active tectonics and quaternary basin formation along the vienna basin transform fault abstract the vienna basin transform fault is an active fault system extending over a distance of some 300 km from the eastern alps through the vienna basin into the west carpathians active sinistral movement is indicated by moderate seismic activity in a ne striking zone paralleling the fault focal plane solutions and recent stress measurements by analogy to the miocene kinematics we propose that the sinistral strike slip fault terminates in the carpathians where horizontal offset is transformed into thin skinned thrust type deformation hypocenter depths mostly well above 12 km are in line with the inferred thin skinned style of deformation with active faults restricted to the overthrust alpine carpathian units mapping of active fault segments in the vienna basin using subcrop data thickness maps of quaternary deposits seismological data and geomorphological features seen in the digital elevation model shows that virtually all active faults are reactivated miocene structures in the southern part of the basin active faulting defines a small scale pull apart structure with an actively subsiding quaternary basin which is filled with up to 140 m fluvial gravel sand and paleosoils for this basin quaternary sinistral displacement was quantified by adopting a geometrical model for thin skinned extensional strike slip duplexes accordingly 1 5 2 km sinistral slip accumulated during deposition of the basin fill in the last 400 ky corresponding to a slip rate of 1 6 2 5 mm y results are in good agreement with published gps data indicating 2 mm slip per year a second group of quaternary basins is related to listric normal faulting rollover and crestal collapse of the reactivated normal faults at the nw basin margin rollover also resulted in tilting and dissecting late pleistocene river terraces of the danube

3 d modelling of the crustal s wave velocity structure from active source data application to the eastern alps and the bohemian massif summary here i present results from 3 d modelling of crustal s wave velocities in the eastern part of the eastern and southern alps and the southern part of the bohemian massif data were acquired between 2000 and 2003 during three large 3 d wide angle reflection and refraction experiments the surveys aimed at the p wave velocity structure of the crust and uppermost mantle and therefore only vertical component geophones were used nevertheless many shot gathers show strongs waves in particular refractions from the crust sg waves and reflections from the moho discontinuity sms waves compared to p wave arrivals the traveltimes of s waves can only be picked with a relatively large uncertainty furthermore approximately 80 per cent of the data represent crossline recordings on which it is more difficult to assign certain phases to the arrivals for these reasons i apply signal detection and stacking routines to put the 3 d data set to best possible use concerning the crust a smooth 3 d velocity model is based on refractions from within the crust sg whereas the crust mantle boundary is modelled by reflections sms from the moho discontinuity considering that the projects were designed for p wave studies the proposed methodology provides surprisingly detailed images s wave velocities and poisson s ratio correlate with tectonic units and show significant features in the upper crust a high poisson s ratio is observed in the moravian part of the bohemian massif in the southern alps and in the northern calcareous alps and their basement within the eastern alps the middle and lower crust are only covered in the moldanubian part of the bohemian massif where poisson s ratio is low this would favour a felsic composition the evaluation of sms waves is in accordance with previously proposed p wave velocity models which indicate a fragmentation into three crustal blocks in the centre of the eastern alps

states of paleostress north and south of the periadriatic fault comparison of the drau range and the friuli southalpine wedge this study focuses on the analysis of structures and kinematics of a n s profile along the axis of maximum shortening of the european eastern alps the area includes the southern austroalpine unit in the north and the southalpine unit which is a part of the adriatic indenter the stratigraphically different units are separated by the periadriatic fault the major strike slip fault within the alps in order to assess the kinematics of these units mainly fault slip data from north and south of the periadriatic fault were analyzed we distinguish a succession of five main kinematic groups in both units 1 n s compression 2 nw se compression 3 ne sw compression 3 changes gradually from subvertical to subhorizontal 4 n s compression and 5 nw se compression our study reveals that the deformation sequence on either sides of the paf is similar the mean orientations of the principal stress axes however show small but consistent differences the subhorizontal axes north of the periadriatic fault plunge northward in the south southward a counterclockwise ccw rotation of the southern part in respect to the north is evident and in line with the well known counterclockwise rotation of the adriatic indenter as well as dextral displacement of the n fanning stress field along the periadriatic fault opposing plunge directions are interpreted as a primary feature of the internal stress field within an orogenic wedge further increased during ongoing compression

polyphase tectonic subsidence evolution of the vienna basin inferred from quantitative subsidence analysis of the northern and central parts the vienna basin is a tectonically complex neogene basin situated at the alpine carpathian transition this study analyzes a detailed quantification of subsidence in the northern and central parts of the vienna basin to understand its tectonic subsidence evolution about 200 wells were used to arrange stratigraphic setting and wells reaching the pre neogene basement were analyzed for subsidence to enhance the understanding of the regional subsidences the wells were sorted into ten groups based on their position on major fault blocks in the early miocene subsidence was slow and along e w to ne sw trending axis indicating the development of thrust controlled piggyback basins during the late early miocene data show abruptly increasing subsidence making the initiation of the vienna pull apart basin system from the middle miocene the tectonic subsidence curves show regionally different patterns the tectonic subsidence during the middle miocene varies laterally across the vienna basin and the differential subsidence can be related to the changing tensional regime of weakening transtension and strengthening extension toward the late middle miocene from the late middle miocene to the late miocene the tectonic subsidence occurred dominantly along the regional active faults and corresponds to the axis of e w trending extension of the western parts of the pannonian basin system in the quaternary the vienna basin has been reactivated and resulted in subsidence along the ne sw trending vienna basin transfer fault system

palinspastic reconstruction and topographic evolution of the eastern alps during late tertiary tectonic extrusion this paper presents a new palinspastic restoration of the eastern alps for neogene time and an attempt to reconstruct the neogene palaeogeology palaeotopography and palaeohydrography in connection with the structural evolution the eastern alps underwent radical horizontal displacement during the neogene due to large strike slip systems and formation of structural windows our palinspastic reconstruction considers a the rearrangement of tectonic units dismembered during tectonic extrusion b the tectonic denudation driven by displacement of the crystalline blocks c geochronological arguments and d the sedimentary record of the syn extrusion basins the rearrangement of tectonic blocks results in a remarkably good fit of highly dismembered zones both in crystalline and sedimentary areas and shows the pre miocene unstretched pattern of the eastern alps reduced to 65 of its present day e w elongation using this structural frame and considering the sedimentary record a set of palaeogeologic and palaeotopographic sketch maps with the palaeo river systems is presented for three time slices pre syn and post extension situation in late oligocene and early miocene times the western eastern alps were already mountainous whereas the eastern part of the orogen formed lowlands or hilly areas enhanced block movement in the course of the extrusion process around the early middle miocene boundary led to the formation of intramontane sedimentary basins and a fault induced reorientation of the drainage pattern which forms the basis of the modern river system in the area east of the tauern window this region where pre miocene land surfaces are preserved probably became a mountainous area not before late miocene time and never reached the elevations of the areas further west

laterally varying structure and kinematics of the molasse fold and thrust belt of the central eastern alps implications for exploration the molasse deposits of the central eastern alps are partly incorporated into a fold and thrust belt that recently has come into exploration focus the structural style and timing of deformation varies significantly alongstrike regional three dimensional seismic and well data interpretation indicate three different structural segments from east to west 1 the sierning imbricates have a decollement close to the base of the molasse sequence and consist of varying numbers of thrust sheets alongstrike early miocene shortening of the molasse is at least 6 2 km 3 9 mi overthrusting of the internal penninic and helvetic wedge since the oligocene accommodated at least 25 km 15 5 mi of additional shortening 2 the regau segment is dominated by one to two small thrust sheets above a shallow detachment this segment is dominated by overthrusting of the alpine wedge 3 the perwang imbricates consist of an oligocene wedge with complex deformed thrust sheets above a detachment horizon in upper cretaceous marls minimum shortening in the imbricates is 18 5 km 11 5 mi with overthrusting 33 3 km 20 7 mi all shortening estimates have an uncertainty of approximately 20 to 35 the laterally varying thrust belt architecture results from predeformational conditions e g sediment thickness mechanical stratigraphy and basement dip in the sierning imbricates hydrocarbon trap definition and charge issues are exploration risks in the regau segment exploration is focused on the subthrust play the perwang imbricates have hydrocarbon shows but no economic discoveries charge and seal issues are the main risks the petroleum systems in the context of the structural evolution are not yet fully understood

role of topography induced gravitational stresses in basin inversion the case study of the pannonian basin numerical stress models suggest that gravitational body forces associated with elevated topography around sedimentary basins can significantly influence the stress and strain pattern in basin interiors in the absence of tectonic forces basins surrounded by high altitude mountain ranges experience net horizontal compression owing to gravitational forces pointing from areas of high gravitational potential energy to subsided basin areas further lithospheric extension can eventually terminate leading to a gradual late stage inversion of the entire basin system modeling results suggest that the state of recent stress in the pannonian basin particularly in its western part is controlled by the interplay of plate boundary forces i e the counterclockwise rotation and northward indentation of the adriatic microplate against the alpine dinaric belt and buoyancy forces associated with the elevated topography and related crustal thickness variation of the alpine dinaric belt model calculations show that uplifted regions surrounding the basin system can exert compression on the thinned pannonian lithosphere of 40 60 mpa that is of the order of the assumed far field tectonic stress magnitudes the combined analysis of stress sources of tectonic and gravitational origin helps estimating the magnitude of maximum horizontal compression high levels of compressional stresses up to 100 mpa are concentrated in the elastic core of the lithosphere consistent with the ongoing structural inversion of the pannonian basin system

mineralogical geochemical and microbial investigation of a sulfide rich tailings deposit characterized by neutral drainage mineralogical geochemical and microbial characterization of tailings solids from the greens creek mine juneau alaska was performed to evaluate mechanisms controlling aqueous geochemistry of near neutral ph pore water and drainage core samples of the tailings were collected from five boreholes ranging from 7 to 26 m in depth the majority of the 51 samples 77 were collected from the vadose zone which can extend 18 m below the tailings surface mineralogical investigation indicates that the occurrence of sulfide minerals follows the general order pyrite fes 2 sphalerite zn fe s galena pbs tetrahedrite fe zn cu ag 12 sb 4 s 13 arsenopyrite feass and chalcopyrite cufes 2 pyrite constitutes 35 wt of the tailings mineral assemblage whereas dolomite camg co 3 2 and calcite caco 3 are present at 30 and 3 wt respectively the solid phase geochemistry generally reflects the mineral assemblage the presence of additional trace elements including cd cr co mo ni se and ti is attributed to substitution into sulfide phases results of acid base accounting aba underestimated both acid generating potential ap and neutralization potential np recalculation of ap and np based on solid phase geochemistry and quantitative mineralogy yielded more representative results neutrophilic s oxidizing bacteria nsob and so 4 reducing bacteria srb are present with populations up to 10 7 and 10 5 cells g 1 respectively acidophilic s oxidizing bacteria asob and iron reducing bacteria irb were generally less abundant primary influences on aqueous geochemistry are sulfide oxidation and carbonate dissolution at the tailings surface gypsum precipitation dissolution reactions as well as fe reduction below the zone of sulfide oxidation pore water ph values generally ranged from 6 5 to 7 5 near the tailings surface and from approximately 7 8 below the oxidation zone elevated concentrations of dissolved so 4 s 2 o 3 fe zn as sb and ti persisted under these conditions

evolution of retreating subduction boundaries formed during continental collision retreating subduction boundaries formed where the rate of subduction exceeds the rate of overall plate convergence appear to be commonly developed features within regions of early or incomplete continent continent collision they are characterized by regional extension within the overriding plate and at their leading edge by thin skinned arcuate thrust belts that are concave towards the overriding plate as is illustrated by examples from the mediterranean region the formation of retreating subduction boundaries is intimately related to the process of continental collision during the early stages of collision retreating subduction boundaries are commonly formed by lateral ejection from zones of crustal shortening along the main collision boundary retreating plate boundaries can also form before the main collision and the associated thrust belts emplaced as precollisional accretionary assemblages because the driving mechanism for retreating subduction boundaries appears to be gravity acting on a dense subducted slab slab pull subduction usually ceases when and only when thick buoyant continental crust enters the subduction zone thus differences in the evolution and duration of retreating subduction systems can be largely attributed to the size and configuration of the deep water regions available to be subducted in some cases retreating subduction boundaries may escape into the open ocean where they form nearly isolated local tectonic systems in these systems the rate of subduction is approximately compensated by the rate of upper plate extension and migration of the system across the oceanic region may be very rapid for example the horseshoe seamounts located about 800 km offshore in the eastern north atlantic may be the active expression of an east dipping westwardly migrating retreating subduction boundary that has evolved from the betic cordillera rif system active in miocene time and may now be progressing across the atlantic at approximately 50 mm yr an analogous situation may be represented by the scotia arc system a westward dipping retreating subduction system located between the south american and antarctic plates which may have escaped into the south atlantic ocean from a zone of crustal shortening in the andes and is now progressing across the atlantic at a rate of about 80 mm yr

dynamics of the polish and eastern slovakian parts of the carpathian accretionary wedge insights from palaeostress analyses the arcuate outer carpathian accretionary wedge formed in front of the east alpine carpathian pannonian alcapa megablock during the eocene sarmatian the wedge accreted sediments of the subducting remnants of the carpathian flysch basin a large oceanic tract left in front of the alpine orogen the palaeostress data for the orogenic hinterland particularly the data related to the early miocene extension that was expanding towards the ne combined with coeval subduction related volcanism that was expanding towards the ne indicate that the uneven roll back of the subduction zone was the main mechanism controlling the development of the northern west carpathian arc the palaeostress data for the tertiary accretionary wedge from the same time period are characterized by outward fanning 1 trajectories that changed gradually during the wedge development in contrast the palaeostress data for the hinterland are characterized by preferred directional stress events that changed abruptly during the wedge development these palaeostress results are in accordance with the behaviour of the wedge and the hinterland as the wedge behaved as a weak continuum and the hinterland behaved as a block mosaic with weak boundaries the fault traces of the northern west carpathian arc converge to both ends of the arc and suggest that the pre existing basin was the factor that controlled the arc location these fault trace patterns are asymmetric indicating a slightly oblique overall convergence in a ne sw direction in accordance with this convergence the palaeostress data for the accretionary wedge indicate that the western part of the wedge which is characterized by nw se oriented maximum principal compressional stress 1 was undergoing sinistral transpression meanwhile the eastern part which is characterized by ne sw oriented 1 was undergoing compression apparently the dynamics of the accretionary wedge was further influenced by the shape of an elongated ne sw trending alcapa megablock which was located behind the wedge and advanced in the direction of the general early miocene convergence during the most pronounced stages of the wedge development this megablock served as the local indenter as its strength surpassed that of the accretionary wedge located to its front further dynamic complexities were added because of the complex shape of the magura unit which was located in the most proximal portion of the wedge and was stronger than the units in front of it wedge outcrops indicate that the large scale shortening which is characterized by the development of detachments and ramps was preceded by an initial layer parallel shortening this is indicated by scaly fabrics and minor reverse faults that rotated into locked positions during the later accretion several outcrops with a wedge detachment fault indicate that there was a relatively low amount of friction during its development the decollement zone is several hundred metres thick and shows evidence of transient fluid flow that was driven by pressure gradients this is documented by frequent hydrofracturing sandstone dykes and fibrous veins that opened against the weight of the whole wedge all of which indicate cycles of higher pore fluid pressures that lowered the basal friction

changing patterns of exhumation and denudation in front of an advancing crustal indenter tauern window eastern alps the changing shape of indenting crustal blocks during northward motion of the adriatic microplate induced migration of miocene doming and orogen parallel extension of orogenic crust in the tauern window new structural and kinematic data indicate that initial shortening of the penninic nappe pile in the tauern window by upright folding and strike slip faulting was transitional to coeval north south shortening and east west extension the latter was accommodated by normal faulting at the eastern and western margins of the window retrodeforming these post nappe structures in map view yields a map view reconstruction of the orogenic crust back to 30 ma including the onset of pronounced indentation at 21 ma this model supports the notion that indentation involved approximately equal amounts of north south shortening and orogen parallel stretching and extrusion toward the pannonian basin as measured from the indenter tip to the european foreland in the north and austroalpine units in the east comparison of areal denudation of the orogenic crust before and after indentation indicate that erosion associated with upright folding was the primary agent of denudation whereas extensional unroofing and limited erosion along normal faults at the eastern and western ends of the tauern window accounted for only about a third of the total denudation

polyhalite microfabrics in an alpine evaporite melange hallstatt eastern alps in the hallstatt salt mine austria polyhalite rocks occur in 0 5 1 m thick and several metre long tectonic lenses within the protocataclasite to protomylonite matrix of the alpine haselgebirge fm thin section analysis of hallstatt polyhalites reveals various fabric types similar to metamorphic rocks of crust forming minerals e g quartz and feldspar polyhalite microfabrics from hallstatt include 1 polyhalite mylonites 2 metamorphic reaction fabrics 3 vein filling fibrous polyhalite and 4 cavity filling polyhalite the polyhalite mylonites contain a wide range of shear fabrics commonly known in mylonitic quartzo feldspathic shear zones within the ductile crust and developed from a more coarse grained precursor rock the mylonites are partly overprinted by recrystallised statically grown polyhalite grains metamorphic reaction fabrics of polyhalite fibres between blodite or astrakhanite na2mg so4 2 4h2o and anhydrite have also been found according to previous reports blodite may occur primarily as nodules or intergrown with loweite reaction fabrics may have formed by exsolution re crystallisation parallel growth or replacement this fabric type was only found in one sample in relation with the decomposition of blodite at ca 61 c in the presence of halite or slightly above testifying therefore a late stage prograde fabric significantly younger than the main polyhalite formation

lateral extrusion in the eastern alps part 1 boundary conditions and experiments scaled for gravity lateral extrusion encompasses extensional collapse gravitational spreading away from a topographic high in an orogenic belt and tectonic escape plane strain horizontal motion of wedges driven by forces applied to their boundaries in the eastern alps it resulted from 1 an overall northerly compression apulia against eurasia 2 a strong foreland bohemian massif 3 lack of constraint along a lateral boundary carpathian region and 4 a previously thickened gravitationally unstable thermally weakened crust eastern alpine orogenic belt six indentation experiments reproduce lateral extrusion at lithospheric scale the models have two to four lithospheric layers with a mohr coulomb rheology for the upper and a viscous rheology for the lower crust the lithosphere rests upon a low viscosity asthenosphere a broad indenter a narrow deformable area and a weakly constrained eastern margin fullfill as closely as possible conditions in the eastern alps indentation produces both thickening in front of the indenter and escape of triangular wedges lateral variations in crustal thickness become attenuated by gravitational spreading the overall fault pattern includes domains of reverse strike slip oblique normal and pure normal faults strike slip faults in conjugate sets develop serially the narrow width of the deformable area and the strength of the foreland determine the angles between the sets gravitational spreading produces a rhombohedral pattern of oblique and pure normal faults along the unconstrained margin opposite the unconstrained margin the indenter front shows thrusts and folds intersecting with the conjugate strike slip sets a triangular indenter favors spreading high velocity of indentation favors escape high confinement limits lateral motion inhibits spreading and favors thickening lateral extrusion in the eastern alps is best modeled by 1 a weak lateral confinement 2 a broad and straight indenter 3 a narrow width of the deformable area and 4 a rigid foreland crustal thickening lateral escape and gravitational spreading all contribute to the overall deformation

continental collision with finite indenter strength 2 european eastern alps 1 comparison of the results of a thin viscous sheet model with the velocity field determined by gps stations in the alpine pannonian realm shows that the adriatic plate is only slightly stronger than the eastern alps the observed velocity field is best approximated with a newtonian fluid however this scenario must be fairly recent as the overall geometry of the orogen can only be reproduced if the rheology contrast was about 1 10 before the late miocene the boundary conditions for this model are tested against the orientation of the intraplate stress field and are robust for argand numbers between 1 and 5 we conclude that the convergence rate between the adriatic and european plates must have slowed since the miocene and that the present day eastward extrusion of the eastern alps is largely due to lateral escape and only to a minor degree due to gravitational collapse scaled viscosities of the eastern alps are on the order of 1023 pa s

morphological analysis of the drainage system in the eastern alps abstract we study the morphology of the major rivers draining the eastern alps to test whether the active tectonics of this part of the orogen is reflected in the shape of channel profiles of the river network in our approach we compare channel profiles measured from digital elevation models with numerically modelled channel profiles using a stream power approach it is shown that regions of high stream power coincide largely with regions of highest topography and largest uplift rates while the forelands and the pannonian basin are characterised by a significantly lower stream power from stream power modelling we conclude that there is young uplift at the very east of the eastern alps in the bohemian massif and in the pohorje range the impact of the pleistocene glaciations is explored by comparing properties of rivers that drain in proximal and distal positions relative to the ice sheet during the last glacial maximum our analysis shows that most knick points wind gaps and other non equilibrium features of catchments covered by ice during the last glaciations salzach enns can be correlated with glacial processes in contrast the ice free catchments of the mur and drava are characterized by channels in morphological equilibrium at the first approximation and are showing only weak evidence of the strong tectonic activity within these catchments finally the channel profiles of the adige and the divide between the upper rhine and danube catchments differ significantly from the other catchments we relate this to the fact that the adige and the rhine respond to different base levels from the remainder of the eastern alps the adige may preserve a record from the messininan base level change and the rhine is subject to the base level lowering in the rhine graben

the tertiary dynamics of the northern eastern alps austria changing palaeostresses in a collisional plate boundary abstract six tertiary deviatoric palaeostress tensor groups from 165 stations in the calcareous alps describe the upper crustal dynamics of the leading edge of the adriatic plate during protracted continental collision with the european lower plate palaeostress changes are correlated to the kinematic evolution of the plate boundary and to independently derived plate kinematic data of the alpine carpathian pannonian area each palaeostress direction is defined by 32 to 89 individual tensors which constrain 1 late eocene to oligocene nw directed compression during thrusting and dextral shearing on wnw striking faults nw directed compression along the northern margin of the adriatic plate is correlated to its n directed translation combined with a counterclockwise rotation 2a late eocene to early miocene n directed compression during n directed thrusting of penninic and helvetic units and the molasse 2b early to middle miocene n directed strike slip compression during the onset of eastward lateral extrusion the change from nw to n directed compression is interpreted to result from strain partitioning at the periadriatic fault which has formed the new adriatic plate boundary since the oligocene dextral shearing on this fault accommodated continued anticlockwise rotation and decoupled the northern eastern alps from the rotational component n directed compression in the calcareous alps paralleled the n directed translation of the adriatic plate 3 middle miocene ne directed compression of thrust and strike slip type during lateral extrusion ne directed compression in the calcareous alps resulted from the drag of the eastward extruding central eastern alps sinistral shear stress was transmitted across the ene trending salzach ennstal fault ne oriented 1 axes include 45 with the e w striking zone of distributed sinistral shear in the calcareous alps 4 middle miocene e directed extension associated with orogen parallel normal faulting of the central eastern alps e directed extension paralleled the direction of mass transfer towards the pannonian basin during lateral extrusion normal faulting was induced by reduced lateral confinement due to removal of material east of the alps on the large scale eastward motion was enabled by the e directed retreat of the eastern carpathian subduction zone 5 late miocene e directed compression orogen parallel compression obstructed lateral extrusion the stress change from extension to e directed compression was caused by the end of subduction retreat in the eastern carpathians due to dynamic changes in the subduction zone 6 n directed extension late to post miocene extension paralleled recent topographic slopes in the foothill of the eastern alps palaeostresses changes correspond to distinct phases in the kinematic evolution of the northern eastern alps and to the systematic formation and reactivation of major fault zones wnw striking faults changed deformation styles from dextral shear to dextral transpression reverse faulting and finally to sinistral shear the early to middle miocene salzach ennstal fault which formed the northern boundary of the extruded central eastern alps changed from sinistral transpression to sinistral shear sinistral transtension and finally to dextral shear

growing folds and sedimentation of the gosau group muttekopf northern calcareous alps austria analysis of the three dimensional geometry of upper cretaceous clastics in the muttekopf area northern calcareous alps austria indicate fold and fault structures active during deposition coniacian continental to neritic sedimentation lower gosau subgroup was contemporaneous with displacements on nw trending faults and minor folding along ne trending axes from the santonian onwards sedimentation of the deep marine upper gosau subgroup the nw trending faults were sealed and large folds with wsw trending axes developed the direction of contraction changed to n s after the end of gosau deposition in the danian paleocene synorogenic sedimentation patterns indicate continuous contraction from the coniacian to the late maastrichtian danian therefore large scale extension as observed in the central part of the eastern alps cannot be documented in the western parts of the northern calcareous alps a combination of subduction tectonic erosion for the frontal parts and gravitational adjustment of an unstable orogen after nappe stacking for the internal parts possibly accounts for the different development of gosau basins in the frontal and trailing regions of the austroalpine wedge

palaeogeography and geodynamic evolution of the gosau group of the northern calcareous alps late cretaceous eastern alps austria abstract the sedimentation of the late cretaceous gosau group of the northern calcareous alps records the complex geodynamic evolution of the northern part of the austroalpine microplate the tectonically controlled sedimentation and facies distribution were mainly governed by the oblique subduction of the pennic ligurian ocean below the austroalpine margin most of the gosau successions comprise two distinct sedimentary complexes the lower gosau subgroup upper turonian campanian is characterized by terrestrial to shallow marine facies associations alluvial fan and fan delta deposits shallow marine sandstones and sandy limestones and storm influenced nearshore and shelf deposits during the early santonian sea level highstand a great part of the northern calcareous alps was covered by a shallow shelf sea palaeotransport directions point to source areas situated both to the north and to the south of the northern calcareous alps the upper gosau subgroup upper santonian eocene comprises deep water hemipelagic and turbiditic deposits rapid subsidence into bathyal to abyssal depths started diachronously from the northwest santonian to the southeast maastrichtian after a short phase of deformation and erosion abyssal deposits in the northern parts of the northern calcareus alps and north directed palaeotransport indicate a tilting of the slope towards the north this subsidence pulse is attributed to an event of subcrustal tectonic erosion probably triggered by the subduction of a topographic high of the south penninic ocean the relationships of the gosau group of the austroalpine unit to late cretaceous deposits of the carpathians and southern alps are discussed in the framework of a plate tectonic model

exploring the ar isotope record of an early miocene pseudotachylyte in an early oligocene intrusion rieserferner pluton eastern alps abstract we investigate the influence of unmelted clasts on the 40ar 39ar age record of a miocene pseudotachylyte within the early oligocene riesenferner pluton eastern alps this case study is ideal to investigate the effect of inherited ar retained in survivor clasts because although seismic faulting was only slightly younger 39ar laser analyses of low k microlitic domains free of discernable clasts yield slightly but significantly older ages than those from the high k matrix results suggest that older ages up to 4 on average from low k domains are due to contamination by plagioclase clasts and suggest an age of 17 12 0 22 ma for coseismic slip this age dates the last stage of activity of the giudicarie fault during tectonic indentation of the dolomites block of the southern alps against the nappe stack of the eastern alps

towards a mechanical model for the formation of the pannonian basin abstract new maps showing crustal and lithospheric thickness variations in the pannonian basin and the surrounding east alpine carpathian and dinaric mountains have been prepared on the basis of recent seismic seismologic and electromagnetic data a map presenting miocene faults of regional significance has been also constructed for the same region by using a wealth of recently available national and or more local studies it is suggested that observed crustal and lithospheric structural contrasts have been controlled primarily by neogene kinematic history of the region kinematic history is characterized by the following main patterns 1 1 indentation by adria and large scale backthrusting in the southern alps 2 2 eastward escape and extension of the eastern alps 3 3 extensional collapse in the pannonian basin area 4 4 formation of broad wrench fault systems along strike in the dinarides and southern carpathians and the western carpathians with dextral and sinistral shear respectively 5 5 compression and accretion of the external thrust and fold belt in the eastern carpathians these kinematic patterns are thought to be interrelated and all are manifestations of the late stage evolution of an overthickened orogenic wedge in order to arrive at a better understanding of the mechanism of extension which formed the pannonian basin deep crustal seismic profiles hydrocarbon exploration reflection lines and borehole data have been analyzed in the little hungarian plain this plain represents the transition zone between the alps and the pannonian lowlands and the results are illustrated by eight interpreted cross sections one result of regional importance is the clear recognition that the transdanubian central range at the southeastern flank of the little hungarian plain is composed of alpine pre senonian thrust sheets this finding marks the end of a century of debate the allochthony of the substrata of the pannonian basin can be now considered proven another result of more general interest is that these cross sections document the mode of lithospheric extension preexisting compressional detachment planes reactivate as low angle normal faults and lead to tectonic unroofing of deeply buried metamorphic terranes characterized by ductile flow along subhorizontal lineation

strengthening the link between geochronology textures and petrology time must be integrated with other geologic parameters such as pressure temperature p t composition or structural textural information in order to quantify the dynamics of geologic processes like mountain building faulting metamorphism or magmatism in the past this connection was weak due to large sample sizes required in geochronology however recent developments open up exciting new possibilities texturally controlled in situ dating of minerals utilizing uv laser ablation 40ar 39ar or rb sr microsampling facilitates the crucial link between ages and textures at high spatial resolution in situ u pb ages of accessory minerals can now be linked to the corresponding p t evolution via their characteristic trace elemental signatures indicative of mineral reactions in rocks garnet dating by sm nd and more recently lu hf can greatly benefit from both laser ablation inductively coupled plasma mass spectrometry icpms screening and improved leaching strategies improving the link between time and p t such integrated approaches can yield the duration and rates of deformation in shear zones the rates of burial and exhumation of subducted rocks or the duration of entire metamorphic loops to name a few potential for further development is identified in diverse areas dating of carbonate minerals related to brittle faulting using u pb could provide previously unavailable constraints on rates and duration of brittle deformation in the earth s upper crust in situ rb sr dating applicable to micas could become available using either laser ablation dynamic reaction cell icpms or microbeam accelerator mass spectrometry other future developments and trends and their limitations are discussed briefly

challenges in constraining ages of fluvial terraces in the vienna basin austria using combined isochron burial and pirir225 luminescence dating abstract burial dating with terrestrial cosmogenic nuclides and luminescence dating techniques have become two powerful tools to temporally constrain quaternary deposits a combination of both methods at the same geological setting has rarely been realized to date although their viable time frames overlap by several tens of thousands of years when middle pleistocene sediments with depositional ages ranging around ca 120 ka to ca 300 ka are targeted both methods are employed but come towards their lower and upper limits respectively a combined dating approach can be worthwhile at this age range and allows not only exploring the edges of both methods but holds the opportunity to do a cross check of results at an age spectrum where both dating techniques are at risk to become fuzzy here we present a case study where numerical ages of two middle pleistocene terraces located in the vienna basin were generated by combining burial and luminescence dating a variety of processes such as changing sediment input rates erosion and tectonics controlled the formation of fluvial terraces in the basin and shaped its complex modern surface age correlation of the evolved mosaic of blocks and dislocated sediment bodies is challenging and requires quantitative geochronological information in order to establish a coherent terrace stratigraphy luminescence and burial samples originating from two fluvial terraces the lower gaenserndorf terrace gdt and the higher schlosshof terrace sht were analyzed and evaluated luminescence and burial ages at the gdt site are in good agreement and suggest a depositional age of 140 170 ka bracketed by pirir225 luminescence ages ranging from 120 10 ka to 260 30 ka luminescence samples at the sht site are in saturation but provide minimum ages which are coherent with the burial dating result of 340 170 ka the new numerical ages indicate that the vertical offset between the gdt site and the sht site was not purely caused by fault activity but suggest two independent episodes of sediment accumulation besides providing new insights into the stratigraphic and morphological configuration of the central vienna basin area the cosmogenic nuclide data set is compelling from a methodological point of view at the gdt site several samples exhibited 26al 10be nuclide ratios exceeding the surface production ratio of 6 75 even though affected samples were excluded from burial age calculations a detailed investigation on possible scenarios which could have caused an upwards shift of 26al 10be ratios was carried out

syn convergent exhumation and lateral extrusion in continental collision zones insights from three dimensional numerical models abstract three dimensional thermomechanical finite element models are used to simulate the evolution of collisional orogens of finite axial extent special focus is on the spatial and temporal variations of stress and strain in the resulting orogen leading to lateral extrusion and syn convergent exhumation besides the collision zone the model incorporates an area which is not constrained by a convergent boundary condition and thus allows orogenic material to flow out laterally altogether 17 different model scenarios were tested starting from a model with standard material parameters and boundary conditions several variations concerning crustal temperature rheology convergence rates crust mantle coupling as well as the geodynamic setting of the evolving orogen are examined modelling results indicate that orogen parallel extension is intimately related to continental collision and occurs even during the early stages of convergence unless a rigid block adjoins and prevents lateral extrusion it typically reaches 20 40 of the amount of convergence the models show substantial spatial and temporal variations of stress and strain in the collision zone and its surrounding in particular the near surface stress field in the orogen s interior completely reorganises during convergence at later convergence stages the uppermost crust is subject to normal faulting while contemporaneously at deeper crustal levels compressive stress fields prevail the spatial relation of these different stress regimes in the orogenic crust strongly favours syn convergent exhumation by tectonic denudation finally a semiquantitative comparison between the modelling results and three modern collision zones in the alpine himalayan belt addresses the distribution of different tectonic styles the respective amounts of lateral extrusion as well as seismological observations

build up and dismembering of the eastern northern calcareous alps the structural geometry and kinematics of a segment of the classical fold and thrust belt of the northern calcareous alps nca is analyzed by map mesoscale fault slip and calcite twin data the most distinct feature of the eastern nca is the miocene semp salzachtal ennstal mariazell puchberg lineament which extends 400 km wsw ene from the northern tauern window in the west to the vienna basin in the east it forms an orogen parallel strike slip zone constitutes the major left lateral wrench corridor accommodating eastward lateral extrusion of crustal wedges along the central eastern alps and crosses the nca as an anastomosing zone of distributed shear the semp line and related structures dismember a fold and thrust belt formed during early transpressional and subsequent orthogonal contraction most early miocene structures are reversed in the late miocene accommodating little strain distinct strain fields are calculated based on fault slip and calcite deformation twin data they are regionally consistent in orientation and relative age and correlate with the following deformation stages 1 late cretaceous to early tertiary top to nw nappe stacking and right lateral wrenching along nw trending tear transfer faults as an expression of the build up of the austroalpine orogenic wedge e3 317 17 e1 058 28 e1 e2 e3 principal strains 2 early tertiary top to n stacking and conjugate strike slip faulting reflecting the change from transpressional to frontal contraction within the nca e3 356 12 e1 088 10 3 early to middle miocene large scale left lateral wrenching including early transpression and late transtension as expression of eastward displacement of the southern part of the nca e3 019 22 e1 109 27 4 post middle miocene e w contraction reactivating strike slip and normal faults e3 092 10 e1 004 12 the distributed nature of the lateral extrusion deformation and the anastomosing faulting along the semp line reflect the rheological heterogeneity inherited by the lithology and multiple deformations of the nca a combined extension and stress deflection model possibly accounts best for the pattern of northward concave faults branching off the semp line

active crustal deformation in two seismogenic zones of the pannonian region gps versus seismological observations abstract the seismicity and the associated seismic hazard in the central part of the pannonian region is moderate however the vulnerability is high as three capital cities are located near the most active seismic zones in our analysis two seismically active areas the central pannonian and mur murz zones have been considered in order to assess the style and rate of crustal deformation using global positioning system gps and earthquake data we processed data of continuous and campaign gps measurements obtained during the years 1991 2007 velocities relative to the stable eurasia have been computed at hgrn cegrn and epn gps sites in and around the pannonian basin uniform strain rates and relative displacements were calculated for the investigated regions gps data confirm the mostly left lateral strike slip character of the mur murz vienna basin fault system and suggest a contraction between the eastward moving alpine north pannonian unit and the carpathians the computation of the seismic strain rate was based on the kostrov summation the averaged unit norm seismic moment tensor which describes the characteristic style of deformation has been obtained from the available focal mechanism solutions whereas the annual seismic moment release showing the rate of the deformation was estimated using the catalogues of historical and recent earthquakes our analysis reveals that in the central pannonian zone the geodetic strain rate is significantly larger than the seismic strain rate based on the weakness of the lithosphere the stress magnitudes and the regional features of seismicity we suggest that the low value of the seismic geodetic strain rate ratio can be attributed to the aseismic release of the prevailing compressive stress and not to an overdue major earthquake in the mur murz zone although the uncertainty of the seismic geodetic strain rate ratio is high the seismic part of the deformation seems to be notably larger than in the case of the central pannonian zone these results reflect the different deformation mechanism rheology and tectonic style of the investigated zones

the tectonic expression slab pull at continental convergent boundaries examination of five thrust belt systems developed at continental subduction boundaries suggests that they comprise two distinct groups that display pronounced and systematic differences in structural style topographic elevation denudation metamorphism postcollisional convergence and foredeep basin geometry and facies the distinctive geological features developed within each thrust belt group appear to be causally linked to the relative rates of subduction and convergence via the magnitude of horizontal compressional stress transmitted across the subduction boundary at subduction boundaries where the rate of overall plate convergence is less than the rate of subduction termed here retreating subduction boundaries the transmission of horizontal compressive stress across the plate boundary is small and regional deformation of the overriding plate is by horizontal extension the tectonic expression of these retreating subduction boundaries includes topographically low mountains little erosion or denudation low grade to no metamorphism little to no involvement of crystalline basement in shortening little to no postcollisional convergence anomalously deep foredeep basins and a protracted history of flysch deposition within the adjacent foredeep basin analysis of deflection and gravity data across three retreating subduction boundaries apennine carpathian and hellenic systems shows that subduction is driven by gravitational forces acting on dense subducted slabs at depths between about 40 and 80 km carpathians 50 and 150 km apennines and 50 and 250 km hellenides the total mass anomalies represented by the slabs are approximately 3 1012 6 1012 and 12 1012 n m respectively the slabs are partially supported by flexural stresses transmitted through the subducted lithosphere to the foreland and partially supported by dynamic viscous stresses in the asthenosphere at subduction boundaries where the rate of overall plate convergence is greater than the rate of subduction termed here advancing subduction boundaries the transmission of horizontal compressive stress across the plate boundary is large and regional deformation of the overriding plate is by horizontal shortening the tectonic expression of these advancing subduction boundaries includes topographically high mountains antithetic thrust belts large amounts of erosion and denudation exposure of high grade metamorphic rocks at the surface extensive deformation of crystalline basement to midcrustal depths protracted postcollisional convergence tens of millions of years and a protracted history of molasse deposition within the adjacent foredeep basins analysis of gravity and deflection data across two advancing subduction boundaries developed within the continental lithosphere western to eastern and southern alps and himalayas shows that the thrust sheets have been translated for great distances over the foreland lithosphere relative to the point at which the subduction forces are applied thus obscuring any flexural and gravity signals from the subducted slab however it appears that far field stresses presumably related to global plate motions drive most of the convergent motion across these subduction boundaries the concept that orogenic belts formed above retreating subduction boundaries have recognizable tectonic signatures that differ from those of orogenic belts formed above advancing subduction boundaries suggests that it may be possible to interpret the plate boundary settings in which ancient orogenic belts evolved appendix b is available with entire article on microfiche order from the american geophysical union 2000 floridaavenue n w washington d c 20009 document t92 004 2 50 payment must accompany order

evolution of the pannonian basin system 1 tectonics the carpathian arc formed during cretaceous to miocene time by continental collision between europe and smaller continental fragments following southward and westward subduction of ocean floor during the last stages of thrusting in the outer carpathians a set of discrete basins formed behind the carpathian loop these basins are regions of middle to late miocene extension and are connected to each other and to areas of coeval shortening in the outer carpathian thrust belt by a system of strike slip faults sinistral northeast trending and dextral northwest trending sets of conjugate shears reflect overall east west extension of the intra carpathian region during middle to late miocene time palinspastic reconstruction of the basins indicates about 100 50 km of east west extension across the intra carpathian region during this time we interpret the vienna basin which is superimposed partly on the flysch nappes of the outer west carpathians as the result of thin skinned extensional tectonics above a shallow detachment surface within the crust extension of upper crustal rocks above this detachment was probably accomodated by thrusting of the outermost nappes of the west carpathians over the european platform extension of basins farther inside the carpathian loop probably involved rocks at deeper crustal levels and within the upper mantle the most internally situated basins formed by extensional processes that involved the entire lithosphere thus the depth to which extension occurred seems to be closely related to the proximity of each basin to the active thrust front in the carpathians this can be related to the geometry of the subduction zone extension within the intra carpathian basins began first in the northernmost basins and migrated southward and eastward over a ten million year period palinspastic reconstruction of the basins at three different times during the miocene 17 5 16 5 and 13 0 ma predicts eastward migration of the zone of thrusting and shortening within the carpathian mountains to accomodate the synchronous eastward and southward migration of areas of extension from these reconstructions about 120 60 km of east west shortening is predicted across the outer east carpathians from about 17 5 ma until present both predictions are in good agreement with the timing and magnitude of shortening in the carpathian thrust belt as determined directly from rocks within the belt from this we infer a close relationship for middle to late miocene extension of the intra carpathian region and middle to late miocene crustal shortening within the outer carpathians during middle and late miocene time deformation of the pannonian fragment was dominated by extensional and wrench tectonics except along a narrow zone in the outer carpathian thrust belt middle and late miocene thrusting in the carpathians is interpreted as the result of simple shear caused by relative motion between europe and the overriding pannonian fragment at the subduction boundary rather than of regional compression of lithospheric rocks at depth the initiation of extensional tectonics within the intra carpathian region in middle miocene time can be related to reorganization of major fragment boundaries of the eastern european alpine system

paleomagnetism and the adriatic promontory a reappraisal the geodynamic evolution of the western mediterranean area was influenced strongly by the adriatic promontory of the african plate which can be outlined at present by current seismicity and by facies and ophiolite distributions paleomagnetic results from different parts of the promontory contribute useful information about its past history the evaluation of these data is made difficult by the lack of a well defined apparent polar wander path for africa this has resulted in occasional overinterpretation of some paleomagnetic studies results from umbria and the southern alps cover a long enough period of time to define part of an apw path and support the idea that the promontory moved as an adjunct to the african plate during the late mesozoic and early cenozoic a conservative evaluation of cretaceous paleomagnetic data the most abundant for the promontory as a whole shows no strong evidence for previously proposed counterclockwise rotations of sicily or the southern alps relative to the african plate paleomagnetic data however suggest about 17 degrees counterclockwise rotation of autochthonous gargano and istria and about 25 degrees counterclockwise rotation of allochthonous umbria tectonic rotation of the middle part of the promontory appears to have occurred without significant rotation of its northern and southern extremities

the diavik waste rock project geochemical and microbiological characterization of drainage from low sulfide waste rock active zone field experiments abstract a field experiment was conducted at the diavik diamond mine to evaluate the potential for acid generation and metal release from the active layer of unsaturated waste rock piles in the arctic four active zone lysimeters azls were constructed in 2006 using high density polyethylene tanks filled with and surrounded by waste rock to evaluate the geochemical and biogeochemical characteristics in the upper 2 m of waste rock stockpiles two azls were filled with waste rock containing an average of 0 014 wt s predominantly as pyrrhotite type i azls and two azls were filled with waste rock containing an average of 0 035 wt s type iii azls the geochemistry and microbiology of the effluent from the azls was monitored for 4 years the effluent from the type iii azls was characterized by low ph

long range downstream effects of urban runoff and acid mine drainage in the debed river armenia insights from lead isotope modeling lead concentrations and isotopic compositions measured along 80 km of the debed river in the republic of armenia provide new insights into the geochemical and physical controls on riparian pb transport by allowing comparison of the long range downstream impacts of acid mine drainage with runoff from an industrialized city the modern background pb concentration in armenian surface waters is estimated to be 0 01 lg l based on analyses of remote alpine rivers in armenia the lead concentration in the debed river is 8 lg l 800 times background after passing through vanadzor the second largest industrial city in armenia it then decreases to 1 lg l before the debed river flows into the alaverdi mining district there the debed river receives waters from two mining drainage streams with pb concentrations 3000 lg l but those concentrations decrease 3 orders of magnitude to 3 lg l by the time the river exits armenia and flows into the republic of georgia isotope mixing plots show shifts in pb isotope composition as the river flows out of vanadzor evidencing the mixture of an average terrestrial pb composition 206 pb 207 pb 1 17 208 pb 207 pb 2 45 with past leaded gasoline and other industrial pb emissions retained in the river s sediments within that region 208 pb 207 pb 6 2 45 the isotopic composition again shifts e g 208 pb 207 pb p 2 46 as the river passes through the alaverdi mining district where isotopic ratios in the water are characteristic of pb in the area s massive sulfide deposits modeling both downstream elemental concentrations and pb isotopic compositions further resolves the physical and chemical behavior of the contaminants in the river system a multi element model of concentration gradients in the acid mine drainage streams indicates pb is attenuated by al oh 3 precipitation 54 of the loss and by adsorption onto other particles settling out of the water column 46 of the loss modeling of pb transport in the debed river indicates the natural outflow of pb is 10 kg a while the contributions from industrial runoff and acid mine drainage are each 10 3 kg a two orders of magnitude greater than the natural flux thus the total annual flux of pb from the debed river as it leaves armenia and flows into georgia is calculated to be 2500 kg a this value is consistent with the average annual pb flux of 2360 kg a estimated for the last 20 a the predicted effects of local climate change over the next 100 a may reduce annual pb flux by 10 15 slowing the removal of contaminant pb and maintaining the two order of magnitude increase over the natural flux 2004 elsevier ltd all rights reserved

geochemical mineralogical and microbiological characterization of a sulphide bearing carbonate rich gold mine tailings impoundment joutel quebec abstract the results of an integrated geochemical and mineralogical study conducted at the agnico eagle gold mine tailings impoundment joutel quebec are correlated with bacterial populations determined from an enumeration of 3 groups of thiobacilli the tailings were determined to contain approximately 5 wt sulphide s predominantly as pyrite and up to 30 wt carbonate minerals chiefly as dolomite ankerite and siderite the objective of the study was to evaluate the potential for the development of acidic drainage and dissolved metal migration in carbonate rich tailings impoundments and to compare the results of the geochemical and microbiological characterization of the tailings sulphide oxidation reactions have proceeded to a depth of 20 100 cm below the tailings surface pyrrhotite consistently shows more alteration than pyrite and arsenopyrite pyrrhotite is altered mainly through the replacement by goethite the most abundant thiobacilli are neutrophilic bacteria of the thiobacillus thioparus type the maximum most probable number values for these bacteria occur 20 40 cm below the tailings surface a depth that coincides with the disappearance of oxide coatings this observation coupled with the sharp decline in gas phase o 2 concentration suggests that rapid bacterially mediated s oxidation is occurring at this depth the pore water ph throughout the tailings varies between 6 5 and 8 5 no low ph waters were observed in the impoundment these neutral ph conditions are attributed to the effect of acid consuming carbonate mineral dissolution reactions which are also indicated by increased concentrations of mg and ca and alkalinity in the shallow zone of the tailings as a result of these acid neutralization reactions dissolved metal concentrations are low

kinematics of the alpine plate margin structural styles strain and motion along the penninic austroalpine boundary in the swiss austrian alps a structural and kinematic analysis of parts of the alpine suture zone i e the arosa zone and the edges of the overlying austroalpine and underlying penninic units is presented the arosa zone is interpreted as part of an accretionary wedge formed by the overriding of the austroalpine units the northern part of the adriatic plate over the penninic units structures strain and stretching trajectories indicate that two main deformation events followed each other discontinuously the earlier event was a wsw to nw directed thrusting under noncoaxial deformation and led to melange type structures the second event less penetrative in the arosa zone and with a downward increase in strain and noncoaxial flow formed n to ne verging folds and imbrication zones west directed displacement commenced in the early cretaceous and the motion changed to a prevailing northerly direction during the eocene as revealed by sediments involved in thrusting and by radiometric dating of the mylonites the kinematic history deduced from structural analysis agrees with the history obtained by recent work on plate margin sediments we correlate the anticlockwise rotation of the adriatic plate relative to europe between about 130 and 60 ma with the west directed motion in the arosa zone a change to relative n s motion during the lower tertiary led to the n to ne directed displacements a direct relationship thus exists between the motion of the adriatic plate and the resulting deformation along its northern margin during the early history of the eastern alps partitioning in brittle and ductile deformation and structural slicing under noncoaxial deformation is responsible for the melange type structures

the transylvania basin transfer zone between coeval extending and contracting regions inferences on the relative importance of slab pull and rift push in arc back arc regions 1 structural analysis and paleostress fault slip inversion of the transylvanian basin and its border regions with the surrounding east and south carpathians and the pannonian basin e g the apuseni mountains reveal at least two distinct tectonic phases for the neogene evolution for the eastern part of the pannonian basin system our main focus is on the role of the transylvanian basin and its border regions in the neogene as a transition zone between the extending pannonian basin and the converging east and south carpathians the results provide constraints on the mechanisms responsible for as well the formation of the transylvanian basin itself as on the relation between the basin formational processes operating in the pannonian basin and the contractional history of the east and south carpathian mountain belt in the middle miocene 17 14 12 myr the transylvanian basin underwent e w extension coeval with the first and major phase of overall e w extension affecting the pannonian basin and with submarine accretionary wedge tectonics in the east carpathian arc in the late miocene to early pliocene 12 8 6 myr the transylvanian basin experienced a strong pulse of e w oriented shortening coeval with the climax of compression in the east carpathians and a second rift phase affecting the pannonian basin continued contractional deformation affected the transylvanian basin during the pliocene and pleistocene with compression directions shifting to ese wnw directions

transpressional collision structures in the upper crust the fold thrust belt of the northern calcareous alps abstract two major structural events characterize the tectonic evolution of the northern calcareous alps nca 1 late early cretaceous to late eocene nw directed dextral transpressional stacking of nappes as an expression of the formation of the austroalpine orogenic wedge and 2 miocene sinistral wrenching due to eastward lateral extrusion of crustal wedges along the central eastern alps three first order detachment horizons are defined by differences of competence within areas of facies transition preexisting normal faults control the thrust architecture transpressional contraction in the nca is indicated by a nw directed thrusting oblique to both the long axis of the nca and the edge of the orogenic foreland b the occurrence of en echelon arrays of thrusts and folds laterally displaced by dextral strike slip faults the thrusts and strike slip faults are kinematically connected to each other and dissect the nca into rhomboidal blocks c ne directed extension parallel to fold and ramp axes and the internal strike of the nca and d clockwise rotation 30 of the entire nca around a vertical axis kinematic and dynamic analysis of mesoscale fault striae data related to transpressional stacking indicates a nw trend of contraction directions and in general a ne trend of the extension directions parallel to fold axes and branch lines of thrusts before rotation the average contraction direction was probably parallel to the generally w directed shear direction recorded in the crystal plastically deformed central part of the eastern alps three balanced cross sections across the nca yield a minimum of 54 65 total shortening

constraining long term fault activity in the brittle domain through in situ dating of hydrothermal monazite sims th pb dating of hydrothermal fissure vein monazite ce has the unique potential to date multiple tectonic events under low grade metamorphic brittle ductile conditions over large time frames monazites ce from brittle fault systems in the eastern alps allow us to constrain their cretaceous activity over 20 ma within single crystals recording all major tectonic events eo alpine formation of the fluid filled fissure veins occurred 90 ma ago at 352 19 c and 342 42 mpa this corresponds to peak conditions during regional metamorphism of the cretaceous collisional nappe stacking several stages of dissolution reprecipitation recrystallization record fault activity between 84 and 70 ma corresponding fluid inclusions indicate conditions of 229 10 c and 143 20 mpa this correlates with the formation of sedimentary basins during post orogenic extension associated with strike slip movements the results strengthen the hypothesis that many large fault systems in the eastern alps developed during the cretaceous orogeny and became reactivated during neogene alpine tectonics

fault slip analysis along the northern margin of the eastern alps molasse helvetic nappes north and south penninic flysch and the northern calcareous alps fault slip data are analyzed and paleostress tensors computed from 84 stations along the northern margin of the eastern alps between liechtenstein and vienna most fault sets resulted from more than one deformation heterogenous sets are divided into homogenous subsets by cross cutting relationships observed in the field and stress tensors are calculated separately for each subset the deviatoric stress tensors fall into six distinct groups that are regionally consistent in orientation stress ratio and relative age throughout the northern margin of the eastern alps from oldest to youngest the tensor groups are as follows 1 1 subhorizontal e w 3 subvertical thrusting related e w compression this group is only encountered in the south penninic flysch and the northern calcareous alps 2 1 subhorizontal n s 3 subvertical thrusting related n s directed compression 3 1 subhorizontal n s 3 subhorizonal e w strike slip faulting conjugate to n s compression 4 1 subvertical 3 subhorizontal e w e w directed subhorizontal extension 5 1 subhorizontal e w 3 subhorizontal n s strike slip faulting during e w compression and 6 1 subvertical 3 subhorizontal about n s 3 trajectories are oriented perpendicular to the general strike of the eastern alps and parallel topographic gradients the six trensor groups correlate with distinct steps in the cretaceous and the post eocene tectonic evolution of the northern units of the eastern alps 1 1 thrusting related e w compressional structures in the south penninic flysch and the northern calcareous alps are correlated to cretaceous top to w directed thrusting in the south penninic and austroalpine domains 2 2 thrusting related n s compressional structures encompass large scale folds with e w trending axes rare e w oriented thrust branch lines and cut off lines and s dipping ramps in the rhenodanubian flysch tensors reflect the stresses during northward thrusting in the late eocene early miocene 3 3 4 strike slip faults and extensional structures depicting n s compression and e w extension formed during the eastward lateral extrusion of the eastern alps prominent reactivations of strike slip faults during subhorizontal extension in the east and permutation between 1 and 2 reflecting periodic superposition of strike slip and normal faulting in the western eastern alps during overall e w extension suggest a close relationship of both tensor groups deformation resulted in the eastward lateral motion of the northern units of the eastern alps that started during the miocene 4 5 the significance of late miocene e w directed compression reactivating pre existing fractures and faults is presently not well understood we tentatively relate this event to a major change of boundary conditions within the miocene 5 6 the youngest deformation recorded is caused by surface uplift and gravitational collapse of the eastern alps

geochemical and mineralogical aspects of sulfide mine tailings abstract tailings generated during processing of sulfide ores represent a substantial risk to water resources the oxidation of sulfide minerals within tailings deposits can generate low quality water containing elevated concentrations of so 4 fe and associated metal loid s acid generated during the oxidation of pyrite fes 2 pyrrhotite fe 1 x s and other sulfide minerals is neutralized to varying degrees by the dissolution of carbonate oxy hydroxide and silicate minerals the extent of acid neutralization and therefore pore water ph is a principal control on the mobility of sulfide oxidation products within tailings deposits metals including fe iii cu zn and ni often occur at high concentrations and exhibit greater mobility at low ph characteristic of acid mine drainage amd in contrast hydr oxyanion forming elements including as sb se and mo commonly exhibit greater mobility at circumneutral ph associated with neutral mine drainage nmd these differences in mobility largely result from the ph dependence of mineral precipitation dissolution and sorption desorption reactions cemented layers of secondary oxy hydroxide and hydroxy sulfate minerals referred to as hardpans may promote attenuation of sulfide mineral oxidation products within and below the oxidation zone hardpans may also limit oxygen ingress and pore water migration within sulfide tailings deposits reduction oxidation redox processes are another important control on metal loid mobility within sulfide tailings deposits reductive dissolution or transformation of secondary oxy hydroxide phases can enhance fe mn and as mobility within sulfide tailings production of h 2 s via microbial sulfate reduction may promote attenuation of sulfide oxidation products including fe zn ni and tl via metal sulfide precipitation understanding the dynamics of these interrelated geochemical and mineralogical processes is critical for anticipating and managing water quality associated with sulfide mine tailings

orogen parallel extension and oblique tectonics the relation between stretching lineations and relative plate motions many collisional orogens exhibit two distinct deformation phases the first and relatively early phase forms within an obliquely subducting continent and is characterized by regionally consistent stretching lineations subparallel to the orogen and to associated isoclinal and sheath folds second phase folds and stretching lineations develop during and after imbrication of the subducting plate into the overriding plate and they become progressively disharmonic with stretching lineations oriented perpendicular to the orogen structural morphology and stretching lineations indicate that a fundamental kinematic transition occurs as material is imbricated from footwall to hanging wall kinematic modeling based on modern oblique convergent boundaries and considerations of buoyancy forces suggest that only the relatively early structures reflect the relative plate motion but that the correspondence is not simple in particular the orientation of stretching lineations is a function of finite strain kinematics of deformation and angle of subduction and convergence and it will consistently underestimate the angle of oblique convergence second phase structures reflect isostatic emergence of the hanging wall and are independent of relative plate convergence examples are drawn from the south central canadian rockies the western alps the variscides of ireland and france and the himalaya

long term mineralogical and geochemical evolution of sulfide mine tailings under a shallow water cover abstract the long term influence of a shallow water cover limiting sulfide mineral oxidation was examined in tailings deposited near the end of operation in 1951 of the former sherritt gordon zn cu mine sherridon manitoba canada surface water pore water and core samples were collected in 2001 and 2009 from above and within tailings deposited into a natural lake mineralogical and geochemical characterization focused on two contrasting areas of this deposit i sub aerial tailings with the water table positioned at a depth of approximately 50 cm and ii sub aqueous tailings stored under a 100 cm water cover mineralogical analyses of the sub aerial tailings showed a zone of extensive sulfide mineral alteration extending 40 cm below the tailings surface moderate alteration was observed at depths ranging from 40 to 60 cm and was limited to depths 60 cm in contrast sulfide mineral alteration within the submerged tailings was confined to a

ongoing tectonic reactivation of the outer carpathians and its impact on the foreland results of borehole breakout measurements in poland abstract the direction of present day maximum horizontal compression shmax tectonic stress was interpreted for 62 wells in poland using the method of borehole breakout analysis of 4 arm and 6 arm dipmeter logs the study area covers complex tectonic junction of the carpathian orogen and its foreland which comprises the east european craton eec divided by the teisseyre tornquist zone ttz from the palaeozoic platform of western poland for this area frequent deviation of the shmax direction from nw se characteristic for the atlantic ridge push has been interpreted in terms of the alcapa tectonic push in the upper silesian segment of the polish outer carpathians poc nne ssw oriented shmax in the accretionary wedge differs significantly from nnw sse shmax in the autochthonous basement the above discrepancy points to uncoupled type of the suture in this segment of the poc in this scenario the alcapa push involves the nappes and is compensated in the top of the basement which is expressed by systematic shmax rotations in the accretionary wedge of the eastern malopolska segment shmax follows the trend perpendicular to the strike of nappes it is in general agreement with nne ssw oriented shmax in the autochthonous basement that also parallels the alcapa push direction similarity in stress orientation between these structural levels implies coupled suture zone in this segment of the poc further to the north alcapa push is transmitted into the foreland plate where it causes n s orientation of shmax as determined for sedimentary cover of the eec within the baltic portion of the eec further shmax rotation towards the intermediate nnw sse position suggests balance between the alcapa push and the ridge push components within the ttz common shmax rotations from n s to nw se indicate structurally controlled accommodation of the alcapa push in the palaeozoic platform of western poland mesozoic complex of the fore sudetic monocline reveals nne ssw directed shmax that differs from nw se oriented shmax in the variscan accretionary wedge here mechanical decoupling along zechstein evaporates is likely presented set of breakout data from poland shows that recent compressive reactivation of the carpathians exerts strong impact on the stress field of the foreland plate at a distance of 700 km from the suture due to this effect the fore carpathian stress domain within the north european stress province can be discriminated

the diavik waste rock project geochemical and microbiological characterization of low sulfide content large scale waste rock test piles abstract two experimental waste rock piles test piles each 15 m in height 60 m 50 m were constructed at the diavik diamond mine in northern canada to study the behavior of low sulfide content waste rock with a similarly low acid neutralization potential in a continuous permafrost region one test pile with an average of 0 035 wt s 4 2 and dissolved metals with a decrease in ph to 1 ni 2 3 mg l 1 cu 3 7 mg l 1 zn 35 g l 1 cd and 3 8 mg l 1 co corresponded to decreases in flow rate which were observed at the end of each field season when the contribution of the total outflow from the central portion of the test pile was greatest bacteria were present each year in spite of annual freeze thaw cycles the microbial community within the type i test pile included a population of neutrophilic s oxidizing bacteria each year changes in the water quality of the type iii test pile effluent were accompanied by changes in the microbial populations populations of acidophilic s oxidizing bacteria and fe oxidizing bacteria became more abundant as the ph decreased and internal test pile temperatures increased irrespective of the cold climate conditions and low s content of the waste rock the geochemical and microbiological results of this study are consistent with other acid mine drainage studies indicating that a series of mineral dissolution precipitation reactions controls ph and metal mobility and transport is controlled by matrix dominated flow and internal temperatures

lower miocene structural evolution of the central vienna basin austria abstract the tectonic evolution of the vienna basin overlying the alpine carpathian fold and thrust belt includes two stages of distinct basin subsidence and deformation the earlier phase contemporaneous with thrusting of the alpine carpathian floor thrust is related to the formation of a wedge top basin piggy back which was connected to the evolving foreland basin lower miocene c 18 5 16 ma this stage is followed by the formation of a pull apart basin middle to upper miocene c 16 8 ma sediments of the latter unconformably overly wedge top basin strata and protected them against erosion analyses of subcrop data from the central part of the basin focus on the complex stratal geometries and tectonics of the lower miocene wedge top basin during that period the overriding allochthon is characterised by syntectonic subsidence and sedimentation out of sequence fold thrusting normal faulting and sinistral wrenching all types of faults are dated as lower miocene by the occurrence of growth strata and the age of overlying post tectonic sediments related to the pull apart basin stage faults mapped in 3d seismic are compared to faults along the sw margin of the vienna basin they prove that complex lower miocene deformation occurred in large parts of the austroalpine overriding nappes concurrent with thrusting at the alpine floor thrust and in the molasse unit the structural analysis of 3d seismic data shows that lower miocene sediments of the ottnangian and karpatian stage unconformable overly the alpine carpathian thrust nappes with a thickness of up to 1500 m geometries include onlaps to the basin floor internal unconformities and toplaps to the overlying middle miocene sediments these toplaps are the results of tilting and subsequent erosion of the sediment pile by out of sequence thrusting in the central part at the karpatian badenian transition c 16 3 ma prior to the onset of pull apart deformation

microbial populations associated with the generation and treatment of acid mine drainage bacterial populations and water chemistry were profiled throughout the groundwater flow system associated with the nickel rim mine tailings impoundment ontario canada groundwater containing high concentrations of sulfate 2000 12 000 mg l and iron 500 4000 mg l flows from the tailings into an adjacent aquifer a portion of the plume then discharges to the surface where ferrous iron is oxidized creating low ph ph 3 conditions the remaining groundwater passes through a permeable reactive barrier which induces sulfate reduction and metal sulfide precipitation elevated populations of iron oxidizing bacteria iob and sulfur oxidizing bacteria sob are restricted to hydrologically defined zones of recharge and discharge sulfur oxidizers are highest in the tailings 1 27 103 most probable number mpn g where sulfide minerals are exposed to oxygen and oxygen rich recharge water iob were highest 9 56 105 mpn g where tailings derived effluent rich in fe ii discharges to the aerobic surface water environment populations of both iron and sob bacteria in the zone of active oxidation are low compared to those found at other less mature tailing sites active oxidation in the nickel rim tailings is occurring immediately above the water table where the water content is high the high water content limits oxygen ingress and sulfide oxidation and the associated populations of oxidizing bacteria are low populations of sulfate reducing bacteria srb are elevated in the tailings and in portions of the down gradient aquifer where organic carbon concentrations are high the highest population 3 73 107 mpn g of srb were found where sulfate bearing water migrates through the organic carbon rich permeable reactive barrier at locations with high populations of srb elevated populations of sob were also found suggesting sob in these zones are metabolizing the reduced sulfur species produced by the srb in adjacent but disparate redox microenvironments

conversion of carbonaceous material to graphite within the greywacke zone of the eastern alps morphology and reflectance of carbonaceous material cm in late carboniferous metasediments of the eastern greywacke zone eastern alps indicate a mixture of vitrinite grainy textured and lamellar shaped particles as imaged by high resolution atomic force microscopy vitrinite and the grainy textured particles show mesophase structures which can be described as facetted nanocrystals within the carbon matrix high resolution transmission electron microscopy has revealed two types of microtextures representing different degrees of graphitization the first type is characterized by elongated ring shaped microtextures whereas the second type is characterized by graphite lamellae and polygonal flakes with long range ordered aromatic layers in spite of the heterogeneity of the cms the geographical distribution of quantitative metamorphic parameter raman spectra parameter x ray diffraction pattern microscopic reflectance suggests a graphitization process which is promoted by advective heat transport during post collisional processes in a tentative pressure time path late cretaceous thrusting results in a turbostratic ordering of the aromatic layer ordering to long range ordered aromatic layers was achieved during the late cretaceous paleogene exhumation of mid crustal rocks beneath the eastern greywacke zone

geochemical evolution of inactive pyritic tailings in the elliot lake uranium district geochemical data obtained between 1979 and 1983 from a network of piezometer nests and cores from three inactive uranium tailings impoundments in the elliot lake district indicate that oxidation of pyrite taking place in the shallow part of the zone above the water table is causing the chemistry of the pore water above and below the water table to change a two layer hydrochemical zonation has developed in which infiltration water from rain and snow has resulted in an upper zone of low ph water with high concentrations of so4 fe and heavy metals this zone is gradually expanding downward at rates generally between 0 2 and 2 m year causing displacement of the original mill process water which has neutral ph and low concentrations of heavy metals high concentrations of fe iii at shallow depth in the zone above the water table indicate that ferric iron is an important oxidizer of pyrite in the presence of free oxygen the pe of the groundwaters is controlled by the ferric ferrous redox couple and trend

waste rock hydrogeology and geochemistry abstract the oxidation of sulfide minerals in waste rock has the potential to generate low quality drainage that can present a significant challenge to mine owners regulators and other stakeholders challenges involved in managing waste rock include the large volume of waste rock produced and the difficulty in predicting the quality and quantity of leach water due to the chemical and physical heterogeneities in the waste rock and the highly non linear coupling of geochemical and physical processes many important studies have been conducted over the past decade particularly at the field scale that have investigated the geochemical hydrological microbiological and gas and heat transport aspects of waste rock these studies show that although the parameters and processes that influence amd generation and solute release are fundamentally similar between different waste rock piles major differences in the dominant mechanisms of water gas and heat transport result from differences in the physical and mineralogical properties of the rock piles and the climatic conditions including the amount of precipitation and prevailing temperatures accurate prediction of the leach water quality from waste rock requires a detailed characterization of the properties of the rock piles and the coupling of processes specific to the particular conditions this paper provides a review of the physical and mineralogical characteristics of waste rock piles followed by a discussion of the principal processes related to sulfide oxidation and solute loading and concluding with a discussion on acid mine drainage prediction and prevention techniques

redistribution of recent collision push and ridge push in central europe insights from fem modelling summary 2 d elastic finite element models of the recent stress field of central europe are built to evaluate the loads exerted on the continental boundary and the magnitude of tectonic stresses within the continental part of the plate the models comprise 24 tectonic blocks their stiffness is either constant throughout the model or varies from block to block 16 fault zones and 12 geologically significant boundary segments we have obtained a relatively unique balance of external tectonic forces by 1 careful adjustment of calculated stress directions and regimes to complex pattern of stress from data and 2 by calibration with gravitational potential energy a high level of compression ca 9 10 12 nm 1 exerted to the short ionian side of the adriatic indenter is crucial for the stress field pattern in central europe the adria microplate rotates due to eccentricity between the africa push from the south and the alpine buttress to the north a free boundary of the apennines does not contribute significantly to this motion kinematics of this indenter is controlled by friction on the dinaric suture which in turn is decisive for strain energy distribution between the alpine and the pannonian domains the predicted pronounced extension in the greece aegean segment 2 5 10 12 nm 1 implies active pull transferred from the hellenic subduction zone this extension releases stress in the balkan pannonian region and enables the eastward escape of tectonic blocks in front of advancing adria significant changes of tectonic push trends are found along the black sea caucasus boundary segment and at the european passive margin from the north sea to the arctic ocean differential stresses in central europe are estimated in the range of 10 60 mpa when averaged over the 30 80 km thick mechanically heterogeneous lithosphere the maximum stiffness contrast across the model is predicted to be of one order of magnitude apparent friction coefficients of fault zones differ between the north european part of the plate 0 4 0 7 the pannonian region 0 15 0 25 and the dinaric suture 0 55

u pb ages of apatite in the western tauern window eastern alps tracing the onset of collision related exhumation in the european plate we performed single spot u pb analyses of zircons and apatites from eighteen samples distributed along three sections crossing the western tauern window eastern alps zircon analyses yield concordant ages of similar to 295 ma dating the variscan emplacement of the zentralgneiss batholith common pb corrected apatite u pb ages show two age groups the first is characterized by apparent pb 206 u 238 ages scattering between similar to 300 and 40 ma and a second having a relatively uniform cluster of age values around 30 ma we applied an age extractor algorithm tuffzirc isoplot to all apatite analyses of each sample to calculate median ages from the younger age cluster and asymmetric 2 sigma errors as their uncertainties which are mostly in the range of similar to 10 these median ages are interpreted to date cooling below similar to 450 500 degrees c during alpine orogeny after the thermal climax of barrovian metamorphism in the western tauern window cooling ages give a consistent pattern over the study area of similar to 31 29 ma along each section younger cooling ages were obtained in the center compared to its margins the eastern section shows older cooling ages of similar to 36 34 ma whereas the western section younger cooling ages of similar to 26 25 ma the reliability of both age trends 1 younging towards the centers of the sections and 2 younging towards the west across all three sections were verified by six independent two sample student s t tests spatially the cooling age pattern resembles those observed from geochronometers having lower closure temperatures similar to 375 110 degrees c that are largely related to doming of the tauern window cooling rates of five samples where additional fission track ages are available yielded uniform results and were averaged to 15 3 1 9 k myr 2 sigma linear extrapolation using the specific cooling rates and the estimated maximum temperature t max indicates a time range of similar to 37 34 ma interpreted to date the thermal climax of barrovian metamorphism in the western tauern window

carbon isotope evidence for microbial involvement in exotic copper silicate mineralization huinquintipa and mina sur northern chile exotic copper silicate and oxide mineralization a peripheral facies of several cenozoic porphyry cu mo systems in northern chile is traditionally ascribed to the lateral migration of cu rich initially highly acidic waters away from active zones of supergene leaching and sulfide enrichment copper precipitation as cu fe silicates and cu mn fe oxides in permeable accumulating pediment gravels or underlying fractured bedrock resulted in part from fluid neutralization attending hydrolytic alteration supergene activity was most intense in the late oligocene early miocene during a protracted middle cenozoic semiarid interval along the lower pacific slope of the central andean cordillera occidental samples from the huinquintipa and mina sur deposits contiguous with respectively the 32 7 to 34 4 ma rosario collahuasi and 31 1 to 34 6 ma chuquicamata porphyry centers were examined for carbon isotope evidence of the conditions of ore formation carbon was extracted as co2 from representative high grade chrysocolla rich samples using four different techniques combustion pyrolysis crushing and edta leaching and has a widely varying isotopic composition consistent with mixing of atmosphere derived carbon with a 13c value of 0 per mil plant derived carbon with 13c values between 25 and 15 per mil and carbon with exceptionally low 13c values of 47 per mil the extremely light carbon sampled primarily by leaching with a 10 percent edta solution is most plausibly ascribed to a microbial consortium including anaerobic methanogenic microbes the presence of mineralized carbon having such low 13c values provides evidence that microbial metabolism may have contributed directly to copper silicate precipitation in these deposits lower 13c values at huinquintipa than at mina sur could be attributed to higher water tables and higher toxic metal contents in the mineralizing fluids the new data reinforce the role played by microbes in the economically critical supergene modification of porphyry and epithermal ore deposits in the semiarid environment

routing of heterogeneous sediments over movable bed model verification a one dimensional numerical model of heterogeneous size density sediment transport has been developed to simulate the movement of graded sediments in natural and laboratory flow reaches predicted temporal and spatial variations in bed and armor layer grain size distributions eroded grain size distribution eroded thicknesses and total bedload transport rates compare quite favorably to observed variations in flumes the san luis canal colorado and the east fork river wyoming for a large variety of flow scales and flow conditions the main advantages of this model over others is the high degree of accuracy of model results obtained using only bed and flow variables as input the treatment of turbulent fluctuations of bed shear stress the minimization of calibration factors and the explicit treatment of multiple grain densities in addition only the active layer thickness must be calibrated

mesozoic and tertiary evolution of the alpine carpathian foreland in eastern austria abstract the bohemian massif partly covered by mesozoic sediments extends southward some 50 km under the alpine carpathian nappe complex a major basement spur devoid of mesozoic sediments and referred to as the south bohemian basement spur separates the jurassic cretaceous upper austrian basin from the lower austrian basin the latter came into evidence during the middle jurassic under a tensional setting late jurassic shelf carbonates and basinal shales were deposited under a tectonically quiet regime early cretaceous uplift of the south bohemian basement spur induced the truncation of jurassic strata along its margins transgressive late cretaceous elastics overlap the truncated jurassic series and locally onlap on basement upper austria latest cretaceous to paleocene foreland deformations may have caused a renewed uplift of the south bohemian basement spur the eocene to late miocene evolution of the molasse foredeep went hand in hand with the emplacement of the alpine carpathian nappe system differential movements between the eastern alpine nappes and the carpathian nappes combined with tensional stresses in the basement caused the subsidence of the vienna basin

are the alps collapsing abstract orogenic collapse is a process that transfers gravitational potential energy from regions of high potential energy to regions of lower potential energy this transfer is classically considered to be accomplished by extension in the orogenic core and by synchronous shortening in foreland regions of the orogen not all extensional features in collisional mountain belts need however reflect orogenic collapse normal faulting thrust faulting and strike slip faulting are all active in different parts of the alps today and reflect complex local responses to ongoing europe adria convergence the western alps is the only area today where extension and shortening radial to orogen trend occur synchronously and where orogenic collapse may be an important process elsewhere in the alps normal faults are oriented at a high angle to orogen trend and were primarily active in oligocene and miocene time most present day activity in the central and eastern alps is on strike slip faults that are accommodati

paleomagnetic implications on the evolution of the tethys belt from the atlantic ocean to the pamirs since the triassic abstract we first re examined the apparent polar wander curves for stable eurasia and africa since the triassic these curves were then combined together with curves of north and south america according to the kinematics of the atlantic ocean and a synthetic polar wander curve was given then most of the paleomagnetic results from the tethys mobile belt from the atlantic to the pamirs were analysed several groups of plates microplates and blocks can be seen first relatively stable regions like maghreb and sicily which have not moved much then we have a group formed by iberia sardinia italy and to a lesser extent corsica and the western and central alps for these blocks movements are anticlockwise rotations chiefly driven by the anticlockwise rotation of africa but they are sometimes stronger to the east a major change takes place the north of the aegean sea and the ionian zone are clockwise rotated and these rotations are recent oligocene miocene for the first part pliocene to the present for the second part a major problem arises in turkey caucasus and iran paleomagnetic results indicate a position far to the south of eurasia and at the same time geological evidence is in favour of a position close to eurasia we discuss these discrepancies

reconciling plate tectonic reconstructions of alpine tethys with the geological geophysical record of spreading and subduction in the alps article a new reconstruction of alpine tethys combines plate kinematic modelling with a wealth of geological data and seismic tomography to shed light on its evolution from sea floor spreading through subduction to collision in the alps unlike previous models which relate the fate of alpine tethys solely to relative motions of africa iberia and europe during opening of the atlantic our reconstruction additionally invokes independent microplates whose motions are constrained primarily by the geological record the motions of these microplates adria iberia alcapia alkapecia and tiszia relative to both africa and europe during late cretaceous to cenozoic time involved the subduction of remnant tethyan basins during the following three stages that are characterized by contrasting plate motions and driving forces 1 131 84 ma intra oceanic subduction of the ligurian part of alpine tethys attached to iberia coincided with eo alpine orogenesis in the alcapia microplate north of africa these events were triggered primarily by foundering of the older 170 131 ma neotethyan subduction slab along the ne margin of the composite african adriatic plate subduction was linked by a sinistral transform system to e w opening of the valais part of alpine tethys 2 84 35 ma subduction of primarily the piemont and valais parts of alpine tethys which were then attached to the european plate beneath the overriding african and later adriatic plates nw translation of adria with respect to africa was accommodated primarily by slow widening of the ionian sea 3 35 ma recent rollback subduction of the ligurian part of alpine tethys coincided with western alpine orogenesis and involved the formation of the gibraltar and calabrian arcs rapid subduction and arc formation were driven primarily by the pull of the gravitationally unstable retreating adriatic and african slabs during slow convergence of africa and europe the upper european iberian plate stretched to accommodate this slab retreat in a very mobile fashion while the continental core of the adriatic microplate acted as a rigid indenter within the alpine collisional zone the subducted lithosphere in this reconstruction can be correlated with slab material imaged by seismic tomography beneath the alps and apennines as well as beneath parts of the pannonian basin the adriatic sea the ligurian sea and the western mediterranean the predicted amount of subducted lithosphere exceeds the estimated volume of slab material residing at depth by some 10 30 indicating that parts of slabs may be superposed within the mantle transition zone and or that some of this subducted lithosphere became seismically transparent

the nysa morava zone an active tectonic domain with late cenozoic sedimentary grabens in the western carpathians foreland ne bohemian massif we give an interpretive review of the geological evolution of the nysa morava zone nmz a late cenozoic tectonically active region of the ne bohemian massif located at its contact with the western carpathians orogenic front this crustal domain delimited by generally nw se striking fault system is characterised by oligo miocene and plio pleistocene volcanic activity regionally anomalous weak historical and present day seismicity and increased co2 flux the nmz hosts several elongated mostly nw se trending graben like sedimentary basins upper morava basin system which are filled by more than 300 m thick succession of clastic fluvial lacustrine sediments of pliocene quaternary age based on geometric relations basin architecture coincidence of seismicity with co2 escape and sparse focal mechanism data a model is proposed which explains this active domain as a transfer zone developed between major wnw ese and nw se faults in a right lateral transpressional setting it is suggested that slow horizontal slip at these faults resulted in local permutations of the largest and medium stress directions and formation of transtensional crustal domains in the nmz moreover relation of the nmz to the alpine carpathian system and sedimentary grabens in its foreland is discussed the absence of paleogene and lower miocene deposits suggests that subsidence in the nmz was commenced later than in the european cenozoic rift system ecris which is in agreement with later thrusting in western carpathians at 17 ma the quantitative contrasts to the ecris in terms of faulting and subsidence rates are explained by the absence of lithospheric crustal thinning in the nmz

far field effects of late miocene subduction in the eastern carpathians e w compression and inversion of structures in the alpine carpathian pannonian region kinematic and paleostress data constrain a late miocene e w compressional event that affected the entire alpine carpathian pannonian system after 9 ma and prior to 5 3 ma the maximum horizontal compression directions obtained from 110 stations show a mean 1 orientation of 083 deformation is mainly strike slip e w directed compression followed early to middle miocene upper plate extension in the pannonian basin which was caused by the retreating subduction boundary in the outer carpathians this compressional event terminated early to middle miocene eastward lateral extrusion of the eastern alps and reverted strike slip faults which bounded earlier extruded wedges such as the salzachtal ennstal fault the periadriatic fault the mur murz vienna basin fault system and strike slip faults in the western carpathians e w compression caused the reorientation of the extension direction of the alpine crustal stack east directed tectonic unroofing of the metamorphic domes in the central eastern alps terminated between 9 and 6 ma and early to middle miocene orogen parallel e w extension switched to late miocene n s extension which parallels modern topographic slopes in the pannonian basin the change from synrift extension to late miocene compression during the postrift phase caused the pronounced postrift subsidence by stress induced downward flexure of the loaded lithosphere we relate late miocene e w compression to coeval late stage west directed subduction of the european plate below the eastern carpathians slab pull of the subducted plate caused subduction roll back and upper plate extension of the pannonian area up to the middle miocene subduction slowed down and ceased when up to 60 km thick buoyant continental crust entered the subduction zone during the short period of continued convergence e w directed compressive stress was transmitted across the subduction boundary into the upper plate compressive stress was transferred through the uppermost brittle crust of the earlier extended pannonian region into the eastern alps up to 1400 km behind the subduction zone e w compression terminated during the pliocene when the pliocene to recent nnw sse compressive stress field was established in central europe

geomorphic expression of neotectonic activity in a low relief area in an airborne laser scanning dtm a case study of the little hungarian plain pannonian basin abstract the nw corner of the little hungarian plain which lies at the junction of the eastern alps the pannonian basin and the western carpathians is a neotectonically active region linking the extrusional tectonics of the eastern alps with the partly subsiding little hungarian plain the on going deformation is verified by the earthquake activity in the region an extremely flat part of the area east of neusiedlersee the so called seewinkel has been investigated with airborne laser scanning als also known as airborne lidar techniques resulting in a digital terrain model dtm with a 1 m grid resolution and vertical precision of better than 10 cm the dtm has been compared with known and inferred neotectonic features potential neotectonic structures of the dtm have been evaluated together with geological maps regional tectono geomorphic studies geophysical data earthquake foci as well as geomorphological features and the quaternary sediment thickness values of the seewinkel and the adjacent parndorfer plateau a combined evaluation of these data allows several tectonic features with a relief of

styles of extension in the pannonian basin abstract structural interpretation of reflection seismic profiles reveals distinct modes of upper crustal extension in the pannonian basin while some subbasins in the pannonian basin complex show little extension planar rotational normal faults others are characterized by large magnitude of extension detachment faults metamorphic core complexes gravitational collapse of the intra carpathian domain combined with subduction zone roll back is thought to be the driving mechanism of the neogene back arc extension the very heterogeneously distributed extension is accommodated by transfer faults which bound regions characterized by different polarity direction or amount of extension in cross section these transfer faults are characterized by flower structures typical for strike slip faults seismic stratigraphic interpretations indicate that the non marine post rift sedimentary fill of the pannonian basin can be described in terms of sequence stratigraphy the exceptionally good seismic sequence resolution allows recognition of third order and also fourth order depositional sequences which may reflect the interplay of tectonics and eustasy and milankovitch scale climatic variations respectively

localized ductile shear below the seismogenic zone structural analysis of an exhumed strike slip fault austrian alps 1 the miocene salzachtal ennstal mariazell puchberg semp strike slip fault in austria allows study of the internal structure of a fault zone from the near surface to 30 km depth as it enters the tauern window along the rinderkarsee shear zone the semp fault passes from a dominantly brittle to a dominantly ductile structure the shear zone consists of three 1 to 100 m wide zones of brittle ductile and ductile deformation separated by 500 m wide zones of less deformed rocks the southern shear zone is mylonitic with ductile amphibole and plagioclase weak crystal preferred orientations imply that the main deformation mechanism was dislocation accommodated grain boundary sliding the northern and central shear zones are characterized by discrete millimeter wide shear zones with ductile quartz muscovite and biotite and brittle feldspar shear zone nucleation at the grain scale involved dislocation creep and the transformation of plagioclase to muscovite strain then localized in muscovite rich grain boundary shear zones that linked to form throughgoing shear zones

kinematic evolution of the tethys belt from the atlantic ocean to the pamirs since the triassic abstract we present an updated series of kinematic reconstructions of the major plates around the tethys from the atlantic ocean to the pamirs between the early jurassic and the present this set is used elsewhere as a basis for paleogeographic maps of the entire region the problems related to the positions of the continents in the lower triassic are also discussed no direct analyses of magnetic anomalies and fracture zones in the atlantic have been made rather all available poles and rotations have been tested in order to eliminate or minimize possible kinematic errors the reconstructions are shown for nine key geological periods which correspond to well recognized magnetic anomalies except for the jurassic cretaceous boundary and the cretaceous tertiary boundary which correspond to interpolated positions paleolatitudes have been drawn using the study of westphal et al 1986 an attempt has been made to take into account the displacements caused by formation of the continental margins and basins by stretching the resulting relative vector of motions along the northern boundary of the tethys shows a significant change 80 m y ago left lateral motion with compression dominates before whereas right lateral motion with compression dominates after to the east rates of motion vary by a factor of three with time and four maxima can be clearly related to tectonic events in the late jurassic late cretaceous eocene and post middle miocene to the west north of apulia on the contrary the motion rate has not changed significantly since the early cretaceous and is close to 1 cm yr as an average these rather complex adjustments in rates and directions of relative motion are produced in great part through a complex migration of the africa eurasia pole of rotation and seem to be mostly governed by the tectonics of the tethys plate boundary

evidence for east west crustal extension in the eastern alps implications for the unroofing history of the tauern window the contact between the western border of the tauern window and the overlying austroalpine nappes austria and italy is marked by a structural petrologic and geochronologic discontinuity that developed in the early stages of unroofing of the window within the window pressure temperature time paths j selverstone 1985 indicate that significant ductile thinning occurred shortly after the cessation of thrusting paleocene eocene sense of shear indicators rotated porphyroblasts asymmetric augen and pressure shadows s c fabrics associated with a west plunging stretching lineation indicate that this thinning occurred in response to top to the west low angle normal shear during metamorphism the same sense of normal shear is present in the mesozoic members of the austroalpine sequence west of the window in these rocks however west directed shear occurred at low temperatures 300 c after the thermal peak of metamorphism structural data and the regional geometry imply that the western end of the tauern window is a low angle normal fault brenner line that juxtaposed brittlely deformed rocks of the austroalpine nappes against more ductilely deformed rocks from the window biotite k ar and rb sr data suggest a miocene age for final movement on the brenner line these data indicate a prolonged history of east west extension in the eastern alps that affected all crustal levels early ductile thinning of lower crust followed by mid to upper crustal low angle normal faulting a model is presented that relates the young east west extension to displacement transfer from dextral movement on the periadriatic lineament in this model the brenner line and by analogy the simplon line can be thought of as detachment faults that tectonically unroofed the tauern window and lepontine thermal highs respectively

the palaeogene forearc basin of the eastern alps and western carpathians subduction erosion and basin evolution scarce palaeogene sediment remnants in the eastern alps and western carpathians are interpreted as remains of a continuous forearc basin new apatite fission track geochronological data corroborate mild paleocene eocene exhumation and relief formation in the eastern alps palinspastic restoration and nine palaeogeographical maps of the eastern alps and western carpathians ranging from the paleocene to the late oligocene epoch illustrate west to east migration of subsidence in the forearc basin subsidence isochrons indicate that oblique subduction of the european plate below the adriatic plate was responsible for forearc basin migration at a rate of 8 mm a 1 the periadriatic lineament was formed as a result of shearing by oblique subduction the neogene to recent sumatra forearc basin is an analogue for the evolution of the east alpine west carpathian forearc basin

fault slip analysis and late exhumation of the tauern window eastern alps exhumation of the eastern alps from the early tertiary to the late miocene was localized mainly in the tauern window a thermal and structural dome located in front of the dolomites indenter stress inversions based on new structural investigations over the entire tauern window indicate a regional zoning of the paleostress field with a predominance of strike slip states of stress in the core of the investigated area and dominant extensional regimes in the eastern and western borders of the dome few inverse fault structures have been highlighted we propose a two stage deformation history in order to explain the different types of structures that characterise the ductile and the brittle domains during the first stage of exhumation of the tauern window corresponding to the folding event the brittle crust was probably dominated by n s shortening and compression the second stage of exhumation was marked by normal faulting at the borders of the dome and strike slip faulting in the core during the second stage the brittle part of the crust that was previously affected by compressive structures belonging to the first stage was eroded normal faulting associated to e w extension along the eastern and western borders of the tauern window was accommodated by strike slip faulting located in the core of the tauern window yielding e w extension and n s shortening the orientation of the extensional axes and the nature of the stress tensors are similar to the ones inferred for the late stage brittle overprint of the internal basement massifs of the central alps pointing to a possible common large scale state of stress acting well beyond the area of the eastern alps

the structure of the hallstatt evaporite body northern calcareous alps austria a compressive diapir superposed by strike slip shear based on old detailed mining maps and own observations in the hallstatt salt mine we reinterpret the structure of the hallstatt evaporite body of the upper permian to lower triassic haselgebirge fm within the northern calcareous alps nca the haselgebirge fm represents a rocksalt mylonite with abundant lenses of sulphates mudstones and limestones in comparison to published results of analogue modeling we interpret the present shape of the hallstatt body as a wnw ese elongated compressive teardrop like diapir this is overprinted by nne ssw shortening and dominantly sinistral shearing along a w trending shear zone the internal structure shows steeply dipping rock units and foliation earlier dextral ductile shear fabrics of likely late early cretaceous age are preserved in sulphate rocks and are subsequently overprinted by mylonitic fabrics in rocksalt and cataclastic fabrics in other rocks the low strength of halite results in recent subvertical shortening and a strain rate e of 8 10 10 s 1 is deduced from deformed subhorizontal boreholes this value is similar to such strain rates 10 10 to 10 9 s 1 estimated by the halite grain size distribution from other salt mines in the nca and thus indicative of sub recent formation of the halite microfabrics

balancing lateral orogenic float of the eastern alps abstract oligocene to miocene post collisional shortening between the adriatic and european plates was compensated by frontal thrusting onto the molasse foreland basin and by contemporaneous lateral wedging of the austroalpine upper plate balancing of the upper plate shortening by horizontal retrodeformation of lateral escaping and extruding wedges of the austroalpine lid enables an evaluation of the total post collisional deformation of the hangingwall plate quantification of the north south shortening and east west extension of the upper plate is derived from displacement data of major faults that dissect the austroalpine wedges indentation of the south alpine unit corresponds to 64 km north south shortening and a minimum of 120 km of east west extension lateral wedging affected the eastern alps east of the giudicarie fault west of the giudicarie fault north south shortening was compensated by 50 to 80 km of backthrusting in the lombardian thrust system of the southern alps the main structures that bound the escaping wedges to the north are the inntal fault system ca 50 km sinistral offset the konigsee lammertal traunsee klt fault 10 km and the salzach ennstal mariazell puchberg semp fault system 60 km these faults as well as a number of minor faults with displacements less than 10 km root in the basal detachment of the alps the thin skinned nature of lateral escape related structures north of the semp line is documented by industry reflection seismic lines crossing the northern calcareous alps nca and the frontal thrust of the eastern alps complex triangle zones with passive roof backthrusts of middle miocene molasse sediments formed in front of the laterally escaping wedges of the northern eastern alps the aim of this paper is a semiquantitative reconstruction of the upper plate of the eastern alps most of the data is published elsewhere

environmental geochemistry of the guanajuato mining district mexico abstract the guanajuato mining district once one of the major silver producers in the world has been exploited for silver and gold from low sulfidation quartz and calcite rich epithermal veins since 1548 currently there are some 150 million tonnes of low grade ore piles and mine waste material mostly tailings piles covering a surface area of 15 to 20 km2 scattered in a 100 km2 region around the city of guanajuato most of the historic tailings piles were not deposited as formal tailings impoundments they were deposited as simple valley filling piles without concern for environmental issues most of those historical tailings piles are without any vegetation cover and undergo strong eolian and hydrologic erosion besides the natural leaching during the rainy season which can bring strong thunderstorms and flash flows there is public concern about possible contamination of the local aquifer with heavy metals fe mn zn as and se derived from the mining activities experimental and field data from this research provide strong geochemical evidence that most of the mine waste materials derived from the exploitation of the epithermal veins of the region have very low potential for generation of acid mine drainage due to the high carbonate sulfide ratio 12 1 and very low potential for leaching of heavy metals into the groundwater system furthermore geochemical evidence experimental and modeled indicates that natural processes like metal adsorption onto fe oxy hydroxides surfaces control the mobility of dissolved metals stable isotope data from surface water groundwater wells 150 m depth and mine water 300 to 500 m depth define an evaporation line d 5 93 18o 13 04 indicating some deep infiltration through a highly anisotropic aquifer with both evaporated water from the surface reservoirs and meteoric water not evaporated zinc concentrations in groundwater 0 03 to 0 5 ppm of the alluvial aquifer some 15 km from the mineralized zone are generally higher than zn concentrations in experimental tailings leachates that average less than 0 1 ppm groundwater travel time from the mineralized area to the alluvial valley is calculated to range from 50 to several hundred years thus although there has been enough time for zn sourced from the tailings to reach the valley zn concentrations in valley groundwater could be due to natural dissolution processes in the deep portions of the epithermal veins

identifying fault segments from 3d fault drag analysis vienna basin austria abstract the segmented growth of the markgrafneusiedl normal fault in the late miocene clastic sediments of the central vienna basin austria was investigated by construction of a detailed three dimensional 3d structural model using high resolution 3d seismic data the fault surface and marker horizons in the hanging wall and the footwall of the markgrafneusiedl fault were mapped and orientation displacement and morphology of the fault surface were quantified individual fault segments were identified by direct mapping of the deflection of the marker horizons close to the fault surface correlating the size of the identified segments with the magnitude of fault drag and displacement distribution showed that fault evolution progressed in several stages the proposed method allows the detection of segments that are not recorded by the magnitude of displacement or fault morphology most importantly detailed mapping of marker deflections in the hanging wall could help to constrain equivalent structures in the footwall which may represent potential hydrocarbon traps

evolution of lignite seams within the south moravian lignite coalfield based on certain qualitative data abstract this paper focuses on evolution of lignite seams the pannonian in the south moravian lignite coalfield smlc it is based on data analysis seam geometry ash yield sulfur content and lithology from more than 3300 boreholes and many channel samples the results show that the vienna basin in the pannonian period gradually developed into a freshwater bay in the early pannonian the sedimentary environment was tectonically calm the salinity of the sedimentary environment was changing as a consequence of recurring transgressions the studied area was under the influence of rivers flowing into the region from the west north and northeast in the upper part of zone b papp s classification of the pannonian sediments especially in the northern areas of the smlc suitable conditions for coal bearing sedimentation the kyjov seam occurred zones c f were characterized by simple or incomplete cyclic sedimentation processes the vienna basin opened and the subsidence between the steinberg fault zone and lu ice lan hot fault zone interconnected with the polesovice fault zone took place in the smlc at the beginning of zone f the swamp areas suitable for dub any seam formation developed in the smlc the coal forming conditions were repeatedly restored the sedimentary cycles with the coal bearing deposits occurred also in zone g however only in the central and southern parts of the smlc the increasing thickness of the deposits in zone g and the increasing number of cycles with lignitic layers in the southern part of the smlc indicate a shift of the suitable conditions for swamps towards the south and into the overlying rocks a distinct tectonic deformation of the lignite seam in the smlc started only in the pliocene when due to the change of the stress field in the vienna basin the rejuvenation of the tectonic zones of the pull apart system took place towards the ne sw and nw se to nnw sse

kinematics of the alpine arc and the motion history of adria the alps have been interpreted traditionally in terms of north or northwest directed convergence between africa and europe1 with adria the continental underpinnings of the adriatic sea and northern italy acting as a promontory of the african continent2 this has been supported by recent analyses of africa europe relative plate motions3 5 which indicate dominantly north south directed convergence during the tertiary phase of intracontinental shortening we show here however that kinematic indicators from alpine tectonites are difficult to reconcile with this motion history figs 1 and 2 and are explained best by roughly west northwest directed adria europe motion since about 70 million years ago combined with an arc normal pattern of motion driven by local body forces this implies that adria has moved independently of both africa and europe since at least the late cretaceous

quantifying early miocene in sequence and out of sequence thrusting at the alpine carpathian junction a detailed reconstruction of late oligocene and early miocene thrusting at the leading edge of the east alpine fold thrust belt is achieved from well data seismic and interpretative cross sections data are used for constraining the paleogeographic positions of the alpine thrusts quantifying in sequence out of sequence thrust distances assessing the timing of thrust propagation from structurally higher units into more external ones and estimating thrust velocities results are depicted in five palinspastic maps for time slices between 26 ma and 16 ma the termination of foreland propagating thrusting at the alpine front is apparently controlled by the subcrop topography of the european basement which includes a major recess in the east leading to a diachronic along strike termination of foreland propagating thrusting with younger thrust ages and higher in sequence thrust distances in the east early locking of foreland propagating thrusting in the west causes prominent out of sequence thrusts which add to the in sequence thrust distances there continuing consecutive detachment of foreland units in the east occurs at rather fast propagation velocities with time intervals between foreland thrust propagations ranging between 0 1 and 0 7 ma the resulting increase of in sequence thrust distances from west to east is balanced by out of sequence thrusts in the west the total amount of late oligocene to early miocene thrusting is quantified with a minimum of 51 km average thrust velocities range between 4 6 and 5 2 mm yr this rate refers to the movement of the basal thrust at the leading edge of the fold thrust belt which occurs contemporaneous with the eastward lateral extrusion of the eastern alps in the hinterland

dynamic modeling of the transition from passive to active rifting application to the pannonian basin we examine a number of first order features of pannonian basin evolution in terms of the feedback relation between passive far field induced extension and active raleigh taylor instable upwelling of the astheno sphere we show that active mantle upwelling following a phase of passive extension are viable mechanisms ex plaining the pannonian basin formation the dynamic interplay between far field driven passive extension and active thinning of the mantle lithosphere by convective upwelling beneath the rift zone is modeled using ther momechanical finite element methods our modeling results predict a first phase of passive lithospheric thin ning which is followed by a second phase of late synrift to postrift active mantle lithosphere thinning due to buoyancy induced flow beneath the rift zone we argue that the pattern of coeval extension in the thinning re gion and compression in the flanking regions may be explained by the buoyancy forces due to lithosphere thinning it is demonstrated that timescales of and stresses generated by both processes are comparable the model appears also to explain the occurrence of late shallow mantle related decompression melts in the pannonian region and late regional doming

crustal structure and active tectonics in the eastern alps 1 during the last decade a series of controlled source seismic experiments brought new insight into the crustal and lithospheric structure of the eastern alps and their adjacent tectonic provinces a fragmentation of the lithosphere into three blocks europe eu adria ad and the new pannonian fragment pa was interpreted and a triple junction was inferred the goal of this study has been to relate these deep crustal structures to active tectonics we used elastic plate modeling to reconsider the moho fragmentation we interpret subduction of eu below ad and pa from north to south and underthusting of ad mantle below pa from southwest to northeast the moho fragmentation correlates well with major upper crustal structures and is supported by gravity seismic and geodetic data an analysis of crustal thickening suggests that active convergence is associated with continued thrusting and lateral extrusion in the central eastern alps and thickening of the adriatic indenter under the southern alps according to the velocity relations at the triple junction pa moves relative to eu and ad along ene and se striking faults mainly by strike slip an eastward directed extensional component is compensated by the lateral extrusion of the central eastern alps the periadriatic insubric line east of the triple junction and the mid hungarian fault zone have relatively recently lost their role as first order active structures we favor the idea that the pannonian fragment and the tisza block merged to a soft microplate surrounded by the eastern and southern alpine carpathian and dinaric orogens