northern part of east carpathians and the southeastern bend of the carpathians arc are largely controlled by lateral variations in crustal structure topography emplacement and surface processes along the arc mechanical heterogeneity of the carpathians subduction leads to the development of two end member modes of collision allowing a study of these states and their transition lithospheric configuration and tectonic topography appear to be prime factors controlling variations in slab behavior in the se carpathians at the terminal phase of continental convergence slab delamination roll back and depocenter migration appear to play a more limited role at shallow and lithospheric levels

new seismic and tomography data in the southern part of the harghita mountains romania southeastern carpathians connection with recent volcanic activity the southern part of the southeastern carpathians represents the site of the most recent volcanic eruptions of the entire carpathian pannonian region the products of these eruptions range from 42 to 10 ka radiocarbon ages in the south harghita mountains high k calc alkaline rocks with adakite like features and at 1 2 0 6 ma k ar ages in the persani mountains alkali basalts they were emplaced in a post collisional regime ciomadul volcano is located at the southernmost part of the nw se oriented c limani gurghiu harghita range crossing the inner part of the southeastern carpathians and in the rough proximity of the vrancea seismic zone at ca 60 km toward nw its magma generation is attributed to geodynamic events closely related to the seismogenic area a number of particular geophysical and geochemical features located in the study region including 1 the abrupt attenuation of the seismic waves originating from the vrancea intermediate depth foci 2 the most intense heat flow anomaly in romania 3 the most prominent 3he 4he anomaly measured in natural postvolcanic gas emanations are all in favor of the hypothesis of a still existing hot local magma chamber data acquired during recent seismic monitoring of the vrancea zone and its neighborhoods suggest an enhancement of the local seismicity beneath the southern edge of the south harghita mts both at crustal and subcrustal levels at the same time recent tomography images obtained using local earthquake data correlate well with the presence of a vertically extended low velocity zone coming from the upper mantle to the assumed magmatic chambers located in the crust the present data supporting the presence of an active crustal magma chamber beneath ciomadul allow us to consider that future volcanic activity at this volcano cannot be discarded

active deformation in the vrancea region rumania recent and historical seismicity as well as reliable fault plane solutions are used to study the active deformation caused by the occurrence of intermediate depth 60 170 km earthquakes of the vrancea region rumania in this area located in the southeastern part of the carpathian arc the westward subduction of the carpathian trench has terminated leaving continental lithosphere at present at the arc the principalt axis of the intermediate depth events trends n159 e and has a plunge of 74 which is the same as the dip of the subducted plate thep axis has a trend of 314 and a shallow plunge of 15 the analysis of the moment tensor of six focal mechanisms showed that the dominant mode of deformation of the subducted lithosphere is a down dip extension at a rate of about 2 cm yr based on seismicity data

tertiary tectonic evolution of the external east carpathians romania abstract paleostress calculation and analysis of mesoscopic structures are integrated with depth interpreted geological profiles based on seismic studies and well correlation to derive a tertiary tectonic model for the east carpathians following early miocene and older orogenic phases the first tectonic event that affected the studied area is characterised by a wsw ene oriented shortening of middle miocene late burdigalian in age resulting deformations induced ene ward thrusting of tarcau and marginal units as well as the internal part of the subcarpathian nappe a second shortening event with an e w to wsw ene contraction direction took place in the late miocene sarmatian characterised by further foreland thrusting of the subcarpathian nappe and out of sequence deformation in the tarcau and marginal folds nappes along strike differences in deformation mechanisms are controlled by the friction coefficients along the main detachment layers by the lateral variations in the wedge thickness and by the involvement in the northern part of the thrusting system of the thick competent east european platform tear faulting occurred in both tectonic events the main resulting structure being the triangle zone developed south of the trotus valley the latest miocene latest sarmatian early pliocene is characterised by a strike slip stress field with nne ssw compression and wnw ese tension axis left lateral faults being dominant the last deformation which affected the studied area is characterised by nnw sse shortening during the pliocene major deformations taking place mainly in the sw most bending zone

contrasting tectonic and sedimentary history of the central and eastern parts of the polish carpathian foredeep basin results of seismic data interpretation polish carpathian foredeep basin pcfb is located at the junction between western and eastern european platforms such location caused different evolution of various parts of this basin in the central part of the pcfb growth fault propagation folds related to latest badenian stages of thrusting in this segment of the carpathians developed only minor normal faulting related to miocene reactivation of older basement faults was detected paleovalleys mapped within the mesozoic basement were interpreted as palaeogene tectonically controlled erosional features developed after inversion of the polish trough in the central pcfb post evaporitic sediments were supplied into the foredeep basin from south from the eroded carpathians in the eastern part of the pcfb a system of large normal faults related to miocene flexure induced reactivation of inherited mesozoic faults was identified within the hangingwall of this system reverse faults rotated blocks and basement pop up structures were described their formation was related to combined effect of compressional stresses transferred from the carpathian collision zone and reactivation of older large scale fault caused by both flexural extension and strike slip movements during deposition of the miocene foredeep sediments differential compaction also played an important role gentle onlap of the middle badenian evaporites by post evaporitic sediments towards the nw was interpreted as a result of tectonically driven relative sea level rise and re establishment of marine connections with eastern paratethys

crustal constraints on the origin of mantle seismicity in the vrancea zone romania the case for active continental lithospheric delamination abstract the vrancea zone of romania constitutes one of the most active seismic zones in europe where intermediate depth 70 200 km earthquakes of magnitude in excess of m w 7 0 occur with relative frequency in a geographically restricted area within the 110 bend region of the southeastern carpathian orogen geologically the vrancea zone is characterized by a a laterally restricted steeply nw dipping seismogenic volume 30 70 200 km situated beneath b thickened continental crust within the highly arcuate bend region of the carpathian orocline and c miscorrelation of hypocenters with the position of known or inferred suture zones in the carpathian orogenic system geologic data from petroleum exploration in the eastern carpathians published palinspastic reconstructions and reprocessing of industry seismic data from the carpathian foreland indicate that 1 crust of continental affinity extends significantly westward beneath the external thrust nappes sub carpathian marginal folds and tarcau of the eastern carpathians 2 cretaceous to miocene strata of continental affinity can be reconstructed westward to a position now occupied by the transylvanian basin and 3 geologic structure in the carpathian foreland including the moho is sub horizontal directly to the east and above the vrancea seismogenic zone taken together these geologic relationships imply that the vrancea zone occupies a region overlain by continental crust and upper mantle and does not appear to originate from a subducted oceanic slab along the length of the carpathian orogen accordingly the vrancea zone appears to potentially be an important place to establish evidence for active lithospheric delamination

continual fire making by hominins at gesher benot ya aqov israel this paper presents the culmination of an extensive study of fire use at the early and early middle pleistocene site of gesher benot ya aqov using software available in the gis package we have examined the spatial distribution of burned and unburned flint microartifacts from eight acheulian archaeological horizons the results of this study demonstrate that the burned microartifacts are never evenly distributed and dense concentrations are observed the circumstances that introduced these burned flint artifacts to the archaeological layers are examined suggesting that anthropogenic rather than natural fires are responsible for the observed patterns as the evidence for the use of fire is recorded throughout the long stratigraphic sequence it seems that fire was continually used by the acheulian hominins of the site this repetitive use of fire indicates that the hominins of gesher benot ya aqov had a profound knowledge of fire making enabling them to make fire at will

characteristics of collisional orogens with low topographic build up an example from the carpathians sequence stratigraphy in the hinterland kinematic analysis of thin skinned thrusting in the foreland and thermochronological tracking of exhumation in the orogenic core are combined to quantify the mechanics of an orogen with low topographic build up the carpathian system demonstrates that collisional deformation can couple and thicken the lower orogenic plate along reverse faults that dip more steeply than the subduction zone defining a foreland coupling type of collision near the surface this is expressed by wide antiforms in the upper plate and the thin skinned orogenic wedge a sequence stratigraphic analysis of the back arc transylvanian basin demonstrates that the sedimentary architecture records orogenic uplift pulses with both short and long wavelengths these correspond to the activation of individual thrust sheets in the thin skinned wedge and to lower plate coupling events respectively

orogen parallel extension in the southern carpathians a structural study including a kinematic analysis based on sense of shear criteria recorded in fault rocks is combined with fission track dating a two stage alpine tectonic evolution is proposed for the major tectonic units which constitute the southern carpathians of the parang mountains area upper cretaceous top to the sse nappe stacking was followed by wsw ene orogen parallel extension in the eocene top to the ene shearing in lower greenschist facies mylonites from the eastern part of the danubian window parang mountains is associated with a low angle detachment at the base of the brittlely deformed getic nappe the getic detachment below the dome shaped getic detachment east dipping at the eastern termination of the danubian window the danubian units were rapidly exhumed hence the eastern part of the danubian window represents a greenschist facies core complex as a working hypothesis it is proposed that this orogen parallel stretch was originally n s oriented and that it formed when the rhodopean fragment which includes the getic and supragetic nappes moved northward into an oceanic embayment past the western margin of moesia this eocene extension was part of a process of oroclinal bending in the area of the southern carpathians and their continuation into the balkan mountains extension was followed by about 50o clockwise rotation of the southern carpathians associated with dextral wrenching along the northern boundary of moesia and compression in the moldavides of the eastern carpathians 1998 elsevier science b v all rights reserved

lateral variations in mechanical properties of the romanian external carpathians inferences of flexure and gravity modelling we present the results of two dimensional flexure and gravity modelling of the subsidence of the romanian carpathian foreland based on twenty profiles through the southern and eastern carpathians the narrow spacing of the grid of profiles allows us to investigate the lateral tectonic variations transverse to the belt but also along strike the topographic elevation of the romanian carpathian mountain belt is modest and the minimum in the bouguer gravity anomaly characteristic for flexural control of subsidence is located relatively far towards the foreland in respect to the mountain belt as the contribution of topographic loading to the evolution of the romanian carpathian foreland system is small a subduction underplating dominated tectonic regime controlled the nappes emplacement and basin shortening in the external flysch and molasse basins during the late tertiary the modelling results support the existence of important variations in effective elastic thicknesses te and plate boundary forces high flexural bending stresses in the western part of the southern carpathians can explain low te values whereas the increase of te to the east can be explained by changes in rheological properties of the moesian platform field observations indicate that variations in deflection along strike are probably also related to basement unregularities stress field rotations and strike slip movement along lateral ramps during the tertiary in the eastern carpathians the model results indicate a n s trend of lateral back stepping of the subduction system a distinct back step in the vicinity of the seismically active vrancea area supports the involvement of the e w crustal scale trotus fault which forms the transition from the east european platform to the scythian and moesian platforms development of a possible n s migration of plate boundary activity or slab detachment and successive intersection with the trotus fault can explain the large pliocene subsidence in the focsani depression and relative uplife of the east european platform north of the mentioned fault

revised crustal architecture of the southeastern carpathian foreland from active and passive seismic data 1 integration of active and passive source seismic data is employed in order to study the nature of the relationships between crustal seismicity and geologic structures in the southeastern se carpathian foreland of romania and the possible connection with the vrancea seismogenic zone vsz of intermediate depth seismicity one of the most active earthquake prone areas in europe crustal epicenters and focal mechanisms are correlated with four deep industry seismic profiles the reprocessed danube and carpathian integrated action on process in the lithosphere and neotectonics dacia plan profile and the deep reflection acquisition constraining unusual lithospheric activity ii and iii dracula profiles in order to understand the link between neotectonic foreland deformation and vrancea mantle seismicity projection of crustal foreland hypocenters onto deep seismic profiles identifies several active crustal faults in the se carpathian foreland and suggests a mechanical coupling between the mantle located vsz and the overlying foreland crust the coupled associated deformation appears to take place on the trotus fault the sinaia fault and the newly detected ialomita fault seismic reflection imaging reveals the absence of west dipping reflectors in the crystalline crust and a slightly east dipping to horizontal moho in the proximity of the vrancea area these findings argue against previously purported mechanisms to generate mantle seismicity in the vsz including oceanic lithosphere subduction in place and oceanic slab break off furthermore suggesting that the vrancea seismogenic body is undetached from the overlying crust in the foreland

thermal structure of the crust and upper mantle of romania abstract a synthesis of the heat flow data for romania enabled a study of the thermal regime of the crust and upper mantle to be made this showed lateral thermal differences between various tectonic units the thermal structure of the crust and upper mantle appears to be mainly the result of mantle convection and plate interaction in the studied area

vrancea99 the crustal structure beneath the southeastern carpathians and the moesian platform from a seismic refraction profile in romania the vrancea99 seismic refraction experiment is part of an international and multidisciplinary project to study the intermediate depth earthquakes of the eastern carpathians in romania as part of the seismic experiment a 300 km long refraction profile was recorded between the cities of bacau and bucharest traversing the vrancea epicentral region in nne ssw direction the results deduced using forward and inverse ray trace modelling indicate a multi layered crust the sedimentary succession comprises two to four seismic layers of variable thickness and with velocities ranging from 2 0 to 5 8 km s the seismic basement coincides with a velocity step up to 5 9 km s velocities in the upper crystalline crust are 5 9 6 2 km s an intra crustal discontinuity at 18 31 km divides the crust into an upper and a lower layer velocities within the lower crust are 6 7 7 0 km s strong wide angle pmp reflections indicate the existence of a first order moho at a depth of 30 km near the southern end of the line and 41 km near the centre constraints on upper mantle seismic velocities 7 9 km s are provided by pn arrival times from two shot points only within the upper mantle a low velocity zone is interpreted travel times of a plp reflection define the bottom of this low velocity layer at a depth of 55 km the velocity beneath this interface must be at least 8 5 km s geologic interpretation of the seismic data suggests that the neogene tectonic convergence of the eastern carpathians resulted in thin skinned shortening of the sedimentary cover and in thick skinned shortening in the crystalline crust on the autochthonous cover of the moesian platform several blocks can be recognised which are characterised by different lithological compositions this could indicate a pre structuring of the platform at mesozoic and or palaeozoic times with a probable active involvement of the intramoesian and the capidava ovidiu faults especially the intramoesian fault is clearly recognisable on the refraction line no clear indications of the important trotus fault in the north of the profile could be found in the central part of the seismic line a thinned lower crust and the low velocity zone in the uppermost mantle point to the possibility of crustal delamination and partial melting in the upper mantle

understanding salt in orogenic settings the evolution of ideas in the romanian carpathians the romanian carpathians are of global importance in salt tectonics because they host the type locality for the term diapir although there are several historical reviews of worldwide salt tectonics important aspects of how diapirism has been described and defined in the romanian carpathians are missing in these works many of these publications are difficult to access and most are written in romanian german french or polish this paper aims to present in detail the original ideas and to describe the historical development of these concepts we focus particularly on the work of the outstanding romanian geologist ludovic mrazec who defined the folds with piercing core and coined the term diapir

thermomechanical structure of european continental lithosphere constraints from rheological profiles and eet estimates summary the eet equivalent elastic thickness of the lithosphere is a measure of the integrated lithospheric strength it is directly related to the mechanical thickness and rheology of the crustal and mantle lithosphere we present a comparison of eet estimates and strength profiles based on the extrapolation of rock mechanics data for different parts of the european and eurasian continental lithosphere we discuss the temporal and spatial variations in the mechanical thickness and strength inferred from data for precambrian segments of europe s lithosphere variscan europe and the alpine collision belt this analysis demonstrates important spatial and temporal variations in lithospheric rigidity for orogenic belts and sedimentary basins in eastern and western europe and asian parts of eurasia the eet estimates based on synthetic rheological profiles constrained by newly available geophysical data are consistent with the estimates of eet derived from flexural studies of sedimentary basins forelands and orogenic belts these rheological profiles suggest weakening of the major parts of the european and eurasian continental lithosphere by decoupling of the crustal and upper mantle parts a comparison with the seismicity depth distribution for some selected sites suggests that the intra plate seismicity is essentially restricted to the upper crustal parts of europe s lithosphere providing additional support to the notion of the decoupled lithosphere the presence of intra plate stress fields can explain a significant part of the observed variations in eet estimates within individual thermotectonic age groups a comparison of wavelengths of crustal and lithospheric folding with observations shows these wavelengths to be consistent with estimates of eet inferred from the rheological response of basins and orogens at more moderate levels of intra plate stress

subsidence analysis and tectonic evolution of the external carpathian moesian platform region during neogene times abstract the miocene pliocene subsidence of the tectonic platforms in the romanian carpathians foreland is analysed using standard 1d backstripping techniques for individual wells combined in two regional sections and six contour maps the subsidence patterns were integrated together with previous paleostress and kinematic studies in order to derive the tertiary kinematics of the buried faults in the carpathians lower plate the study revealed accelerated subsidence during the early miocene in the western part of the moesian platform getic depression in direct relationship with the opening of a wsw ene trending extensional basin the largest subsidence recorded in the front of the carpathians took place during the late miocene due to final e ward emplacement of the thrust sheets the late miocene subsidence showed anomalous high values between the intramoesian and trotus faults as a result of the orogenic collision with the east european platform northward and acceleration of the subduction process in the se carpathians corner further pliocene subsidence continued only in the latter region the depocenter being shifted southward near the junction with the south carpathians foreland

architecture of the focsani depression a 13 km deep basin in the carpathians bend zone romania 1 in front of the se carpathians bend a very deep basin focsani depression developed in miocene to recent times an important part of its subsidence occurred after the main stages of thrusting in the carpathians apparently the basin lies in the wrong place and evolved in the wrong time in this study we constrain its architecture and evolution by analyzing a large database consisting of more than 1000 km two dimensional seismic lines and more than 60 wells around 13 km thick badenian to quaternary 16 5 myr sediments were deposited in the central part of the focsani depression during the badenian 16 5 13 myr the foreland south of trotus fault underwent ne sw directed extension and nw trending basins opened in the eastern moesian platform a nw se oriented area of subsidence stretched from the transylvania basin through the focsani depression to the se of the moesian platform while thrusting was going on in the east european scythian platform east carpathians and getic depression starting with the sarmatian 13 10 myr the focsani depression depocenter moved out of the carpathian belt coeval with the exhumation of the south and the east carpathians north of the trotus fault the basin became wider and was tilted toward the belt tilting was accompanied by dextral shearing mainly along the intramoesian and peceneaga camena faults after sarmatian times subsidence occurred practically only sse of trotus fault during meotian pontian 10 5 myr subsidence slowed down stronger pliocene quaternary subsidence is coeval with normal faulting and shearing in moesian platform the western margin of the focsani depression was then tilted eastward coeval with the exhumation of the bend zone and opening of the intramontane basins in the inner part of the belt

slab behaviour and its surface expression new insights from gravity modelling in the se carpathians abstract we use lithosphere scale gravity models to calculate gravity anomalies resulting from oceanic subduction continental collision slab steepening delamination and break off local isostasy was assumed for determining vertical movements caused by mass changes related to these tectonic processes our results show that subduction is accompanied by basin subsidence on the upper plate caused by the heavy lithospheric root of the subducting slab the basin evolution goes parallel with the slab evolution and shows considerable modifications when the processes at depth change slab steepening delamination break off characteristic gravity anomaly curves were acquired for the different tectonic scenarios these curves together with other data e g basin evolution on the upper and the lower plate were used for the reconstruction of the tectonic evolution of the se carpathians which includes tertiary subduction and collision followed by slab steepening and delamination

operating systems in units b and e of the notarchirico basilicata italy ancient acheulean open air site and the role of raw materials abstract the succession of archaeological units at notarchirico offers technical and environmental arguments aimed at the characterization of the variability of the european ancient palaeolithic analysis shows the presence of distinctive features within the acheulean assemblage besides the presence of handaxes hominins used flint and limestone on the site a lithological analysis shows a predominance of the same raw materials in every unit and a partial selective exploitation in unit b traditionally associated with so called mode 2 the knapper principally intended to produce a sharp or convergence of the sharps choppers or bifacial tools in the e e1 units flaking prevails on the sporadic shaping the presence of cores with polyhedral forms and the extreme dimensional reduction of objects are other main technical features associated with this core and flake assemblage the presence or absence of handaxes is not the only element of variability the presence of micro tools and other technical elements represent technological innovations in the lower pleistocene assemblages common to many italian sites during the so called mode 1 2 transition the traditional idea of acheulean as an uniform entity characterized by the presence of handaxes does not seem to be valid

slab in the wrong place lower lithospheric mantle delamination in the last stage of the eastern carpathian subduction retreat a model with a new type of delamination of the lower lithospheric mantle is proposed to explain the pliocene to recent tectonic evolution of the eastern carpathians we suggest that after the continental collision in middle miocene time break off of the west dipping subducting slab occurred at a depth of 70 km slab break off propagated horizontally toward the east inducing lithospheric delamination and movement of the vrancea slab into its present position delamination was followed by rapid asthenospheric rise resulting in magma generation and the explosive alkaline basaltic magmatism of the persani mountains contamination of the former subduction related magmatic reservoirs with the alkalic basaltic material and differentiation processes produced the harghita calc alkaline and shoshonitic rocks the asthenospheric rise induced crustal uplift which is the triggering mechanism for extension and formation of the brasov gheorghieni hinterland basins the extension was accommodated by shortening and folding in the foreland the vertical vrancea slab appears in our model as a segment of delaminated lower lithospheric mantle that is seismically active due to the ongoing pull of the eclogitized oceanic crust the model explains the displaced and shallow position of the slab relative to the eastern carpathian suture zone

deep seismic soundings in romania this paper describes the deep seismic soundings performed in romania the technique of field works the characteristics of the recorded waves and the main results obtained on the profiles is analysed

3 d upper crustal tomographic structure across the vrancea seismic zone romania abstract the vrancea99 and vrancea2001 seismic refraction experiments are part of a multidisciplinary project to study the eastern carpathians in romania the objectives of these studies are intended to disclose a more detailed picture of the crustal and upper mantle structures above the seismically active vrancea region in this paper we provide additional constraints for the upper crustal structures of the area the 1999 campaign consisted of a 320 km long n s profile and a 70 km long e w profile the intersecting 2001 profile extended in e w direction from the hungarian border to the black sea in order to enhance the model resolution first arrival data from local crustal earthquakes were also included this configuration allowed for the first time to derive a 3 d velocity model for the upper crust of the romanian carpathian orogen within a 115 235 km wide region centred over the vrancea seismic zone the 3 d model reveals lateral velocity variations which were not visible on the in line interpretations it allows us to distinguish between foreland platform areas foreland basins and the carpathian orogen clear velocity differences between the foreland basins south and southeast of the eastern carpathians and the focsani basin further north indicate different pre miocene sedimentary compositions and geological evolutions of these foreland platforms the involved moesian and scythian platforms are separated by the trotus fault system which is observed as a velocity discontinuity an upper crustal high velocity zone above the northern vrancea seismic zone could also be identified this high velocity zone is explained by a middle pliocene to pleistocene e w oriented out of sequence thrust of the crystalline basement below the decollement of the flysch nappes

near vertical seismic reflection image using a novel acquisition technique across the vrancea zone and foscani basin south eastern carpathians romania the dacia plan danube and carpathian integrated action on process in the lithosphere and neotectonics deep seismic sounding survey was performed in august september 2001 in south eastern romania at the same time as the regional deep refraction seismic survey vrancea 2001 the main goal of the experiment was to obtain new information on the deep structure of the external carpathians nappes and the architecture of tertiary quaternary basins developed within and adjacent to the seismically active vrancea zone including the focsani basin the seismic reflection line had a wnw ese orientation running from internal east carpathians units across the mountainous south eastern carpathians and the foreland focsani basin towards the danube delta there were 131 shot points along the profile with about 1 km spacing and data were recorded with stand alone reftek 125s also known as btexansq supplied by the university texas at el paso and the passcal institute the entire line was recorded in three deployments using about 340 receivers in the first deployment and 640 receivers in each of the other two deployments the resulting deep seismic reflection stacks processed to 20 s along the entire profile and to 10 s in the eastern focsani basin are presented here the regional architecture of the latter interpreted in the context of abundant independent constraint from exploration seismic and subsurface data is well imaged image quality within and beneath the thrust belt is of much poorer quality nevertheless there is good evidence to suggest that a thick 10 km sedimentary basin having the structure of a graben and of indeterminate age underlies the westernmost part of the focsani basin in the depth range 10 25 km most of the crustal depth seismicity observed in the vrancea zone as opposed to the more intense upper mantle seismicity appears to be associated with this sedimentary basin the sedimentary successions within this basin and other horizons visible further to the west beneath the carpathian nappes suggest that the geometry of the neogene and recent uplift observed in the vrancea zone likely coupled with contemporaneous rapid subsidence in the foreland is detached from deeper levels of the crust at about 10 km depth the moho lies at a depth of about 40 km along the profile its poor expression in the reflection stack being strengthened by independent estimates from the refraction data given the apparent thickness of the meta sedimentary supracrustal units the crystalline crust beneath this area is quite thin b20 km supporting the hypothesis that

2 5d seismic velocity modelling in the south eastern romanian carpathians orogen and its foreland 2 5 d seismic velocity modelling in the south easter romainan carpathians orogen and its foreland

the faunal remains from evron quarry in relation to other lower paleolithic hominid sites in the southern levant abstract the mammalian assemblage and archaeological finds from the lower palaeolithic hominid site of evron quarry situated on the northern coastal plain of israel are described and discussed in their lithic and faunal composition the sites of latamne qfiii latamne formation orontes syria and sitt markho nahr elkebir syria resemble evron and are probably contemporaneous it is suggested here based on their lithic and faunal composition that these sites may be chronologically closer to the site of ubeidiya ubeidiya formation jordan valley israel 1 4 myr than to the sites of gesher benot ya akov dated as

paleostress characterization of the wallachian phase in its type area southeastern carpathians romania abstract the wallachian phase is defined in the east carpathians a convex to the east mountain belt in romania as a tectonic event occurring between pliocene and quaternary times this event formed folds and minor thrusts structures that are usually located in internal parts of the somewhat older fold and thrust belt structure this location contrasts with the location one would predict from their recent age and contrasts with the older cretaceous middle tortonian piggyback thrust mode of propagation in the southeastern carpathians this late overstep sequence of thrusting resulted from a modification in the stress field our data indicate that the direction of compression changed from nw se to n s during middle tortonian time this is further supported by stratigraphic dating of structures and thereby paleostresses indicating that the wallachian episode was not a brief event at the pliocene quaternary boundary but lasted from middle tortonian to early pleistocene

characteristics of romanian lithosphere from deep seismic reflection profiling abstract the tectonic units of romania contain both alpine orogenic regions and platforms the investigations of crustal structure by near vertical reflection seismic profiling are based on less than 100 lines unequally distributed and of limited lengths 5 30 km the seismic features studied are the crustal seismic reflectivity and transparency dipping events and diffractions and the moho and subcrustal reflectivity the major common features are a reflective sedimentary cover of mostly neogene layers a weak signal from the sedimentary basement boundary a quasi transparent upper crust a mid crust with short and subhorizontal events a transparent or layered lower crust and a moho that is either poorly visible or evidenced by a zone with reflection bands and some subcrustal reflections the moesian platform together with the adjacent carpathian foredeep show a mid crust with short and subhorizontal events a crust mantle transition zone in the west an unclear or prominent moho and some subcrustal reflectivity the northern part of the carpathian foredeep shows strong seismic layering of the lower crust the central part of the transylvanian depression is characterized by short and subhorizontal events at mid crustal level a slightly reflective lower crust with diffractions and a weak moho signal the southern sector of the pannonian depression is generally marked by a reflective lower crust the tectonic significance of these seismic signatures is interpreted as follows a brittle upper crust a decoupling mid crustal zone a lower crust with brittle to ductile behaviour a possible extensional or isostatic rebalanced moho and laminated zones with reduced viscosities at the lower crust and upper mantle levels a series of crustal models based on the reflection seismic sections are presented for several areas of romania

velocity structure of the vrancea region romania abstract a set of 26 earthquakes recorded by a newly installed telemetered network was used for a simultaneous inversion of hypocenters and velocities the travel times and their partial derivatives were computed for flat lying layers of constant velocity gradients after a velocity model was found and the 26 foci relocated three different velocity models for three different zones covered by the network were succesfully inverted with the foci kept fixed the procedure was applied for first arriving p waves and also tried for s wave arrivals two low velocity zones were put into evidence

late pliocene quaternary tectonics in the frontal part of the se carpathians insights from tectonic geomorphology abstract the romanian east carpathians display large scale heterogeneities along the mountain belt unusual foredeep geometries significant post collisional and neotectonic activity and major variations in topography mostly developed in the aftermath of late miocene sarmatian 11 ma subduction underthrusting and continental collision between the east european scythian moesian foreland and the inner carpathians tisza dacia unit in particular the se corner of the arcuate orogenic belt represents the place of still active large scale differential vertical movements between the uplifting mountain chain and the subsiding focsani foredeep basin in this key area we have analysed the configuration of the present day landforms and the drainage patterns in order to quantify the amplitude timing and kinematics of these post collisional late pliocene quaternary vertical movements a river network is incising in the upstream a high topography consisting of the external carpathians nappes and the pliocene lower pleistocene sediments of the foreland further eastwards in the downstream this network is cross cutting a low topography consisting of the middle pleistocene holocene sediments of the foreland geological observations and well preserved geomorphic features demonstrate a complex succession of geological structures the late pliocene holocene tectonic evolution is generally characterised by coeval uplift in the mountain chain and subsidence in the foreland at a more detailed scale these vertical movements took place in pulses of accelerated motion with laterally variable amplitude both in space and in time after a first late pliocene uplifting period subsidence took place during the earliest pleistocene resulting in a basal quaternary unconformity this was followed by two quantifiable periods of increased uplift which affected the studied area at the transition between the carpathians orogen and the focsani foreland basin in the late early pleistocene and the late middle to late pleistocene both large scale deformation events affected the western focsani basin flank tilting the entire structure with 9 during the late early pleistocene and uplifted it as a block during the early late pleistocene the late early pleistocene tilting resulted in 750 m uplift near the frontal monocline and by extrapolation in a presumed 3000 m uplift near the central parts of the carpathians the late middle to late pleistocene cumulative uplift reaches 250 m and correlates with a contemporaneous progradation of the uplifted areas towards the focsani basin the uplifting events are separated by a second quaternary unconformity on the whole the late pliocene quaternary evolution of the carpathians orogen focsani basin structure indicate large scale differential uplift during the latest stages of a continuous post collisional orogenic evolution

large scale deformation in a locked collisional boundary interplay between subsidence and uplift intraplate stress and inherited lithospheric structure in the late stage of the se carpathians evolution 1 the interplay between slab dynamics and intraplate stresses in postcollisional times creates large near surface deformation particularly in highly bent orogens with significant lateral variations in mechanical properties this deformation is expressed through abnormal foredeep geometries and contrasting patterns of vertical movements intraplate folding is often the controlling mechanism particularly when the orogenic belt is locked the study of these tectonic processes in the se carpathians indicates a generalized subsidence period during latest miocene pliocene times driven by the slab pull and an intraplate folding due to an overall quaternary inversion the latter accommodates 5 km ese ward movement of this area with respect to the neighboring units which creates complicated three dimensional deformation patterns potentially driven at a larger scale by the interaction between the adriatic indentor and the entire carpathians system the lithospheric anisotropy inherited from the subduction times concentrates strain and induces large scale deformation far away from the active plate margins this anisotropy is dynamic because of deep mantle processes related to the subducted slab during postcollisional times such as thermal reequilibration or increase in slab dip

palaeotectonic reconstruction of the central alpine mediterranean belt for the neogene abstract the structural patterns of the central alpine mediterranean belt ranging from the eastern balearic sea to the western aegean sea have been reconstructed for 10 and 20 ma b p they have been obtained in the frame of the africa europe convergence through a step by step rigid plastic reconstruction using available geological and palaeomagnetic data all domains outlined in the present situation are shown in the palaeotectonic reconstructions while the structural pattern at 10 ma b p is similar to that of the present except for the tyrrhenian region that at 20 ma b p differs from it in most areas the well known adriatic promontory of the african plate is recognizable in both pictures and at 20 ma its original boundaries are revealed as strongly deformed flysch belts the adriatic promontory was broken up in the early or middle miocene into two microplates of comparable sizes the norther one is the adriatic microplate s s which suffered counter clockwise rotation by 20 relative to africa around the alpine apenninic whirl centre the southern one is the apulian microplate first outlined in the present work including the south apenninic and the apulian s s south of the gargano peninsula platforms which suffered no rotations relative to africa but which moved towards the northeast of it the primary reason for the break up of the adriatic promontory was most probably the opening of the balearic ligurian sea since 10 ma the adriatic and apulian microplates were again integral with africa or perhaps they moved towards the west relative to africa pushed by the turkish microplate the orogeny in the area discussed is mostly linked with collisional processes on the boundaries of the adriatic apulian unit

vertical movements in and around the south east carpathian foredeep lithospheric memory and stress field control a 10 km thick basin formed in tertiary to quaternary times in front and overlapping with the south east carpathians the focs depression is part of this system and overlies the vrancea seismogenetic volume thought to correspond to the remnants of the continental slab subducted beneath the carpathians slab detachment and its lateral migration are considered to control vertical movements in the area we present the first complete analysis of subsidence patterns in the depression and derive a substantially different picture the strongest subsidence is sarmatian in age coeval with the main nappe emplacement events subsequently subsidence did not stop and persisted until present times despite cessation of thrusting the main depocen

geodynamics and intermediate depth seismicity in vrancea the south eastern carpathians current state of the art abstract the vrancea region of the south eastern carpathians is a remarkable site of intra continental intermediate depth seismicity a large set of geological geophysical and geodetic observations has been accumulated for the last few decades and utilised to improve our knowledge of the shallow and deep structures beneath vrancea the crustal and mantle dynamics and the linkage between deep and surface processes in the region in this article we review geology and tectonics of the vrancea region including post collisional to recent deformations syn to post collisional magmatism and orogenic exhumation along the east and south carpathians the regional seismicity is analysed and the recent seismic studies including reflection refraction body and surface wave tomography are reviewed we discuss new geodetic measurements of horizontal and vertical movements in the region geoelectric studies density gravity and thermal modelling qualitative and quantitative including retrospective geodynamic models developed for vrancea are analysed the knowledge of regional tectonics geodynamics seismicity lithospheric deformation and stress regime in the vrancea earthquake prone region assists in an assessment of strong ground motion seismic hazard and risk the earthquake simulation seismic hazard and earthquake forecasting models have also been reviewed providing a link between deep geodynamic processes and their manifestation on the surface finally we discuss unresolved problems in vrancea in order to improve our understanding of the regional evolution present tectonics mantle dynamics intermediate depth seismicity and surface manifestations of the lithosphere dynamics and to enhance our ability to forecast strong earthquakes in the vrancea region the problems to be solved include i the origin of the high velocity body revealed by seismic tomography studies oceanic versus continental ii the lithospheric scale mechanism driving the miocene subsidence of the transylvania basin iii sub crustal structure between 40 and 70 km iv contemporary regional horizontal and vertical movements and v a comprehensive seismic hazard assessment in the region

the syn and post collisional evolution of the romanian carpathian foredeep new constraints from anisotropy of magnetic susceptibility and paleostress analyses abstract the first results of anisotropy of the magnetic susceptibility ams data from the romanian carpathian foredeep reveal compression directions generally perpendicular to the highly bended carpathian orogenic arc the distribution of the present day stress field in the pannonian carpathian region reflects pre imposed plate boundaries that were established during late miocene collision analysis of the ams along the eastern and southern carpathian foredeep at the contacts of the orogenic nappe pile the lower plate and the overlying sedimentary rocks indicates that two factors are critical for the distribution of the stress field during and after collision i e 1 the inherited highly bended plate geometry and 2 the quaternary deformation that lead to differential vertical and horizontal movements in the se carpathians the ams analysis was successfully used in the weakly deformed mio pliocene sedimentary rocks from the carpathian foredeep revealing information about the deformation history of the soft non competent rocks where the poor preservation of traditional kinematic indicators e g faults and folds is difficult

partial delamination of continental mantle lithosphere uplift related crust mantle decoupling volcanism and basin formation a new model for the pliocene quaternary evolution of the southern east carpathians romania abstract a geodynamic model is proposed for the mid miocene to quaternary evolution of the southern east carpathians in order to explain the relationships between shallow and deep geological phenomena that occurred synchronously during late collision tectonics in this area an active volcanic zone cross cuts since 2 my the suture between the overriding tisza dacia and subducting european continental plates mafic calc alkaline and alkaline magmas south harghita and persani volcanoes erupted contemporaneously these magmas were supplied by partial melting of the mantle lithosphere of the subducting and not of the overriding plate in an effort to decipher this geodynamically a typical setting of magma generation the spatial and temporal distribution of shallow and deep phenomena was successively examined in order to establish the degree of their interdependence our model indicates that intra mantle delamination of the subducting european plate is the principal cause of a succession of events it caused upwelling of the hot asthenosphere below a thinned continental lithosphere of the carpathians inducing the uplift of the lithosphere and its internal decoupling at the moho level by isostatic and mostly thermal effects during this uplift the crust deformed flexurally whilst the mantle deformed in a ductile way this triggered decompressional partial melting of the uppermost mantle lithosphere flexural deformation of the crust induced its fracturing allowing for the rapid ascent of magmas to the surface as well as reactivation of an older detachment horizon at the base of the carpathian nappe stack above which the brasov ciuc and gheorghieni hinterland basins formed by extension and gravity spreading the rapid subsidence of the focsani foreland basin is controlled by the load exerted on the lithosphere by the delaminated mantle slab that is still attached to it in this model crust mantle decoupling magma genesis and volcanism local near surface hinterland extension are consequences of uplift induced by asthenospheric upwelling triggered by intra mantle delamination this model enables to conceive that delamination induced decoupling began to be efficient 9 4 my ago at the northern end of the east carpathians when the mantle slab dipped westwards since then intra mantle delamination migrated laterally normal to the slab strike and follows the arcuate shape nw se sw of the carpathians nowadays whereas the mantle slab is still actively foundering below the vrancea seismic zone to the se of the most recent volcanic area south harghita persani a significant southwestward shift of the delamination process can be discerned

three dimensional imaging of the p and s wave velocity structure and earthquake locations beneath southwest iceland three dimensional imaging of the p and s wave velocity structure and earthquake locations beneath southwest iceland