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We investigated the 2009-2020 instrumental seismicity of the Matese Massif. With the exception of two relevant seismic sequences (2013-2014 and 2016-2017, MMAX = 4.9), the background seismicity consists of low magnitude seismic swarms (MMAX = 3.3) located at the borders of the massif, and sparse single events (MMAX = 3.5). The focal mechanisms of the single events located near the NW and west edges of the massif suggest that this seismicity occurs on SW dipping, ca. NW-SE striking normal fault segments, in accordance with the kinematics of the Aquae Iuliae Fault. The focal mechanisms of two low magnitude seismic swarms located in the morphological depression, separating the Matese Massif from the Sannio Mountains, provide seismological evidence, never previously observed in this area, of the existence of an active east-western fault segment with dextral strikeslip kinematics. To the west of this area, there is no seismological evidence of strike-slip kinematics, whereas such evidence is found to the east. This area could represent the westernmost expression of the active strike-slip regime that characterises the Apulian foreland. Along the faults situated on the southern side, the very rare detected seismicity could be related to the high emission of CO2-bearing gas vents located near these faults. Considering the time elapsed from the last destructive earthquake (1349), the possible sources of the poorly known 346 and 1293 earthquakes, and the rare seismicity detected in the last 25 years, we speculate that the south-western side of the Matese may be affected by large earthquakes in the future. [ABSTRACT FROM AUTHOR]

The performance of both the tectonic uplift and of the 4th-order glacial eustatic sea level fluctuations in controlling the stratigraphic architecture of Quaternary lowstand prograding wedges of the Salento continental shelf (Southern Adriatic sea, Italy) during a time interval spanning from the Middle Pleistocene to the Holocene has been pointed out through the interpretation of high-resolution seismic reflection profiles and their correlation to the curves of the isotopic stratigraphy. Three main transgressive surfaces of erosion (RS1, RS2 and RS3) punctuate the stratigraphic architecture of the Salento continental shelf, separating Quaternary lowstand prograding wedges between them. All along the Middle Pleistocene, increasing the tectonic uplift of the Puglia offshore, combining with 4th-order glacio-eustatic variations, have dealt with the pattern of a broad forced regression prograding wedge, favoring a platform progradation of approximately 15 km. The architectural stacking patterns of the overlying Late Pleistocene and Holocene prograding wedges are controlled by 4th-order glacio-eustatic sea level changes, allowing for the formation of incomplete depositional sequences. In this period, the eustatic signature overcomes the tectonic mark, implying a decline in the uplift of the Apulian foreland in the course of the final 250 ky. [ABSTRACT FROM AUTHOR]

The portion of the southern Adriatic Sea, adjacent to the Murge area (Apulian Foreland, Southern Italy), is considered mainly aseismic. The recent March 23rd 2018 earthquake (Mw 3.7), occurred near Brindisi (Puglia Region), giving us occasion to reconsider data coming from different sources (instrumentally-recorded, historically-documented and palaeoseismologically-interpreted earthquakes), that suggest some moderate seismic shocks in this portion of the Adriatic Sea. The present study, based on the re-interpretation of public domain seismic profiles and exploration well logs available in the ViDEPI Project, has been focused on the recognition of faults with Quaternary activity in the epicentral area. A S-dipping fault, with a main dip-slip component of movement, is suggested to be the seismogenic source. Its geometry is consistent with the fault plane solution and the depth of the hypocenter calculated by the INGV (Istituto Nazionale di Geofisica e Vulcanologia). [ABSTRACT FROM AUTHOR]

It has long been recognized that the Adria Plate, as well as the Dinaric-Hellenic sector, contains a large volume of Triassic salt associated with diapirism, and it is well known that Triassic evaporites in the Mediterranean Sea region were deposited over epicratonic platforms surrounding the Mesozoic passive margin of Tethys Ocean. However, the real extent of these evaporites is still unknown; especially in the deep-water offshore area where publicly available seismic reflection profiles are scarce and petroleum exploration wells are missing. Several authors highlighted the presence of Triassic salt structures, mostly triggered by Meso-Cenozoic compressions and associated with fold-and-thrust belts. Both the lack of data and the later compressions contribute to hiding how a diapiric structure, formed in a passive margin and characterized by dome's geometry, is remoulded to assume a teardrop geometry typical of diapirs in fold-and-thrust belts. Two end members of diapiric structures are discussed: extensional structures formed in a passive margin, and compressional structures formed in a fold-thrust belt. The transformation of one end-member into the other is not well known. In the Northern Ionian Sea, the Apulian foreland, belonging to the southernmost termination of the Adria Plate and considered one of the largest preserved Mesozoic passive margin block of the Tethys Ocean, is a deep-water area associated with the opposing fronts of the nearby Calabrian Arc/Apennines and Dinaric-Hellenic Chains since the Cretaceous. Therefore, it represents an ideal area for investigating both the real extent of Triassic evaporites and the transformation of the diapiric structures under different regional geodynamic contexts. Based on seismic reflection profiles but no petroleum exploration wells, we present evidence of Triassic evaporites in the deep-water portion of the Apulian foreland, as indicated by the interpretation of two diapiric structures never described previously. These two new diapirs likely formed from inherited Mesozoic salt structures such as pillows and/or salt domes. The identification of halokinetic-related sequences affecting the Plio-Quaternary foreland sediments allows constraining the polyphaser evolution of the two diapirs. We suggest they are reactivated in response to the compressive stresses transmitted by the nearby Calabrian Arc/Southern Apennines and Hellenides. But, after the Middle Pleistocene, extensional tectonics, related to Adria Plate flexuring, acted again, and the diapirs were cross-cut by normal faults. These observations and findings are integrated into the geological context that controls the fundamental features of the diapirs, providing new insights on the fate of diapiric structures formed in a passive margin, later involved in a subducting and colliding plate, and before they become part of a fold-and-thrust belt. Furthermore, the study provides new constraints on the Triassic paleogeographic reconstruction of the Northern Ionian and Central Mediterranean Seas at the continental margin of the Tethys Ocean. • Seismo-stratigraphic data interpretations reveal the evidence of two new diapiric structures in the southern Adria Plate. • The compressive stress transmitted by the Calabrian Arc-Hellenides to the Apulian foreland triggered evaporitic squeezing. • The Northern Ionian Sea represents the southernmost termination of the Adriatic/Hellenic evaporitic Triassic basin. • The continental portion of the Adria Plate is present further to the West in the Northern Ionian Sea. • The study allows to give new insights on the fate of diapiric structures formed in a subducting and colliding plate. [ABSTRACT FROM AUTHOR]

The structural setting of the northern Ionian Sea is the result of the collision between the Calabrian Accretionary Wedge (CAW) and the adjacent foreland, i.e. the Apulian Carbonate Platform. The CAW represents a sector of the Apennine accretionary system extending in the Ionian Sea, bounded to the west by the Malta Escarpment and to the east by the Apulia Escarpment. This work presents the results of the interpretation of new seismic and bathymetric data acquired on the north-eastern edge of the CAW, in the N-Ionian Sea. The data interpretation has identified four main structural domains from NE to SW: 1. The Apulian carbonate Platform consisting of foreland shelf and transitional Mesozoic-Cenozoic carbonate deposits; 2. A narrow foredeep basin, filled by a very thick Plio-Quaternary succession; 3. A deformed domain, at the front of the CAW, incorporating thrusted foredeep sequences and a carbonate block of the Apulian Platform (Transpressed Apulian Block, TAB); 4. A highly deformed pre-Pliocene accretionary wedge. A mid-Pliocene unconformity interpreted on both the CAW and Apulian Foreland suggests that a regional tectonic event occurred at that time, related to the evolution of Calabrian Arc, moving on the subducting oceanic Ionian slab before the collision. This event would correspond to a main tilting and faulting phase of the Apulian Foreland during the diachronous oblique collision with the CAW. The collision and the presence of a remnant of Ionian foreland at the southern front of the accretionary prism, caused a gradual transition to a transpressional tectonics which produced the uplift of the TAB. The TAB would be the south-east continuation of the Amendolara ridge transpressed structure, which forms the offshore extension of the Pollino range. This transpressed shear zone involving the Apulian Foreland developed above the transition between the Adriatic continental crust and the subducting Ionian oceanic crust. [ABSTRACT FROM AUTHOR]

Geological and geophysical data generated during the mid-1990s and early 2000s indicate that the Montenegro - NW Albania area may have hydrocarbon potential. Thrust-related structures and sub-thrust autochthonous Mesozoic platform carbonates in the Dinaride-Albanide fold-and-thrust belt are potential exploration targets. Potential play types include structurally inverted autochthonous platform carbonates both on- and offshore Montenegro, and platform build-up closures located offshore. Potential source rocks are of Cretaceous age, analogous to those at oil discoveries in the Southern Apennines, and have been modelled to generate economic volumes of light oils which may be trapped in fractured shallow-water carbonates and sealed by deep-water Oligocene shales. The Neogene succession in Montenegro is dominated by turbidite sandstones which have the potential to contain biogenic gas. Structural and stratigraphic traps have been identified in 2D and 3D seismic reflection profiles but no wells have tested this play to date. However the biogenic gas play is considered to be of less importance than the potential oil play involving Mesozoic carbonates. [ABSTRACT FROM AUTHOR]

Abstract: Soft-sediment deformation structures are exposed in sea cliffs in the lower part of the Calcarenite di Gravina Formation (late Pliocene–early Pleistocene) in the Cala Corvino area N of Monopoli (Adriatic sector of the Apulian Foreland, southern Italy). Deformation affects a thickness of about 5m involving a lower calcareous–terrigenous sand and gravel unit and an upper heavily bioturbated grainstone and packstone unit. Deformation is absent from the overlying part of the succession. Large-scale soft-sediment deformation structures are collapse features comprising irregularly elongated conical zones of sinking. In vertical section, narrow “drop” zones occur in the lower sandy–gravelly facies and large gentle folds in the upper grainstone–packstone beds. The degree of deformation decreases upwards. Small-scale soft-sediment deformation structures adjacent to the large-scale conical collapse structures are narrow, vertically elongated load structures about 2m high and 30–50cm wide that involve only the basal terrigenous facies. The distribution of small- and large-scale soft-sediment deformation structures corresponds closely to zones of fracturing in the underlying Cretaceous limestones, and the elongation directions of soft-sediment deformation structures correspond to the orientation of major fractures in the limestones. The soft-sediment deformation occurred due to collapse associated with karstic sinkhole formation along fractures in the bedrock. Geometrical relationships between deformed and undeformed sedimentary units show that deformation occurred in a shallow marine environment. The structures at Cala Corvino provide a rare outcrop-scale record of sinkhole-induced soft-sediment deformation occurring in a shallow marine environment. [Copyright &y& Elsevier]

Integration of structural, stratigraphical, and sedimentological data and instrumental records of some recent low-energy seismic events in the Murge area allow us to suggest a new seismotectonic picture of this region, generally considered an aseismic and stable sector of the Apulian foreland.

The analysis of a set of public seismic reflection profiles allows to unravel the evolution of a segment of the Adria Plate in the Salento offshore, i.e., the Apulian swell (southeastern Italy). The study area was and still is shrinking in the foreland of two orogens and related opposed subduction zones, i.e., the southern Apennines and the Hellenides. The two thrust belt fronts of the opposite and converging orogens become very close (up to 150 km) giving rise, in the Salento offshore, to one of the largest lithospheric anticlines in the world. In this area, the deposits of the Hellenides foreland basin migrated towards W-SW at least from the Oligocene due to the E-NEward flexure of the Adria Plate in the northeastern part of the Ionian sea (i.e., on the area of the future Apulian swell). The same area, arching, was involved in the eastward roll-back of Adria Plate at least from the early Pleistocene, and the sedimentary wedge of the south Apennines foreland basin migrated towards E-NE beginning to occupy the outermost part of the Hellenides foreland basin. Therefore, the two related foredeeps overlapped in time, interfering during Quaternary. From late Early and Middle Pleistocene the area coinciding with the culmination of the arc began to uplift, forming the Apulian swell. While uplifting, the Apulian swell was affected by regularly-spaced normal faults, and became a threshold for sediments coming from the two opposite orogens. Two different narrow depocenters, well separated from each other, represent today the Apennines and Hellenides foredeeps, respectively. • Southern Apennines and Hellenides are opposite verging orogens whose approaching produces one of the worldwide largest lithospheric anticline in their shared foreland, e.g. the Apulian swell in the Ionian Sea. • Due to the migration of the two opposite verging orogens, an interference between the two respective foredeeps occurs along the Apulian swell anticline. • The reactivation of inherited extensional dominating faults, previously occurred in the subducting plate during the eastward roll-back, characterizes the foreland when affected by tectonic uplift, as observed in the Apulian swell. • Due to its progressive buckling and uplift, the Apulian swell, a foreland-basin area shared by the opposite verging orogens, turns into a ridge precluding sediments supply from each orogen to the foredeep depocenter of the other. [ABSTRACT FROM AUTHOR]