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Using combined datasets from ground penetrating radar (GPR) and terrestrial laser scanning (TLS) we document the variety of tectono-geomorphic features that contribute to the morphology of bedrock scarps associated with active extensional faulting in central Italy. Measurement of faulted offsets across such scarps can provide important fault slip-rate data relevant to seismic hazard analysis if ages can be established for offset features. However, interpretation of these offsets is challenging when geomorphic processes as well as fault slip contribute to exhumation of the bedrock during scarp development. Through the integration of surface (TLS) and subsurface (GPR) datasets, we show that the surface expression of three bedrock scarps results from the interaction between footwall incision, hangingwall sedimentation, channel incision and landsliding as well as fault slip and fault linkage. We further illustrate how these processes can be differentiated to identify locations suitable for determining fault slip-rates. The identification of such features has important implications for our understanding of the relationship between bedrock faulting and geomorphic processes, in turn contributing to improved assessment of fault slip-rates in the central Apennines. The use of combined GPR and TLS datasets here has shown that the tectono-geomorphic features of the studied scarps vary greatly over short distances and we emphasise the need for detailed scarp analysis to elucidate the processes responsible for bedrock exhumation before estimating the rates of fault slip over the timescale of scarp formation.

The transverse 'Sillaro line' is merely the outcrop line of the north-west dipping overthrust plane of the Liguride Complex. The anti-Apenninic strike of this overthrust plane is the result of the 'Sillaro flexure', a large synsedimentarily developed flexure of the basement of the Northern Apennines. The Liguride Complex overlies to the north-east progressively younger deposits dating from Early Miocene to eventually Pliocene: the Liguride overthrust is tectonically transgressive. The Liguride Complex is made up largely of clay, the Argille Scagliose; the overthrusting was gravitational. Just like glaciers and ice-sheets the Liguride Complex is a plastic mass capable of spreading under the influence ofgravitation. Olistostromization played a role ofvarying importance in the advance of the Liguride Complex. During the Pliocene, when a shallow molasse basin was invaded, it was the dominating mechanism. Locally the Liguride Complex interfingers with autochthonous deposits, as a result of a temporary standstill of the thrust sheet. The deposits just below the overthrust plane often show the influence of the approaching Liguride Complex. The Marnoso Arenacea is a turbidite formation of Miocene age. The configuration of its sedimentation basin was influenced strongly by an anticline that developed synsedimentarily, resulting in the Castel Vecchio 'high'. This 'high' divided the basin into an inner and outer basin in the south-west and north-east respectively, each with its own sedimentary history. The position of the inner basin axis was defined by the Rovigo syncline, which was also synsedimentary. A 'klippe sedimentaire', the Casaglia Member, invaded the basin from the south-west, and carne to a standstill near the basin axis. It proved impossible to describe the turbidites in terms of inner and outer fan and basin plain deposits by analogy with recent turbidite sedimentation in oceanic environments. A purely descriptive classification in facies associations is introduced here. The thickest and coarsest turbidites were usually deposited in the deepest parts of the basin. Towards the 'high' they became thinner and finer grained, until only marls were deposited. Upon the Castel Vecchio 'high' moluscs are found in living position, indicating that occasionally this 'high' approached sea-level. The Castel Guerrino Formation which constitutes a separate tectonic unit, was probably deposited in a more internal part ofthe Marnoso Arenacea basin. This formation thrust from the south-west upon the Marnoso Arenacea, after which it overthrust 5 km further to the north-east over a thin slice of Liguride rocks which had already overthrust the Marnoso Areacea.

The sedimentary cover of the investigated area consists of a thick sequence (Triassic-Miocene) of limestones and marls, overlain by turbiditic sandstones of the "Laga Formation" (Messinian- Early Pl iocene). No pre-Triassic basement is exposed. The most consipicuous structural feature is the Umbria Thrust Zone, a segment of the so-called Ancona-Anzio Line. This oblique lineament is generally taken as the boundary between the Northern and Southern Apennines, although its significance is highly controversial. But thrusting and associated folding is not confined to the Umbria Thrust Zone: it prevails allover the Central Apennines. The thrusts are mostly not single planes, but pervasive deformation zones, strongly affected by pressure solution. Slip, as indicated by slickensides, was everywhere towards the NE, regardless of the strike of the various structures. The style of deformation is "thin-skinned". Two major detachment levels - a lower, subsurface one at the base of the cover sequence, and a higher one just below the Laga Formation - are connected by a series of ramps where thrusts cut up-section. Doubling of strata above and beyond these ramps has resulted in large rootless anticlines with complicated, disharmonic forward limbs. The thrust steps developed successively, from the internal (SW) side outward. The arcuate and oblique trends of many rootless anticlines, or rather of the ramps below, have been controlled by pre-existing irregularities inside the sedimentary cover due to Jurassic block-faulting. By repeated doublings, the lower part of the cover has been shortened considerably. But very little of this shortening has affected the Laga Formation, which belongs almost entirely to the hanging wall and has been displaced as a whole. Thus the investigated area, as well as the adjacent Umbria Marche Apennines and Abruzzi including the "Ancona-Anzio Line", belong to a single allochthonous thrust complex.

SUMMARY We provide the analytical formulation for calculating the displacement and stress field forced by internal sources in a stratified, self-gravitating, viscoelastic earth. This model is specialized to study the rate of vertical motion and shear stress accumulation produced by lithospheric density anomalies. These sources are allowed to vary in the lateral direction. We show that sphericity plays a crucial role for elongated lithospheric anomalies while self-gravitation produces minor deviations from a gravitating Earth. When the model is applied to the Apennines we get, for lithospheric viscosity ranging between 10" and loz3 Pas, the subsidence of the plate underlying the active front of the overthrusting load to be around 0.5-1.0 mm yr-'. This is consistent with the amount of sedimentation in the Adriatic foredeep. The deformation pattern is very peculiar, with the largest subsidence localized beneath the active front of the topography. Our model enlightens the impact of discontinuities of tectonic phases on vertical motions in collision zones. If lithospheric viscosity is around 10'' Pa s, vertical motions decay drastically on time scales of 105yr if lateral migration of density anomalies comes to an end. For higher viscosities, deformation rates are maintained longer. This correlation between horizontal and vertical motions suggests that altimetric geodetic surveying along levelling lines of a few hundred kilometers can be an important tool to constrain the tectonics of the studied region. Results are also shown for vertical motions along a transect perpendicular to the Apennines, when the crustal structure inverted from Bouguer gravity data is considered. Analysis of the stress field induced by an overthrusting load shows that principal stress differences of a few bar (or a few tenths of MPa) can be accumulated on time scales of 102-103yr. These low values agree with the average stress drop of earthquakes in the Appalachians and northern Apennines where our modelling can be applied. We find that lateral density variations certainly contribute to intraplate stresses, but they are less efficient in triggering earthquakes than other mechanisms, such as transcurrent motions along active plate margins. Seismicity induced by lateral variations of crustal and lithospheric density must be moderate, characterized by long return times. These results are in agreement with the recorded seismicity in the northern Apennines where the largest earthquakes have return times of lo2 yr. If shear stress is forced by an overthrusting load, we find that the largest rate of stress accumulation in the crust is concentrated beneath the active front, close to the boundary with the ductile lithosphere. Discontinuities of tectonic phases play an important role in controlling the amount of shear stress due to density anomalies.

Since the early 70’s the majority of tectonic reconstructions of the western Mediterranean employ the Alboran domain notion as a migrating microcontinent or landmass mainly composed of Paleozoic-Triassic rocks affected by ‘Alpine’ HP-LT metamorphism. For nearly three decades, since the mid-80’s, the Alboran domain was considered as a fragment of the Alpine chain that moved westward, colliding into Iberia and North Africa to produce the Gibraltar arc and Betic-Rif chain. In 2012, a new hypothesis for the evolution of the western Mediterranean was presented in which the Betic-Rif orogenic chain originates from rollback of an initially SE-dipping subduction of the westernmost segments of the Ligurian-Tethys under the Africa margin. This interpretation considers the metamorphic ‘Alboran domain’ rocks as crustal successions of the hyper-extended African and Iberian continental margins, which have undergone a complete subduction-exhumation cycle above a NW- to W-retreating subduction. A key outcome of this hypothesis is that the Alboran domain is not a fragment of the Alpine chain but a consequence of rollback dynamics. In this contribution we try to elucidate the historical reasons behind the classical ‘Alpine’ interpretation of the Betic-Rif, by briefly describing key contributions, which appear linked in a logical sequence that traces the evolution of the Alboran domain concept since its original formulation by Andrieux and coauthors in 1971., This study was developed during a JAEDOC project (E.C.) in the frame of the FSE 2007-2013 Program, and benefitted from the constructive environment and discussions generated around the TopoMed CGL2008e03474-E/BTE, ESFEurocores 07-TOPOEUROPE-FP006, and Consolider-Ingenio 2010 Topo-Iberia (CSD2006e00041) projects.

Geoelectrical fluctuations are the end product of several geophysical phenomena. In particular geoelectrical signals measured in seismically active areas can be attributed to stress and strain changes, associated with earthquakes. The complexity of this problem has suggested the development of advanced statistical methods to investigate the heterogeneous nature of these fluctuations. In this paper we analysed the time dynamics of short-term variability of geoelectrical field measured at Giuliano station, located in Basilicata Region, one of the most seismically active areas of southern Italy. We applied the principal component analysis (PCA). The analysis has shown earthquake precursory patterns in the daily variation of the principal components, revealing that the PCA approach is promising for monitoring seismic areas.

We analyzed the distribution of seismic moment in Italy, computed from instrumental seismicity recorded by the Italian National Seismic Network in the past 14 years, to map the areas where seismic deformation processes have been active in this time interval. Seismic moment is the most suitable parameter to quantify earthquake size. It is related to the geometric characteristics of faults, to seismic energy and it is a quantity that can be summed and represented in its cumulative value. The maps of seismic moment distribution display more information than epicentral maps, better showing actively deforming regions. They provide further and original evidence for the existence, within the Apenninic belt, of two regions (north and south) characterized by different seismic energy release. The seismic moment is almost continuously and homogeneously distributed all along the belt in the Northern Apennines, whereas in the Southern Apennines it is concentrated in the zones recently activated by mainshock-aftershock seismic sequences. Seismic deformation takes place in a 30 km narrow belt along the Apennines, while in the transition zone between the Northern and Southern Apennines this belt is about 100 km wide. Comparing instrumental seismic moment release with the areas struck by the largest historical earthquakes which have occurred in the past six centuries, we qualitatively extended back to the past the information on where the seismic deformation occurs. In the Southern Apennines background energy release from instrumental seismicity is very low in the several areas hit by large historical earthquakes, suggesting that these seismogenic zones are currently quiescent.

The Scorciabuoi Fault is one of the major tectonic structures affecting the Southern Apennines, Italy. Across its central sector, we performed several electrical resistivity tomographics with different electrode spacing (5 and 10 in) and using a multielectrode system with 32 electrodes. All tomographies were acquired with two different arrays, the dipole-dipole and the Wenner-Schlumberger. We also tested the different sensitivity of the two arrays with respect to the specific geological conditions and research goals. Detailed geological mapping and two boreholes were used to calibrate the electrical stratigraphy. In all but one tomography (purposely performed off the fault trace), we could recognise an abrupt subvertical lateral variation of the main sedimentary bodies showing the displacement and sharp thickening of the two youngest alluvial bodies in the hanging-wall block. These features are interpreted as evidence of synsedimentary activity of the Scorciabuoi Fault during Late Pleistocene and possibly as recently as Holocene and allow accurate location of the fault trace within the Sauro alluvial plain.

The paper summarizes the state of knowledge and the evolution of the researches on benthic macroinvertebrates of Italian mountain lakes, and identifies key aspects that need to be further explored. Mountain lakes have been investigated since the end of the XIX century. In the beginning, studies focused mainly on their geography, geology, geomorphology and hydrology. Only lately, interests arise on their hydro-chemistry and biology, in relation to water acidification and, in rare cases, to eutrophication. In particular, in the 1920s, the studies dealt mainly on lake basins morphology and their genesis. Later, researches were driven mainly by the growing need of hydroelectric power plants, shifting the attention on their hydrological and geological aspects. Nonetheless, more detailed limno-biological studies began in confined areas. During the 1960s, attention was redirected to the alpine environment in terms of environmental awareness, for the creation of parks, and to analyse the alteration of water quality caused by the deposition of transported pollutants from the lowlands. This created the opportunity to combine observations on both the hydro-chemical and biological aspects, to reach a synoptic view of these environments. It is only in the mid-1990s that ISI journals came to power and, striving for higher visibility, strongly promoted the production of papers. In this decade, the application of paleo-limnology, the creation of a long term ecological research network, the never abandoned idea of implementing best practice management for freshwaters conservation purposes, and the growing attention on the global climatic change gave new impulse to the studies on mountain lakes. Since the 2000s, biodiversity preservation, biological recovery, environmental key-drivers (mainly nitrogen increase) have become the new focus of the current research activities.

The present-day northern Apennines represent an area where two different orogenic cycles took place. The most ancient is the Alpine Orogeny, initiated with a south- to south-eastward subduction of oceanic lithosphere (Early Cretaceous to Late Eocene phase), followed by continental collision. The younger is referred to the Apennines Orogeny, characterized by a west- to north-westward oceanic lithosphere subduction started from Late Eocene and still active in the southernmost sectors of Italy (Calabrian Arc). In this framework, during the Early Oligocene, an ~ 800 m thick conglomeratic succession extremely rich in volcanic material (up to ~ 90% in volume) was deposited in the Northern Apennines, forming the Aveto-Petrignacola Formation (APF). The volcanic fraction of this succession is made up of basaltic andesites, andesites and dacites, with minor rhyolites, basalts and gabbros found as pebbles ~ 0.001-0.5 m3 in size. Petrographic, mineral chemical, major and trace element analyses, as well as Sr-Nd-Pb isotopic ratios are compatible with calc-alkaline magmatism generated as a consequence of metasomatic modifications related to the subduction of oceanic lithosphere. The large spectrum of lithologies is compatible with processes of fractional crystallization of the main phases observed in thin sections. However, the large range of isotopic ratios (87Sr/86Sr = 0.7044-0.71013; 143Nd/144Nd = 0.51278-0.51223; 206Pb/204Pb = 18.44-18.83; 207Pb/204Pb = 15.55-15.67; 208Pb/204Pb = 38.05-38.85) suggests the presence of heterogeneous mantle sources, possibly coupled with interaction of melts with crustal rocks at shallow depth. On the basis of field geology constraints, we propose that the subduction-related geochemical and mineralogical characteristics of the APF volcanic rocks reflect ancient modifications of their mantle sources, lacking any evidence for a genetic link with the Apennine subduction system. Subduction-related metasomatism of APF mantle sources likely occurred during the older south-east dipping subduction of the Alpine Tethys under Northern Adria (present day Northern Italy). ⺠We identify the presence of abundant subduction-related igneous activity in N Apennines. ⺠This activity is related to the extinct Alpine subduction system rather than to the coeval Appennine subduction system. ⺠The detached Alpine oceanic slab is able to metasomatize the Adriatic mantle also 10-15 Myr after the end of the subduction. ⺠These results indicate the care needed when handling geochemical data without geological constraints.

This paper illustrates the Water Erosion Prediction Project (WEPP) model’s performance, to predict stream flow in a study conducted in a watershed in the Apennines Mountain Range, northern Italy. Stream flow and weather information were measured on a daily basis for 9 years. Topography, soil and land use data were also collected. A sensitivity analysis showed that the most sensitive parameters were the soil hydraulic conductivity and soil albedo. A comparison between observed and modeled stream fluxes indicated that the model provided reasonable estimates, although the model tended to overestimated the large events and under estimate the low events. Since low flux events were quantitatively dominant, overall the cumulative annual fluxes were underestimated.

In the Umbria-Marche region, space and time variations concerning the b value were studied by instrumental seismicity from January 1987 to May 1999, according to the Bender method. Data were divided into two partially independent data sets. The first set, (January 1987 - December 1996), does not include the Colfiorito seismic sequence that occurred in the autumn of 1997. The second data set includes all events from January 1987 to May 1999. Using square cell dimensions of 80, 40 and 20 km, the examined area was divided respectively into three grids. The b value was estimated for each cell using the first data set, thus allowing us to reveal b value space variations and determine the resolution. To evaluate the stability of our result we estimated the b value on the basis of historical seismicity within the region. Several synthetic tests were also performed to estimate the stability of the Bender method and to verify its consistency with respect to other methods commonly used. Finally we estimated the b values using the second data set to prove the time variations. Results from the area examined show that the lowest possible spatial resolution of the b value is about 40 km and that there is a correlation between the b value pattern and the main active tectonic structures of the area. The most important time variations occur within the Colfiorito area, in which the b value drops significantly within the second data set. Results suggest two different ways of strain release: the first one produces continuous seismicity that spreads all over the examined area, while the second, which concerns stronger earthquakes, is localized.

In this paper we provide P-wave velocity images of the crust underneath the Apennines (Italy), focusing on the lower crustal structure and the Moho topography. We inverted P-wave arrival times of earthquakes which occurred from 1986 to 1993 within the Apenninic area. To overcome inversion instabilities due to noisy data (we used bulletin data) we decided to resolve a minimum number of velocity parameters, inverting for only two layers in the crust and one in the uppermost mantle underneath the Moho. A partial inversion of only 55% of the overall dataset yields velocity images similar to those obtained with the whole data set, indicating that the depicted tomograms are stable and fairly insensitive to the number of data used. We find a low-velocity anomaly in the lower crust extending underneath the whole Apenninic belt. This feature is segmented by a relative high-velocity zone in correspondence with the Ortona-Roccamonfina line, that separates the northern from the southern Apenninic arcs. The Moho has a variable depth in the study area, and is deeper (more than 37 km) in the Adriatic side of the Northern Apennines with respect to the Tyrrhenian side, where it is found in the depth interval 22-34 km.

The transverse 'Sillaro line' is merely the outcrop line of the north-west dipping overthrust plane of the Liguride Complex. The anti-Apenninic strike of this overthrust plane is the result of the 'Sillaro flexure', a large synsedimentarily developed flexure of the basement of the Northern Apennines. The Liguride Complex overlies to the north-east progressively younger deposits dating from Early Miocene to eventually Pliocene: the Liguride overthrust is tectonically transgressive. The Liguride Complex is made up largely of clay, the Argille Scagliose; the overthrusting was gravitational. Just like glaciers and ice-sheets the Liguride Complex is a plastic mass capable of spreading under the influence ofgravitation. Olistostromization played a role ofvarying importance in the advance of the Liguride Complex. During the Pliocene, when a shallow molasse basin was invaded, it was the dominating mechanism. Locally the Liguride Complex interfingers with autochthonous deposits, as a result of a temporary standstill of the thrust sheet. The deposits just below the overthrust plane often show the influence of the approaching Liguride Complex. The Marnoso Arenacea is a turbidite formation of Miocene age. The configuration of its sedimentation basin was influenced strongly by an anticline that developed synsedimentarily, resulting in the Castel Vecchio 'high'. This 'high' divided the basin into an inner and outer basin in the south-west and north-east respectively, each with its own sedimentary history. The position of the inner basin axis was defined by the Rovigo syncline, which was also synsedimentary. A 'klippe sedimentaire', the Casaglia Member, invaded the basin from the south-west, and carne to a standstill near the basin axis. It proved impossible to describe the turbidites in terms of inner and outer fan and basin plain deposits by analogy with recent turbidite sedimentation in oceanic environments. A purely descriptive classification in facies associations is introduced here. The thickest and coarsest turbidites were usually deposited in the deepest parts of the basin. Towards the 'high' they became thinner and finer grained, until only marls were deposited. Upon the Castel Vecchio 'high' moluscs are found in living position, indicating that occasionally this 'high' approached sea-level. The Castel Guerrino Formation which constitutes a separate tectonic unit, was probably deposited in a more internal part ofthe Marnoso Arenacea basin. This formation thrust from the south-west upon the Marnoso Arenacea, after which it overthrust 5 km further to the north-east over a thin slice of Liguride rocks which had already overthrust the Marnoso Areacea.

The sedimentary cover of the investigated area consists of a thick sequence (Triassic-Miocene) of limestones and marls, overlain by turbiditic sandstones of the "Laga Formation" (Messinian- Early Pl iocene). No pre-Triassic basement is exposed. The most consipicuous structural feature is the Umbria Thrust Zone, a segment of the so-called Ancona-Anzio Line. This oblique lineament is generally taken as the boundary between the Northern and Southern Apennines, although its significance is highly controversial. But thrusting and associated folding is not confined to the Umbria Thrust Zone: it prevails allover the Central Apennines. The thrusts are mostly not single planes, but pervasive deformation zones, strongly affected by pressure solution. Slip, as indicated by slickensides, was everywhere towards the NE, regardless of the strike of the various structures. The style of deformation is "thin-skinned". Two major detachment levels - a lower, subsurface one at the base of the cover sequence, and a higher one just below the Laga Formation - are connected by a series of ramps where thrusts cut up-section. Doubling of strata above and beyond these ramps has resulted in large rootless anticlines with complicated, disharmonic forward limbs. The thrust steps developed successively, from the internal (SW) side outward. The arcuate and oblique trends of many rootless anticlines, or rather of the ramps below, have been controlled by pre-existing irregularities inside the sedimentary cover due to Jurassic block-faulting. By repeated doublings, the lower part of the cover has been shortened considerably. But very little of this shortening has affected the Laga Formation, which belongs almost entirely to the hanging wall and has been displaced as a whole. Thus the investigated area, as well as the adjacent Umbria Marche Apennines and Abruzzi including the "Ancona-Anzio Line", belong to a single allochthonous thrust complex