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During the last millennium, several moderate to strong earthquakes occurred in the Umbria-Marche Apennines and Marche foredeep, making this region one of the most seismically active areas of Europe. Seismic activity is mainly clustered in the southern part of the region. Nevertheless, beside the presence of high magnitude historical earthquakes, the lack of significant instrumental seismicity (i.e. ML > 2.5 earthquakes) makes the northern sector of the study area as a prominent seismic gap. Such a northern area is highly challenging for the detection of active, often blind, faults that are essential to a reliable seismic hazard assessment of the region. To tackle this issue, we test an integrated methodological approach based on available geological information together with the analysis of high-resolution seismological data and stress inversion analysis. Furthermore, GIS-based morphotectonic analyses are also used to study the correlation between the identified structures and neotectonic processes. Topography analysis includes the creation of seven swath profiles (20 km in width) and of maximum, minimum, mean elevation and relief maps. River network analysis is carried out using river long profiles and transformed (𝝌) long profiles coupled with slope/area diagrams. The former allowed the location of knickpoints/knickzones, whereas the latter allowed the spatial distribution of the Ksn (normalized steepness) index to be obtained. Combined data from topography and river network mark the different neotectonic behaviour of the northern and southern sectors of the Umbria-Marche Apennines. In fact, the southward increase of (i) mean and minimum elevations, (ii) local relief, (iii) abundance of non-lithology controlled knickpoints, and (iv) Ksn values, suggest the presence of a locus of enhanced vertical motion (i.e., surface uplift) in the south. Here, the largest historical earthquakes and the strongest instrumental seismicity also occur, thus suggesting active tectonics is more intense in this area of stronger uplift.The results of our multidisciplinary analysis are consistent with evidence of along-strike segmentation of the fold and thrust belt where each sector is characterised by different active tectonic behaviour and thickness of Pliocene deposits. Boundaries of sectors roughly coincide with major transversal fault systems, segmenting the outer portion of the fold and thrust belt in the Marche foothills. Such transversal systems are accompanied by diffuse seismicity (< M= 5.5) and probably mark the loci of long-lived, deep-seated fault zones that exert a major control on the active tectonic behaviour of large crustal blocks also compartmentalizing the axial zone of the chain.

The Neogene to Quaternary southern Apennines mountain belt is flanked to the SW by the Tyrrhenian Sea back-arc basin, which was formed since late Miocene times. Extensional tectonics related to back-arc basin formation affected the Tyrrhenian margin of the southern Apennines since the Quaternary with formation of a series of horst and graben structures. Huge amounts of existing surface, subsurface and offshore data indicate that subsidence on the order of thousands of metres affected the grabens, and remarkable flights of marine terraces are indicative of Quaternary uplift of the horst blocks. The highest and older marine terraces, Early Pleistocene in age, occur up to several hundreds of metres above the sea level.A huge number of former studies have provided fundamental data on both the outcropping (raised) and buried paleoshorelines and littoral deposits, the chronological framework for the identified relative sea level fluctuations mostly rests on local-scale relative chronology reconstructions constrained by dating that are still quite rare and sparse.Detail-scale geomorphological-geological mapping, integrated with Quaternary stratigraphy, aimed at the recognition, characterisation and dating of raised marine terraces and paleoshorelines (tidal notches, platform inner edges) has been carried out in several key areas of the southern Apennines Tyrrhenian Sea margin, from Campania, in the North, to northern Calabria, in the South. The field surveys have been carried out both in rocky coasts (where continental deposits cover and sometimes hide the paleoshorelines) and in the two main alluvial-coastal basins, namely the Campania and Sele River plains. The new geochronological data constrain the ages of several late Middle Pleistocene to Late Pleistocene sea level markers, allowing a better definition of the vertical motions in each study area. Overall, the time-space distribution of the vertical motions on the regional scale is better reconstructed, along with the framework of the Quaternary surface uplift of the southwestern slope of the southern Apennines mountain belt.

Flash floods occur quickly and instantly with respect to triggering rainfall and are particularly frequent in river basins of limited extent. In the Mediterranean area, flash floods are acknowledged as the most widespread geo-hydrological hazard. They may have a particularly catastrophic character due to combination of intense precipitation and strong orographic forcing (cumulative rainfall values in the order of hundreds of mm in a few hours) with the widespread presence of steep, small river basins, referred to as Small Mediterranean Catchments. The natural susceptibility associated with Small Mediterranean Catchments eventually results in high hydrogeological risk notably for densely-urbanized and populated alluvial fans at catchment outlets. Therefore, the evaluation of sediment budgets of flash-flood prone, torrential catchments is important for the assessment of flood susceptibility and hazard in piedmont areas.Our study addresses the evaluation of the sediment volume that has the potential to be entrained and delivered downstream during flash floods in torrential catchments. With the final aim of developing an approach useful to the definition of the order of magnitude of future flash flood events in terms of debris loads, our goal is to obtain reliable quantification of sediment storage through the geomorphological analysis of high-resolution topographic data.We developed and tested a predictive, quantitative geomorphological technique for estimating the magnitude of debris flows related to flash floods triggered by extreme rainfall events. We applied our method to steep torrential catchments that (i) are underlain by resistant rocky bedrock, therefore not prone to large landslides, and (ii) allowed testing of our technique through quantification of the effects of recently-occurred flash floods. The three study catchments are located in southern Italy and experienced flash flood-related debris flows triggered by a rainstorm with a recurrence interval > 200 yrs. We estimated the sediment volumes stored in the investigated mountainous catchments prior to the flash flood and compared our results with the sediment volumes entrained by the debris flows. The latter volumes were estimated by post-event data collected by means of both field surveys and remote sensing (drone surveys). The results were mutually consistent so supporting our approach. The approach can be applied extensively, even in the absence of field data and measurements, to ungauged catchments similar to those we analysed for flash flood hazard assessment and planning of mitigation strategies.

The growth of a mountain chain results from a complex interplay between endogenous and exogenous processes. The former depends on the geodynamic setting and cause the uplift of the orogenic wedge whereas the latter tend to erode the uplifted topography. Surface uplift may act at uneven temporal and spatial scale and reconstructing its distribution through space and time may provide fundamental data to unravel either the future tendency of geomorphic processes (e.g., increased erosion in uplifted areas) or to identify areas affected by active tectonics. In this study, we adopted a morphotectonic approach to unravel the spatial distribution of surface uplift in active orogens, such as the southern Apennines of Italy. Features of the topography (e.g., maximum, mean and minimum elevation maps, relief maps and swath profile) and the river network (e.g., river long profile and chi-long profile, Ksn index, chi index map) have been derived through ArcGis and Matlab softwares. The combined analysis of all indexes allows recognising a locus of enhanced surface uplift that moves from NE (the Bradanic foredeep) to the SW (the outer sector of the orogenic wedge). Surface uplift do not extend towards the inner sector of the orogenic wedge and its spatial distribution roughly follow the main divide. Furthermore, a natural tendency of the main divide to shift towards the NE has been also identified, that is consistent with the uneven spatial distribution of vertical motions. To quantify differences in surface uplift between the foredeep-outer chain and the inner chain, we analysed published data about MIS5 paleoshorelines. These data also confirmed the uneven distribution of surface uplift at the orogen scale, thus confirming that the adopted morphotectonic approach may be considered a powerful tool to constrain the spatial distribution of vertical motions.

The millimetre accuracy of Synthetic Aperture Radar (SAR) measurements and related multi-temporal data analyses provide fundamental information on surface displacements caused by strong earthquakes. The multi-temporal analysis of SAR interferometry data allows for the geometry, kinematics and temporal behaviour of earthquake-generating faults to be better constrained, and is being acknowledged as a promising technique in the field of earthquake precursors. We used SAR data obtained by multi-temporal interferometric techniques such as Permanent Scatterers (PS) interferometry for the investigation of pre- to post-seismic ground displacements in the region struck by the Mw 6.3, 2009 L9Aquila earthquake. We analysed Europen Remote Sensing (ERS) and Envisat PS-datasets from ascending and descending orbits, and COSMO-SkyMed PS-datasets from descending orbit, collectively covering a > 20 year long time span. On a yearly scale, a reversal of motions that affected the hanging-wall and footwall blocks of the earthquake-generating fault is detected. In particular, the hanging-wall block is characterized by pre-seismic uplift – which we document as being independent of any hydrological control – and eastward horizontal motion for about six years, followed by subsidence and westward motion (starting six to eight months prior to the earthquake). We suggest that such a ground displacement pattern may represent an earthquake precursor signal. Supplementary material: Figures showing SAR satellites viewing geometry, examples of raw PS time series of obtained from ERS ascending and descending orbits and maps of LoS-oriented mean velocities obtained from PS datasets from the Envisat ascending and descending orbits and a Table reporting detailed numerical results of the performed statistical analysis are available at https://doi.org/10.6084/m9.figshare.c.5289357

New analyses of marine terraces in the Tyrrhenian Sea margin of Basilicata - northern Calabria (southern Italy) have been carried out. In the study area, c. 25 km in length, an impressive flight of marine terraces occurs, with the highest terraces reaching ~160 m a.s.l. Detailed geomorphological-stratigraphical analyses on remnants of paleoshorelines located within 60 m a.s.l. have shown that the rocky coast of the investigated coastal stretch has been affected by multiple relative sea-level fluctuations, during which reworking of older shorelines has occurred. Dating of the coral Cladocora caespitosa and speleothems, either predating or postdating single paleoshorelines, has allowed the construction of a chronological framework for the identified relative sea-level markers, and their correlation with MIS 7, MIS 6e and distinct peaks of MIS 5. A mean uplift rate of c. 0.25 mm/y since the Last Interglacial has been quantified, one order of magnitude larger than previous estimates. The uplift rate value has been used to infer the elevations of MIS 5a, 5c and 6e sea level peaks, which are higher than those reported in most sea level curves worldwide, although consistent with several findings from the western Mediterranean. Our results demonstrate that a mere sequential correlation may be misleading in the interpretation of flights of marine terraces and indicates that multiple age controls are crucial to unravelling the complex interaction between uplift and sea-level fluctuations in uplifted coastal areas. The reconstructed MIS 5a, 5c and 6e sea level paleo-elevations, besides contributing to the assessment of late Quaternary sea-level fluctuations in the Mediterranean Sea, may contribute to constrain coeval ice sheets volume variations.

Raised paleoshorelines were detected in the eastern margin of the Campania Plain, which is one of the largest coastal basins in the Tyrrhenian back-arc basin system associated with the Neogene to Quaternary Apennine orogen. The paleoshoreline remnants crop out at variable elevations at several sites, including quarry cuts, which provide excellent 3D exposures of the coastal landforms and deposits, the associated continental sediments and faults dissecting those landforms and deposits. Based on the integration of geomorphological, stratigraphic, micropaleontological and facies analyses with structural data, we reconstructed shoreline development in response to erosional/depositional processes governed by relative sea level change in the framework of coeval extensional tectonics. Most of the paleoshoreline remnants are assigned to three displaced marine terraces that, based on new U-series dating, are related to the late part of the Middle Pleistocene. The faults offsetting the marine terraces (namely, E-W striking normal faults and NNW striking transfer faults) are interpreted as part of a single, segmented extensional fault system controlled by roughly N-S to NNW-SSE horizontal extension. The identified extensional system, being consistent with the regional structure imaged by seismic data, represents the first field evidence of the tectonics controlling the formation of the Campania Plain basin. Our results, providing new direct evidence that effectively complements the large amount of existing subsurface datasets, allow for a significant step forward in the understanding of the tectonic and sedimentary processes governing the Quaternary development of the Tyrrhenian back-arc basin margin.

The Zagros thrust belt formed due to the convergence between the Arabian and Eurasian plates during the closure of the Neo-Tethys Ocean. GPS measurements show that the northward relative motion of ...

&ldquo, Geotourism&rdquo, is a particular type of &ldquo, sustainable tourism&rdquo, that is still in an embryonic stage, especially in Italy. The main goal is the transmission of geological knowledge to increase the awareness about geoheritage, geo-resources and geo-hazards. The geoparks represent ideal sites, with a strong educational significance for students, teachers, geo-tourists, and guides interested in geological and environmental sciences, though at different levels. With this in mind, we propose a geoitinerary through some of the most geologically interesting coastal areas in the Cilento, Vallo di Diano, and Alburni Geopark. The aim of the geoitinerary is to provide a good example of how geosites could be promoted through geotourism and used as means of divulgation of geological and environmental knowledge. The selected sites are the San Marco coast, the Licosa Cape and the Elea-Velia archaeological area. They are included in the official list of geosites and geomorphosites of the Geopark and have a relevant stratigraphic and geoarcheological value. The San Marco coast and the Licosa Cape are the &ldquo, best sites&rdquo, in the Geopark where Quaternary coastal deposits and morphologies are represented. The Elea-Velia site is one of the most famous archeological sites in the Geopark, which is also representative of complex human-environment interactions. Despite their high scientific significance, the sites that we have selected are not included in a specific promoting program. We have so tried to fill this gap by providing the scientific background for their geotouristic promotion that could also serve as an instrument for the increase of the local economy.

The Mountain Front Flexure is a major structure of the Zagros orogenic system, and is underlain by the deeply rooted and seismically active Mountain Front Fault system. These coupled structural features divide the belt from its foreland and their trace is sinuous, forming salients and recesses. The origin and tectonic significance of the Mountain Front Fault system and its sinuosity are still unclear, with most of hypotheses pointing to a strong structural control exerted by geological inheritances. In this work we combine interpretation of seismic reflection profiles, earthquake data, geomorphic analysis, and geological observations, to build a balanced cross section across the Mountain Front Flexure in the Lurestan region. Our data are suggestive of a hybrid tectonic style for the Lurestan region, characterised by a major and newly developed crustal ramp in the frontal portion of the belt (i.e the Mountain Front Fault) and by the reactivation of steeply dipping pre-existing basin-bounding faults, along with a minor amount of shortening, in the inner area. Specifically, the integration of our results with previous knowledge indicates that the Mountain Front Fault system developed in the necking domain of the Jurassic rift system, ahead of an array of inverted Jurassic extensional faults, in a structural fashion which resembles that of a crustal-scale footwall shortcut. Within this structural context, the sinusoidal shape of the Mountain Front Flexure in the Lurestan area arises from the re-use of the original segmentation of the inverted Jurassic rift system.

To unravel how and where coseismic and interseismic deformation impacts the spatial and temporal patterns of rock uplift of the Lurestan sector of the Zagros Mountains, we performed an investigation of the large‐scale features of topography and river network coupled with 2‐D finite element modeling. Geomorphological analysis and constraints from parameters such as elevation, local relief, normalized channel steepness index (ksn), river longitudinal profiles, and transformed river profiles (chi plots) were used to unravel the time‐space distribution of vertical motions. Whereas the much longer timescale over which topography grows and/or rivers respond to tectonic or climatic perturbations with respect to even multiple seismic cycles, the outputs of the finite element model yield fundamental information on the source of the late part of the spatiotemporal evolution of surface uplift recorded by the geomorphology. Model outputs shed new light into the processes controlling relief evolution in an actively growing mountain belt underlain by a major blind thrust. The outputs illustrate how coseismic slip controls localized uplift of a prominent topographic feature—the Mountain Front Flexure—located above the main upper crustal ramp of the principal basement thrust fault of the region, while continuous displacement along the deeper, aseismic portion of the same basement fault controls generalized uplift of the whole crustal block located farther to the NE, in the interior of the orogen.

Naples and its surroundings are a very young landscape, originated from 40 ka in response to strong and explosive volcanic processes, which created the Campi Flegrei, one of the largest volcanic fields of the world. Despite the repeated and continuous volcanic activity, this territory was selected for human settlements since Neolithic times and hosted some of the most important Greek and Roman towns in the Mediterranean area (e.g., Cuma, Parthenope, Neapolis, Baia and Puteoli). Geoarcheological data and historical chronicles testify to human coexistence with eruptions, bradyseismic ground motions, coastline changes, floods and landslides. With the aim of describing the geomorphological evolution of this area to a wide audience, including also non-experts, we constructed a synthetic geomorphological map of the area and sketches that synthesise the main stages of the geomorphological evolution of the historical centre of Naples and the coastal belt of the Gulf of Pozzuoli during the last millennia.

The actively extending axial zone of the southern Apennine mountain belt of Italy is characterized by a substantial flow of non- volcanic gas to the surface. In this study, we have analyzed the correlation between the active tectonic framework of the Matese Ridge area and the high gas emissions found to the southwest, which includes large amounts of CO2 (up to 99 vol%), CH4 (up to 0.55 vol%), and He (up to 52 ppmv). We measured CO2 and CH4 fluxes of up to 34000 g d-1 and 2000 g d-1, respectively, from zones of focused degassing (gas vents and associated strong diffuse emission). This anomalously high flux of CO2 (advective plus diffusive) indicates that the study area has one of the largest non- volcanic natural emissions of CO2 ever measured on Earth. The isotope composition of C in CO2 and CH4 shows there is a dominant crustal contribution of emissions (as opposed to a source from the mantle), indicating that thermometamorphism of the buried Apulian Platform carbonates is probably the main cause of CO2 production. This process has likely been enhanced by Quaternary magmatism, which provides an additional local source of heat triggering decarbonation of Apulian Platform limestones and dolostones at depth. The advective flux is concentrated at gas vents located along active fault segments located at the western tip of a major crustal structure, the South Matese fault zone. We believe that the very high gas emission in the Matese Ridge area is the result of both the presence of a dense network of active fault strands, which provides efficient pathways for fluid flow toward the surface, and the dramatically reduced thickness of the clay-rich mélange zone acting elsewhere in the south- ern Apennines as a top seal overlying the buried Apulian Platform carbonates.

The Quaternary evolution of the main coastal basins located along the southwestern margin of the Southern Apennines has been reconstructed by integrating the huge amount of existing stratigraphical and geomorphological data. The information produced in the last twenty years has shed new light on the recent (late Middle Pleistocene to Present) history of the Campanian and Sele plains or basins. During the early Quaternary, the analysed coastal basins originated as half-grabens in response to opening processes active since the late Tortonian in the southern Tyrrhenian back-arc basin. In some of these basins (e.g. the Campanian Plain), volcanism has also played an important role. In the inner sectors of the coastal basins, the complex interplay between block faulting, sedimentary inputs and glacioeustatic fluctuations gave rise to relative sea-level change and related coastline migrations, leading to the formation of the present-day coastal plains. In the Sele Plain basin, the construction of the present-day landscape mainly resulted from the substantial ceasing of subsidence in the final part of the Middle Pleistocene. Conversely, a strong contribution to the recent evolution of the Campanian Plain has been provided by abundant volcaniclastic aggradation, able to hinder the effect of the vertical motions that occurred in the last 100 ka.

The proclivity of river networks to progressively carve mountain surfaces and preserve markers of landscape adjustments has made analyses of fluvial systems fundamental for understanding the topographic development of orogens. However, the transient nature of uplift and erosion has posed a challenge for inferring the roles that tectonics and/or climate have played on generating topographic relief. The Mt. Alpi region in the southern Apennines has a heterogeneous distribution of elevated topography, erosionally-resistant lithology and uplift, making the area optimal for conducting topographic and river analyses to better understand the landscape development of a transient orogen. Stream length-gradient, normalized channel steepness, stream convexity and first-order channel gradient indices from 10 m digital elevation data from the region exhibit stream profile inconsistencies along the current drainage divide and a dominance of high values subparallel but inboard of the primary chain axis irrespective of known transient landscape factors, suggesting that the current river network may be in a state of transition. The location of these stream profile anomalies both near the modern drainage divide and subparallel to an isolated swath of high topography away from catchment boundaries is thought to be the topographic expression of an imminent drainage divide migration driven primarily by the ~ northeast-vergent extension of the western chain axis.

The southern Apennines is a fold-and-thrust belt, which was formed during the late Cenozoic convergence between the African and Eurasian plates. Late Quaternary and active tectonics are dominated by extensional faulting mainly acting in both the inner and the axial belts of the mountain belt. Since the Early-Middle Pleistocene, activity of high-angle normal faults caused the formation of large coastal grabens and intramountain basins that are often limited by mountain fronts, up to 2000 high, formed in carbonate rocks. Late Quaternary activity of some of these high-angle normal faults, that mainly trend NW-SE and E-W, has been proved through field geomorphological and/ or stratigraphical and structural data and could be inferred by quantitative investigation of landforms. To test the suitability of the quantitative analysis approach to assess the state of activity of faults placed at the boundaries between mountain fronts and alluvial basins, and to verify the limits of applicability of this method, we have carried out a comprehensive analysis of some mountain fronts in the Southern Apennines. We have compared the following indexes: mountain front sinuosity, swath profile, river long profile, slope/area data, alluvial fan and drainage basin metrics. Overall data point to variable geomorphic features of different mountain fronts and along-strike variability of some parameters at the mountain front scale in response to either rock-type resistance or fault behaviour. This study highlights the importance of the tectonic geomorphology approach in active orogens and suggest that this method is suitable to application worldwide to compare mountain front maturity.

Rugged peaks, large intermontane basins and frequent seismicity all characterize the active extensional tectonic setting of the southern Apennines. The Matese ridge typifies the active tectonic setting of the southern Apennines with steep carbonate mountain fronts and large depositional centres. Moderate to high magnitude earthquakes have affected the northern, western and eastern sectors of the Matese ridge in historical times. However, the seismogenic potential of the extensional fault system bounding the southern Matese mountain front has not been fully assessed to date. To unravel the active tectonic setting of the southern Matese mountain front, we have carried out a comprehensive geomorphological and tectonic-geomorphology investigation of the mountain front and its piedmont and have constrained results through chronological (i.e., tephrostratigraphical and 40Ar/39Ar) and structural data. Our study highlights that in the last ∼600 ka, activity along E-W trending normal faults has identified a locus of higher slip rate tectonic activity in the central part of the analysed mountain front. These active E-W-striking normal faults are inherited, reactivated structures, which have interacted with newly formed NW-SE-striking normal faults during NE-SW extension active on the regional scale, causing fault bending and local extension to be oriented N-S. Consequently, lower slip rates have been recorded along the NW-SE-striking normal faults at the north-western and south-eastern tips of the southern Matese front. The long-term displacement rate of the fault system at the boundary of the central part of the southern Matese front is consistent with mean values of displacement of faults that, in the southern Apennines, show evidence of activity during the late Quaternary. Despite strong historical seismicity clustering primarily around the study area, our data highlight that it cannot be ruled out that moderate to high magnitude seismicity could affect the southern Matese mountain front. Our case study represents an example of the possible modes of formation and evolution of mountain front-basin systems in extensional setting, and shows how the combination of different data sets allows unravelling the interaction between tectonic, erosional and sedimentary processes, which lead to landscape evolution of active mountain belts.

The Sarno plain corresponds to the southernmost sector of the Campana Plain peri-Tyrrhenian graben, and it is limited towards the northwest by the Somma-Vesuvius volcanic edifice. The Sarno plain corresponds to the depocenter of a Quaternary sedimentary basin which is more than 2000 m thick and is bounded by high angle faults with NE-SW, E-W and NW-SE trends. Our study focussed on the less investigated, inner part of the Sarno plain, and aimed at reconstructing the recent (Late Pleistocene - Holocene) geomorphological and tectonic evolution of the area. The study was based on detailed geomorphological investigation combined with subsurface stratigraphic analyses of around 80 borehole logs. The geomorphological-stratigraphical approach has allowed the identification of the main geomorphological features of the alluvial plain and adjacent piedmont areas, and the reconstruction of the shallow subsurface setting of the inner Sarno Plain. The results indicate post-Late Pleistocene subsidence of the investigated area and the presence of an articulated fault system at the northeastern boundary of the investigated area. Surface morphological features and the characteristics of the drainage network are consistent with the subsurface stratigraphy in pointing to the activity of E-W and NW-SE trending fault strands during the late Quaternary. Overall evidence suggests the occurrence of vertical displacements postdating the emplacement of the Campania Ignimbrite regional chronostratigraphical marker, which implies fault activity continuing in the last 40 ka in the inner part of the densely populated Sarno Plain.

The MS 6.9, 1980 Irpinia earthquake occurred in the southern Apennines, a fold and thrust belt that has been undergoing post-orogenic extension since ca. 400 kyr. The strongly anisotropic structure of fold and thrust belts like the Apennines, including late-orogenic low-angle normal faults and inherited Mesozoic extensional features besides gently dipping thrusts, result in a complex, overall layered architecture of the orogenic edifice. Effective decoupling between deep and shallow structural levels of this mountain belt is related to the strong rheological contrast produced by a fluid-saturated, shale-dominated m&eacute, lange zone interposed between buried autochthonous carbonates&mdash, continuous with those exposed in the foreland to the east&mdash, and the allochthonous units. The presence of fluid reservoirs below the m&eacute, lange zone is shown by a high VP/VS ratio&mdash, which is a proxy for densely fractured fluid-saturated crustal volumes&mdash, recorded by seismic tomography within the buried autochthonous carbonates and the top part of the underlying basement. These crustal volumes, in which background seismicity is remarkably concentrated, are fed by fluids migrating along the major active faults. High pore fluid pressures, decreasing the yield stress, are recorded by low stress-drop values associated with the earthquakes. On the other hand, the mountain belt is characterized by substantial gas flow to the surface, recorded as both distributed soil gas emissions and vigorous gas vents. The accumulation of CO2-brine within a reservoir located at hypocentral depths beneath the Irpinia region is not only interpreted to control a multiyear cyclic behavior of microseismicity, but could also play a role in ground motions detected by space-based geodetic measurements in the postseismic period. The analysis carried out in this study of persistent scatterer interferometry synthetic aperture radar (PS-InSAR) data, covering a timespan ranging from 12 to 30 years after the 1980 mainshock, points out that ground deformation has affected the Irpinia earthquake epicentral area in the last decades. These ground motions could be a result of postseismic afterslip, which is well known to occur over years or even decades after a large mainshock such as the 23 November 1980, MS 6.9 earthquake due to cycles of CO2-brine accumulation at depth and its subsequent release by Mw &ge, 3.5 earthquakes, or most likely by a combination of both. Postseismic afterslip controls geomorphology, topography, and surface deformation in seismically active areas such as that of the present study, characterized by ~M 7 earthquakes. Yet, this process has been largely overlooked in the case of the 1980 Irpinia earthquake, and one of the main aims of this study is to fill such the substantial gap of knowledge for the epicentral area of some of the most destructive earthquakes that have ever occurred in Italy.

Seismically induced ground effects characterize moderate to high magnitude seismic events, whereas they are not so common during seismic sequences of low to moderate magnitude. A low to moderate magnitude seismic sequence with a M w = 5.16 ± 0.07 main event occurred from December 2013 to February 2014 in the Matese ridge area, in the southern Apennines mountain chain. In the epicentral area of the M w = 5.16 main event, which happened on December 29th 2013 in the southeastern part of the Matese ridge, field surveys combined with information from local people and reports allowed the recognition of several earthquake-induced ground effects. Such ground effects include landslides, hydrological variations in local springs, gas flux, and a flame that was observed around the main shock epicentre. A coseismic rupture was identified in the SW fault scarp of a small-sized intermontane basin (Mt. Airola basin). To detect the nature of the coseismic rupture, detail scale geological and geomorphological investigations, combined with geoelectrical and soil gas prospections, were carried out. Such a multidisciplinary study, besides allowing reconstruction of the surface and subsurface architecture of the Mt. Airola basin, and suggesting the occurrence of an active fault at the SW boundary of such basin, points to the gravitational nature of the coseismic ground rupture. Based on typology and spatial distribution of the ground effects, an intensity I = VII−VIII is estimated for the M w = 5.16 earthquake according to the ESI-07 scale, which affected an area of at least 90 km2.

Sinkholes that affect both carbonate rocks and alluvial plain deposits are widely distributed in the southern Apennines. Karst sinkholes, in particular, are generally clustered within High Sinkhole Concentration Area (HSCA). A geological and geomorphologi-cal study of some, selected HSCA, has been carried out, aimed at constraining hypotheses on both factors that control sinkhole spatial distribution and causative mechanisms of karst collapses. Based on independent evidence on the active tectonic framework and deep fluid rising in the HSCA, karst sinkhole phenomena appear related the hypogenic karst controlled by the rise of acidic fluids along active faults.

In this study, we outline the tectonic and surface processes that have governed the landscape evolution of the outer Apenninic wedge and foreland basin in the Molise area during the late stages of the Apennines formation (Amorosi et al., 2009; Bracone et al., 2012; Amato et al., 2017), with a focus on the Trigno, the Saccione, the Biferno, the Sinarca and the Fortore River valleys. The work has been based on the combination of field data with morphometrical analysis of both the topography and the river drainage systems, resulting from the investigation of a 90m resolution DTM in a GIS environment. This approach has been widely used in literature and represents a useful tool to the landscape evolution reconstruction (Scotti et al., 2013; Buscher et al., 2017). In particular, the morphometrical investigation has been based on the elaboration of some swath profiles running parallel to the coastline and on the determination of the: 1- basin asymmetry (AF); 2- the hypsometrical integral (HI); 3- the river long profile and the derived concavity () and normalized steepness (Ksn) indexes of the main trunks and their tributaries. The results point to a north-westward increase of the medium elevation (e.g. from the Fortore to the Trigno valley, Fig. 1), which is independent from the lithological features of the study area. Also the normalized steepness index enhances an increasing trend towards the north-west (Fig. 2a). River long profile enhance a slight concave up shape for the Fortore river and a rectilinear shape for both the Biferno and the Trigno rivers (Fig. 2b). The hypsometrical integral analysis shows a north-westward increase in the HI value, suggesting a decrease in the maturity of the drainage basins from SE (e.g., from the Fortore River) to NW (e.g., to the Trigno River) (Fig. 2c and 2d). In addition, a slight asymmetry of all of the drainage basins has been recognized, with AF values generally lower than 50 suggesting valley shifting towards the hydrographic right flank (Fig. 2d). This data is also consistent with the river terraces distribution, which form a river terrace step on the hydrographic left flank of most valleys and that are less preserved on the opposite sides. The combination of field, morphostructural and morphometrical data with available stratigraphic constraints has allowed a better reconstruction of the growth and evolution of the outer Apenninic wedge in the Molise segment of the Apennines belt. In fact, it has strongly helped unravelling the features and style of the Apennines outer wedge - foredeep system recent (Late Quaternary) uplift. The picture resulting from the geomorphological data set discussed above points to differential uplift along the strike of the Apennines mountain front, with a general increasing trend of uplift towards the NW.

In the southern Apennines, low-temperature thermochronometry data indicate that exhumation of previous tectonically buried sedimentary units started at around 10 Ma and took place mostly during the last 6 Ma. Relatively high exhumation rates are obtained from apatite fission track (AFT) and (U-Th)/He (AHe) analysis, pointing to a substantial contribution of tectonic processes to rock exhumation besides erosion. Exhumation rates derived from new apatite (U-Th)/He data (AHe) for the last 3 Ma are generally lower than rates determined by AFT data and almost in line with erosion rates inferred from cosmogenic nuclides and sediment yield, thus suggesting that tectonic exhumation was dominant during the older exhumation stages of this region. However, younger cooling ages in the Monte Alpi area from both AFT and AHe analyses point out focused exhumation during the last 3 Ma. Structural and morphotectonic analyses indicate that fast exhumation occurred specifically in this area—where the Apulian Platform reservoir carbonates, elsewhere buried beneath a several kilometer-thick allochthonous cover, are exposed at the surface—as a result of a complex interplay between steep-rooted reverse faulting and shallow low-angle extension. This deformation involved the development of foreland-dipping low-angle normal faults affecting the allochthonous cover units during the late stages of reverse fault-related anticlinal growth in the underlying buried carbonates. Extension of the region triggered focused exhumation in the footwall of the extensional low-angle faults, which was followed by widespread crustal extension and associated development of high-angle normal faults, leading to surface uplift of Monte Alpi.

Continental carbonates of Quaternary age in southern Italy commonly exhibit the facies of calcareous tufa, often reported as related to shallow aquifers fed by meteoric waters and to organic processes. A close spatial relationship exists between the mappable tufa deposits and major Quaternary extensional faults. With respect to the Ca-Mg-HCO3 composition of limestone aquifers’ springs, tufa-depositing springs exhibit higher salinity and alkalinity, are slightly warmer, have lower pH and are enriched in SO4 and CO2. Their d 13 C values are systematically positive and compatible with a deep-seated carbon source. A clear input of soil-derived organic carbon is indicated only for small, non-mappable tufas deposited by perched springs. The dataset indicates that the large tufa deposits owe their origin to a supplementary source of CO2 advected by degassing through active faults, as a necessary prerequisite for inducing a rise of total dissolved salts and alkalinity. Meteoric waters that have come from a shallow aquifer are able to precipitate only limited amount of carbonates.

In recent years, contrasting seismic tomographic images have given rise to an extensive debate about the occurrence and implications of migrating slab detachment beneath southern Italy. One of the most pertinent aspects of this process is the concentration of the slab pull force, and particularly its surface expression in terms of vertical motions and related basin subsidence/uplift. In this study we focused on shallow-water to continental, Pliocene-Quaternary basins that formed on top of the Apennine allochthonous wedge after its emplacement onto a large foreland carbonate platform domain (Apulian Platform). Due to the thick-skinned style of deformation controlling the Pliocene-Pleistocene stages of continental shortening, a high degree of coupling with the downgoing plate appears to characterize the late tectonic evolution of the southern Apennines. Therefore, the wedgetop basins analysed in this study, although occurring on the deformed edge of the overriding plate, are capable of recording deep geodynamic processes affecting the slab. Detailed stratigraphic work on these wedge-top basins points to a progressive SE-ward migration of basin subsidence from c. 4 to c. 2.8 Ma over a distance of about 140 km along the strike of the Apennine belt. Such a migration is consistent with a redistribution of slab-pull forces associated with the progressive lateral migration at a mean rate in the range of 12–14 cm y–1 of a slab tear within the down-going Adriatic lithosphere. These results yield fundamental information on the rates of first-order geodynamic processes affecting the slab, and on related surface response.

This study aims at the reconstruction of magnitude and timing of surface uplift affecting a wide sector of the Central Apennines (Italy) by means of morphometric and morphostructural analyses. In the chain interiors (where stratigraphic and geomorphological markers of past sea-level positions are lacking) the study is based on analysis of erosional landforms and river valleys. A large-scale topographic analysis, by processing 90-m and 230-m DEMs, is performed. The spatial distribution of several morphometric parameters, together with characteristic wavelengths of relief, allowed the differentiation of three main regions affected by different cumulative surface uplift and tectonic/erosional fragmentation: a Peri-Tyrrhenian Belt, an Axial Belt and a Peri-Adriatic Belt. Particular attention is devoted to fluvial landforms, with analysis of longitudinal profiles and geometric pattern of the main drainage lines and their relations with the major structures. Major differences occur between the Tyrrhenian and Adriatic valley systems. The Tyrrhenian drainage mainly consists of longitudinal valleys displaying overall concave-up longitudinal profiles. The Adriatic drainage is mainly constituted by transverse streams and shows less regular longitudinal profiles. Topographic features and the river valley architecture seem related to different styles and amounts of uplift in the three belts. Within the study area, a coast to coast transect (Gaeta-Vasto Transect, GVT) has been investigated in detail, focusing the analysis on its axial sector, around the Apennines main divide (Main Divide Area, MDA). A possible scheme of Quaternary surface uplift along the GVT is proposed. In the MDA, the main stages of landscape evolution and drainage organization can be reconstructed by means of the analysis of paleosurfaces coupled with study of the relict and present-day drainage networks. This allowed the recognition of a major phase of surface uplift (exceeding 1500 m in the Meta-Mainarde massif) that occurred in response to thrusting during the Pliocene. For Quaternary surface uplift a minimum value of 400 m can be estimated. This study suggests that, during the Quaternary, the Peri-Tyrrhenian Belt suffered a subdued uplift acting over small wavelengths (10–15 km), while the Axial and Peri-Adriatic Belts were subject to a larger and long-wavelength (90 km) surface uplift, with maximum values (about 700 m) shifted to the NE of the Axial Belt and tapering to zero towards the Adriatic coast. The reconstructed pattern of uplift is coherent with the topographic properties of the three belts and with the observed drainage features.

The recent earthquake sequences of 2012 (northern Italy) and 2013 (Marche offshore) provided new, fundamental constraints to the active tectonic setting of the outer northern Apennines. In contrast to the Po Plain area, where the 2012 northern Italy earthquakes confirmed active frontal thrusting, the new focal mechanisms obtained in this study for the 2013 Marche offshore earthquakes indicate that only minor thrust fault reactivation occurs in the Adriatic domain, even for a theoretically favourably oriented maximum horizontal compression. Recent seismicity in this domain appears to be mainly controlled by transcurrent crustal faults dissecting the Apennine thrust belt. The along-strike stress field variation from the Po Plain to the Adriatic area has been quantitatively investigated by applying the multiple inverse method (MIM) to the analysis of the entire seismicity recorded from January 1976 to August 2014, from the top 12 km of the crust (fault plane solutions from 127 earthquakes with MW ≥ 4), allowing us to obtain a comprehensive picture of the state of stress over the outer zone of the fold and thrust belt. The present-day stress field has been defined for 39 cells of 1.5° × 1.5° surface area and 12 km depth. The obtained stress field maps point out that, although the entire outer northern Apennines belt is characterized by a sub-horizontal maximum compressive axis (σ1), the minimum compression (σ3) is sub-vertical only in the Po Plain area, becoming sub-horizontal in the Adriatic sector, thus confirming that the latter region is dominated by an active tectonic regime of strike-slip type.

Integrated geological, geomorphological, and differential interferometry synthetic aperture radar (DInSAR) data are used to constrain the timing and modes of activity of Quaternary fault systems in the Hyblean Plateau. This area, which represents a unique natural laboratory for studying surface deformation in relation to deep slab dynamics, has grown since middle Miocene times as a doubly plunging forebulge associated with slab rollback during NW-directed subduction. Bimodal extension has produced two mutually orthogonal normal fault systems. The detailed stratigraphic record provided by synrift sediments and postrift marine terraces allowed us to define the timing of activity of an early Pleistocene, flexure-related fault system, thus constraining the duration of a typical foreland extensional tectonic event to ∼1.5 m.y. Subsequent late Quaternary to present deformation was dominated by strike-slip faulting associated with NW-oriented horizontal compression. During this latest stage, regional uplift progressively increased toward the thrust front to the NW and was accompanied by differential uplift accommodated by dip-slip components of motion along active NNW-trending faults. The general active tectonic setting of the study area, characterized by NW-oriented horizontal compression consistent with major plate convergence, and the regional uplift pattern can both be explained within the framework of intraplate shortening and foreland rebound following complete slab detachment, a major geodynamic event interpreted to have taken place at ca. 0.7 Ma in southern Italy.

In the last decades, multidiscipline investigation of the Apennine mountain belt of peninsular Italy has provided fundamental insights into the genesis and evolution of wedge-top basins. In this study, we focus on shallow-water to conti- nental, Pliocene-Quaternary basins that formed on top of the southern Apennine allochthonous wedge after its emplacement onto a large foreland carbonate platform domain (Apulian Platform). The wedge-top basins analyzed in this study are mostly asymmetric, being bounded to the north by a normal fault showing evidence of synsedimentary activity. The basin succes- sions are generally deformed by open folds and reverse faults resulting from shortening coeval with the sedimentation of the Lower Pliocene to lower-middle Pleistocene, upper part of the basin fill. Anisotropy of magnetic susceptibility data from the basin successions are consistent with a basin evolution characterized by an initial stage of tectonic subsidence controlled by roughly north-northwest-south-southeast-oriented extension, followed by southwest-northeast shortening active during subse- quent basin filling. The latter shortening is marked by a dominant northwest-southeast mean trend of the magnetic lineation obtained from most sites in the study area and is interpreted as a result of upward propagation of deep-seated deformation (tectonic inversion) taking place within the buried Apulian Platform sitting in the footwall to the allochthonous wedge. There- fore, our results emphasize a complex interplay of different tectonic processes controlling wedge-top basin development. Resume : Au cours des dernieres decennies, une etude multidisciplinaire de la chaine de montagnes des Apennins dans la peninsule italienne a donne des apercus de la genese et de l'evolution des bassins sur le prisme d'accretion « wedge-top ba- sins ». Dans cette etude, nous ciblons les bassins d'eau peu profonde a continentaux, datant du Pliocene-Quaternaire, qui se sont formes sur le dessus du prisme allochtone du sud des Apennins, apres sa mise en place sur un vaste domaine de plate- forme de carbonate d'avant-pays (la plate-forme apulienne). Les bassins sur le prisme d'accretion analyses dans la presente etude sont surtout asymetriques, puisqu'ils sont delimites au nord par une faille normale montrant des evidences d'activite syn-sedimentaire. Les successions de bassins sont generalement deformees par des plis ouverts et des failles inverses prove- nant d'un retrecissement contemporain de la sedimentation du Pliocene inferieur au Pleistocene inferieur moyen dans la par- tie superieure du remplissage du bassin. L'anisotropie des donnees de susceptibilite magnetique provenant des successions de bassin concorde avec une evolution du bassin caracterisee par un stade initial de subsidence tectonique controlee par une extension a orientation generale nord-nord-ouest-sud-sud-est, suivie d'un retrecissement sud-ouest-nord-est actif durant le remplissage subsequent du bassin. Ce dernier retrecissement montre une tendance moyenne dominante nord-ouest-sud-est de la lineation magnetique obtenue de la plupart des sites dans le secteur a l'etude et il est interprete comme le resultat d'une propagation vers le haut d'une deformation situee en profondeur (inversion tectonique) qui s'est produit dans la plate-forme apulienne enfouie se trouvant dans l'eponte inferieure du prisme allochtone. Nos resultats soulignent donc une interaction complexe entre les differents processus tectoniques qui controlent le developpement des bassins sur les prismes d'accretion. (Traduit par la Redaction)

A seismic sequence offshore the Marche region sheds new light on the active tectonic setting of the outer northern Apennines, revealing the existence of a previously unknown transcurrent seismogenic structure. In contrast to the Po Plain area, where vigorous seismicity testifies to active frontal thrusting, the seismotectonic setting of the Adriatic domain is characterized by the occurrence of active crustal strike-slip faults dissecting the thrust belt. As recent studies suggest that thrust faults represent the unique seismogenic sources characterizing the Adriatic sector of the outer northern Apennines, our results pose new challenges to the identification of seismogenic structures in the region.

After the 6 April, 2009 normal faulting L'Aquila earthquake (Mw 6.3), the attention of many scientists was drawn to the Abruzzo Apennines. Until that time few studies had addressed the geomorphological and morphotectonic features of this area and none to extensive geomorphological mapping.The tectonic-geomorphological map (scale 1:40,000) presented in this work is the result of a morphotectonic investigation of the middle Aterno River valley, which includes the area from the western L'Aquila-Coppito basin (to the northwest) to the Paganica–San Demetrio basin and to the Castelnuovo–Civitaretenga basin (to the southeast).The map is implemented within a GIS environment by means of: DEM and map-based cartographic analysis and morphometry of orography and hydrography (raster and vector data scale 1:25,000, 10 m grid DEM), photogeological analysis (scale 1:10,000), structural geomorphological field mapping (scale 1:10,000), basin fill geometry analysis (geophysical and borehole investigations) and tectonic–geomorphological profiles that couple landforms, deposits and surfaces. The map incorporates orography and hydrography, basin fill geometry, tectonic–geomorphology and tectonic–geomorphological profiles.The result provides a basis for the recognition of morphotectonic features at basin scale, detection of tectonic control on the landscape, and reconstruction of paleo-landscapes and basin geometry.

Soil gas measurements of different gas species with different geochemical behaviors were performed in the area of the Pecore Plain, a 200m x 300m sized, fault-bounded extensional basin located in the northern Mount Marzano massif, in the axial belt of the southern Apennine chain. The Pecore Plain area was affected by coseismic surface faulting during the M-s = 6.9, 1980 Irpinia earthquake, the strongest and most destructive seismic event of the last 30 years in southern Italy. The collected data and their geostatistical analysis provide new insights into the control exerted by active fault segments on deep-seated gas migration toward the surface. The results define anomalies that are aligned with the NW-SE trending coseismic rupture of the 1980 earthquake along the western border of the plain, as well as along the southern border of the plain where a hidden, E-W striking fault is inferred. Geospatial analysis highlights an anisotropic spatial behavior of Rn-222 along the main NW-SE trend and of CO2 along the E-W trend. This feature suggests a correlation between the shape and orientation of the anomalies and the barrier/conduit behavior of fault zones in the area. Furthermore, our results show that gas migration through brittle deformation zones occurs by advective processes, as suggested by the relatively high migration rate needed to obtain anomalies of short-lived Rn-222 in the soil pores.

A signifi cant uncertainty exists in the defi - nition of both surface pattern and subsurface continuity (i.e., coupling vs. decoupling) of active normal faults in the Apennines. In this study, we investigated the epicentral area of the MS = 6.9, 1980 Irpinia earthquake— one of the most destructive historical earthquakes in Italy—based on detailed topography analyses, morphostratigraphic and structural data, and new age constraints from Quaternary deposits. The active tectonic behavior of the study area is controlled by a series of subparallel, mainly WNW-ESE– to NW-SE–trending, dominantly extensional faults spanning over the southern Apennines axial belt. A large part of the active fault strands is characterized by a subdued topographic expression, as a result of the young age of extensional faulting initiation, and of relatively low mean slip rates. In addition, as already known from long historical seismicity records elsewhere, long-lasting quiescence might alternate with clusters of closely spaced, strong earthquakes. The long-term morphostratigraphic record confi rms that long-lasting quiescence may punctuate fault activity, with major implications for seismic hazard assessment. The relatively smallsized cumulative fault throws estimated by surface evidence contrast with subsurface information provided by crustal-scale cross sections and seismological evidence, which both suggest the occurrence at depth of largedisplacement, mature fault zones capable of nucleating large earthquakes. Furthermore, although the surface distribution of active fault strands overlaps the belt affected by present-day low-magnitude seismicity and by large historical earthquakes, a mismatch in the attitude and kinematics of shallow versus deep faults is unraveled by a comparison of surface geological versus seismological data sets. This feature suggests a decoupling between surface and deep fault zones, and that outcropping fault planes cannot always be straightforwardly traced down to hypocentral depths, particularly in fold-andthrust belts characterized by strong rheological contrasts. On the other hand, stress inversion from outcropping active faults and from earthquake focal mechanisms indicates a general consistency of the stress fi eld, thus suggesting that a homogeneous late Quaternary extensional regime produces complex reactivation of the inherited, articulated fault network affecting different structural levels of the southern Apennines

Subduzione e collisione continentale in Appennino meridionale: vincoli da due sezioni crostali.Mediante l’integrazione di dati geologici di superficie e sottosuolo, sono state realizzate due sezioni crostali attraverso il sistema catena-avanfossa-avampaese dell’Appennino meridionale. Di tali sezioni, quella settentrionale e stata elaborata dall’interpretazione del profilo sismico a riflessione CROP 04, mentre quella meridionale attraversa i giacimenti petroliferi della Val d’Agri e di Tempa Rossa, in Basilicata. Le due sezioni mostrano la presenza, nel sottosuolo del Cilento, di unita di basamento continentale coinvolte nella strutturazione della catena appenninica. Queste evidenze suggeriscono che, dopo l’iniziale fase di subduzione oceanica, l’evoluzione tettonica dell’Appennino meridionale e stata caratterizzata da due eventi di subduzione continentale alternati a due stadi di collisione continentale.

This study focuses on karst collapse sinkholes of the southern and central Apennines region (Italy), and has the aim of outlining and discussing the factors whichcontribute to the occurrence of collapse phenomena. By the analysis of the morphometrical/morphological features of the about 600 initially identified sinkholes, about 50% were interpreted as collapse sinkholes related to karst phenomena, whichare the object of this study. These were geo-referred and organised in a data base, in whichinformation on the geological-structural and hydrogeological features of areas affected by the collapses was also reported. The collapse sinkhole inventory was paralleled by an analysis of the distribution of the main mineral springs (H 2 S- and CO 2 - richwaters), of travertine bodies and of extensional faults withlate Quaternary activity, whichwere all considered significant to the study due to the interrelations linking travertines, karst solution processes, CO 2 - richwaters and faults. Furthermore, withthe aim of investigating the role of seismic shaking in the occurrence of the collapses, the karst collapse sinkhole distribution was compared withthe distribution of stronger historical earthquake epicentres. The results of this regional scale synthesis suggests a possible key to the interpretation of karst collapse phenomena. The latter, in fact, appear correlated to the combination of peculiar conditions, whichmay be envisaged in the presence of active faults and mineral waters. The study, in particular, suggests that karst collapse sinkholes result from enhanced dissolution phenomena related to the rising of fluids of deep origin, for which active faults represent preferred pathways, and favoured by the presence of a relatively shallow water table. In the collapse events, an important role is possibly played by seismic shaking.

The Pantano di San Gregorio Magno is a 4.7 km 2 large tectono-karstic basin located in the axial belt of the Southern Apennines, an area affected by intense seismicity. The basin was formed in the Middle Pleistocene and is presently undissected. It is filled by lacustrine sediments (clays, silts and pyroclastic sands) passing laterally into alluvial fan deposits. Geomorphological investigations were integrated with tephrostratigraphical, palynological and palaeoecological analyses of a 61 m thick core (not reaching the bedrock). The multiproxy analysis of the S. Gregorio Magno record shows that, over the last 200k yr, the basin hosted a freshwater lake with an oscillating level. Age constraints provided by the tephrostratigraphic record allowed estimation of the sedimentation rate, which varied strongly through time. Evolution of the basin resulted from the complex combination of tectonic subsidence, karst processes and changing amounts of sedimentary inputs. The latter was influenced by allogenic contributions related both to primary and reworked volcanoclastic inputs and was climate-driven. The overall evidence, which indicates that in the long-term the accumulation rate substantially counterbalanced the accommodation space created by faulting, suggests that the basin evolution was also modulated by changing subsidence rates. Copyright # 2006 John Wiley & Sons, Ltd.

This paper summarises the results of combined structural and geomorphological investigations we carried out in two key areas, in order to obtain new data on the structure and evolution of the Tyrrhenian slope of the southern Apennines. Analysis by a stress inversion method [Angelier, J., 1994. Fault slip analysis and paleostress reconstruction. In: Continental Deformation. P.L. Hancock Ed., Pergamon Press, Oxford, 53–100] of fault slip data from Mesozoic to Quaternary formations allowed the reconstruction of states of stress at different time intervals. By integrating these data with those deriving from the stratigraphic and morphotectonic records, chronology and timing of the sequence of the deformation events was obtained. The tectonic history of the region can be related to four deformation events. Structures related to the first event, that was dominated by a strike-slip regime with a NW–SE oriented σ1 and was active since Mid–Late Miocene, do not significantly affect the present day landscape, as they were strongly displaced and overprinted by subsequent deformation events and/or deleted by erosion. The second and third events, that may be considered as the main responsible for the morphostructural signature of the region, are comparable with the stretching phases recognised offshore and considered to be responsible for the opening and widening of the Tyrrhenian basin. In particular, the second event (with an E–W oriented σ3), took place in the Late Miocene/earliest Pliocene and was first dominated by a strike-slip regime, that was also responsible for thrusting and folding. Since Late Pliocene, it was dominated by an extensional regime that created large vertical offsets along N–S to NW–SE trending faults. The third event, that was dominated by extension with a NW–SE oriented σ3, started in the Early Pleistocene and was responsible for formation of the horst-and-graben structure with NE–SW trend that characterises the Tyrrhenian margin of the southern Apennines. The fourth deformation event, which is characterised by an extensional regime with a NE–SW trending σ3, started in the late Middle Pleistocene and is currently active.

An integrated geomorphological and geophysical investigation was performed in order to reconstruct the Pliocene-Quaternary geomorphologic evolution and recent tectonics of Mt. Marzano massif (Southern Apennines, Italy). The study area belongs to a region of high seismic energy release, the last event being the strong (MS 6.9) 1980 Irpinia earthquake. Most of the main faults of the area ceased their activity before development of the Late Pliocene age palaeosurfaces, widely spread over the massif. Beginning in the lower part of the Middle Pleistocene, strong extensional tectonics took place in the southern portion of the massif. WNW-trending faults created the Buccino and S.Gregorio Magno depressions, which underwent subsidence until the Holocene, according to abundant morphostructural evidence. During the Late Quaternary, the N150° trending Mt. Valva–Mt. Carpineta fault and the N110-100° trending Mt. Ogna fault, previously sealed by Pliocene palaeosurfaces, also were re-activated. Morphostructural data were integrated with a high-resolution seismic survey across the Piano di Pecore basin, which is dammed by a fault that slipped 70 cm during the 1980 earthquake. This fault produced no more than 50–60 m of throw during Quaternary times, most probably starting from 100 to 150 kyr BP.

In this paper, we present the results of an integrated stratigraphical, geomorphological and morphotectonic study carried out in Mt. Bulgheria, a rocky headland located on the eastern margin of the Tyrrhenian extensional basin, in Southern Italy. Such a margin is characterised by the occurrence of uplifted headlands alternated with subsiding half-grabens. In particular, Mt. Bulgheria constitutes the northeastern margin of the Gulf of Policastro peri-Tyrrhenian depression. In the study area, Pliocene–Quaternary continental deposits and erosional landforms are present together with Pleistocene wave-cut and wave-built marine terraces. The integrated study of Pliocene–Pleistocene deposits and landforms allowed a detailed reconstruction of the geomorphological evolution of Mt. Bulgheria to be made. Furthermore, the tectonic behaviour of this portion of the Tyrrhenian margin during Plio-Quaternary times could be characterised. In particular, we recognised that a succession of alternated uplift and subsidence episodes affected the headland since the beginning of Early Pleistocene, when the eastward migrating coastline of the Tyrrhenian extensional basin reached Mt. Bulgheria. The alternated uplift and subsidence events lasted for Early and Middle Pleistocene. Their cessation in Late Pleistocene is demonstrated by the occurrence of Late Pleistocene strandlines at an elevation comparable with that of the 130 ka sea-level highstand as recorded in stable areas of the Mediterranean region. The occurrence of marine terraces allowed the absolute vertical movements to be estimated. Their summation produced an uplift of the headland of 400 m since the beginning of the Santernian, 150 m of which occurred in the Middle Pleistocene. Along the onshore belt of the Tyrrhenian margin of Southern Apennines, other structural highs bordering the peri-Tyrrhenian depressions provide evidence for subsidence episodes interrupting the prevailing uplift trend recorded during the Quaternary. This, together with the distribution of Quaternary marine deposits (both downthrown and raised) and terraces, shows that the Tyrrhenian margin of Southern Apennines was affected by strongly variable vertical movements.