Vincenzo La
email: vincenzolabruna@gmail.com

Fabrizio Agosta

Juliette Lamarche

Sophie Viseur

Giacomo Prosser

Fault growth mechanisms and scaling properties in foreland basin system: The case study of Monte Alpi, Southern Apennines, Italy

Keywords: syn-sedimentary faults, orthogonal fault system; fault dimensional properties, Apulian Platform, 3D geological reconstruction

The present work focuses on the comprehension of the growth mechanisms and dimensional properties of the pre-Pliocene Monte Alpi fault network by mean of integrated field and laboratory analyses. After this multidisciplinary approach, detailed throw profiles are computed for each fault belonging to the Monte Alpi network. Subsequently, the dimensional properties of the individual faults are calculated. Data obtained from this work are discussed in terms of fault growth mechanisms and timing of deformation, and reported in a conceptual tectonic evolution model of the Messinian foreland basin system. Data suggest that originally isolated fault segments developed during the earliest stages of foreland basin formation by reactivation of a pre-existing, Early Cretaceous fault set, and formation of an orthogonal one.

These two fault sets formed a scale-independent network. Differently, the same fault sets were also active during its subsequent development forming a scale-dependent fault network ACCEPTED MANUSCRIPT 2 characterized by T-and Y-shaped fault intersections. This deformation controlled the halfgraben depocenters evolution filled by up to ca. 600 meters of terrigenous deposits during the Late Messinian time.

Introduction

Numerous studies have shed light on the evolution of the foreland basin systems flanking orogenic belts, but some gaps remain in particular related to the understanding of the fault growth mechanism and fault dimensional properties related to the structural networks that control the foreland basin system evolution. This knowledge is important to decipher the modalities of the extensional deformation associated to foreland flexure, which is commonly due to migration of Fold-and-Thrust belts (FTB), and unveil the possible role exerted by preexisting, inherited faults on development of foreland basin systems (Gawthorpe and Leedert, 2000). As documented in literature, longitudinal extensional faults parallel to the main thrust front of the FTB are frequently observed across the whole foreland basin system [START_REF] Harding | Structural interpretation of hydrocarbon traps sealed by basement normal block faults at stable flank of foredeep basins and at rift basins[END_REF][START_REF] Lorenzo | Inelastic yielding and forebulge shape across a modern foreland basin: North West Shelf of Australia, Timor Sea[END_REF][START_REF] Ranero | Bending-related faulting and mantle serpentinization at the Middle America trench[END_REF]. Moreover, subordinated transverse extensional faults, which are perpendicular to the main thrust front can develop because of the stress release in the fault hanging wall of longitudinal faults [START_REF] Destro | Release fault: A variety of cross fault in linked extensional fault systems, in the Sergipe-Alagoas Basin, NE Brazil[END_REF][START_REF] Medwedeff | Kinematic and long modelling of 3-D extensional ramps: observations and a new 3-D deformation model[END_REF][START_REF] Tavani | A review of deformation pattern templates in foreland basin systems and fold-and-thrust belts: Implications for the state of stress in the frontal regions of thrust wedges[END_REF], or be present as transfer faults within linked extensional systems [START_REF] Tavarnelli | Evidenze di tettonica distensiva sinsedimentaria nel Bacino messiniano della Laga:implicazioni per l'evoluzione dell'Appennino Settentrionale[END_REF].

Subsequently, during the migration of the orogenic chain this inner portion of the foreland basin system and its orthogonal fault network could experience orogenic compression and incorporated in FTBs.

In this paper, we present the results of a study performed in the Monte Alpi area which represent a key tectonic window of the southern Apennines FTB of Italy [START_REF] Alberti | New geological data on the basin units surrounding the Monte Alpi unit (southern Italy)[END_REF][START_REF] Patacca | Geology of southern Apennines. Results of the CROP Project. Sub-project CROP-04[END_REF]. There, Mesozoic carbonates pertaining to the Inner Apulian Platform [START_REF] Sartoni | Ricerche biostratigrafiche nel Mesozoico dell'Appennino Meridionale[END_REF] and overlapping Lower Messinian carbonates and Upper Messinian siliciclastic rocks [START_REF] Sgrosso | Nuovi dati biostratigrafici sul Miocene del M. Alpi (Lucania) e conseguenti ipotesi paleogeografiche[END_REF][START_REF] Taddei | Analisi biostratigrafica e considerazioni paleoecologiche sulla successione neogenica del Alpi Mt. (Lucania)[END_REF] crop out in the axial portion of the belt [START_REF] Cello | Apennine tectonics in southern Italy: a review[END_REF].

This peculiar site represents a unique opportunity to study and unveil the structural control exerted by an orthogonal fault network which controlled the evolution of the Messinian foreland basin system [START_REF] Patacca | The Numidian-sand event in the Southern Apennines[END_REF], subsequently involved in several tectonic phases [START_REF] Van Dijk | Tectonic model and three-dimensional fracture network analysis of Alpi Mt. (southern Apennines)[END_REF][START_REF] Mazzoli | Pliocene-Quaternary thrusting, syn-orogenic extension and tectonic exhumation in the southern Apennines (Italy): Insights from the Alpi Mt. area. In Styles of Continental Contraction[END_REF][START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF].

The results of this work may provide useful insights in order to better assess the timing of formation of the two aforementioned high-angle fault sets, which pre-date Early-Middle Pliocene contractional deformation associated to the FTB migration [START_REF] Patacca | Geology of southern Apennines. Results of the CROP Project. Sub-project CROP-04[END_REF]. In particular, data obtained after a detailed field structural and stratigraphic analyses are employed, together with available subsurface data, to perform 3D geological reconstruction of a ca. 320 km 2 wide area. As a result, both attitude and cumulative throw profiles are computed for the individual, outcropping, high-angle faults crosscutting the Monte Alpi Unit. By also considering the displacement of specific chronostratigraphic surfaces, the dimensional properties of the evolving pre-Pliocene fault network are discussed in terms of either scale-independent [START_REF] Schultz | Dependence of displacement-length scaling relations for fractures and deformation bands on the volumetric changes across them[END_REF] or scale-dependent geometries [START_REF] Kim | The relationship between displacement and length of faults[END_REF]. In fact, as described in literature, when initially isolated fault segments interact and, possibly, link together during ongoing deformation, they modify their dimensional properties [START_REF] Walsh | Analysis of the relationship between displacements and dimensions of faults[END_REF][START_REF] Peacock | Displacement, segment linkage and relay ramps in normal fault zones[END_REF][START_REF] Cartwright | Fault growth by segment linkage: an explanation for scatter in maximum displacement and trace lenght data from Canyonlands Graben of SE Utah[END_REF][START_REF] Dawers | Displacement-length scaling and fault linkage[END_REF][START_REF] Mansfield | High resolution fault displacement mapping from three-dimensional seismic data: evidence for dip linkage during fault growth[END_REF][START_REF] Crider | Fault linkage: Three-dimensional mechanical interaction between echelon normal faults[END_REF][START_REF] Cowie | Constraining slip rates and spacings for active normal faults[END_REF][START_REF] Walsh | Formation of segmented normal faults: a 3-D perspective[END_REF]. Considering the following relationship between the maximum fault cumulative displacement (D) and its maximum linear dimension (L, length)

D=cL n (eq. 1)

where the c value is related to the rock mechanical properties, it is possible to assess the geometrical properties of the fault network by considering the n value [START_REF] Watterson | Fault dimensions, displacements and growth[END_REF][START_REF] Walsh | Analysis of the relationship between displacements and dimensions of faults[END_REF]Cowie and Scholz, 1992a,b;[START_REF] Scholz | Fault growth and fault scaling laws: preliminary results[END_REF][START_REF] Schlische | Geometry and scaling relations of a population of very small rift-related normal faults[END_REF][START_REF] Kim | The relationship between displacement and length of faults[END_REF][START_REF] Schultz | Dependence of displacement-length scaling relations for fractures and deformation bands on the volumetric changes across them[END_REF]. Values of n=1 indicate a linear scaling law (i.e. self-similarity), which implies that faults grew under conditions of constant driving stress at different scales, whereas values of n>1 suggest a scale-dependent geometry.

Regarding the study area of Monte Alpi, the contribution provided by the different angles among intersecting faults forming a scale dependent geometry is investigated by considering both T-and Y-shaped intersections [START_REF] Maerten | Slip distributions on intersecting normal faults[END_REF]. Finally, evolution of the pre-Pliocene fault network is summarized in a conceptual model of Messinian foreland basin system evolution by taking the computed time-dependent activity of individual fault sets into account (sensu Gawthorpe and Leedert, 2000).

Geological setting

Southern Apennines

The Apennines are an arc-shaped FTB that formed in response to the Oligocene-to-Pliocene continental collision between Eurasian and African lithospheric plates [START_REF] Royden | Segmentation and configuration of subducted lithosphere in Italy: An important control on thrust-belt and foredeep-basin evolution[END_REF][START_REF] Locardi | The origin of the Apennine Arcs[END_REF]. Such a process caused the formation of east-propagating thrust sheets, which involved Meso-Cenozoic terranes originally pertaining to the Neo-Tethys Ocean, and of its south-eastern continental margin, and/or to the subduction-related accretionary wedge [START_REF] Patacca | Tyrrhenian basin and Apenninic arcs: kinematic relations since late Tortonian times[END_REF][START_REF] Doglioni | A proposal for kynematic modeling of W-dipping subductions -Possible applications to the Tyrrhenian-Apennines system[END_REF]. Commonly, the Apennines are sub-divided along-strike into three sectors named as northern, central, and southern, respectively, bounded by lithospheric discontinuities trending at high-angles with respect to the belt axis [START_REF] Locardi | The origin of the Apennine Arcs[END_REF][START_REF] Ghisetti | Interfering paths of deformation and development of arcs in the fold-and-thrust belt of central Apennines (Italy)[END_REF][START_REF] Vai | Basament and early (pre-Alpine) history[END_REF][START_REF] Cavazza | The Mediterranean Area and the Surrounding Regions: Active Processes, Remnants of Former Tethyan Oceans and Related Thrust Belts[END_REF][START_REF] Patacca | Geology of southern Apennines. Results of the CROP Project. Sub-project CROP-04[END_REF]. Most of the paleogeographic models proposed for the Mesozoic Neo-Tethys ocean invoked two main carbonate platforms commonly identified as Apenninic, to the west, and Apulian, to the east, separated from each other by communicating basins [START_REF] D'argenio | Schema geologico dell'Appennino Meridionale (Campania e Lucania). Atti del Conv. Moderne vedute sulla geologia dell'Appennino (Roma 16-18[END_REF][START_REF] Ippolito | Structural-stratigraphic units and tectonic framework of Southern Apennines[END_REF][START_REF] Mostardini | Appennino centro-meridionale. Sezioni geologiche e proposta di modello strutturale[END_REF][START_REF] Tavarnelli | The complete Apennines orogenic cycle preserved in a transient single outcrop near San Fele, Lucania, Southern Italy[END_REF][START_REF] Schettino | Tectonic history of the western Tethys since the late Triassic[END_REF].

The current structural setting of the southern Apennines FTB includes the following tectonostratigraphic units, from the top to the bottom, which respectively correspond to specific paleogeographic domains arranged from west to east, respectively [START_REF] Patacca | Geology of southern Apennines. Results of the CROP Project. Sub-project CROP-04[END_REF]: i) siltstones and claystones originally pertaining to the Liguride/Sicilide oceanic Basin;

ii) carbonates derived from the Apennine Platform; iii) mixed terrigenous-carbonate rocks derived from the Lagonegro basin, divided into two different tectonic Units, Lagonegro I and II; and iv) carbonates of the Apulian Platform (Figure 1). Miocene-to-Pliocene terrigenous infill of foredeep, thrust-top, and piggyback basins were involved in contractional deformation, and currently crop out in the axial and outer portions of the belt [START_REF] Ghisetti | Contribution of structural analysis to understanding the geodynamic evolution of the Calabrian Arc (Southern Italy)[END_REF][START_REF] Dewey | Kinematics of the western Mediterranean[END_REF][START_REF] Boccaletti | Palinspastic restoration and paleogeographic reconstruction of the peri-Tyrrhenian area during the Neogene[END_REF][START_REF] Carbone | Migrazione neogenica del sistema catena-avampaese nell'Appennino meridionale: problematiche paleogeografiche e strutturali[END_REF]Van Dijk andOkkes, 1990, 1991;Monaco and Tanzi, 1992;[START_REF] Catalano | Pleistocene strike-slip tectonics in the Lucanian Apennine (Southern Italy)[END_REF][START_REF] Monaco | Tectonic role of ophiolitic-bearing terranes in the development of the Southern Apennine orogenic belt[END_REF][START_REF] Monaco | Structural evolution of the Lucanian Apennines, southern Italy[END_REF][START_REF] Pescatore | Stratigraphic and structural relationships between Meso-Cenozoic Lagonegro basin and coeval carbonate platforms in southern Apennines, Italy[END_REF][START_REF] Menardi Noguera | Deep structure of the Campanian-Lucanian Arc (southern Apennines)[END_REF][START_REF] Patacca | Geology of southern Apennines. Results of the CROP Project. Sub-project CROP-04[END_REF]. The Inner Apulian Platform was involved in Late Pliocene-Early Pleistocene thick-skinned tectonics [START_REF] Mostardini | Appennino centro-meridionale. Sezioni geologiche e proposta di modello strutturale[END_REF][START_REF] Cello | Apennine tectonics in southern Italy: a review[END_REF][START_REF] Butler | Applying thick-skinned tectonic models to the Apennine thrust belt of Italy -Limitations and implications[END_REF][START_REF] Shiner | Thin-skinned versus thick-skinned structural models for Apulian Carbonate Reservoirs: constraints from the Val D'Agri Field[END_REF], whereas the Outer Apulian Platform is now days either exposed or buried underneath a Plio-Pleistocene sedimentary cover in the orogenic foreland of the Southern Apennines [START_REF] Pieri | Quaternary tectonic activity of the Murge area (Apulian foreland-Southern Italy)[END_REF][START_REF] Borgomano | The Upper Cretaceous carbonates of the Gargano-Murge region, southern Italy: a model of platform-to-basin transition[END_REF][START_REF] Spalluto | Facies evolution and sequence chronostratigraphy of a "mid"-Cretaceous shallow-water carbonate succession of the Apulia Carbonate Platform from the northern Murge area (Apulia, southern Italy)[END_REF][START_REF] Panza | Fracture stratigraphy and fluid flow properties of shallow-water, tight carbonates: The case study of the Murge Plateau (southern Italy)[END_REF][START_REF] Petrullo | Cenozoic tectonic evolution of the northern Apulian carbonate platform (southern Italy)[END_REF]. (insert Figure 1).

Monte Alpi Unit

The study area is located in the axial portion of the southern Apennines FTB (Figure 1). Over the years, according to the presumed age of the sedimentary cover, many authors proposed two conflicting hypotheses on the origin of the Monte Alpi carbonates. Assigning a Lower Miocene age to its sedimentary cover, the Mesozoic carbonates were interpreted as part of the Apennine Platform [START_REF] Ogniben | Schema introduttivo alla geologia del confine calabro-lucano[END_REF][START_REF] Mostardini | Appennino centro-meridionale. Sezioni geologiche e proposta di modello strutturale[END_REF][START_REF] Muller | Significance of the Alpi Mt. in the geodynamic evolution of the Southern Apennines[END_REF].

Differently, by assigning a Messinian age, other authors included them in the Inner Apulian Platform [START_REF] Carbone | Le unità stratigrafico-strutturali dell'Alta Val d'Agri (Appennino lucano) nel quadro dell'evoluzione del sistema catenaavanfossa[END_REF][START_REF] Sgrosso | Nuovi dati biostratigrafici sul Miocene del M. Alpi (Lucania) e conseguenti ipotesi paleogeografiche[END_REF][START_REF] Van Dijk | Tectonic model and three-dimensional fracture network analysis of Alpi Mt. (southern Apennines)[END_REF][START_REF] Alberti | New geological data on the basin units surrounding the Monte Alpi unit (southern Italy)[END_REF][START_REF] Mazzoli | Pliocene-Quaternary thrusting, syn-orogenic extension and tectonic exhumation in the southern Apennines (Italy): Insights from the Alpi Mt. area. In Styles of Continental Contraction[END_REF][START_REF] Mazzoli | Lowangle normal faulting and focused exhumation associated with late Pliocene change in tectonic style in the southern Apennines (Italy)[END_REF]. Structurally, the two most recent studies interpreted Monte Alpi as comprised of Apulian carbonates either forming a push-up structure [START_REF] Van Dijk | Tectonic model and three-dimensional fracture network analysis of Alpi Mt. (southern Apennines)[END_REF] or as the product of complex thin-and thick-skinned tectonics [START_REF] Shiner | Thin-skinned versus thick-skinned structural models for Apulian Carbonate Reservoirs: constraints from the Val D'Agri Field[END_REF][START_REF] Mazzoli | Pliocene-Quaternary thrusting, syn-orogenic extension and tectonic exhumation in the southern Apennines (Italy): Insights from the Alpi Mt. area. In Styles of Continental Contraction[END_REF][START_REF] Mazzoli | Lowangle normal faulting and focused exhumation associated with late Pliocene change in tectonic style in the southern Apennines (Italy)[END_REF].

According to their inferred age of activity, La [START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF] recognized six different structural networks and documented two main sets of high-angle faults pre-dating Early-Middle Pliocene emplacement of the allochthon over the Mesozoic carbonates and their Upper Miocene cover [START_REF] Cello | Apennine tectonics in southern Italy: a review[END_REF]Buttler et al., 2004). The two high-angle fault sets formed an almost orthogonal fault system, which developed during either Cretaceous strike-slip and dip-slip tectonics [START_REF] Pieri | Tettonica e sedimentazione nei depositi senomiani delle Murge sud-orientali (Ostuni)[END_REF][START_REF] Festa | Cretaceous structural features of the Murge area (Apulian Foreland, southern Italy)[END_REF][START_REF] Mazzoli | Pliocene-Quaternary thrusting, syn-orogenic extension and tectonic exhumation in the southern Apennines (Italy): Insights from the Alpi Mt. area. In Styles of Continental Contraction[END_REF][START_REF] Bertok | Kilometre-scale palaeoescarpements as evidevce for Cretaceous synsedimentary tectonics in the external Briançonnais domain (Ligurian Alps, Italy)[END_REF][START_REF] Tavani | Transpressive inversion of a Mesozoic extensional forced fold system with an intermediate décollement level in the Basque-Cantabrian Basin (Spain)[END_REF][START_REF] Korneva | Structural properties of fractured and faulted Cretaceous platform carbonates, Murge Plateau (southern Italy)[END_REF][START_REF] Panza | Structural architecture and Discrete Fracture Network modelling of layered fractured carbonates (Altamura Fm., Italy)[END_REF][START_REF] Panza | Fracture stratigraphy and fluid flow properties of shallow-water, tight carbonates: The case study of the Murge Plateau (southern Italy)[END_REF][START_REF] Laurita | Shearing of synsedimentary carbonate breccia along strike-slip faults, Altamura Fm., Southern Italy[END_REF][START_REF] Vitale | Structural, stratigraphic, and petrological clues for a Cretaceous-Paleogene abortive rift in the southern Adria domain (southern Apennines, Italy)[END_REF], or Upper Miocene foreland bulging [START_REF] Doglioni | Geological remarks on the relationships between extension and convergent geodynamic settings[END_REF] and/or along-foredeep stretching (Tavani et al., 2015a).

The Monte Alpi Unit is made up of ca. 2,000 m-thick, Jurassic-to-Lower Cretaceous limestones and dolostones, and Messinian carbonates-terrigenous rocks (Figure 2). The Jurassic carbonates are Middle-to-Upper Jurassic in age, whereas the Lower Cretaceous ones are ascribed to the Neocomian [START_REF] De Lorenzo | Osservazioni geologiche nell'Appennino della Basilicata meridionale[END_REF][START_REF] Selli | Sulla trasgressione del Miocene nell'Italia meridionale[END_REF][START_REF] Sartoni | Ricerche biostratigrafiche nel Mesozoico dell'Appennino Meridionale[END_REF][START_REF] Grandjacquet | Schéma structural de l'Apennin campano-lucanien (Italie)[END_REF][START_REF] Roda | Livelli a struttura grumosa e livelli ad ooliti rotte e rigenerate nel calcare miocenico del Alpi Mt. (Potenza)[END_REF][START_REF] Ogniben | Schema introduttivo alla geologia del confine calabro-lucano[END_REF]. The Messinian sedimentary succession is stacked into two main intervals [START_REF] Sgrosso | Nuovi dati biostratigrafici sul Miocene del M. Alpi (Lucania) e conseguenti ipotesi paleogeografiche[END_REF][START_REF] Ortolani | Il Mt. Alpi (Lucania) nella paleogeografia dell'Appennino meridionale[END_REF][START_REF] Taddei | Analisi biostratigrafica e considerazioni paleoecologiche sulla successione neogenica del Alpi Mt. (Lucania)[END_REF][START_REF] Van Dijk | Tectonic model and three-dimensional fracture network analysis of Alpi Mt. (southern Apennines)[END_REF]. 2).

Data and Methods

The proposed integrated approach includes a variety of methods such as geological mapping, field structural and stratigraphic analyses, well log correlation, seismic profile interpretation, and 3D surfaces reconstruction.

Field analysis

The large-scale geological map was compiled at a 1:25,000 scale (Figure 2) by taking into account available published data (Foglio IGM 211, S. Arcangelo;[START_REF] Bonardi | Carta delle principali unità cinematiche dell'Appennino meridionale. Nota illustrativa[END_REF][START_REF] Cavalcante | Carta geologica delle Unità Liguridi dell'area del Pollino (Basilicata): Nuovi dati geologici, mineralogici e petrografici[END_REF][START_REF] Lentini | Carta geologica del Bacino del Fiume Agri[END_REF], and the detailed geological map originally compiled at a 1:10,000 scale by La [START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF]. Field structural analyses focused on the fault zones exposed in the Monte Alpi area. Eight stratigraphic logs were measured in key sites, which expose significant portions of the Lower and Upper Messinian deposits.

Seismic profile interpretation

Interpretation of the four stacked seismic reflection profiles (courtesy of Eni) was aimed at deciphering the geometry of the buried Apulian carbonates (Figure 3). Due to the general poor quality of the seismic profiles, such an interpretation was compared with published well log data, seismic reflection profile and isobaths maps [START_REF] Mazzoli | Pliocene-Quaternary thrusting, syn-orogenic extension and tectonic exhumation in the southern Apennines (Italy): Insights from the Alpi Mt. area. In Styles of Continental Contraction[END_REF][START_REF] Mazzoli | Lowangle normal faulting and focused exhumation associated with late Pliocene change in tectonic style in the southern Apennines (Italy)[END_REF][START_REF] Nicolai | Structural architecture of the Adria platform-and-basin system[END_REF]. The original jpeg images were first converted into seg-y files, by using the image2segy 2.2.6 Matlab script developed by the Instituto de Cièncias del Mar (Barcelona, Spain), and then imported into the Move TM software for subsequent digitalization of the main stratigraphic horizons and fault surfaces. Afterwards, the time-to-depth conversion was computed by assigning a specific velocity value to the individual tectono-stratigraphic units [START_REF] Dix | Seismic velocities from surface measurements[END_REF][START_REF] Improta | Inferences on the upper crustal structure of Southern Apennines (Italy) from seismic refraction investigations and sub-surface data[END_REF]. (insert Figure 3).

3D geological reconstruction

This work involved several steps of activities aimed at reconstructing both stratigraphic and tectonic surfaces pertaining to the Monte Alpi Unit. First, the Digital Elevation Model (DEM), the large-scale geological map, and all the available subsurface data in jpeg format were imported into Gocad®, and then georeferenced for calibration and consistency checking.

The imported DEM was characterized by a 20x20 m resolution. A triangulated mesh was built from the DEM data points using both the Delaunay triangulation and interpolation in order to obtain a continuous and optimized representation of the topography (Mallet et al., 2002).

Then, the georeferenced geological map was draped onto the topographic surface to obtain a textured topographic surface.

In order to constrain the buried portions of the Apulian carbonates, we performed time-todepth conversion of four seismic profiles by using the GeolToolbox plugin (www.ringteam.org/consortium). Furthermore, six geological cross-sections obtained from the published geological map of Monte Alpi (La [START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF] and existing bibliography related to geometry of the buried Top Apula surface underneath the southern Apennines FTB (Niccolai and Gambini, 2007) were taken into account. The eight stratigraphic logs performed in correspondence of the outcropping mixed carbonate-terrigenous Messinian cover were also imported in GOCAD. The 3D geological model of Monte Alpi was finally obtained by constructing the individual fault and stratigraphic surfaces by using the Discrete Smooth Interpolation tool [START_REF] Mallet | GOCAD project: Geometric modeling of complex geological surfaces, In SEG Technical Program Expanded Abstracts[END_REF]Mallet et al., 2002), which allowed to constrain on fault-fault and fault-stratigraphic surfaces in the light of the aforementioned data. Both resolution and convergence criteria were defined according to the protocol recommended by [START_REF] Caumon | Surfacebased 3D modeling of geological structures[END_REF].

Fault analysis

Fault throw computation for individual faults was carried out by considering the cutoff lines along the fault hanging walls (Figure 4). This data was obtained by following the aforementioned procedure, in which the individual stratigraphic surfaces were cut by the high-angle fault surfaces. Subsequently, as a first step, the total amount of throw distribution (cumulative throw) was computed for each fault surface. This value corresponded to the current vertical offset of the bottom Early Cretaceous surface. Then, the pre-Messinian throw distribution was calculated by subtracting the amount of Early Messinian vertical displacement from the cumulative throw. Similarly, the Early Messinian throw data were obtained by subtracting the amount of Late Messinian vertical displacement from the pre-Messinian throw data. (insert Figure 4).

Results

Syn-sedimentary extensional faulting I -Mesozoic carbonates

Mid-Upper Jurassic carbonates crop out only along the NW edge of Monte Alpi (Figure 5a), whereas the Lower Cretaceous ones are widespread in the study area [START_REF] De Lorenzo | Osservazioni geologiche nell'Appennino della Basilicata meridionale[END_REF][START_REF] Selli | Sulla trasgressione del Miocene nell'Italia meridionale[END_REF][START_REF] Sartoni | Ricerche biostratigrafiche nel Mesozoico dell'Appennino Meridionale[END_REF][START_REF] Grandjacquet | Schéma structural de l'Apennin campano-lucanien (Italie)[END_REF][START_REF] Roda | Livelli a struttura grumosa e livelli ad ooliti rotte e rigenerate nel calcare miocenico del Alpi Mt. (Potenza)[END_REF][START_REF] Ogniben | Schema introduttivo alla geologia del confine calabro-lucano[END_REF].

The former carbonates consist of greyish-to-black limestones and minor dolomites, which are conformably overlain by Lower Cretaceous, peritidal, whitish-to-dark grey limestones

showing multiple dissolution evidences such as karst solution grooves and fissures. Both Jurassic and Lower Cretaceous limestone beds are quite tabular, 10's of cm-to m-thick, and commonly consist of grainstones and packstones, and less frequent mudstones, wackestones, bindstones, floatstones and rudstones [START_REF] Dunham | Classification of Carbonate Rocks According to Depositional Textures[END_REF][START_REF] Embry | A late Devonian reef tract on northeastern Banks Island, NWT[END_REF]. Results of thin section analysis are consistent with abundance of benthic foraminifera, peloids, and fenestral structures within both Jurassic and Lower Cretaceous carbonate rocks (Figures 5b-f).

In particular, the Jurassic limestones include cm-sized stromatoporoids (Cladocoropsis mirabilis, Figure 5b), whereas the Cretaceous ones contain oolites (Figure 5c) and red algae (Salpingoporella annulata, Figures 5d andf). Dolomites are petrographically heterogeneous in texture, crystal size, and crystal shape (Rustichelli, personal communication); late diagenetic fabric-destructive zebra (saddle) dolomites are also documented (Figure 5g).

Blocky calcite cement fills the pore space. Calcite veins, rare quartz veins, and dark microstylolites crosscut the Mesozoic carbonates (La [START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF]. Along the western cliff of the carbonate massif, within the Lower Cretaceous limestones, a ENE-striking, NNWdipping, syn-sedimentary normal fault is documented (Figures 5a andh). There, the carbonate succession shows an increase of thickness toward the major slip surface (Figures 5h andi).

(insert Figure 5).

II -Lower Messinian carbonates

Up to 35 m-thick, Lower Messinian limestones crop out along both the western cliff of Monte Alpi and the eastern slope of the Santa Croce Peak (cf. Figures 2 and6a). These limestones consist mainly of grey-to-dark gray skeletal grainstones with minor packstones, floatstones, rudstones and bindstones (Figures 6b-g). Biota is dominated by red algal (Lithothamniun) debris with minor benthic foraminifera, echinoid plates and spines, and fragments of serpulids (Ditrupa) and bivalves, collectively pointing to an inner-middle ramp depositional setting.

The individual limestone beds are tabular, laterally continuous, characterized by a thickness variation comprised between 10's of cm and ca. 4 m, and show thinning upward trends. The topmost portion of the Lower Messinian limestones is made up of thinly-bedded, bituminous, planktonic foraminiferal wackestones including fish remains and intervening marl beds (Figures 6b-f). The Lower Messinian limestones, which include blocky calcite cements, dark stylolites, and multiple sets of calcite veins, were originally deposited in an outer ramp depositional setting, which became progressively deeper with time [START_REF] Taddei | Analisi biostratigrafica e considerazioni paleoecologiche sulla successione neogenica del Alpi Mt. (Lucania)[END_REF][START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF]. ENE-striking, and both NNW-and SSE-dipping, syn-sedimentary normal faults are exposed along the north-eastern sector of Monte Alpi (Figures 6a andh).

These faults produced an accommodation space in their hanging wall in which limestone beds were deposited (Figures 6h andi). The two sets of ENE-striking faults form a conjugate fault system that also crosscut the Lower Cretaceous limestone rocks, causing roll over (higher dip angles towards the faults) of the limestone beds located at the hanging wall of the major, Early Messinian normal fault. (insert Figure 6).

III -Upper Messinian terrigenous deposits

The Upper Messinian siliciclastic beds, which respectively form both onlap and downlap geometries with the high-angle faults and low-angle erosional surfaces crosscutting both Lower Cretaceous and Lower Messinian limestones (Figures 7a andb), are made up of conglomerates, sandstones and siltstones. The heterometric conglomerates include subrounded to flattened, polygenic pebbles (Figure 7c), whereas the litharenitic sandstones contain coarse-to-thin rock fragments arranged in either parallel or cross laminated beds (Figure 7d). The former rocks are located at the western and north-eastern edges of Monte Alpi, whereas the sandstones throughout its north-eastern and eastern sectors (La [START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF]. The exposed Upper Messinian succession is up to ca. 300 m-thick. (insert Figure 7).

To better decipher its depositional architecture, multiple stratigraphic logs have been measured throughout the study area. Logs #1 to #4 highlight the northward thinning of conglomerates along the southern sector of Monte Alpi, whereas logs #5 to #7 show their westward thinning along its eastern sector (Figure 8). (insert Figure 8).

By considering thickness variations of the Upper Messinian terrigenous deposits, an isopach map of the Upper Messinian deposit is computed, which shows that the two maxima located at the SW and NW edges of Monte Alpi are bound by the F2 and F3 Faults (Figure 9a). A third, less pronounced maximum is also computed at the intersection of the two aforementioned faults. In order to decipher the bedding attitude of both Lower Cretaceous and

Lower Messinian limestones at the onset of deposition during Upper Messinian, data are restored accordingly (Figure 9b). Results are consistent with the west-and southwest-dipping limestone beds of the Canale del Grillone area, western sector of Monte Alpi, separated by a structural horst bounded by both F4 and F5 Faults from northeast-dipping beds of the Santa Croce area, eastern sector of Monte Alpi. (insert Figure 9).

Fault dimensional analysis

The 3D geological model constructed for the whole study area consists of a 2*10 3 km 3 volume that includes three stratigraphic surfaces pertaining to the Monte Alpi Unit, and fortythree fault surfaces. Both dip azimuth and dip angle data were then computed for the largest, twenty-seven fault surfaces (Figure 10a, Table1). Results are shown with histograms (Figures 10b and10c). (insert Figure 10 and Table 1). According to their strike direction, the twentyseven fault surfaces are sorted into the following five sets:

Set 1 -NW-SE faults with throws between 100 and 1,300 m;

Set 2 -NNW-SSE faults with throws between 100 and 1,300 m;

Set 3 -ENE-WSW faults with throws between 50 and 800 m;

Set 4 -WNW-ESE faults with throws between 170 and 1,100 m;

Set 5 -NNE-SSW faults with throws between 50 and 150 m.

Results of mesoscale structural analysis performed at specific outcrops have been used to better constrain both attitude and kinematics of individual fault sets, as well as to document their relative abutting and crosscutting relationships (Figure 11). Sets 1 and 2 mainly consist of left-lateral, strike-slip faults, which were then re-activated as normal faults during the latest exhumation stages (La [START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF]. Sets 3 and 4 comprise normal faults likely reactivated as reverse faults during Early Pleistocene times [START_REF] Van Dijk | Tectonic model and three-dimensional fracture network analysis of Alpi Mt. (southern Apennines)[END_REF], whereas Set 5 only includes normal faults. (insert Figure 11).

Fault throw analysis

Fault throw analysis is carried out by taking the computed cumulative throw (D) and length (L) values into account. Error bars were estimated for the individual fault surfaces (cf. Figure 4) on the basis of the resolution obtained. Errors are reported hereafter. D: ± 50m (F1, F2, F3 and F5 Faults), ± 10m (F4 Fault), ± 5m (F6, F7, F9 and F12 Faults), ± 2m (F8 Fault), ± 1m (F11 Fault), and ± 0,5m (F10 Fault). L: ± 50m (F1, F2, F3, F5, F11 and F12 Faults), ± 25m (F4, F6, F7, F8, F9 and F10 Faults).

Results of throw-length computations are consistent with different shapes of the fault throw profiles (Fig. 12). In fact, both F10 and F3 faults show symmetric, bell-shaped profiles, whereas F6, F8, and F12 faults are characterized by flat-topped profiles. Moreover, F1, F4, and F11 faults show asymmetric profiles with steep gradients towards one of the fault tips, whereas F2, F5, F7, and F9 faults display asymmetric profiles with steep gradients toward both fault tips. (insert Figure 12).

The computed pre-Messinian, Early Messinian, and post-Early Messinian throw profiles are reported in Figure 13, and summarized in the following text (negative values correspond to either reverse displacements or rotated normal faults). (insert Figure 13).

Fault scaling properties

Based upon the fault throw profiles shown above, the maximum computed vertical Displacement (D) -Length (L) data for the twelve faults (Table 2) that dissect the exposed Monte Alpi Unit are plotted in a log-log diagram (Figure 14a). As reported in the first section of the manuscript, the slope of the computed power law, best-fit line corresponds to the growth line of individual, isolated faults [START_REF] Cartwright | Fault growth by segment linkage: an explanation for scatter in maximum displacement and trace lenght data from Canyonlands Graben of SE Utah[END_REF]. As a result, a n value of ca.

1 is computed for the pre-Messinian faults. We note that a n value of ca. 0.8 is computed for the three faults active during Lower Messinian (Figure 14b), which is obviously not statistically significant due to the small number of data points [START_REF] Massot | Implementation of 3D balanced restoration methods[END_REF].

Differently, a n value of ca. 1.5 was computed for the post-Early Messinian fault growth line (Figure 14c). (insert Table 2 and Figure 14).

Data interpretation and discussion

Fault growth mechanisms

The most pronounced strike variations are computed for Set 1 Faults (Table 1). Assuming that these faults developed by mean of subsidiary, extensional faults localized at their releasing jogs and/or at the extensional quadrants of mode-II edges (Segall andPollard, 1980, 1983;Mollema and Antonellini, 1999;[START_REF] Myers | The evolution of faults formed by shearing across joint zones in sandstones[END_REF][START_REF] Flodin | Evolution of a strike-slip fault network, Valley of Fire State Park, southern Nevada[END_REF][START_REF] Agosta | Architecture and deformation mechanism of a basin-bounding normal fault in Mesozoic platform carbonates, central Italy[END_REF][START_REF] Antonellini | Failure modes in deepwater carbonates and their impact for fault development: Majella Mountain, Central Apennines, Italy[END_REF][START_REF] Agosta | Oblique normal faulting along the northern edge of the Majella anticline, central Italy: Inferences on hydrocarbon migration and accumulation[END_REF][START_REF] Aydin | Deformation along the leading edge of the Maiella thrust sheet in central Italy[END_REF], these variations could be due to either Early Pleistocene or Middle Pleistocene strike-slip tectonics.

In fact, many authors assessed the occurrence of strike-slip along NW-SE striking faults exposed in the study area, and its surrounding regions, during Quaternary times [START_REF] Knott | The Liguride Complex of southern Italy-a Cretaceous to Paleogene accretionary wedge[END_REF][START_REF] Carbone | Carta geologica del bacino del fiume Agri[END_REF][START_REF] Monaco | Strutture transpressive lungo la zona trascorrente sinistra nel versante orientale del Pollino (Appennino calabro-lucano)[END_REF][START_REF] Oldow | Largescale longitudinal extension in the southern Apennines contractional belt, Italy[END_REF][START_REF] Monaco | Structural evolution of the Lucanian Apennines, southern Italy[END_REF][START_REF] Cello | Apennine tectonics in southern Italy: a review[END_REF][START_REF] Tavarnelli | Fault growth by segment linkage in seismically active settings: examples from the Southern Apennnines, Italy, and the Coast Ranges, California[END_REF][START_REF] Van Dijk | Tectonic model and three-dimensional fracture network analysis of Alpi Mt. (southern Apennines)[END_REF][START_REF] Lentini | Confronti sedimentologicopetrografici e posizione strutturale dei flysch di Albidona e di Gorgoglione nella media val d'Agri (Appennino lucano)[END_REF][START_REF] Mazzoli | Pliocene-Quaternary thrusting, syn-orogenic extension and tectonic exhumation in the southern Apennines (Italy): Insights from the Alpi Mt. area. In Styles of Continental Contraction[END_REF][START_REF] Mazzoli | Lowangle normal faulting and focused exhumation associated with late Pliocene change in tectonic style in the southern Apennines (Italy)[END_REF][START_REF] Bruna | New insights on the structural setting of the Monte Alpi area, Basilicata, Italy[END_REF]. Bearing the aforementioned interpretation in mind, the modalities of growth of the Monte Alpi extensional fault network are discussed hereafter by considering the computed fault throw profiles. Bell-shaped, flattopped, and asymmetric cumulative fault throw profiles (Figure 12) indicate presence of isolated fault segments that likely interacted with each other during deformation [START_REF] Muraoka | Displacement distribution along minor fault traces[END_REF]Barnet et al., 1987;[START_REF] Walsh | Distributions of cumulative displacement and seismic slip on a single normal fault surface[END_REF], 1988, 1990;[START_REF] Peacock | Displacement, segment linkage and relay ramps in normal fault zones[END_REF]Cowie and Scholz, 1992a;[START_REF] Cartwright | Fault growth by segment linkage: an explanation for scatter in maximum displacement and trace lenght data from Canyonlands Graben of SE Utah[END_REF]Huggings et al., 1995;[START_REF] Nicol | The shapes, major axis orientations and displacement patterns of fault surfaces[END_REF][START_REF] Mcleod | The propagation and linkage of normal faults: insight from the Strathspey-Brent-Statfjord fault array, northern North Sea[END_REF][START_REF] Manighetti | Slip accumulation and lateral propagation of active normal faults in Afar[END_REF][START_REF] Schlagenhauf | Incremental growth of normal faults: Insights from a laser-equipped analog experiment[END_REF].

A more detailed interpretation of the growth mechanisms can be deciphered by considering the pre-Messinian, Early Messinian, and post-Early Messinian fault throw profiles (Figure 13), and the results of stratigraphic field logging (Figure 8), Upper Messinian isopach map computation (Figure 9), and detailed field structural analyses (Figures 5 to 7). The pre-Messinian fault network was comprised of Sets 1, 2, and 3 faults, respectively striking NW-SE, NNW-SSE, and ENE-WSW. Among all the inferred syn-sedimentary Early Cretaceous faults, the greatest throw values were computed for Set 1 faults. The computed throw data for Sets 1 and 2 faults show that they were likely comprised of original, isolated fault segments, up to a few km-long, and characterized by bell-shaped throw profiles. The computed n value, ca. 1, indicates that these faults grew under constant driving stress conditions [START_REF] Schultz | Dependence of displacement-length scaling relations for fractures and deformation bands on the volumetric changes across them[END_REF], forming self-similar geometries (Mandelbrodt and Pignoni, 1983;[START_REF] Torabi | Scaling of fault attributes: A review[END_REF]). However, interaction and possible linkage processes [START_REF] Walsh | Analysis of the relationship between displacements and dimensions of faults[END_REF] occurred among the isolated fault segments, as suggested by the wide data point dispersion (Figure 14a). Such a dispersion shifted the power law best fit line with respect to the theoretical fault growth line, traced according to the highest displacements values [START_REF] Schultz | Fault populations[END_REF]. Linkage processes took place in correspondence of stepover/relay zones [START_REF] Trudgill | Relay-ramp forms and normal-fault linkages[END_REF][START_REF] Fossen | Fault linkage and relay structures in extensional settings-A review[END_REF], and determined lower D/L values for given fault lengths (Figure 14d). Then, displacement localization within the linkage zones due to enhanced shear stress [START_REF] Aydin | Effect of mechanical interaction on the development of strike-slip faults with echelon patterns[END_REF]) caused higher D/L values up to the theoretical fault growth line (Cowie and Scholz, 1992a,b;[START_REF] Cartwright | Fault growth by segment linkage: an explanation for scatter in maximum displacement and trace lenght data from Canyonlands Graben of SE Utah[END_REF][START_REF] Mansfield | High resolution fault displacement mapping from three-dimensional seismic data: evidence for dip linkage during fault growth[END_REF].

Regarding the age of faulting, Sets 1 and 2 faults are ca. sub-parallel to those crosscutting the Outer Apulian Platform, and exposed at the Gargano Promontory and Murge Plateau of southern Italy (cf. inset of Figure 1). Since the latter faults were interpreted as Cretaceous structures [START_REF] Bertotti | Neogene to Quaternary sedimentary basins in the south Adriatic (Central Mediterranean): foredeeps and lithospheric buckling[END_REF][START_REF] Korneva | Structural properties of fractured and faulted Cretaceous platform carbonates, Murge Plateau (southern Italy)[END_REF][START_REF] Laurita | Shearing of synsedimentary carbonate breccia along strike-slip faults, Altamura Fm., Southern Italy[END_REF][START_REF] Petrullo | Cenozoic tectonic evolution of the northern Apulian carbonate platform (southern Italy)[END_REF][START_REF] Vitale | Structural, stratigraphic, and petrological clues for a Cretaceous-Paleogene abortive rift in the southern Adria domain (southern Apennines, Italy)[END_REF], a similar age is hence proposed for the study faults. In fact, these Sets 1 and 2 faults were likely coeval to the Set 3 faults, which strike ENE-WSW, documented along the western cliff of the Monte Alpi (Figures 5a and5h).

The pre-Messinian, likely Early Cretaceous in age, fault system was re-activated during onset of the Monte Alpi foreland basin system, as suggested by both computed (Figure 13) and measured structural data (Figures 6a,h,i). This fault system included either isolated (ie. F5 and F12 faults), or interacting faults (ie. F3 Fault), which were characterized by flat-topped and asymmetric profiles, respectively. Focusing on post-Early Messinian times, all faults pertaining to the Monte Alpi network show evidences of slip. The computed n value is about 1.5 (Figure 14c). This value, which is significantly greater than those computed for both pre-Messinian and Early Messinian faults, is therefore consistent with a scale-dependent geometry of the post-early Messinian fault network [START_REF] Watterson | Fault dimensions, displacements and growth[END_REF][START_REF] Walsh | Analysis of the relationship between displacements and dimensions of faults[END_REF]Cowie and Scholz, 1992a,b;[START_REF] Scholz | Fault growth and fault scaling laws: preliminary results[END_REF][START_REF] Schlische | Geometry and scaling relations of a population of very small rift-related normal faults[END_REF][START_REF] Kim | The relationship between displacement and length of faults[END_REF][START_REF] Schultz | Dependence of displacement-length scaling relations for fractures and deformation bands on the volumetric changes across them[END_REF].

By considering both T-and Y-shaped intersections, we observe that the former geometry is quite common in the modelled fault system (Figures 10,14e). In fact, these types of intersection characterize F6, F7 and F8 faults, which are bounded on both sides by the F4 and F5 and the F5 and F8 faults, respectively. On the other hand, the bounding F4 and F5 faults intersect southward the F3 fault also forming T-shaped intersections. Among these, we focus on the detailed throw profile analysis of both F7 and F5 faults (Figure 14e), which downdrop the same block but unfortunately do not show very significant evidences of mechanical interaction [START_REF] Walsh | Formation of segmented normal faults: a 3-D perspective[END_REF]. Differently, the T-shaped intersection formed by both F5 and F3 faults is characterized by a marked increases of vertical displacement in the zone where the two fault footwalls coincide (Fig. 14e). Y-shaped intersections are investigated by considering small (ca. 30°) and large (ca. 130°) alpha angles [START_REF] Maerten | Slip distributions on intersecting normal faults[END_REF]. The former case is displayed by the F11 Fault intersecting against the F4 Fault (Fig 14e). There, a pronounced increase of vertical displacement occurs in the zone where the two fault footwalls coincide (Fig. 13). The latter case if formed by the F12 Fault intersecting the F5 Fault (Fig. 14e), but the two fault throw profiles do not show any variation in coincidence of the intersection line (Fig. 13).

Implication for the evolution of the Messinian foreland basin system

Results of the integrated field and laboratory analyses are consistent with a pre-Messinian orthogonal fault system made up of isolated, interacting faults (Figure 15). During Early Messinian times, with ongoing roll-back of the Apulian Platform [START_REF] Royden | The tectonic expression slab pull at continental convergent boundaries[END_REF][START_REF] Doglioni | On the origin of west-directed subduction zones and applications to the western Mediterranean[END_REF], shallow-water marine basins characterized by anoxic conditions [START_REF] Taddei | Analisi biostratigrafica e considerazioni paleoecologiche sulla successione neogenica del Alpi Mt. (Lucania)[END_REF] formed within the back-bulge deposition zone of the Inner Apulian Platform [START_REF] Patacca | The Numidian-sand event in the Southern Apennines[END_REF][START_REF] Critelli | Relationships between lithospheric flexure, thrust tectonics and stratigraphic sequences in foreland setting: the southern Apennines foreland basin system, Italy[END_REF][START_REF] Vitale | Modes and timing of fracture network development in poly-deformed carbonate reservoir analogues, Mt. Chianello, southern Italy[END_REF] or, alternatively, within outer secondary basins (sensu [START_REF] Flemings | A synthetic stratigraphic model of foreland basin development[END_REF]. According to both basin geometry and infill, similar conclusions were proposed for the Sunda shelf region, Indonesia [START_REF] Ben-Avraham | Structural framework of Sunda shelf[END_REF], the Cordilleran foreland basin, USA [START_REF] Decelles | Non-marine sedimentation in the overfilled part of the Jurassic-Cretaceous Cordilleran foreland basin: Morrison and Cloverly Formations, central Wyoming, USA[END_REF][START_REF] Plint | Lithospheric flexure as a control on stratal geometry and facies distribution in Upper Cretaceous rocks of the Alberta foreland basin[END_REF] and the Taranaki foreland basin, New Zealand [START_REF] Holt | Subduction, platform subsidence, and foreland thrust loading: The late Tertiary development of Taranaki Basin, New Zealand[END_REF]. The Early Messinian basin of Monte Alpi was mainly bounded by re-activated Set 1 (NW-SE) and Set 3 (ENE-WSW) faults. Activity of an orthogonal fault system during the earliest stages foreland basin systems evolution was already documented by [START_REF] Tavani | Transverse versus longitudinal extension in the foredeep-peripheral bulge system: Role of Cretaceous structural inheritances during early Miocene extensional faulting in inner central Apennines belt[END_REF] in the Prenestini Mt. of central Apennines, Italy, and interpreted as due to along-foredeep stretching (Tavani et al., 2015a). This process commonly takes place in correspondence of curved orogens [START_REF] Doglioni | Geological remarks on the relationships between extension and convergent geodynamic settings[END_REF][START_REF] Zhao | Formation of regional cross-fold joints in the northern Appalachian Plateau[END_REF][START_REF] Whitaker | Plate-scale stress fields driving the tectonic evolution of the central Ouachita salient, Oklahoma and Arkansas[END_REF], such as the southern Apennines FTB [START_REF] Locardi | The origin of the Apennine Arcs[END_REF].

Differently, the erosional surface topping the Early Messinian limestones possibly formed in the forebulge (Figure 15), which is an area commonly characterized by a significant uplift [START_REF] Decelles | Foreland basin systems[END_REF], and considered as a non-depositional and/or erosional zone [START_REF] Flemings | A synthetic stratigraphic model of foreland basin development[END_REF][START_REF] Crampton | Recognition of forebulge unconformities associated with early stage foreland basin development: example from the North Alpine Foreland Basin[END_REF]. On the basis of the restored bottom Late Messinian surface (Figure 6l), a structural horst bounded by Set 1 faults formed at that time. This deformation caused emersion, and partial erosion, of both Mesozoic and Lower Messinian carbonates. Subsequently, the stratigraphy of the Late Messinian deposit also suggests that nucleation of the Monte Alpi foredeep basin was controlled by re-activation of Set 3 faults (ENE-WSW), whereas as shown by the computed fault throw profiles its later development was mainly due to activity of Set1 fault (NW-SE).

According to [START_REF] Walsh | An alternative model for the growth of faults[END_REF], we interpret that the steeper slope of the post-Early Messinian fault growth line with respect to both pre-Messinian and Early Messinian lines (Figures 14a to c) reflects the higher degree of maturity of the post-Early Messinian fault network [START_REF] Cartwright | Fault growth by segment linkage: an explanation for scatter in maximum displacement and trace lenght data from Canyonlands Graben of SE Utah[END_REF][START_REF] Nicol | The shapes, major axis orientations and displacement patterns of fault surfaces[END_REF][START_REF] Gupta | A model of normal fault interaction based on observations and theory[END_REF], and/or the pronounced lithostatic loading that occurred during post-Messinian times [START_REF] Mazzoli | Pliocene-Quaternary thrusting, syn-orogenic extension and tectonic exhumation in the southern Apennines (Italy): Insights from the Alpi Mt. area. In Styles of Continental Contraction[END_REF]. Focusing on Late Messinian times, the foredeep basin was characterized by isolated depocenters, in which up to 600 m-thick terrigenous sediments were deposited [START_REF] Monaco | Structural evolution of the Lucanian Apennines, southern Italy[END_REF]cf. well 2 of Figure 2). Compared to the 1,000's m-thick Lower Pliocene [START_REF] Casero | Structural setting of petroleum exploration plays in Italy[END_REF][START_REF] Shiner | Thin-skinned versus thick-skinned structural models for Apulian Carbonate Reservoirs: constraints from the Val D'Agri Field[END_REF] and Upper Pliocene-Lower Pleistocene foredeep infills [START_REF] Balduzzi | Il Plio-Pleistocene del sottosuolo del bacino lucano (Avanfossa appenninica)[END_REF], Casnedi, 1988a, b), the Late Messinian succession is interpreted as due to a first-order stage of forebulge progradation [START_REF] Catuneanu | Retroarc foreland systems evolution through time[END_REF], which occurred during thrusting of the outermost portions of the southern Apennines FTB [START_REF] Marabini | Analisi di facies e macrotettonica della vena del gesso di Romagna[END_REF][START_REF] Cavazza | Upper Messinian siliciclastic rocks in southeastern Calabria (southern Italy): palaeotectonic and eustatic implications for the evolution of the central Mediterranean region[END_REF][START_REF] Vitale | Tectono-stratigraphic and kinematic evolution of the southern Apennines/Calabria-Peloritani Terrane system (Italy)[END_REF]. It can be therefore argued that the Messinian foreland basin system of Monte Alpi developed during a rapid migration of the southern Apennines FTB, which triggered a predominant elastic response to flexure of the Apulian plate due to the low amount of its tectonic load [START_REF] Crampton | Recognition of forebulge unconformities associated with early stage foreland basin development: example from the North Alpine Foreland Basin[END_REF][START_REF] Decelles | Foreland basin systems[END_REF][START_REF] Catuneanu | Retroarc foreland systems evolution through time[END_REF]. (insert Figure 15).

Conclusions

The present work combined geological field mapping and stratigraphic logging with subsurface seismic and well log data interpretation to perform the 3D geological reconstruction of the Monte Alpi area, southern Italy. The goals were the assessment of both growth mechanisms and scaling properties of the pre-Pliocene fault network, and the understanding of the structural control played by high-angle extensional faults on the timespace evolution of the Messinian foreland basin system. Field analyses were aimed at assessing the stratigraphy of the Messinian mixed carbonate-terrigeneous deposits, and at documenting Early Cretaceous, Early Messinian, and Late Messinian syn-sedimentary faults.

Seismic reflection profiles and well logs were interpreted in order to decipher the geometry of the topmost surface of the Monte Alpi Unit. Results of both surface and subsurface analyses were then input in Gocad® to perform the 3D geological reconstruction of the Monte Alpi massif and its surrounding areas. This procedure was then followed by the computation of Late Messinian isopach map, and of throw profiles for the individual structures forming the Monte Alpi fault network. Results after 3D geological modelling and throw profile analysis were discussed to assess its following time-dependent evolution:

• During pre-Messinian times, main NW-SE to NNW-SSE fault segments were active as isolated structures, which likely interacted and linked together during ongoing deformation. According to literature data, these faults likely formed during Early Cretaceous times within the Inner Apulian Platform. Field evidences also show minor ENE-WSW, Early Cretaceous, syn-sedimentary extensional faults. Dimensional properties computed for the NW-SE to NNW-SSE faults showed that these features formed as isolated faults within a network characterized by self-similar geometries.

• During Early Messinian time, most of the pre-existing NW-SE and ENE-WSW faults were re-activated in the back-bulge zone during the earliest stages of foreland basin system evolution. These faults bounded shallow-water marine basins, in which carbonate sediments were deposited under anoxic conditions. The computed dimensional properties are also consistent with a self-similar fault network.

• Subsequently, isolated structural horsts formed in the forebulge zone of the foreland basin system. The horsts were bounded by NW-SE faults, which caused uplift, tilting, and partial erosion of both Mesozoic and Lower Messinian carbonates.

• (Foglio IGM 211, S. Arcangelo;[START_REF] Bonardi | Carta delle principali unità cinematiche dell'Appennino meridionale. Nota illustrativa[END_REF][START_REF] Cavalcante | Carta geologica delle Unità Liguridi dell'area del Pollino (Basilicata): Nuovi dati geologici, mineralogici e petrografici[END_REF][START_REF] Lentini | Carta geologica del Bacino del Fiume Agri[END_REF]. (b) Location of the sites of stratigraphic logging analysis; (c) Traces of the main faults pertaining to the Monte Alpi structural network. (1995). (e) Cartoons showing both T and Y-shaped intersections for some of the studied faults.

Figure 15. Time/space evolutionary model proposed for the Monte Alpi foreland basin system. The faults active during the main tectonic stages are illustrated in the 3D block diagrams, in which the geometry of the sedimentary depocenters is also reported. Table 1. Results of fault analysis performed on the 27 faults used for the 3D geological reconstruction. The 75, 50, and 25 percentile distributions of both dip azimuth and dip angle computed for the individual faults are shown, respectively. The two main clusters of dip azimuth values are computed on the basis of the obtained histograms (ie. Figure 10b), in order to decipher the possible horizontal veering of the modelled 3D fault surfaces. In fact, the amount of strike variation reported in the last column is related to the difference between the two clusters computed, along a horizontal plane, for each modelled fault.

ACCEPTED MANUSCRIPT

In • Both timing and growth processes are deciphered for the pre-Pliocene fault network;

Log Displacement Displacement Log Length f a u l t g r o w t h l i n e f a u l t g r o w t h l i n e f a u l t g r o w t h l i n e f a u l t g r o w t h l i n e f a u l t g r o w t h l i n e

• Main dimensional attributes computed for all analyzed faults;

• Inferences on the fault-control evolution of the Messinian foreland basin system;

F1

  Fault (Set 2): the post-Early Messinian throw profile shows an asymmetric shape, with values increasing towards the NNW edge; along the central portion of the fault, the profile is flat-topped. The Early Messinian throw profile does not record any displacement, whereas the pre-Messinian throw profile shows two maxima separated by a flat-topped throw profile. F2 Fault (Set 1): the post-Early Messinian throw profile shows a bell-shaped geometry, with a very pronounced peak in the central portion of the fault. The Early Messinian throw profile does not show any displacement, whereas pre-Messinian throw profile displays both a flattopped geometry at ca. -200 m-throw along the NW edge, and a bell-shaped geometry, with a peak at ca. 450 m-throw, along the SE edge. F3 Fault (Set 3): the post-Early Messinian throw profile shows a bell-shaped geometry, with two nearby maxima in the central portion of the fault. The Early Messinian throw profile shows a slightly asymmetric geometry, with higher values towards the WSW edge of the fault. The pre-Messinian throw profile displays a flat-topped geometry at around 100 mthrow. F4 Fault (Set 1): the post-Early Messinian throw profile shows an asymmetric shape, with the greater values towards the NW edge of the fault. The Early Messinian throw profile does not show any displacement, whereas the bottom pre-Messinian throw profile displays a slightly pronounced, bell-shaped geometry towards the NW edge of the fault. F5 Fault (Set 1): the post-Early Messinian throw profile shows a sort of asymmetric geometry, with the greatest values localized at the NW edge of the fault. The Early Messinian throw profile shows a flat-topped geometry, with values at ca. 100 m-throw. The pre-Messinian throw profile displays two flat-topped geometries, localized at values of ca. 100 m. and -100 m-throw, respectively. F6 Fault (Set 3): the post-Early Messinian throw profile forms a smooth, flat-topped geometry. Both Early Messinian and pre-Messinian throw profiles do not show any significant displacement. F7 Fault (Set 3): the post-Early Messinian throw profile displays an asymmetric shape, with a maximum towards the WSW edge of the fault. The Early Messinian throw profile does not show any displacement, whereas the bottom pre-Messinian throw profile displays an asymmetric geometry characterized by two maxima localized at the fault tips. F8 Fault (Set 3): the post-Early Messinian throw profile shows an asymmetric shape, with the greatest displacement localized at the WSW edge of the fault. The Early Messinian throw profile displays a very small amount of displacement, with a flat-topped geometry at ca. 70 m-throw. The pre-Messinian throw profile shows an asymmetric shape, with the greatest negative values towards the WSW edge of the fault. F9 Fault (Set 1): the post-Early Messinian throw profile shows a bell-shaped geometry, with a maxima at around 100 m-throw. The Early Messinian throw profile shows a flat-topped geometry at around 60 m-throw. The pre-Messinian throw profile shows an asymmetric shape, with a maximum towards the SE edge of the fault. F10 Fault (Set 4): all stratigraphic horizons display a flat-topped geometry, with a maximum of ca. 50 m-throw. F11 Fault (Set 2): all stratigraphic horizons display a flat-topped geometry, with a maximum of ca. 90 m-throw (post-Early Messinian) and 50 m-throw (pre-Messinian and Early Messinian), respectively. F12 Fault (Set 3): the post-Early Messinian throw profile shows a bell-shaped geometry, with a maximum at ca. 200 m-throw. The Early Messinian profile shows a flat-topped geometry localized in the WSW portion of the fault at ca. 80 m-throw. The pre-Messinian profile displays a bell-shaped geometry, with negative values down to around -120 m-throw.

  During Late Messinian times, a 100's m-deep foredeep basin characterized by halfgraben depocenters bounded by NW-SE faults developed in the study area. Minor ENE-WSW faults were likely active during that time, forming a scale-dependent network in which the individual faults intersected the previously formed structures producing higher displacement/length values. The complex tectonic evolution that affected the study area since Early Pliocene times profoundly modified the aforementioned structural configuration, and partially obliterated the original fault network. However, the results presented in this work shed a new light into the structural control exerted by inherited faults on the development of the Messinian foreland basin system of Monte Alpi. Further analysis focused on the sedimentological and petrographic characterization of the Messinian mixed carbonate-terrigeneous deposits are required to better assess the geometry of the depositional environments, and their relationships with the bounding high-angle faults.

Figure caption Figure 1 .

 1 Figure captionFigure1. Simplified geological map of the Southern Apennines, Italy, and NE-SW geological cross section (fromVitale and Ciarcia, 2013, and references therein). Location of the study area of Monte Alpi is shown both in the geological map and in the inset figure. Figure2. (a) Geological map of the Monte Alpi area, and surrounding regions, at a 1:25.000 scale. Data after original field survey and available bibliograpy(Foglio IGM 211, S. Arcangelo;[START_REF] Bonardi | Carta delle principali unità cinematiche dell'Appennino meridionale. Nota illustrativa[END_REF][START_REF] Cavalcante | Carta geologica delle Unità Liguridi dell'area del Pollino (Basilicata): Nuovi dati geologici, mineralogici e petrografici[END_REF][START_REF] Lentini | Carta geologica del Bacino del Fiume Agri[END_REF]. (b) Location of the sites of stratigraphic logging analysis; (c) Traces of the main faults pertaining to the Monte Alpi structural network. Figure 3. Original and interpreted seismic reflection profiles available for the study area. Traces of individual seismic profiles are reported in Figure 2. Interpreted sections show the main structural features crosscutting the Apulian Platform and allochthonous units. Interpretation of stratigraphic horizons and both low-angle and high-angle faults are based on available well log data.Figure 4. (a) Modelled fault surface view due to west. Grey lines represent points with similar amounts of throw present along the fault surface, whereas dashed lines show the cutoff of the bottom Lower-Cretaceous, Early Messinian and Late Messinian surfaces. (b)Throw profile computational process on the F1 Fault.Figure 5. (a) Panoramic view of the western edge of Monte Alpi. There, Mesozoic platform carbonates are overlain by two Messinian sedimentary intervals. The lower interval is made up of ramp limestones, whereas the upper one includes shallow-marine siliclastics. (b to g) Photomicrographs of representative samples of the Mesozoic platform carbonates. (h, i) Outcrop view of a portion of the Monte Alpi western cliff, along which a ENE-WSW striking, Early Cretaceous, syn-sedimentary normal fault is exposed.

Figure 2 .

 2 Figure captionFigure1. Simplified geological map of the Southern Apennines, Italy, and NE-SW geological cross section (fromVitale and Ciarcia, 2013, and references therein). Location of the study area of Monte Alpi is shown both in the geological map and in the inset figure. Figure2. (a) Geological map of the Monte Alpi area, and surrounding regions, at a 1:25.000 scale. Data after original field survey and available bibliograpy(Foglio IGM 211, S. Arcangelo;[START_REF] Bonardi | Carta delle principali unità cinematiche dell'Appennino meridionale. Nota illustrativa[END_REF][START_REF] Cavalcante | Carta geologica delle Unità Liguridi dell'area del Pollino (Basilicata): Nuovi dati geologici, mineralogici e petrografici[END_REF][START_REF] Lentini | Carta geologica del Bacino del Fiume Agri[END_REF]. (b) Location of the sites of stratigraphic logging analysis; (c) Traces of the main faults pertaining to the Monte Alpi structural network. Figure 3. Original and interpreted seismic reflection profiles available for the study area. Traces of individual seismic profiles are reported in Figure 2. Interpreted sections show the main structural features crosscutting the Apulian Platform and allochthonous units. Interpretation of stratigraphic horizons and both low-angle and high-angle faults are based on available well log data.Figure 4. (a) Modelled fault surface view due to west. Grey lines represent points with similar amounts of throw present along the fault surface, whereas dashed lines show the cutoff of the bottom Lower-Cretaceous, Early Messinian and Late Messinian surfaces. (b)Throw profile computational process on the F1 Fault.Figure 5. (a) Panoramic view of the western edge of Monte Alpi. There, Mesozoic platform carbonates are overlain by two Messinian sedimentary intervals. The lower interval is made up of ramp limestones, whereas the upper one includes shallow-marine siliclastics. (b to g) Photomicrographs of representative samples of the Mesozoic platform carbonates. (h, i) Outcrop view of a portion of the Monte Alpi western cliff, along which a ENE-WSW striking, Early Cretaceous, syn-sedimentary normal fault is exposed.

Figure 3 .

 3 Figure captionFigure1. Simplified geological map of the Southern Apennines, Italy, and NE-SW geological cross section (fromVitale and Ciarcia, 2013, and references therein). Location of the study area of Monte Alpi is shown both in the geological map and in the inset figure. Figure2. (a) Geological map of the Monte Alpi area, and surrounding regions, at a 1:25.000 scale. Data after original field survey and available bibliograpy(Foglio IGM 211, S. Arcangelo;[START_REF] Bonardi | Carta delle principali unità cinematiche dell'Appennino meridionale. Nota illustrativa[END_REF][START_REF] Cavalcante | Carta geologica delle Unità Liguridi dell'area del Pollino (Basilicata): Nuovi dati geologici, mineralogici e petrografici[END_REF][START_REF] Lentini | Carta geologica del Bacino del Fiume Agri[END_REF]. (b) Location of the sites of stratigraphic logging analysis; (c) Traces of the main faults pertaining to the Monte Alpi structural network. Figure 3. Original and interpreted seismic reflection profiles available for the study area. Traces of individual seismic profiles are reported in Figure 2. Interpreted sections show the main structural features crosscutting the Apulian Platform and allochthonous units. Interpretation of stratigraphic horizons and both low-angle and high-angle faults are based on available well log data.Figure 4. (a) Modelled fault surface view due to west. Grey lines represent points with similar amounts of throw present along the fault surface, whereas dashed lines show the cutoff of the bottom Lower-Cretaceous, Early Messinian and Late Messinian surfaces. (b)Throw profile computational process on the F1 Fault.Figure 5. (a) Panoramic view of the western edge of Monte Alpi. There, Mesozoic platform carbonates are overlain by two Messinian sedimentary intervals. The lower interval is made up of ramp limestones, whereas the upper one includes shallow-marine siliclastics. (b to g) Photomicrographs of representative samples of the Mesozoic platform carbonates. (h, i) Outcrop view of a portion of the Monte Alpi western cliff, along which a ENE-WSW striking, Early Cretaceous, syn-sedimentary normal fault is exposed.

Figure 4 .

 4 Figure captionFigure1. Simplified geological map of the Southern Apennines, Italy, and NE-SW geological cross section (fromVitale and Ciarcia, 2013, and references therein). Location of the study area of Monte Alpi is shown both in the geological map and in the inset figure. Figure2. (a) Geological map of the Monte Alpi area, and surrounding regions, at a 1:25.000 scale. Data after original field survey and available bibliograpy(Foglio IGM 211, S. Arcangelo;[START_REF] Bonardi | Carta delle principali unità cinematiche dell'Appennino meridionale. Nota illustrativa[END_REF][START_REF] Cavalcante | Carta geologica delle Unità Liguridi dell'area del Pollino (Basilicata): Nuovi dati geologici, mineralogici e petrografici[END_REF][START_REF] Lentini | Carta geologica del Bacino del Fiume Agri[END_REF]. (b) Location of the sites of stratigraphic logging analysis; (c) Traces of the main faults pertaining to the Monte Alpi structural network. Figure 3. Original and interpreted seismic reflection profiles available for the study area. Traces of individual seismic profiles are reported in Figure 2. Interpreted sections show the main structural features crosscutting the Apulian Platform and allochthonous units. Interpretation of stratigraphic horizons and both low-angle and high-angle faults are based on available well log data.Figure 4. (a) Modelled fault surface view due to west. Grey lines represent points with similar amounts of throw present along the fault surface, whereas dashed lines show the cutoff of the bottom Lower-Cretaceous, Early Messinian and Late Messinian surfaces. (b)Throw profile computational process on the F1 Fault.Figure 5. (a) Panoramic view of the western edge of Monte Alpi. There, Mesozoic platform carbonates are overlain by two Messinian sedimentary intervals. The lower interval is made up of ramp limestones, whereas the upper one includes shallow-marine siliclastics. (b to g) Photomicrographs of representative samples of the Mesozoic platform carbonates. (h, i) Outcrop view of a portion of the Monte Alpi western cliff, along which a ENE-WSW striking, Early Cretaceous, syn-sedimentary normal fault is exposed.

Figure 5 .

 5 Figure captionFigure1. Simplified geological map of the Southern Apennines, Italy, and NE-SW geological cross section (fromVitale and Ciarcia, 2013, and references therein). Location of the study area of Monte Alpi is shown both in the geological map and in the inset figure. Figure2. (a) Geological map of the Monte Alpi area, and surrounding regions, at a 1:25.000 scale. Data after original field survey and available bibliograpy(Foglio IGM 211, S. Arcangelo;[START_REF] Bonardi | Carta delle principali unità cinematiche dell'Appennino meridionale. Nota illustrativa[END_REF][START_REF] Cavalcante | Carta geologica delle Unità Liguridi dell'area del Pollino (Basilicata): Nuovi dati geologici, mineralogici e petrografici[END_REF][START_REF] Lentini | Carta geologica del Bacino del Fiume Agri[END_REF]. (b) Location of the sites of stratigraphic logging analysis; (c) Traces of the main faults pertaining to the Monte Alpi structural network. Figure 3. Original and interpreted seismic reflection profiles available for the study area. Traces of individual seismic profiles are reported in Figure 2. Interpreted sections show the main structural features crosscutting the Apulian Platform and allochthonous units. Interpretation of stratigraphic horizons and both low-angle and high-angle faults are based on available well log data.Figure 4. (a) Modelled fault surface view due to west. Grey lines represent points with similar amounts of throw present along the fault surface, whereas dashed lines show the cutoff of the bottom Lower-Cretaceous, Early Messinian and Late Messinian surfaces. (b)Throw profile computational process on the F1 Fault.Figure 5. (a) Panoramic view of the western edge of Monte Alpi. There, Mesozoic platform carbonates are overlain by two Messinian sedimentary intervals. The lower interval is made up of ramp limestones, whereas the upper one includes shallow-marine siliclastics. (b to g) Photomicrographs of representative samples of the Mesozoic platform carbonates. (h, i) Outcrop view of a portion of the Monte Alpi western cliff, along which a ENE-WSW striking, Early Cretaceous, syn-sedimentary normal fault is exposed.

Figure 13 .

 13 Figure13. Pre-Messinian (blue), Early Messinian (green), and post-Early Messinian (yellow) throw profiles computed for the 12 major faults pertaining to the Monte Alpi network. See text for explanation. Figure14. Log-Log plots of displacement vs. length data computed for (a) pre-Messinian faults (y=0.07x 0.9 ; R 2 =0.42), (b) Early Messinian faults (y=0.06x 0.8 ; R 2 =0.86), and (c) post-Early Messinian faults (y=0.08x 1.5 ; R 2 =0.71). (d) Cartoons showing the main stages of fault growth, and their related log displacement/ log length data, according to[START_REF] Cartwright | Fault growth by segment linkage: an explanation for scatter in maximum displacement and trace lenght data from Canyonlands Graben of SE Utah[END_REF]. (e) Cartoons showing both T and Y-shaped intersections for some of the studied faults. Figure15. Time/space evolutionary model proposed for the Monte Alpi foreland basin system. The faults active during the main tectonic stages are illustrated in the 3D block diagrams, in which the geometry of the sedimentary depocenters is also reported. Table1. Results of fault analysis performed on the 27 faults used for the 3D geological reconstruction. The 75, 50, and 25 percentile distributions of both dip azimuth and dip angle computed for the individual faults are shown, respectively. The two main clusters of dip azimuth values are computed on the basis of the obtained histograms (ie. Figure10b), in order to decipher the possible horizontal veering of the modelled 3D fault surfaces. In fact, the amount of strike variation reported in the last column is related to the difference between the two clusters computed, along a horizontal plane, for each modelled fault. Table2. Name, length and vertical throw of the computed fault segments related to the Pre-Messinian (blue), Early Messinian (green), and post-Early Messinian (yellow) structural network.

Table 2 .

 2 Name, length and vertical throw of the computed fault segments related to the Pre-Panoramic view of the western edge of the Monte Santa Croce peak (cf. Figure2). (b to g) Photomicrographs of representative samples of the Lower Messinian carbonates. (h and i) Outcrop view and line-drawing of a ENE-WSW striking, Early Messinian, syn-sedimentary normal fault.

	Messinian (blue), Early Messinian (green), and post-Early Messinian (yellow) structural
	network.

P.E.M.

Acknowledgments

The present work is part of the first author's Ph.D. Thesis Dissertation. Authors want to thank Enrico Tavernelli and an anonymous reviewer for their advices and their helpful correction on the paper manuscript. VLB acknowledges Stefano Mazzoli, Italo Sgrosso, Marcello Schiattarella, Jean Borgomano, Sergio Longhitano and Carlos Pirmez for their thoughtful and constructive discussions. The first author also acknowledges the great support provided by Paola Castelluccio, Alessandro Giuffrida, Arturo La Bruna, Andrea Rustichelli, Anthony Tendill, Christophe Matonti, and Sebastien Chatelée during field and laboratory analyses. This work was supported by the Ministry of Education, University and Research (MIUR), and by the Reservoir Characterization Project, a consortium of universities and energy companies (www.rechproject.com). ENI is acknowledged for providing seismic reflection data pertaining to the Monte Alpi and surrounding areas.