the puglia uplift se italy an anomaly in the foreland of the apenninic subduction due to buckling of a thick continental lithosphere the apenninic foreland shows two distinct structural signatures comparing the central adriatic sea and the puglia region during the pliocene pleistocene the central adriatic underwent high subsidence rates due to the eastward rollback of the hinge of the west dipping apenninic subduction the puglia region and the bradanic foredeep are located southward along strike in the same foreland but in contrast with the central adriatic after pliocene early pleistocene subsidence they underwent uplift since the middle pleistocene the geometry and the kinematics of the frontal accretionary wedge and related foreland changed from that moment on between the two areas at the front of the central northern apennines off scraping and subsidence continued whereas the foredeep and foreland of the southern apennines were buckled those differences are interpreted as being due to the larger subduction hinge rollback rate since middle pleistocene of the central adriatic lithosphere 70 km thick with respect to the thicker puglia 110 km the different thicknesses of the continental crust and lithosphere were inherited from the mesozoic rifting that disrupted the adriatic plate the different thicknesses appear to have controlled the variable degree of flexure of the lithosphere and its asthenospheric penetration rate the tremiti e w alignment is the right lateral lithospheric transfer zone of those different tectonic regimes the consequent different dip of the subduction in the two sections steeper west of puglia could also explain the lower elevation of the southern apennines compared to their central northern sector

a new view of italian seismicity using 20 years of instrumental recordings in this paper we show the seismicity of the past 20 years that occurred in italy and surrounding regions hypocentral locations have been obtained by using p and s wave arrival times from the ingv national and several regional permanent seismic networks more than 48 000 events selected from an original data set of about 99 780 are used to reconstruct the most complete seismic picture of the italian region so far the seismicity distribution allows inference on seismotectonics of this complex region of subduction versus continental collision our results clearly reveal the geometry of the adria and the ionian subduction and a continuous normal fault belt in the upper crust following the apennines mountain range the depth of the seismogenic layer is computed from the cut off of seismicity at depth and shows large variations along and across the seismic active regions earthquakes are generated by the different velocity of slab retreat and the subsequent asthenospheric upwelling d 2004 elsevier b v all rights reserved

segmentation and configuration of subducted lithosphere in italy an important control on thrust belt and foredeep basin evolution the apennine foredeep basin system located on continental crust consists of four roughly parallel basin segments each containing a flexural outer rise and an inner trough that deepens continuously toward the thrust belt flexural modeling of subsidence data across the basin indicates that this foredeep basin results mainly from deep subsurface loads acting on the subducted slab from within the subduction zone rather than from the topographic load of the apennine mountains the geometry of the four basin segments observed within the apennine foredeep is thus inferred to reflect subduction of segmented lithosphere where each lithospheric segment corresponds to a segment of the foredeep basin beneath the basin and in the foreland the lithosphere is continuous segmentation occurs only at depth beneath the thrust belt this pattern olf segmentation of the subducted lithosphere at depth is reflected in the large scale geometry of the outer part of the apennine thrust belt and appears to control it similarly the pattern of segmentation also appears to control the position of the eastern limit of back arc type extension in western italy these relations strongly suggest a genetic relation between subduction zone processes foredeep basin geometry and thrust belt evolution in which the configuration of the subducted lithosphere largely controls the large scale surface deformation observed in the apennine system

glacial landforms and their paleoclimatic significance in sierra de guadarrama central iberian peninsula abstract this paper investigates the glacial evolution on the east face of pico de penalara 40 51 n 3 57 w 2428 m the highest elevation of sierra de guadarrama in the center of the iberian peninsula the geomorphologic stability of glacial landforms and permanence of snow cover were examined and 18 samples were selected for dating with cosmogenic isotope 36cl from moraine formations in four well differentiated phases as well as from a pre glacial periglacial blockfield and a glacial threshold near the headwall the results show the synchrony between the last glacial maximum lgm advance and most results obtained recently by cosmogenic dating in southern europe within the mis marine isotope stage 2 stadial but earlier than the global lgm i e between 25 and 19 ka bp there was slow glacial retreat with minor re advances between 19 and 16 ka and rapid deglaciation from 16 ka this paper presents initial results still pending confirmation for the minimum age of the periglacial summit block formation around 80 ka for the existence of moraine formations older than the last advance and for the existence of glaciers during the younger dryas stadial to explain the synchrony between two moraine formations at different altitudes this paper formulates the hypothesis of the secondary moraine evidenced in currently existing glaciers similar to those which existed on penalara

active intraplate deformation within adria examples from the adriatic region abstract recent seismicity recorded in the adriatic region suggests that active deformation occurs within the adria plate earthquakes are common in the adjoining chains and in particular along the northern apennines in the southern alps and along the dinaric albanian hellenic thrust fronts in addition medium to low grade seismicity also affects the foreland and is clustered along two main transects through the centre of the adriatic region the two zones of active deformation correspond to the mid adriatic ridge and the gargano region and approximately trend nw se and e w respectively several interpretations have been proposed to explain the deformation observed within the adriatic foreland including a variety of contrasting kinematic and geodynamic models we attempted to unravel the complicated structural evolution of the central adriatic region by interpreting industrial and ministerial shallow and deep seismic profiles and the recent seismicity recorded in the adriatic the subsurface study allowed us to better understand the structural style timing and rates of deformation affecting the mid adriatic ridge and the gargano region and to unravel the relationships of active deformation with respect to the adjacent chains the results of our study indicate that the structural setting and type of seismicity of the central adriatic can be explained in terms of active intraplate deformation with the reactivation of inherited discontinuities

styles of positive inversion tectonics in the central apennines and in the adriatic foreland implications for the evolution of the apennine chain italy abstract integration of new field structural and geophysical data with existing information from the apennines chain in italy and its adjacent adriatic foreland indicates that the styles of positive inversion tectonics and the modes of interaction between the extensional and the subsequent compressive structures vary starting from the cretaceous the contractional deformation induced by the mainly north directed convergence of africa adria with respect to the european plate promoted the closure of various arms of the atlantic and the neo tethys oceans which opened in different times and with distinct orientations the mosaic of continental blocks carbonate platforms rift basins and oceanic domains with several geometries and orientations with respect to the axis of the subsequent compression and the resulting heterogeneities within the shallow sedimentary cover and the overall lithosphere strongly influenced both the structural evolution of the apennine orogenic belt and the intra continental deformation within the adriatic foreland field observations reveal that the steeply e and w dipping mesozoic cenozoic normal faults are systematically decapitated by sub horizontal or gently west dipping thrusts propagating with short cut trajectories pre thrusting normal faults were commonly deformed by later thrusts but little evidence seems to support their entire reactivation as high angle reverse faults this suggests that these shallow and steeply dipping discontinuities were not suitable to be reutilized by the superficial thin skinned thrust faults propagating within the sedimentary cover in contrast presumably late paleozoic and mesozoic w dipping normal faults appear moderately reactivated in the adriatic foreland and strong positive inversion tectonics affect the deeper and buried structural levels of the apennine chain within the latter the syn rift sediments in the hangingwall blocks of the fault bounded basins were totally extruded and generated the strong uplift of the thinned adria continental crust finally the contrasting styles of interactions of the pre existing normal faults with later thrusts i e passive truncation or positive reactivation strictly result from the different evolution of the apennine chain and the combined thin and thick skinned modes of deformation of the stretched lithosphere of the adria plate

deep structure and tectonics of the northern central apennines as seen by regional scale tomography and 3 d located earthquakes 1 in this study we present new high resolution regional scale vp and vp vs models of the northern central apennines along with accurate 3 d locations of a large set of local earthquakes the main velocity anomalies are consistent with the surface geology in the shallow layers and present evidence for fluids stored within the basement at greater depths beneath the extensional belt the adria and tyrrhenian mantle are defined by positive velocity anomalies below 30 km depth while a low vp high vp vs region in between indicates the existence of a hydrated wedge the results yield new constraints on active processes in the apennines and more generally envisage the evolution of a postcollisional belt velocity anomalies and earthquakes are consistent with a complex system of delamination and sinking of the adria continental lithosphere with the peeling of the crust identified by intermediate depth seismicity change of seismicity and structural patterns along the belt indicates that this tectonic process is diachronous and that fluids released by sunken lithosphere are stored within the crust conditioning the occurrence of seismicity and the onset of extension

fault plane solutions and seismicity of the italian peninsula abstract a new fault plane solution map of the italian peninsula is presented in this paper the earthquakes analyzed are included in the period 1905 1980 with magnitudes ranging 4 7 75 earthquakes are located in the crust while 31 are related to the deep and intermediate zone of the calabrian arc the large seismic events of the italian peninsula are generally associated with normal faulting while strike slip motion is mostly related to small earthquakes located along lateral segments of the mountain chain the deep and intermediate earthquakes of the tyrrhenian sea indicate predominant down dip compression and strike slip motion at the boundaries of this benioff zone this last is interpreted as a remnant of a subduction zone active since oligocene extending to 500 km depth with a very small lateral size about 300 km the present tectonics of this benioff zone is strongly conditioned by the lateral bending more so than the gravitational sinking process the coexistence of thrust and normal faulting motion associated to the earthquakes within a few tens of kilometers of each other seems to be explained by the strong lateral inhomogeneities of the crustal rocks present in this region more so than to the depth of the seismogenetic zone and the nature of the faulting process

do earthquake storms repeat in the apennines of italy terra nova 23 300 306 2011 abstract series of multiple main shocks that develop on adjacent faults is a typical way in which active extension is accommodated in the apennines of italy this behaviour is explained by fault interaction that occurs at a scale ranging from seconds to days yielding a space time clustering of earthquakes termed as earthquake storms we show that the seismic energy released by historical earthquakes in central apennines is clustered into two main small time periods around 600 and 300 years ago during which a great portion of the normal faulting belt failed we favour the hypothesis that clustering results from sudden input of deep fluids into the brittle upper crust the roughly 300 years periodicity and the 3 4 mm year 1 of tectonic extension suggest that earthquake storms need to be taken into account in seismic hazard scenarios

deriving thrust fault slip rates from geological modeling examples from the marche coastal and offshore contraction belt northern apennines italy abstract we present a reconstruction of the central marche thrust system in the central northern adriatic domain aimed at constraining the geometry of the active faults deemed to be potential sources of moderate to large earthquakes in this region and at evaluating their long term slip rates this system of contractional structures is associated with fault propagation folds outcropping along the coast or buried in the offshore that have been active at least since about 3 myr the ongoing deformation of the coastal and offshore marche thrust system is associated with moderate historical and instrumental seismicity and recorded in sedimentary and geomorphic features in this study we use subsurface data coming from both published and original sources these comprise cross sections seismic lines subsurface maps and borehole data to constrain geometrically coherent local 3d geological models with particular focus on the pliocene and pleistocene units two sections crossing five main faults and correlative anticlines are extracted to calculate slip rates on the driving thrust faults our slip rate calculation procedure includes a the assessment of the onset time which is based on the sedimentary and structural architecture b the decompaction of clastic units where necessary and c the restoration of the slip on the fault planes the assessment of the differential compaction history of clastic rocks eliminates the effects of compaction induced subsidence which determine unwanted overestimation of slip rates to restore the displacement along the analyzed structures we use two different methods on the basis of the deformation style the fault parallel flow algorithm for faulted horizons and the trishear algorithm for fault propagation folds the time of fault onset ranges between 5 3 and 2 2 myr overall the average slip rates of the various thrusts are in the range of 0 26 1 35 mm yr

seismicity of the adriatic microplate abstract the adriatic microplate was previously considered to be a unique block tectonically active only along its margins the seismic sequences that took place in the basin from 1986 to 1990 give new information about the geodynamics of this area three subsets of well recorded events were relocated by the joint hypocentre determination technique on the whole this seismic activity was concentrated in a belt crossing the southern adriatic sea around latitude 42 in connection with regional e w fault systems some features of this seismicity similar to those observed in other well known active margins of the adriatic plate support a model of a southern adriatic lithospheric block detached from the northern one other geophysical information provides evidence of a transitional zone at the same latitude

recent tectonic evolution and present stress in the northern apennines italy the present day stress field and its recent tectonic evolution in the northern apennines are reconstructed from borehole breakout analysis and focal mechanisms of crustal earthquakes and through the comparison with paleostress data we have considered 86 wells for breakout analysis with depths down to 6 7 km 125 fault plane solutions of crustal earthquakes with m 5 that occurred between 1988 and 1995 in the northern and central apennines and data of stronger earthquakes m 6 reported in other studies the tyrrhenian coastal region and the apenninic belt are characterized by shmin direction mainly trending ne sw with predominantly normal fault plane solutions along the outer front of the belt and the adriatic offshore shmin is oriented nw se and focal solutions are thrust or strike slip with maximum compression around ne sw conversely south of 43 n breakouts evidence an orthogonal direction of horizontal compression nw se following the southern apennine trend where a widespread ne sw extension was recognized by previous investigations comparing these results to the recent tectonic evolution inferred from structural geology we argue that the extension compression pair characteristic of the post tortonian evolution of the mountain belt has been migrating in time from late miocene to present only in the northern sector of the arc whereas the southern sector underwent a generalized extension at least since middle pleistocene the striking correspondence between the active compression front and the region with evidence of a remnant subducted slab suggests that the migrating extension compression pair has been controlled by progressive retreat of the slab

from mesozoic rifting to apennine orogeny the gran sasso range italy the apennines are a low temperature accretionary prism generated by the west directed subduction of the adriatic ionian plate whose structural origin is still to be fully understood the highest and best exposed seg ment of the apennines the gran sasso range is here documented to unravel the tectonic history of the northern tip of gondwana it is located along a ne verging salient of thrust sheets decoupling the sedimentary cover of the subducting adriatic lithosphere field mapping and structural analysis along the e w trending left lateral transpressive segment of the salient highlight the interplay of the inherited mesozoic passive margin stratigraph ic and tectonic framework with the neogene contraction the rheological differences between the massive carbonate platform and the well bedded turbiditic and pelagic limestones determined along strike undulations of the thrusts geometries and fold styles during shortening heterogeneities are due to inherited syn and post rift mesozoic tectonics the gran sasso overturned anticline shows a backlimb anomalously tilted toward the foreland and we infer this dip as being related to a deeper back thrust of a triangle zone the pinching out of the foredeep sequence on the growth anticline forelimb dates the contractional phases of the region to the late messinian from the late pliocene to present the area has been uplifted and extended about 2 km by oblique normal faults cross cutting the accretionary prism some of them are seismically active as shown by the 2009 mw 6 3 l aquila earthquake

subduction and the depth of convection in the mediterranean mantle 1 we tie together geological data paleotectonic reconstruction plate motion and tomographic analysis to unravel the history of subduction and back arc extension of the eastern and central mediterranean in these two regions extensional processes started contemporaneously around 30 myr ago but with marked differences in the eastern region the aegean basin opened slowly 1 cm yr behind a shallow dipping slab 40 45 the corresponding high velocity anomaly extends inside the upper mantle and can be also followed in the midmantle down to a depth of at least 1500 km its descent into the midmantle initiated most probably during the late cretaceous and the trench moved northeastward following the path of the eurasian plate and under the persistent push of the african plate conversely in the central mediterranean region subduction initiated later and the motion of the subducting slab is confined to the upper mantle causing punctuated and rapid episodes of back arc extension provencal and tyrrhenian basins behind a slab that dips steeply 75 we explore the causes that control how the slab subducted and interacted with the lower more viscous part of the mantle

gps based monitoring of land subsidence in the po plain northern italy abstract we use regional and local networks of continuously operating gps stations cgps distributed in the northern central part of the italian peninsula to investigate the subsidence phenomenon of the po plain sedimentary basin and vertical movements of the surrounding areas the observations of 146 scientific and commercial stations are analyzed and compared adopting analytical techniques widely used to study gps coordinate time series the use of simple antenna supports in commercial installations instead of a more rigorous geodetic monument does not seem to induce significant differences in the noise characteristics and in the amplitudes of annual and semi annual periodic signals the vertical velocity field deduced from 129 sites with observation time spans greater than one year located in the central northern italian peninsula indicates the presence of two mainly subsidence areas the po plain and the arno plain while the sites located in the alps and apennine domains show relatively low uplift the areas of the po plain monitored by gps seem to indicate that the subsidence rate is constant or in some cases decreasing with respect to the values obtained from the last measurements performed up to 2006 by means of both sar and levelling techniques only the central part of the eastern po plain close to the apennine border modena city area is characterized by a peak in subsidence consisting in a velocity of about 15 mm yr

apennines subduction related subsidence of venice italy 1 the foreland regional monocline related to the northern apennines subduction can be followed from the po basin to the friuli region italy at least 240 km north eastward in seismic reflection profiles of the po basin and of the northern adriatic sea the dip of the regional monocline gradually decreases from about 22 to close to 0 pleistocene sediments onlap and pinchout to the northeast venice is located on a segment of the active monocline dipping about 1 8 to the southwest in sediments around the venice area the 1 43 ma limit is in the 960 1500 m depth range indicating a long term subsidence rate of about 0 7 1 0 mm yr therefore a significant part of the natural component of the town subsidence is related to the north eastward retreat of the adriatic subduction the subduction related downflexure affects the whole of the po plain basin and part of the southern alps where it opposes to the general uplift related to orogenesis

the ombrina rospo plateau apulian platform evolution of a carbonate platform and its margins during the jurassic and cretaceous abstract in this paper we analyze the jurassic and cretaceous evolution of the buried northwards stretch of the apulia platform southern italy ombrina rospo plateau orp and adjacent adriatic basin exploration wells indicate that inner platform carbonate facies across the orp in the jurassic and lower cretaceous are capped along a subaerial exposure surface by oligocene miocene carbonates a nw trending intra platform basin casalbordino corridor was infilled with shallow to deeper water sediments in the late early to late cretaceous interval while platform margins were experiencing tectonic reactivation the orp to basin transitional belt formed a corner defining a nw and a ne margin the nw margin was essentially stationary a syn and early post rift platform toe bypass wedge formed when late hettangian sinemurian extension produced the platform basin relief export of platform material coupled with a halt of faulting made the platform slope profile continuous in the late early or early middle jurassic possibly across an ooidal rim late jurassic ellipsactinia coral reefs passed downdip into bioclastics the maiolica fm displays two cycles m1 m2 where m2 onlaps the slope built by m1 in the aptian with lithospheric arching a high angle fault rejuvenated the margin off this margin a narrow basin locked between the orp and a pelagic carbonate platform was largely infilled with turbidites sourced by the orp but the high hampered the dispersal of the sand fraction the ne margin displays prograding ooidal to bioclastic clinoforms middle and upper jurassic downlapping onto the rift basin in the lower cretaceous the platform recovered after a slow down of carbonate productivity m1 2 boundary the marne a fucoidi fm thickens at the toe of and seals a fault backstepping the margin further backstepping occurred 5 km platformwards along a cenomanian normal fault producing room for a rudist factory a retreating rocky shoreline sourced breccias while downdip the shallow water facies graded into the scaglia fm basin along a ramp like profile with low angle clinoforms merging with turbidites

structural setting of the adriatic basin and the main related petroleum exploration plays abstract most of the oil and gas resources located within the adriatic domain are genetically linked to the flexure of the adria continental margin and to the evolution of the apennines fold and thrust belt the source rocks contained in the pre flexure epi continental successions reached the maturity window during the flexural subsidence or alternatively the flexural accommodating siliciclastic flysch themselves generated and stored hydrocarbons the petroleum exploration plays of the adriatic domain are tentatively classified in this paper according to their geological evolution with respect to the apennines fold and thrust belt the description of the geological evolution of these structures and related petroleum plays are described including plays set in undeformed or poorly deformed foreland areas a new isochrones map showing the structural setting of the substratum at the level of the fucoidi fm is presented several different groups of structures can be recognized in the adriatic domain that can be connected to the final phases of deformation of the apennines or to the interaction with the dinarides fold and thrust belt front to the east

thrust fold activity at the mountain front of the northern apennines italy from quantitative landscape analysis abstract we document the active tectonics of growing anticlines embedded in the northern apennine mountain front using a quantitative analysis of the topography these structures appear to be growing at rates of 0 1 0 3 mm year more slowly than the long term general rate of emergence of the apennines from the po plain our analysis is dedicated to extract the signal of this tectonic activity recording it primarily by the channel steepness ksn of streams traversing the mountain front and by swath profiles and relief of the topography topographic swath profiles and ksn are consistent with field stratigraphic structural mapping and seismic reflection profile relationships in general the spatial distribution of ksn values of small channels with upstream drainage area quantitatively we use local development of relief as a proxy for rock uplift measured as river incision across the mountain front and anticlines to test the expected linear scaling between rock uplift rates relief and ksn in this low rock uplift setting 0 1 0 3 mm year this predicted scaling relationship is not supported by ksn and topographic data suggesting a condition of transient response of fluvial incision that generates the relief to the tectonic forcing where ksn and relief have not achieved steady state values however a weak linear scaling between rock uplift and ksn may hold for the local highest uplift settings where over 40 m of relief have been generated thus establishing a lower threshold for where the channel steepness approach may be valid in this slowly deforming landscape assuming a state of transient response of fluvial incision to tectonic forcing the high ksn values can be explained as places where the channels are being actively deformed by tectonics but have not yet fully responded by incising and generating relief therefore in the absence of relief generation the spatial distribution of ksn maximum values for small streams can hold for rock uplift and work as a model for indicating locations of strongest anticlinal growth collectively the correspondence among the stratigraphic markers used to define the structures topography and relief as quantified in the swath profiles and the ksn values that indicate active channel adjustments to tectonic forcing support the evidence of continued shortening across the european adria plate boundary and the contemporary slow growth of the structures embedded in the emergent apennines mountain front

thrust front segmentation induced by differential slab retreat in the apennines italy new seismic reflection data reveal that the south eastward prolongation of the apennine thrust front in the central adriatic sea is most likely located in a more external position with respect to the traditional interpretation in this new interpretation the apennine thrust front shows a segmented geometry in correspondence to the tremiti lithospheric transfer zone the available data suggest that the north eastward flexural retreat of the subducting adriatic lithosphere and the related frontal accretion of the apennine accretionary prism have acted during the last 5 ma and may be considered still lively in both the po plain and in the central adriatic domain north of the tremiti lineament by analysing the tectonic evolution of the apulo adriatic areas it may be argued that the differential slab retreat between the central and southern sectors of the subducting adriatic plate has been able to induce the segmentation of the apennine thrust front

scenarios of earthquake generated tsunamis for the italian coast of the adriatic sea we calculated the expected impact on the italian coast of the adriatic sea of a large set of tsunamis resulting from potential earthquakes generated by major fault zones our approach merges updated knowledge on the regional tectonics and scenario like calculations of expected tsunami impact we selected six elongated potential source zones for each of them we determined a maximum credible earthquake and the associated typical fault described by its size geometry and kinematics we then let the typical fault float along strike of its parent source zone and simulated all tsunamis it could generate simulations are based on the solution of the nonlinear shallow water equations through a finite difference technique for each run we calculated the wavefields at specified simulation times and the maximum water height field above mean sea level then generated travel time maps and maximum water height profiles along the target coastline maxima were also classified in a three level code of expected tsunami threat we found that the southern portion of apulia facing albania and the gargano promontory are especially prone to the tsunami threat we also found that some bathymetric features are crucial in determining the focalization defocalization of tsunami energy we suggest that our results be taken into account in the design of early warning strategies

a proposal for the kinematic modelling of w dipping subductions possible applications to the tyrrhenian apennines system in w dipping subduction zones there is a general eastward progression of the back arc basin accretionary wedge foredeep complex with the forward progression early stages of the complex are revealed by slices of upper crust and sedimentary cover abandoned to the west left floating above a new section of mantle a major shear zone should form at the new moho separating upper crust slices of earlier accretionary stages and the eastward flowing mantle the mantle wedging at the top of the subduction plane could be responsible for the uplift of the central parts of the belt the retreating of the subduction hinge is interpreted as due to the push generated by the eastward mantle flow detected in the hot spot reference frame the foredeep depth is mainly a function of the radius of curvature of the subduction hinge the frontal wedge is constructed from the stacking of the upper layers of the subducting plate and the syntectonic clastics that fill the foredeep which are progressively involved in thrusting and later by extension in order to preserve volume balance the lithosphere of the eastern plate before subduction has to be the same size as that which has been subducted due to the longer length of the arc with respect to the original length of the linear margin between the two converging plates laterally stretched subducted lithosphere is predicted at depth w dipping subductions usually have a short life probably due to their inherent capability to produce new lateral heterogeneities of the lithosphere the thin back arc which are a key factor in controlling and generating new subductions both e and w dipping this model is applied to the apennines tyrrhenian sea system

seismic velocity depth relation in a siliciclastic turbiditic foreland basin a case study from the central adriatic sea abstract starting from reprocessed seismic profiles and borehole data we investigate the central adriatic foredeep basin by deriving velocity depth trend of the pliocene quaternary pq siliciclastic succession mainly composed by shales and sands relying on independent approaches to map two way time twt thickness of the pq deposits we converge on testing linear and exponential functions to predict vp depth trend results suggest that for large 1500 m thicknesses of the pq deposits best fit is achieved by the exponential function vp z c z 1 n while for shallower and thinner deposits a linear function like vp z v0 k z provides the best fitting estimates we also investigate anomalies in velocity trend with depth and suggest that velocity drops observed within the pq succession at significant depth 2500 3500 m may reflect overpressured deposits this hypothesis is consistent with the apennine compression and high sedimentation rates in central adriatic during the pliocene quaternary finally we stress the importance of considering vertical component phenomena and their time evolution when modeling foreland basins

neogene quaternary evolution of the offshore sector of the southern apennines accretionary wedge gulf of taranto italy abstract southern apennines represent a collisional orogenic belt whose compressional regime is commonly assumed to have ceased during middle quaternary on the other hand to the south the calabria arc is still characterized by subduction and the principal aim of the present research is to shed some light on the space and time transition from the ceased collision to the active subduction accordingly we investigated the offshore sector of the southern apennines accretionary wedge corresponding to the taranto gulf to gain insights into the offshore accretionary wedge we reconstructed a 3d geological and tectonic model by interpreting a grid of 40 seismic reflection lines 1100 km 80 intersections within an area of ca 104 km2 calibrated with 17 wells the geometric and chronological constraints allow documenting a systematic messinian quaternary thrust migration from internal towards external sectors of the wedge the migrating deformational process was essentially associated with a leading imbricate thrust system with a general ne younging direction where we could recognize and distinguish some major advancing phases characterized by alternating fast thrust propagation events and strain accumulation periods within the wedge this process is well emphasized by the jump of the foredeep and piggy back basins the ne wards wedge migration was also associated with a lithospheric scale flexural folding that generated a set of normal faults striking parallel to the coeval thrusts likely reactivating optimally oriented structures inherited from mesozoic events finally a persisting thrust activity up to the latest quaternary and possibly up to present in correspondence of the externalmost sector of the accretionary wedge has been documented and explained in terms of strain partitioning in the frame of a recent oblique convergence the results of this research have possible implications for the seismic hazard assessment of the broader region which is possibly greater than previously assumed

tertiary geodynamic evolution of the southern adria microplate the southern adria microplate is the common foreland for the hellenide and southern apennine thrust belts the apulian platform dominates the microplate outcrop well and seismic data allow us to trace the carbonate platform edge whilst structural analysis geophysical and palaeomagnetic data provide important clues to the geodynamic evolution of the region the present structural fabric of apulia is dominated by several e w lineaments that divide the region into different blocks rospo plateau gargano promontory murge ridge salento peninsula apulian plateau one such lineament the pescara dubrovnik line a prominent feature traversing the adriatic sea between central italy and southern croatia has been active since the early mesozoic when it acted as a major transform fault controlling sedimentation along the northern margin of southern adria during the cenozoic the pescara dubrovnik underwent predominantly vertical and oblique movement due to a differential flexural response of the platform and the adjacent pelagic sequences to the thrust belt loading in tertiary time the southern adria microplate was partly involved in heilenide collision the apulian platform can be considered as an area of thicker crust more resistant to underthrusting than the surrounding basins during the orogenic events it acted as a passive rigid indentor causing local distortion of the most external hellenide structures the dextral transpressive activity recorded along the south east margin of this indentor kephallinia line can be interpreted as the result of the oblique collision between the margin of the thick apulian platform in this zone nne ssw striking and the nw se striking hellenic thrust belt horizontal stress generated during the collision was partly transmitted to the rigid foreland re activating palaeo e w faults within the south adria microplate in a dextral strike slip sense the clockwise rotation recorded in the salento peninsula can be explained by the rotation of several nw se striking faulted blocks the rotation was accompanied by the opening of small transtensional basins between blocks this block rotation was caused by the dextral shear that is expressed along the north and the south salento fault zones

quaternary geomorphological evolution of the tremiti islands puglia italy abstract the archipelago of the tremiti islands situated in the centre of the adriatic sea is considered nationally and internationally a very important geological laboratory in the area of connection between the central and southern apennines already rich in cenozoic stratigraphic structural and seismological data this study discusses structural geomorphologic data with particular attention to features useful to define the islands quaternary evolution the identification of the main morphogenic events is based on the study of landforms that are spatially and chronologically comparable with depositional erosional features of the quaternary continental succession analysis of geomorphology and quaternary continental deposits supported by radiometric dating allows reconstruction of the islands quaternary evolution and provides some contributions at a regional scale

a new active tectonic model for the construction of the northern apennines mountain front near bologna italy 1 we integrate existing and new geologic data retreating trench extension and accretion tectonics retreat project particularly on the origin growth and activity of the mountain front at bologna italy into a new model that explains apennine orogenesis in the context of a slab rollback upper plate retreat process the bologna mountain front is an actively growing structure driving rock uplift 1 mm year cored by a midcrustal flat ramp structure that accommodates ongoing shortening driven by adria subduction at a rate of 2 5 mm year the data we use are assembled from river terraces and associated pleistocene growth strata geodesy including releveling surveys reinterpretation of published reflection lines and a new high resolution reflection line these data constrain a simple trishear model that inverts for blind thrust ramp depth dip and slip apennine extension is recognized both in the foreland as high angle normal faults and modest stretching in the carapace of the growing mountain front and in the hinterland with larger normal faults that accomplish some crustal thinning as the upper plate retreats this coevolution of extension and shortening shares some notable characteristics with other basement involved collisional orogens including the early tertiary laramide orogeny in the american west and the oligocene to miocene evolution of the alps we propose a possible relationship between underplating and the development of the po as a sag basin as a quaternary phenomenon that may also apply to past periods of apennine deformation tortonian continued shortening on the structure beneath the bologna mountain front represents by far the most important and underappreciated seismogenic source in the front of the northern apennines

spectral element simulations of seismic waves generated by the 2009 l aquila earthquake abstract we adopt a spectral element method sem to perform numerical simulations of the complex wavefield generated by the 6 april 2009 m w 6 3 l aquila earthquake in central italy the mainshock is represented by a finite fault solution obtained by inverting strong motion and global positioning system data testing both 1d and 3d wavespeed models for central italy surface topography attenuation and the moho discontinuity are also accommodated including these complexities is essential to accurately simulate seismic wave propagation three component synthetic waveforms are compared to corresponding velocimeter and strong motion recordings the results show a favorable match between data and synthetics up to 0 5 hz in a 200 km 200 km 60 km model volume capturing features mainly related to topography or low wavespeed basins we construct synthetic peak ground velocity maps that for the 3d model are in good agreement with observations thus providing valuable information for seismic hazard assessment exploiting the sem in combination with an adjoint method we calculate finite frequency kernels for specific seismic arrivals these kernels capture the volumetric sensitivity associated with the selected waveform and highlight prominent effects of topography on seismic wave propagation in central italy online material movie of wave propagation waveform fits and stable of station parameters

geomorphic evidence for an emergent active thrust along the edge of the po plain the broni stradella fault 1 we present here geomorphic evidence for an emergent active thrust along the northwestern apennine front about 50 km south of milano fieldwork combined with spot image analysis attests to the presence of a 35 km long en echelon cumulative fault scarp that cuts e w across quaternary surface deposits from casteggio to sarmato the scarp offsets vertically alluvial fans and terraces emplaced by tributaries of the po river that flow northward from the apennines incision by such tributaries occurs only south of the scarp valleys of smaller streams stand in hanging position to the northeast the buried east dipping pavia lateral ramp bounds the san colombano anticline we interpret the montebello sarmato scarp to result from the emergence of an active thrust fault dipping south the stradella thrust which splays eastward from that ramp total station profiles leveled perpendicular to the stradella thrust show variable cumulative surface throws ranging from 2 to 25 m scarp degradation analysis indicates fairly recent offset of the terrace surfaces 10 100 kyr suggesting a minimum uplift rate of 0 3 mm yr the underlying fault might thus be one of the most active thrust ramps along this segment of the apennines n s to n15 w shortening is consistent with both the e w strike of this thrust ramp and with coeval oblique sinistral motion on the nne ssw trending pavia lateral ramp the vogherese bobbiese earthquake of 1828 i ix south of casteggio and broni may have activated one segment of this lateral ramp rather than the stradella thrust other historical events i 7 that caused damage in pavia piacenza lodi and milano in the last 2000 years 290 a d 1249 a d 1276 a d 1473 a d may have occurred on the broni stradella thrust or on the blind san colombano and lodi thrusts farther north this makes detailed paleoseismological studies and trenching across its trace mandatory

orogens and slabs vs their direction of subduction abstract subduction zones appear primarily controlled by the polarity of their direction i e w directed or e to nne directed probably due to the westward drift of the lithosphere relative to the asthenosphere the decollement planes behave differently in the two end members in the w directed subduction zone the decollement of the plate to the east is warped and subducted whereas in the e to nne directed it is ramping upward at the surface there are w directed subduction zones that work also in absence of active convergence like the carpathians or the apennines w directed subduction zones have shorter life 30 40 ma than e or ne directed subduction zones even longer than 100 ma the different decollements in the two end members of subduction should control different ptt paths and therefore generate variable metamorphic assemblages in the associated accretionary wedges and orogens these asymmetries also determine different topographic and structural evolutions that are marked by low topography and a fast eastward migrating structural wave along w directed subduction zones whereas the topography and the structure are rapidly growing upward and expanding laterally along the opposite subduction zones the magmatic pair calc alkaline and alkaline tholeiitic volcanic products of the island arc and the back arc basin characterise the w directed subduction zones magmatic rocks associated with e or ne directed subduction zones have higher abundances of incompatible elements and mainly consist of calc alkaline shoshonitic suites with large volumes of batholithic intrusions and porphyry copper ore deposits the subduction zones surrounding the adriatic plate in the central mediterranean confirm the differences among subduction zones as primarily controlled by the geographic polarity of the main direction of the slab the western margin of the adriatic plate contemporaneously overridden and underthrust europe toward the west to generate respectively the alps and the apennines while the eastern margin subducted under the dinarides hellenides these belts confirm the characters of the end members of subduction zones as a function of their geographic polarity similarly to the pacific subduction zones

onshore to offshore anatomy of a late quaternary source to sink system po plain adriatic sea italy abstract in understanding the evolution of siliciclastic systems late quaternary analogs may enable reliable predictive models of facies tract architecture the po plain adriatic sea system where a wealth of research has been conducted during the last 20 years represents one of the most intensively investigated late quaternary successions with the aid of a chronologically well constrained stratigraphy paleoenvironmental evolution is tracked for the first time from fluvial to deep marine realms over 1000 km in length vertical stacking trends onshore and stratal terminations offshore are the key observations that allow identification of surfaces with sequence stratigraphic significance systems tract boundaries in the distinct segments of the system recurring motifs in stratigraphic architecture showing tight coupling of sedimentary responses among source area catchment basin and coastal and marine depocenters reveal a cyclicity driven by glacio eustatic fluctuations in the milankovitch band due to high rates of subsidence middle pleistocene forced regressive systems tracts are exceptionally expanded and the mis5e mis2 interval late pleistocene preserves a nearly continuous record of fourth order 100 kyr stepwise sea level fall the stratigraphic architecture of last glacial maximum deposits highlights the genetic relations between channel belt development pedogenesis and sediment delivery to the lowstand delta through narrow incised valley conduits the late glacial holocene succession records the last episode of sea level rise and stabilization through well developed patterns of shoreline transgression regression tst hst that can be readily traced updip from offshore to onshore locations architectural styles across the whole system reflect a dominance of allogenic forcing in the tst as opposed to a predominantly autogenic control on stratigraphic development in the hst external drivers of facies architecture were also effective on millennial timescales the younger dryas cold reversal which marks the transgressive surface on land records a short lived episode of subaqueous progradation that is correlative onshore with widespread immature paleosol development and small sized channel belt formation quantitative assessment of sediment budgets over different time intervals requires precise positioning of the key bounding surfaces based on this approach we outline for the first time over the entire po adriatic basin an estimate of the sediment volumes stored in each systems tract

different foreland basins in italy examples from the central and southern adriatic sea abstract the central adriatic basin cab and the southern adriatic basin sab are foreland or foredeep basins relative to the non coeval apenninic and dinaric hellenic orogenic systems and currently characterized by different physiographies these are separated by a major forebulge of the adriatic lithosphere running throughout the adriatic region from istria to the gargano promontory the clastic basin filling of the cab is mostly plio pleistocene whereas it is upper oligocene pleistocene in the sab stratigraphy reveals that the cab has experienced an overfilling regime throughout the plio pleistocene whereas the sab has been probably continuously underfilled during the same time span in the cab the foreland plate dips westward at an average angle of 5 6 whereas in the sab the basement dips to the east at an angle of 1 2 this discrepancy is congruent with the already noticed distinction between east and west dipping subduction systems and possibly has geodynamical implications in the cab the non homogeneous distribution of thrust sheets suggests strike slip tectonic movements along roughly ne trending lineaments that occurred up to the middle late pliocene on the western part of the sab the overall structural assemblage recalls the fabric typical to strike slip regimes and includesboth extensional and contractional structures it is proposed that the messinian salinity crisis and relative eustatic lowstand affected the subsequent tectono sedimentary evolution of the cab in terms of subsidence rate and depositional style one still tentative hypothesis is that water and sediment removal in the basin lasted for a sufficient time span to promote viscoelastic relaxation temporary migration of the forebulge towards the thrust belt and downwarping of the foreland plate

tracing deep fluid source contribution to groundwater in an active seismic area central italy a combined geothermometric and isotopic δ13c perspective abstract an understanding of the origin and migration pathways of geofluids in an active seismic area is of paramount importance in terms of societal challenges such as mitigation of seismic hazards this study investigates the relationship between the stable isotope ratio 13c 12c of deep co2 and geothermometry in selected groundwater samples located close to extensional faults in central italy the temperature range is inferred from an equation based on the na li ratio and chemical geothermal modelling 113 130 c globally the calculated temperature range agrees with that resulting from deep boreholes in the northern apennines an alternative method is also included to better evaluate the difference in isotopic composition between the aqueous and gaseous 13c co2 at deep condition a review of previously published data shows that monitoring of the isotopic composition of the dissolved inorganic carbon dic in springs fed by meteoric origin located in seismically active areas must take into account mass and isotopic balance to correctly evaluate the component and the role of deep fluid during seismic events in particular the coupled and corrected isotope and geothermometrical monitoring of the springs could help to distinguish between deep gas or deep fluid contributions to shallow aquifers the results of this study indicate that faults play a crucial role in controlling the migration of crustal fluids in addition they reveal that possible evaluation of potential seismic precursors mandatorily requires a long period of monthly monitoring

tomographic images of the upper mantle below central europe and the mediterranean results from delay time tomography of the european mediterranean upper mantle are discussed and where possible interpreted in terms of geodynamic processes slab like positive velocity anomalies of which the locations correlate well with deeper seismicity are found beneath spain the tyrrhenian basin and the aegean these structures are interpreted as images of subducted slabs large aseismic regions with positive velocity anomalies are found beneath the western mediterranean italy the alps dinarides the pannonian basin northern greece and the aegean these anomalies can also be linked to subducted lithosphere from the anomaly patterns it is deduced that subduction occurred below the western mediterranean and along both sides of the adriatic micro plate beneath the dinarides and northern greece the velocity structures suggest detachment of the slab from the surface

flexural behavior of the continental lithosphere in italy constraints imposed by gravity and deflection data a procedure is developed that systematically matches observations of plate flexure and gravity anomalies at simple convergent boundaries to the bestfitting two dimensional flexural geometry obtained by a thin elastic sheet of specified elastic strength the procedure allows analytical solution for three independent variables one of which is the initial preflexure elevation of the reference surface and two of which are related to the vertical forces and bending moments that act on the plate application to four profiles constructed across the apennine convergent system in italy shows that the observed depth of the basal pliocene surface which marks the base of the foredeep basin and the observed bouguer gravity anomalies can be fit by a two dimensional elastic plate model with an effective elastic thickness of about 20 km on three profiles and about 10 km on the fourth profile the initial elevation prior to flexure is determined to have been about 1000 m below sealevel on all profiles large bending moments and or vertical shear forces are required to act at the effective plate ends in order to maintain the observed deflection moments between 0 5 1017 and 3 1017 n and shear forces between 3 1012 and 3 1012 n m gravity modelling indicates that on the two northernmost profiles these terminal forces can not be supplied by a static mass at crustal depths and suggests that on all four profiles the terminal forces are supplied by anomalously dense material present at depths of 75 150 km beneath and west of the west coast of italy this dense material probably corresponds to westward subducted lithosphere of the adriatic plate extending from the northern apennines to the southern apennines and calabria this study suggests that in subduction systems like the apennines that are characterized by backarc extension forces acting on subducted lithosphere at depth can be expressed at the surface in the geometry of the foredeep basin that forms adjacent to the subduction zone

seismicity in central and northern apennines integrating the italian national and regional networks abstract in this paper we present and discuss an improved picture of the seismicity distribution of the umbria marche abruzzi apennines as obtained through the integration of the national and the regional seismic networks operating from 2002 to 2006 during this period both the istituto nazionale di geofisica e vulcanologia ingv national seismic network and the regional networks have been greatly improved we compare the results of the integrated catalogue obtained in this study with the catalogue of the italian seismicity between 1981 and 2001 castello b selvaggi g chiarabba c amato a 2006 csi catalogo della sismicita italiana 1981 2002 versione 1 1 ingv cnt roma http legacy ingv it csi confirming the basic known features of the seismic activity in the region but also evidencing some original and interesting results in particular the new data set allows us to better define the geometry and kinematics of the crustal seismicity which is confined to the upper 20 km and shows a clear general deepening from west to east in the crust we find additional evidence of extensional seismicity below the central portion of the belt and thrust reverse faulting mechanisms at the outer fronts of the apennines looking at the seismicity along the belt it is also possible to observe aseismic regions which could be due to either locked or creeping portions of the apenninic fault system at greater depth the west dipping seismicity distribution down to about 70 km confirms the hypothesis of a slab of adriatic lithosphere subducted below the apennines but also suggests that there are strong lateral heterogeneities and possibly tears in the slab

fault slip rates for the active external dinarides thrust and fold belt 1 we present estimates of slip rates for active faults in the external dinarides this thrust and fold belt formed in the adria eurasia collision zone by the progressive formation of ne dipping thrusts in the footwalls of older structures we calculated the long term horizontal velocity field slip rates and related uncertainties for active faults using a thin shell finite element method we incorporated active faults with different effective fault frictions rheological properties appropriate geodynamic boundary conditions laterally varying heat flow and topography the results were obtained by comparing the modeled maximum compressive horizontal stress orientations with the world stress map database the calculated horizontal velocities decrease from the southeastern external dinarides to the northwestern parts of the thrust and fold belt this spatial pattern is also evident in the long term slip rates of active faults the highest slip rate was obtained for the montenegro active fault while the lowest rates were obtained for active faults in northwestern slovenia low slip rates influenced by local active diapirism are also characteristic for active faults in the offshore central external dinarides these findings are contradictory to the concept of adria as an internally rigid aseismic lithospheric block because the faults located in its interior release a part of the regional compressive stress we merged the modeling results and available slip rate estimates to obtain a composite solution for slip rates

tomographic constraints on the geodynamic evolution of the italian region in this paper we present p wave tomographic images of the mantle beneath italy obtained by inverting 6000 teleseismic p and pkp wave arrival times accurately repicked recorded in the time period 1988 1994 by the stations of the national seismic network of the istituto nazionale di geofisica we pay great attention in the data selection and picking procedure of seismic phases to obtain a very high quality data set the data were inverted with the well established aki christofferson husebye tomographic technique different reference models and residuals computation have been tried to verify the stability of the results the high quality of the repicked arrival times allows us to enhance the definition of the deep structures beneath both the alps and the apennines looking for their lateral and vertical continuity down to 800 km depth the main finding of this study is a continuous high velocity body located between 250 and 670 km depth beneath the entire apenninic system dipping toward the tyrrhenian area which continues upward segmented in two main anomalies in the northern apenninic and the calabrian arcs we interpret this high velocity feature as the subducted oceanic lithosphere between the eurasian and african plates dipping down to the upper lower mantle boundary beneath the tyrrhenian sea the retrieved images of the lithosphere subducting beneath apennines are reliable in terms of thickness about 80 90 km and p wave velocity contrast 2 4 higher than the normal mantle furthermore our tomographic images which focus on the deep geometry and continuity of the velocity structures provide new keys to understanding the geodynamic evolution of the italian region the segmentation of the high velocity slab upward suggests a complex evolution of the arc trench system and the initially continuous subduction of the ionian adriatic plate progressively developed in subordinate arcs probably due to lateral heterogeneity of the subducting lithosphere

neogene to quaternary sedimentary basins in the south adriatic central mediterranean foredeeps and lithospheric buckling up to several kilometers deep sedimentary basins of neogene to quaternary age are found in the south adriatic between the apennines and the dinarides albanides they are the apennines foredeep the central adriatic basin and the south adriatic basin two regional seismic lines 260 and 170 km long across the entire system provide hitherto unavailable constraints on the kinematics and dynamics of basin development the apennine foredeep imaged along the lines formed in middle to late pliocene times through a rapid westward tilting of the basin floor a paleobathymetry of few kilometers was created in which allochthonous bodies were emplaced and sediments deposited unaffected by deformation and farther rotations the central and south adriatic basins formed in neogene to quaternary times and are both characterized by strong subsidence in their central parts gradually diminishing toward the edges in the sw and ne depocenters did not shift laterally through time subsidence rates increase through time and subsidence continued also following the end of main shortening episodes in the dinarides albanides the central and south adriatic basins form two crustal scale synclines with subsidence concentrated in their central parts basins geometries and subsidence patterns indicate that the adriatic crust has undergone episodes of buckling since miocene times wavelengths and amplitudes of such folds change along strike corresponding to mechanical changes of the folded medium

marine palaeoseismology from very high resolution seismic imaging the gondola fault zone adriatic foreland we present a marine palaeoseismology analysis of a dense network of very high resolution seismic profiles along the gondola fault zone gfz a right lateral e w striking active fault system in the adriatic foreland this case study aims to show how time and space variations in the activity of a dominantly right lateral fault system can be assessed using the vertical component of slip the gfz has been investigated for a length of 50 km it includes two parallel subvertical fault sets and two main anticlines the late middle pleistocene to holocene vertical component of displacement along the fault is bell shaped suggesting that in the long term the fault zone acts as a single kinematically coherent structure slip rates are 0 0 18 mm a 1 and vary temporally on individual segments this variability is consistent with a model in which individual fault segments rupture independently during earthquakes with magnitudes up to 6 4 and 1 3 1 8 ka recurrence intervals

pliocene quaternary sedimentation in the northern apennine foredeep and related denudation the deposits of the pliocene quaternary foredeep of the northern apennine cover at present an area of 103000 km2 the original boundaries of the basin are not known since marginal deposits have been eroded in particular those of the inner southwestern border during pliocene times the basin area was reduced by thrust tectonics and the amount of shortening may be tentatively estimated the present volume of pliocene and quaternary sediments may be inferred with good approximation from the maps of the base of the pliocene and of the quaternary base of the hyalinea balthica zone successions the pliocene volume has been corrected adding the estimate of the underthrust sediments while no correction has been attempted for the eroded marginal deposits the estimates of 97000 and 95000km3 reflecting the present volume of the pliocene and quaternary deposits are therefore significantly less than the volumes originally deposited present volumes have been transformed in net 0 porosity volumes in order to obtain the relative net supply rates 0 021 pliocene and 0 047 quaternary km3 a other unmeasurable factors volume variations due to the weathering of silicates loss of leached carbonates may induce a probably unimportant underestimate of the supply rates available data allow an approximate estimate of the range of the net volume of the holocene sediments deposited during the last 6000 a bp 221 276km3 and of the relative net supply rate 0 037 0 046km3 a that is not significantly different from the quaternary one applying a porosity correction these supply rates may be related to the quaternary source area 128000km2 to obtain the relative denudation rates 0 41 0 46mm a quaternary and 0 36 0 51 mm a holocene present supply and denudation rates deduced from the direct measurements of the bed load and suspended load of the apenninic and alpine rivers do not differ significantly from the quaternary and holocene ones available data do not allow a reliable estimate of the pliocene source area and consequently of the pliocene denudation rate however a minimum of 160000 177 000 km3 has been eroded during pliocene and quaternary times assuming as a working hypothesis that the pliocene source area did not significantly differ from the present one an average thickness of 1240 1390 m could have been eroded since the beginning of pliocene this estimate is in agreement with the values obtained from the measurements of coalification of vegetal organic matter in the outcrops and suggests that post orogenic successions and higher thrust sheets may have been completely removed in vast areas