evolution of a fold thrust belt deforming a unit with pre existing linear asperities insights from analog models abstract heterogeneity whether geometric or rheologic in crustal material undergoing compression affects the geometry of the structures produced this study documents the thrust fault geometries produced when discrete linear asperities are introduced into an analog model scaled to represent bulk upper crustal properties and compressed varying obliquities of the asperities are used relative to the imposed compression and the resultant development of thrust fault traces and branch lines in map view is tracked once the model runs are completed cross sections are created and analyzed the models show that asperities confined to the base layer promote the clustering of branch lines in the surface thrusts strong clustering in branch lines is also noted where several asperities are in close proximity or cross slight reverse sense reactivation of asperities cut through the sedimentary sequence is noted in cross section where the asperity and the subsequent thrust belt interact the model results are comparable to the situation in the dinaric alps where pre existing faults to the sw of the ne adriatic fault zone contribute to the clustering of branch lines developed in the surface fold thrust belt these results can therefore be used to evaluate the evolution of other basement involved fold thrust belts worldwide

eocene to present subduction of southern adria mantle lithosphere beneath the dinarides we modeled global positioning system measurements of crustal velocity along a n13 e profile across the southern adria microplate and south central dinarides mountain belt using a one dimensional elastic dislocation model we assumed a n77 w fault strike orthogonal to the average azimuth of the measured velocities but we used a constrained random search algorithm minimizing misfit to the velocities to determine all other parameters of the model the model fault plane reaches the surface seaward of mapped sw verging thrusts of eocene and perhaps neogene age along the coastal areas of southern dalmatia consistent with sw migrating deformation in an active fold and thrust belt p wave tomography shows a ne dipping high velocity slab to 160 km depth which reaches the surface as adria dips gently beneath the foreland and becomes steep beneath the dinarides topographic high the thrust plane is located directly above the shallowly dipping part of the slab the pattern of precisely located seismicity is broadly consistent with both the tomography and geodesy deeper earthquakes down to 70 km correlate spatially with the slab and shallower earthquakes are broadly clustered around the geodetically inferred thrust plane the model fault geometry and loading rate ages of subaerially exposed thrusts in the fold and thrust belt and the length of subducted slab are all consistent with adria eurasia collision involving uninterrupted subduction of southern adria mantle lithosphere beneath eurasia since eocene time

source rock distribution model of the periadriatic region the periadriatic area is a mosaic of geological provinces comprised of spatially and temporally similar tectonic sedimentary cycles tectonic evolution progressed from a triassic early jurassic liassic continental rifting stage on the northern edge of the african craton through an early jurassic middle liassic late cretaceous eocene oceanic rifting stage and passive margin formation to a final continental collision and active margin deformation stage in the late cretaceous eocene to holocene this evolution occurred in a transtensional and transpressional framework resulting from the oblique separation and convergence of the african and european plates extensive shallow water carbonate platform deposits covered large parts of the periadriatic region in the late triassic platform breakup and development of a platform to basin carbonate shelf morphology began in the late triassic and extended through the cretaceous on the basis of this paleogeographic evolution the regional geology of the periadriatic region can be expressed in terms of three main upper triassic paleogene sedimentary sequences the platform sequence sequence a the platform to basin sequence sequence b and the basin sequence sequence c these sequences developed during the initial rifting and subsequent passive margin formation tectonic stages three distinct episodes of source bed deposition can be identified middle upper triassic to lower jurassic liassic organic rich oil prone and mature source beds generally are structurally controlled and are closely associated with transtensional intraplatform basins formed in the early continental rifting stage the principal triassic source basins and most of the surface hydrocarbon indications and economically important oil fields of the periadriatic region are associated with sequence b areas the second episode of organic rich rocks deposition includes both shallow and deeper water facies of jurassic cretaceous age thin immature deep water epioceanic organic rich marls and shales are generally bathymetrically controlled these units are related to basin wide anoxic events in the tethys ocean and its submerged continental margin and are associated with sequence b areas middle upper cretaceous shallow water oil prone facies occur in isolated anoxic basins within carbonate platforms these source sequences are generally thicker and are associated with sequence a areas no major hydrocarbon accumulation can be directly attributed to the jurassic cretaceous epioceanic and intraplatform source rock sequences the third episode of source bed deposition characterizes the final active margin deformation stage and is represented by upper tertiary organic rich terrigenous units mostly gas prone these are essentially associated with turbiditic and flysch sequences of foredeep basins and have generated the greater part of the commercial biogenic gases of the periadriatic region

dynamics of tethyan carbonate platforms tethyan carbonate platforms are relatively short lived depositional systems which were born developed died and sometime resurrected in a tectonically active area in contrast with pericratonic platforms which are generally huge in size hundreds of kilometers across and show wide facies belts very gentle slopes ramps and transitional boundaries tethyan carbonate platforms are smaller tens of kilometers and have steep slopes generally faulted boundaries and abrupt facies changes it appears clear that the overall control on these two contrasting systems is the geodynamic milieu relatively stable in the first case where eustatic oscillations and long term subsidence are probably the main dictators quite dynamic and aggressive in the second one where carbonate platforms developed through the entire geodynamic spectrum rifting transtension transpression and collision of the wilson cycle primary controls on tethyan carbonate platforms appear to be tectonics most important and eustatic sea level oscillations which determine their emplacement growth and decay their overall shape and architecture are a function of these factors secondary factors affecting tethyan carbonate platform evolution are physiography oceanographic conditions and biology as a function of geologic time especially across the mesozoic tertiary boundary facies and facies distribution and to a lesser extent their shape are controlled by thesemore variables less

upper cenomanian lower turonian sea level rise and its consequences on the adriatic dinaric carbonate platform the adriatic carbonate platform existed throughout most of the mesozoic as an isolated intraoceanic carbonate platform it is characterized by what has been traditionally labelled a continuous shallow marine carbonate sedimentation without terrigenous influences however global sea level changes left unequivocal imprints in the continuous carbonate record thus proving that the carbonate platform sensitively responded to sea level fluctuations this paper focuses on the relatively short cenomanian turonian drowning event which temporarily submerged the platform below the euphotic zone and which is related here to the well known global cenomanian turonian sea level highstand this drowning episode is characterized by the abrupt disappearance of numerous shallow water benthic invertebrate taxa and by an abundant occurrence of planktonic organisms including calcispheres and primitive planktonic foraminifera near the middle of the turonian the platform regime was re established correlating with the global fall in sea level the situation is different only at the south west margin of the platform where pelagic sedimentation initiated near the end of the cenomanian continues into the santonian and probably marks the adriatic trough the drowning began earlier in the middle cenomanian in those areas nearer to the north east margin of the platform the area of what is today central croatia and then progressed gradually towards the more interior areas of the platform the middle dalmatian islands which were drowned near the end of the cenomanian

mesozoic tertiary tectonic evolution of albania in its regional eastern mediterranean context abstract research carried out since the opening of albania to the western geological community in the 1990s allows the geology and tectonics of this small balkan country to be integrated into an overall interpretation of neotethys in the eastern mediterranean region specifically greece and the former yugoslavia region albanian geology is most famous for the occurrence of contrasting ophiolites of jurassic age the country is sub divided into three main geotectonic units those in the west i e sazani ionian kruja krasta cukali and the albanian alps relate to the western margin of apulia effectively part of north africa from early mesozoic time onwards in the east is the korabi zone interpreted as a microcontinent located further northeast within neotethys between the two is the mirdita zone dominated by two contrasting jurassic ophiolites the western type ophiolite and the eastern type ophiolite taking account of evidence from greece and former yugoslavia the following tectonic evolution is proposed from early mesozoic time onwards neotethys in albania existed as a northward continuation of the pindos oceanic basin in greece pindos mirdita ocean a korabi microcontinent was rifted off apulia in the early mid triassic followed by passive margin subsidence until late middle jurassic time a rifted slow spreading mor type ophiolite formed within the western pindos mirdita oceanic basin in late triassic early late jurassic time using present co ordinates the shkoder peje scutari pec lineament in the north of albania is interpreted as an important transform fault zone that influenced the regional tectonic evolution during the entire mesozoic early tertiary rift drift emplacement history of the pindos mirdita ocean taking account of evidence from the greek and former yugoslavia ophiolites the easterly albanian ophiolites formed within the pindos mirdita ocean above a westward dipping intra oceanic subduction zone in the early late jurassic metamorphic soles were formed during initial intra oceanic displacement ca 162 174 m y and underlying melanges originated as subduction accretion complexes the mor western type ophiolite evolved into the iat boninitic eastern type ophiolite after subduction began during tithonian berriasian time trench margin collision emplaced the ophiolites eastwards over the korabi margin coupled with redeposition of ophiolitic and continental margin material as exotic blocks debris flow deposits and turbidites these were emplaced onto the upper surface of the ophiolitic thrust sheet during the latest stages of emplacement onto the korabi microcontinent following collision in the east oceanic crust remained within a small remnant pindos mirdita oceanic basin passive conditions were restored in the mid late cretaceous with shallow water carbonate deposition on microcontinental units and both pelagic and redeposited carbonates in basinal settings from the maastrichtian onwards africa eurasia convergence resulted in large scale westward thrusting deforming the apulian foreland in oligo miocene time the suture zone was re activated in oligo miocene time as the albanie thassalie piggy back type basin in central and southern albania albania as a whole was rotated 45 clockwise as part of the western aegean arc in post eocene time coastal and offshore albania experienced strong subsidence after early miocene time forming the periadriatic basin including the tirana depression interpreted as a foredeep related to continuing regional convergence southern albania experienced extensional tectonics in plio quaternary time related to southward roll back of the aegean active margin

the last glacial aeolian record of the island of susak croatia as seen from a high resolution grain size and rock magnetic analysis abstract the loess palaeosol record on the island of susak in croatia is a unique archive of late glacial climate changes in the adriatic region possibly even in the wider area on susak up to 90 m of thick quaternary sediments were deposited and are accessible for detailed palaeoclimate reconstructions in this paper the results of a high resolution grain size and rock magnetic investigation on the last glacial upper pleniglacial sand pit section from susak are presented in spite of its significant thickness the sand pit section does not represent a continuous record it is a result of a very dynamic environment there the deposition of dust and formation of loess has been interrupted by pedogenesis periods of increased sand accumulation erosion due to slope wash and water activity redeposition and wildfires and all in the time period of about 10 000 years of the upper pleniglacial as seen from the irsl dating results the grain size data clearly show a shift towards coarser grain sizes which differs from typical loess regions such predominance of the coarser grained over the fine grained fraction very likely resulted from the predominance of deposition over pedogenesis increased wind activity and proximal source of material the rock magnetic signal preserved in the sediment also differs compared to loess palaeosol records from other regions the susceptibility values are several times higher than in the records from the pannonian basin and from typical eurasian loess both the increased susceptibility values and the grain size are very likely the result of a significant proximal material input from the po river plain

tertiary to recent oblique convergence and wrenching of the central dinarides constraints from a palaeostress study the late eocene to neogene tectonic evolution of the dinarides is characterised by shortening and orogen parallel wrenching superposed on the late cretaceous and eocene double vergent orogenic system the central dinarides exposes nw trending tectonic units which were transported towards the adria apulian microcontinent during late cretaceous palaeogene times these units were also affected by subsequent processes of late palaeogene to neogene shortening neogene extension and subsidence of intramontane sedimentary basins and pliocene quaternary surface uplift and denudation the intramontane basins likely relate to formation of the pannonian basin major dextral se trending strike slip faults are mostly parallel to boundaries of major tectonic units and suggest dextral orogen parallel wrenching of the whole central dinarides during the neogene indentation of the apulian microplate into the alps and back arc type extension in the pannonian basin these fault systems have been evaluated with the standard palaeostress techniques we report four palaeostress tensor groups which are tentatively ordered in a succession from oldest to youngest 1 palaeostress tensor group 1 d1 of likely late eocene age indicates e w shortening accommodated by reverse and strike slip faults 2 palaeostress tensor group 2 d2 comprises n nw trending dextral and w wsw trending sinistral strike slip faults as well as wnw striking reverse faults these indicate ne sw contraction and subordinate nw se extension related to oligocene to early miocene shortening of the dinaric orogenic wedge 3 palaeostress tensor group 3a d3a comprises mainly nw trending normal faults which indicate early middle miocene ne sw extension related to syn rift extension in the pannonian basin the subsequent palaeostress tensor group 3b d3b includes ne trending se dipping normal faults indicating nw se extension which is likely related to further extension in the pannonian basin 4 palaeostress tensor group 4 d4 i s characterised by mainly nw trending dextral and ne trending sinistral strike slip faults together with some e trending reverse faults they indicate roughly n s shortening and dextral wrenching during late miocene to quaternary this is partly consistent with the present day kinematics with motion of the adriatic microplate constrained by gps data and earthquake focal mechanisms the north north westward motion and counterclockwise rotation of the adriatic microplate significantly contribute the shortening and present day wrenching in the central dinarides d 2005 elsevier b v all rights reserved

the western alps from the jurassic to oligocene spatio temporal constraints and evolutionary reconstructions abstract despite extensive research in the last 150 years the regional tectonic reconstruction of the western alps has remained controversial the curved orogenic belt consists of several ribbon like continental terranes sesia austroalpine internal crystalline massifs brianconnais which are separated by two or more ophiolitic sutures piemonte valais antrona lanzo canavese high pressure hp metamorphism of each terrane occurred during distinct orogenic episodes at 65 ma in the sesia austroalpine at 45 ma in the piemonte zone and at 35 ma in the internal crystalline massifs it is suggested that these events reflect individual accretionary episodes which together with kinematic indicators and the speed and direction of plate motions provide constraints for the discussed reconstruction model the model involves a prolonged orogenic history that took place during relative convergence of europe and adria here considered as a promontory of the african plate the first accretionary event involved the sesia austroalpine terrane final closure of the piemonte ocean occurred during the eocene 45 ma and involved ultra high pressure uhp metamorphism of the piemonte oceanic crust incorporation of the brianconnais terrane in the accretionary wedge occurred thereafter possibly during or after subduction of the valais ocean in the late eocene 45 35 ma this subduction was terminated at ca 35 ma when the internal crystalline massifs i e the assumed internal parts of the brianconnais terrane were buried into great depths and underwent hp and uhp metamorphism

p wave tomography of the mantle under the alpine mediterranean area 1 we study the upper mantle p wave velocity structure below the euro mediterranean area down to 1000 km depth by seismic travel time tomography we invert summary residuals constructed with both regional and teleseismic first arrival data reported by the international seismological centre isc 1964 1995 introducing some alternative strategies in the travel time tomographic approach and a new scheme to correct teleseismic data for global mantle structure our high resolution model pm0 5 is parameterized with three dimensional 3 d linear splines on a grid of nodes with 0 5 spacing in both horizontal directions and 50 km vertical spacing we obtain about 26 root mean square rms reduction of residuals by inversion in addition to roughly 31 reduction after summary rays formation and selection sensitivity analyses are performed through several test inversions to explore the resolution characteristics of the model at different spatial scales the distribution of large scale fast anomalies suggests that two different stages of a convection process presently coexist in very close regions the mantle dynamics of western central europe is dominated by blockage of subducted slabs at the 660 km discontinuity and ponding of seismically fast material in the transition zone contrarily in the eastern mediterranean fast velocity material sinks into the lower mantle suggesting that the flow of the cold downwelling here is not blocked by the 660 km discontinuity on a smaller scale the existence of tears in the subducted slab lithospheric detachment all along both margins of the adriatic plate as proposed by some authors is not supported by our tomographic images

geodynamic evolution of the central dinarides abstract the central part of the dinarides unlike the northwestern and southeastern dinarides shows a consistent pattern in the distribution of the large tectonostratigraphic units from southwest apulia to northeast the following five main units originating in different parts of the mesozoic tethys can be distinguished 1 adriatic dinaridic carbonate platform formations 2 carbonate clastic units flysch bosniaque of the passive continental margin 3 ophiolite bearing formations of the dinaridic ophiolite zone also containing radiolarites greywackes and shales including melange formations and overstepped late jurassic to cretaceous cover sequences 4 active continental margin units represented by upper cretaceous palaeogene trench sediments with blueschists tectonized ophiolite melange alpine medium pressure metamorphic rocks originated from upper cretaceous palaeogene sediments and alpine synkinematic granitoids 5 a nappe consisting of allochthonous palaeozoic triassic formations which is thrust onto the ophiolites and genetically related sedimentary formations the frontal parts of this nappe directly overlie the northeastern margin of the adriatic dinaridic carbonate platform i e the external dinarides the evolution of the central dinarides was controlled by a sequence of tectonic events which took place within the alpine cycle 1 rifting processes lasting some 40 50 ma which started in the late permian and ended in the norian 2 opening of the oceanic dinaridic tethys commenced in the late triassic and persisted for some 70 80 ma until the end of the jurassic 3 subduction processes and emplacement of ophiolites started in late jurassic early cretaceous times during the closing phase of the dinaridic ocean or dinaridic tethys the palaeozoic triassic nappe was emplaced on the ophiolites the thrusting was accompanied by alpine metamorphism 120 100 ma 4 the main alpine deformational event and medium pressure metamorphism with synkinematic granite plutonism took place in late eocene early oligocene times when the ophiolite and palaeozoic triassic nappes were emplaced on the adriatic dinaridic carbonate platform which at the same time was deformed resulting in the development of the external dinarides fold and thrust belt

revision of the earthquake catalogue and seismicity of croatia 1908 1992 the paper presents the results of croatian earthquake catalogue revision for the period 1908 1992 the revised catalogue lists a total of 4853 events 4486 after 1908 of which 3700 are mainshocks all primary data sources available to us seismograms phase onset time readings macroseismic questionnaires were consulted in order to improve the quality and reliability of magnitude intensity and location along with the most important earthquake parameters the catalogue contains entries that enable assessment of the reliability of location and bibliographic references using the temporal analysis of the maximum likelihood estimate of the b value in the frequency magnitude relation the catalogue is estimated to be complete for events with m 4 0 throughout the investigated period the magnitude completeness threshold decreases to 3 8 after the middle of the century and to about 3 6 in the last three decades it is noted that the b value variation with time is closely tied to the seismic activity as well as that at present there seems to be a lack of seismic energy release corresponding to the m 6 0 6 5 earthquake

interaction between perpendicularly trending thrust wedges and its impact on foreland deformation insights from analogue modelling abstract in this work we used analogue models in order to better understand how two orthogonal fold and thrust belts may interact in the foreland and influence the geometry and kinematics of the resulting structures our experimental device has two vertical mobile backstops oriented perpendicular with respect to each other independent and moving coevally with variable or equal velocities there are strong contrasts between our models results and thrust wedges generated using a unique indenter and simple convergence thrust wedge deformation in front of two perpendicular indenters overlying a basal viscous decollement progressed following two major stages i independent growth of each tectonic wedges then ii formation of major oblique and continuous structures that nucleated in the foreland of both indenters in some models the two indenters moving at different velocities favoured the interference and superimposition of structures strain partitioning structure curvature and vertical axis rotation comparison with the friulian venetian basin southern alps and the altomira loranca thrust belt iberian chain central spain supports the hypothesis that foreland deformation can strongly vary if a basal viscous decollement is present during the interaction of two mutually indenters

dinosaurs re write the geodynamics of the eastern mediterranean and the paleogeography of the apulia platform abstract evidence of a sizeable population of large dinosaurs on the apulia carbonate platform calls for a revision of the current paleotectonic and paleogeographic scenario of the eastern mediterranean area a review of geophysical and geological data of the ionian sea and surrounding areas leads to envisage the late jurassic early cretaceous ionian sea region as a cul de sac type basin enclosed by shallow water carbonate banks connecting the apulia carbonate platform to peloponnesus northern cyrenaica cyrene seamount and medina ridge these banks were repeatedly and periodically exposed to subaerial conditions and offered vast land areas for migration of dinosaurs as regards the nature of the mesozoic ionian basin interpretations are quite controversial the continental vs oceanic crust debate will likely be solved only when the ionian basin crust will be reached by drilling the conclusion of the present review leads to consider adria as a true african promontory and the apulia platform as a sort of florida peninsula attached to north africa cyrenaica spur subdividing the oceanic mesozoic mediterranean into a western ionian basin and an eastern levantine basin

provenance of the peloponnese greece flysch based on heavy minerals the heavy mineral distribution of the palaeogene flysch deposits of the ionian gavrovo tripolitza and pindos zones of the peloponnese has been systematically investigated the ionian zone is distinguished from the gavrovo tripolitza zone by higher amounts of detrital chrome spinel the ionian and the western occurrences of the gavrovo tripolitza flysch are comparable with the successions of the greek mainland whereas samples of the gavrovo tripolitza flysch from central and eastern locations of the peloponnese which crop out in tectonic windows are clearly distinct on the basis of heavy mineral distribution the gavrovo tripolitza flysch of the central and eastern peloponnese shows clear relationships to the metaflysch sediments exposed in the tectonic windows of olympos and ossa in thessaly which have no relation to the gavrovo flysch of the mainland the pindos flysch from the peloponnese contains the same heavy mineral assemblages as the pre middle eocene deposits of the mainland younger pindos flysch sediments are not observed on the peloponnese the differences in heavy mineral distribution within the gavrovo tripolitza flysch between the western and eastern localities can be explained by an intensive reworking of pindos flysch during the tectonic progradation of the pindos nappe onto its foreland basin

structural evolution of a fold and thrust belt generated by multiple decollements analogue models and natural examples from the northern apennines italy this study analyses the role played by the mechanical proprieties of the rocks involved in a thrust system focusing on the problem of multiple decollements and of related compressional structures integration of geophysical seismic reflection profiles and geological data and scaled sandbox models are used to study the deformation style of two areas of the northern apennines italy the po plain and the umbria marche apennines both areas are characterised by a complex stratigraphy consisting of decollements located at different depths that influence the geometry and kinematics of the thrust system the main characteristic of the models presented here is the presence of two decollement horizons situated at the base and in an intermediate level of the models during deformation of the models these two decollement horizons generate two sets of structures with different geometrical characteristics and significance through the joint analysis of geophysical and geological data and model results wavelengths of the compressional structures analysed show that the structural style of the two analysed areas is almost similar moreover model results prove that the final configuration of the thrust system follows the general rules of evolution of a wedge deformed above a weak decollement and is largely governed by the larger deep seated structures

orogenic evolution of the external dinarides in the ne adriatic region a model constrained by tectonostratigraphy of upper cretaceous to paleogene carbonates abstract mesozoic to cenozoic evolution of the central part of the adriatic plate external dinarides and adriatic foreland is still a matter of debate this is expressed by opposing paleogeographic models single carbonate platform adriatic or adriatic dinaridic versus two carbonate platforms adriatic and dinaridic separated by the inter platform budva cukali basin estimates of shortening during adria ne subduction that resulted in the development of the dinaric alps differ substantially the single platform model involves minor shortening achieved by folding and faulting along steep reverse faults the two platform model involves significant shortening achieved mainly by thrust stacking which resulted in almost complete underthrusting of the intervening basinal deposits analysis of upper cretaceous to paleogene stratigraphical data from both outcrops and boreholes allows regional correlation and the interpretation of major lithostratigraphic units as a result a few tectonostratigraphic units are recognized the tectonostratigraphy is used as a basis for a new model on the late mesozoic to cenozoic evolution of the region generally adriatic and dinaridic segments acted as major regional crustal entities of adria the upper portions of the sedimentary cover were differentially affected by progressive southwestward verging thin skinned deformations during the paleocene to eocene miocene the adriatic foreland stayed out of the deformations and is characterized predominantly by wrench and salt tectonics the regional tectonic map shows arcuate thrust fronts of the external dinarides they could be a consequence of both differential propagation of early orogenic thin skinned deformations over crustal fragments separated by transversal faults and or differential isostatic movements of the fragments the collision zone of the adriatic and dinaridic segments is characterized by late orogenic oligocene to miocene thick skinned compressional uplift exhumation related gravity gliding and still active escape tectonics wrenching these processes masked primary thin skinned deformations a significant amount of shortening within and between the thin skinned sedimentary covers is proposed therefore the question of the general paleogeography of the region and the original nw extent of the budva cukali basin ne adriatic trough remains open

deep structure of the southern apennines italy thin skinned or thick skinned 1 the deep structure of the southern apennines sa accretionary wedge is still debated since industrial seismic reflection and well data provide reliable constraints only to a depth of about 10 km as a consequence two directly linked questions regard 1 the shortening in the accretionary prism particularly within the buried apulian thrust units and 2 the degree of involvement of the lower plate basement i e the apulian crystalline basement to address these issues we have constructed a regional section along a recently released deep seismic reflection profile crop 04 which intersects the entire sa the resulting cross section adequately constrained to a depth of about 15 km has been framed in a geodynamic scenario characterized by the eastward roll back of the westward subducting apulo adriatic lithosphere on the basis of this section we speculate on the deep structure building both thin and thick skinned thrust models a cross check of these end members models against documented tectonic geophysical and geochemical features shows that the thin skinned model is generally more consistent with the available data the development of basement slices with thicknesses of tens of kilometers is unlikely while it remains possible that the apulian basement could have been involved with its upper few kilometers in the thin skinned model the total shortening of the allochthonous units i e apennine and apulian carbonate platforms and lagonegro basin is estimated to be greater than 280 300 km some 90 km of shortening can be attributed to the apulian thrust units

the pindos fold and thrust belt greece inversion kinematics of a passive continental margin continuous exposure in the pindos mountain chain greece and the detailed stratigraphic measurements in the area enable us to construct eight balanced cross sections across the pindos fold and thrust belt pftb and to approach quantitatively some parameters which controlled foreland evolution the 160 km wide passive continental margin of the apulian continent in greece was progressively shortened from east to west at rates of 6 mm year between the early oligocene and late eocene from the rear to the frontal part of the wedge fault bend folds duplexes and imbricates were formed while strain was partitioned into faulting 34 layer parallel shortening 23 and buckling 9 foreland subsidence and internal deformation of the orogenic wedge are strongly affected by two parameters of equal importance the thrust load of the overthrusted microcontinents and the rigidity of the underthrusted apulian passive margin changes in the thickness of the pre orogenic sediments and reactivated transform faults induced salients during the lower miocene the orogenic wedge in the peloponnese suffered additional uplift and westward gravitational gliding induced by the intracontinental subduction of the palaeozoic rift zone of the phyllite quartzite series which was reactivated and returned to the earth s surface during the hellenic orogeny

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

active fragmentation of adria the north african promontory central mediterranean orogen global positioning system gps velocities indicate that adria no longer behaves as a rigid tectonic indenter into southern europe and is divided into northwestern and southeastern velocity domains differential motions are recognized in a velocity field determined from the peri tyrrhenian geodetic array ptga and international gps service igs sites in the circum tyrrhenian region of the central mediterranean and published gps velocities from the eastern adriatic coast in a fixed eurasian reference frame ptga and igs site velocities in sicily and southern italy are as much as 10 mm yr in a northward direction similar to gps velocities along the eastern coast of the adriatic sea in contrast velocities in northern italy are small or statistically insignificant and similar to velocities in sardinia and corsica outboard of western adria the tectonic boundary dividing adria is seismically active and passes around the southern and eastern margins of the tyrrhenian basin crosses central italy extends into the adriatic sea and follows the western margin of the dinaride tectonic belt north to the gulf of venice the eastern margin of adria is approximately located and follows the axis of the central dinaric alps southeast to the hellenic arc southeastern adria has a velocity related to northward motion of africa whereas northwestern adria has negligible differential motion in the eurasian frame and now is part of the alpine collage of southern europe

characteristics of fluid inclusions in the porphyry copper deposit at la granja peru abstract at la granja northern peru a granodiorite porphyry of probably mid tertiary age intruded into an upper triassic to lower tertiary volcano sedimentary sequence it was followed by intensive hydrothermal alteration and cogenetic mineralization processes which influenced the intrusive body as well as its sedimentary cover and host rocks producting hydrothermal alteration assemblages typical of porphyry cu deposits potassic propylitic phyllic advanced argillic silicic the investigation of fluid inclusions showed that 1 generally three types of fluid inclusions can be distinguished apparently coexisting vapour and liquid rich inclusions are taken as evidence for boiling in the hydrothermal system and 2 the overall abundance of different inclusion types correlates well with different alteration types the microthermometric data obtained fit well into the published range for other cu porphyry deposits together with the petrographic data the following model of fluid and alteration development is proposed highly saline fluids of probably magmatic origin developed possibly by dilution towards a boiling system of moderate salinity producing potassic alteration centers surrounded by propylitic alteration and or skarnification a younger low salinity fluid regime affected the centers by overprinting phyllic and or advanced argillic alteration silicification partly occurred during the latest stage of hydrothermal activity possible practical aspects of the fluid inclusion investigations are discussed

structural geological and karst feature investigations of the limestone flysch thrust fault contact using low frequency ground penetrating radar adria dinarides thrust zone sw slovenia the karstic thrust edge a pronounced geomorphologic step which is a result of the tectonostratigraphic evolution of the active adria dinarides thrust zone represents a major obstacle for the planned new railway route divaca koper thus the geotechnical and structural properties as well as the geometry of the thrust fault planes in this area are of great importance since geological mapping cannot give insight into the subsurface to reveal a complex 3d structure and the numerous boreholes needed to investigate the area would be too expensive and time consuming the application of a geophysical method such as ground penetrating radar gpr is needed to test the method for determining near surface features and detecting low angle inclined thrusts a low frequency gpr system with 50 mhz rough terrain antenna was used to record 13 gpr profiles along all three floors of the crnotice quarry where the spatial position of the socerb thrust fault that separates limestones above and flysch layers below is relatively well documented the profiles were positioned across selected existing boreholes the gpr results were correlated with borehole data as well as geological mapping results the gpr provided not only precise information on the geometry of the socerb thrust fault but was also very useful for establishing the position of some known as well as several potential cavities both air and sediment filled in areas further from the thrust fault zone where the limestone is less tectonically damaged it was also possible to determine apparent dip angles of the strata which after reconstruction matched the true dips gathered from geological mapping

controls on the onset and termination of past hypoxia in the baltic sea the baltic sea is currently the largest marine hypoxic o2 2 mg l 1 dead zone following excessive nutrient input from anthropogenic activities over the past century widespread hypoxia has previously developed in the baltic sea during the holocene thermal maximum htm 8 4 ka before present bp and the medieval climate anomaly mca 1 4 0 7 ka bp here we study the mechanisms that contributed to the onset and termination of this past hypoxia using geochemical and marine palynological data from a sediment record retrieved from the landsort deep during iodp expedition 347 site m0063 dinoflagellate cyst records and tex86l based sea surface temperature reconstructions indicate a major increase in salinity and temperature prior to and across the onset of the htm hypoxic interval underlining the importance of both temperature and salinity stratification in providing conditions conducive to the onset of hypoxia both salinity and temperature decline during the termination of the htm hypoxic interval in contrast we find no evidence for significant changes in surface salinity during the mca hypoxic interval and both the onset and termination of hypoxia appear to have been primarily driven by changes in temperature our results indicate that temperature and salinity changes were key drivers of past hypoxia in the baltic sea and imply that ongoing climate change will delay recovery from the modern nutrient driven hypoxic event in the baltic sea

late orogenic strike slip faulting and escape tectonics in frontal dinarides hellenides croatia yugoslavia albania and greece the frontal zone of the dinarides and its foreland are characterized by the presence of major late orogenic northwest southeast faults trending parallel to and locally dissecting the leading edge of the thin skinned thrust belt on the basis of their geometry and regional distribution these structures are interpreted as right lateral strike slip faults and are related to the formation of en echelon compres sional structures in the split dubrovnik area of the central adriatic region and to the opening of the post messinian pull apart albanian foredeep south adriatic basin in the pliocene holocene these strike slip faults represent the last stage of the mountain building process in the pliocene and holocene when the forelandward prop agation of the dinaric thrust belt was inhibited by stacking of thrust sheets and by overall thickening of the colliding continental crust in that respect the dinaric side of the apulia adria differs from the apenninic side where the thin skinned thrusting progressed normally toward the foreland until the pliocene on a regional scale these northwest southeast trending strike slip faults in the frontal dinarides and their apparent continuation to the hellenides of western greece as well as the dextral vardar fault system indicate the existence of escape tectonics in the di naric hellenic region during the last stage of orogeny the strike slip faults provided a means of tectonic transport from the collision zone of apulia with europe toward the subduction zone of the hellenic trench in southern greece the southeastward moving dinaric hellenic blocks apparently interfered with the westward moving anatolian plate and deflected it southwestward the albanian foredeep in terms of tectonic setting resembles the pull apart vienna basin which formed within the attenuated southwest northeast trending transfer zone of the west carpathi ans during the last stages of the alpine orogeny the late orogenic strike slip faulting may have breached seals and thus negatively affected the hydrocarbon potential of the dinaric hellenic side of the peri adriatic region as contrasted with that of the more prolific apenninic side which was not significantly disrupted by the late orogenic strike slip faulting

reviewing pre transalp dss models abstract the interpretation of dss deep seismic soundings profiles in central and eastern alps is recalled in the paper and the models of the lower crust and moho proposed several years ago are compared to the results of the transalp seismic reflection profile this evaluation highlights a good agreement as far as the geometry of the deep crustal structure is concerned therefore the reliability of the interpretative models previously exclusively based on dss profiles becomes improved the deep structure beneath the whole alpine range is examined reconsidering the map of the moho boundary and the structural model already proposed for the central eastern sector five main interpretative transects are put side by side starting from the western alps and moving eastwards to the swiss lombardian central alps european geotraverse to the cross section from southern bavaria to the euganei hills to the transalp profile and finally to the easternmost profile available so far southern bavaria trieste the comparison outlines lateral variations of the deep crustal structure as well as a sharp contrast between the adria and the european lower crust and moho the transition from the adria plate to the dinaric domain remains up to now undefined

evolution of the adriatic carbonate platform palaeogeography main events and depositional dynamics abstract the adriatic carbonate platform adcp is one of the largest mesozoic carbonate platforms of the perimediterranean region its deposits comprise a major part of the entire carbonate succession of the croatian karst external or outer dinarides which is very thick in places more than 8000 m and ranges in age from the middle permian or even upper carboniferous to the eocene however only deposits ranging from the top of the lower jurassic toarcian to the top of the cretaceous can be attributed to the adcp defined as an isolated palaeogeographical entity although the entire carbonate succession of the karst dinarides was deposited within carbonate platform environments there were different types of carbonate platforms located in different palaeogeographical settings carboniferous to middle triassic mixed siliciclastic carbonate deposits were accumulated along the gondwanian margin on a spacious epeiric carbonate platform after tectonic activity culminating by regional middle triassic volcanism recorded throughout adria the african promontory a huge isolated carbonate southern tethyan megaplatform abbreviated as stm was formed with the area of the future adcp located in its inner part tectonic disintegration of the megaplatform during the middle to late early jurassic resulted in the establishment of several carbonate platforms including the adriatic apenninic and apulian separated by newly drowned deeper marine areas including the adriatic basin as a connection between the ionian and belluno basins lagonero basin and the area of the slovenian and bosnian troughs the adcp was characterised by predominantly shallow marine deposition although short or long periods of emergence were numerous as a consequence of the interaction of synsedimentary tectonics and eustatic changes also several events of temporary platform drowning were recorded especially in the late cretaceous when synsedimentary tectonics became stronger leading up to the final disintegration of the adcp the thickness of deposits formed during the 125 my of the adcp s existence is variable between 3500 and 5000 m the end of adcp deposition was marked by regional emergence between the cretaceous and the palaeogene deposition during the palaeogene was mainly controlled by intense synsedimentary tectonic deformation of the former platform area some carbonates mostly eocene in age were deposited on irregular ramp type carbonate platforms surrounding newly formed flysch basins and the final uplift of the dinarides reached its maximum in the oligocene miocene the adriatic carbonate platform represents a part although a relatively large and well preserved one of the broader shallow water carbonate platform that extended from ne italy to turkey although its continuity is somewhat debatable in the area near albanian greece boundary this large carbonate body which was deformed mostly in the cenozoic including a significant reduction of its width needs a specific name and the central mediterranean carbonate platform is proposed abbreviated to cmcp although the local names such as adcp for its nw part should be kept to enable easier communication and to facilitate description of local differences in platform evolution

upper cretaceous organic rich laminated limestones of the adriatic carbonate platform island of hvar croatia several organic rich samples taken from upper santonian late campanian laminated limestones of hvar island croatia were investigated to characterize palynofacies macerals type of organic matter and organic geochemistry these characterizations as well as the reconstruction of the depositional environment are interpreted in terms of a source rock perspective the results suggest that the laminated limestones were formed within shallow depressions of the carbonate platform in an anoxic restricted marine environment with increased salinity the hvar island laminated limestones contain type ii s kerogen and they are found to be marginally mature and oil prone

impact of cretaceous sea level rise and anoxic events on the mesozoic carbonate platform of yugoslavia the adriatic dinaric carbonate platform of yugoslavia was influenced by rapid sea level rise and an oceanic anoxic event during the cenomanian turonian open marine biota such as planktonic foraminifera radiolarians and locally even ammonites associated with and bracketed by successions of typical shallow water carbonates indicate partial drowning of substantial areas of the platform during this time suggestive furthermore that the rate of increase of water depth was locally great enough to outpace carbonate production the presence of carbon rich and fish bearing platy limestones commonly cherty as an associated coeval facies indicates the development of anoxic or euxinic environments and the stromatolitic laminations in such rocks are attributed to the action of bacterial mats it is suggested that an extensive column of deoxygenated water developed in the neighboring marche umbrian adriatic deep water basin and was carried on to the carbonate platform during the cenomanian turonian transgression

geochemistry of istrian lower palaeogene bauxites is it relevant to the extent of subaerial exposure during cretaceous times abstract investigation of the origin and occurrence of istrian lower palaeogene bauxites discussed in this work relies on adoption of the recent perspectives on development of the collision induced diachronous discontinuity surface in the istrian part of the adriatic dinaric carbonate platform this process related to the forebulge uplift at the latest stages of alpine orogenesis is amply recorded in the geochemical signature of contemporaneous bauxites in order to elucidate the patterns of bauxite formation a discriminant function model based on the compositional data analysis major and trace elements is constructed providing the solid ground for separation of the bauxite groups deposited in the subaerially exposed istrian palaeoenvironment complete distinction between the four a priori defined istrian lower palaeogene bauxite groups achieved by the analysis demonstrates the highest degree of efficiency in characterizing environmental conditions marked by the unique suite of geochemical variables compositions

influence of palaeogeography on thrust system geometries an analogue modelling approach for the abruzzi molise italy case history abstract the abruzzi molise sector in the central apennines is a part of a fold and thrust belt that has been deforming since the late cretaceous as a result of collision tectonics between the european and adriatic plates the superposition of different deformational styles highly reworked the originally complex palaeogeography of this portion of the southern tethyan margin analogue modelling has been performed on thrusting mechanisms in the abruzzi molise area in order to 1 reduce the number of admissible hypotheses regarding palaeogeographic setting and 2 define thrusting mechanics both of these goals are crucial for hydrocarbon exploration purposes the sandbox apparatus used to simulate the undeformed passive margin consisted of a thin compartment juxtaposed against a thick one along a linear boundary having variable geometries and mechanical stratigraphy a rigid but mobile backstop was used to deform the stratigraphy in a coulomb thrust wedge results from six experiments show that the geometric relationships between different structural units depend on the distribution of palaeogeographic domains these domains are defined by mechanical and or geometrical parameters such as the orientation between the maximum compression direction and the palaeogeographic boundary the mechanical stratigraphy and the thickness of the successions reproduced in the models the present day tectonic styles and meso cenozoic palaeogeography of the abruzzi molise area are discussed in terms of the mechanisms and structures analysed through the models

recently submerged tidal notches in the wider makarska area central adriatic croatia abstract the active tidal notches in the makarska area which were observed and described in historical records from the beginning of the 20th century andrijasevic 1910 have been reanalysed 107 years later detailed mapping of three locations in the wider makarska area revealed their level of submergence which varied between 30 and 37 5 cm below the recent mean sea level msl according to location this investigation points to the recent acceleration of relative sea level change during the current warm period cwp and also to the past temporary still stand according to data from central adriatic islands of vis ravnik and bisevo this still stand probably lasted around 500 years during the little ice age lia period however the notch in the dubrovnik area which was as stated in historical data suess 1885 1908 active at the end of the 19th century is still active today indicating tectonic uplift of the dubrovnik area