Crotone Basin Research Articles

Geomechanics and Geology of Marine Terraces of the Crotone Basin, Calabria (Italy)

This study investigates the geomechanical behavior of five terrace orders in the Crotone Basin. The purpose is to understand the physical–mechanical parameters of these terraces to determine whether rock or soil mechanics principles should be applied for stability analysis. Samples were collected from each terrace following an extensive field survey. Laboratory analyses were conducted to measure pulse velocities, uniaxial unconfined compressive strength, and compressive strength with truncated conical platens. The findings revealed key physical–mechanical parameters of the rocks, which are crucial for stability assessments. The Crotone Basin, known for its mineral resources such as hydrocarbons and rock salts, has been studied geologically since before the 1950s, but there is a lack of geomechanical data in existing literature. Therefore, the results presented here are novel and provide a basis for future studies on the instability of rocky slopes composed of similar soft rock types. These results will aid in accurate geological–geotechnical model reconstructions. While the findings can be applied to similar cases, it is important to note that each analysis site, despite showing similar phenomena, is unique and requires individual investigation.

Depositional and diagenetic facies of Late Pleistocene (MIS 5) shallow-marine carbonates of the Capo Colonna terrace, Crotone Basin, Southern Italy (preliminary data)

Depositional and diagenetic facies of Late Pleistocene (MIS 5) shallow-marine carbonates of the Capo Colonna terrace, Crotone Basin, Southern Italy (preliminary data)

Calcareous bioconstructions formation during the last interglacial (MIS 5) in the central Mediterranean: A consortium of algal, metazoan, and microbial framebuilders (Capo Colonna - Crotone basin - South Italy)

The last interglacial (MIS 5) transgressive-regressive deposits of the Capo Colonna marine terrace provide a good fossil example of a Central Mediterranean infra/circa-littoral setting, characterized by both calcareous coralline algae-dominated low-relief bioherms and biostromes, equivalent respectively to the modern coralligenous and mäerl habitats. The skeletal primary framework of the bioherms, consists of laminar to massive encrusting coralline red algae acting as main bioconstructors, with minor bryozoans, encrusting foraminifera, and serpulids as secondary frame-builders. Whereas, the autochthonous mäerl tabular beds are mainly composed of free-branched coralline red algae rudstone. A variable amount of sandy bioclastic sediment is laterally interbedded with the bioconstructions and tends to be entrapped in their cavities and pockets. All sedimentary sub-facies of the bioconstructions and associated sediment are rich in autochthonous syn-sedimentary microbial-mediated micrite, forming aphanitic, peloidal, clotted peloidal, and filamentous fabrics. Microbial micrite can also trap and bind a variable amount of grains, or be a secondary component of the sandy sediment as micritic rims surrounding the clasts. All these early-lithified micrites show the typical nanostructure of the primary microbial-mediated carbonates, rather than a detrital mud particles accumulation, as they consist of nanospheres coalescing into subhedral microcrystals that replace both microbial cells (present with several morphological types) and extracellular substances. This in turn implies the original widespread presence of benthic lithifying microbial biofilms which colonized both the cavities of the skeletal framework of the bioconstructions, and the intergranular space of the associated sediment. These microbial communities, thanks to the metabolic processes of the microorganisms that induced the carbonate precipitation, significantly contributed to the early cementation of all the studied deposits.

3D modeling of the stratigraphic and structural architecture of the Crotone basin (southern Italy) using machine learning with Python

The 3D modeling and representation of geological data have experienced significant growth within last years, due to the use of new technologies derived from advancements in land representation methods. These technologies enable interactive, intuitive and clear geological visualizations. This paper shows how, by using the open-source Python software (operable with a simple internet browser) for machine learning (linear and KNN interpolations), together with Geographic Information Systems (GIS), it is possible to achieve interactive 3D visualizations of geological features in sedimentary basins. This study is performed in the onshore-offshore Crotone area (southern Italy) where a large amount of stratigraphic datasets are available from core perforation and seismic profiles due to the presence of a natural gas extraction field. Thanks to a database of 63 drilling lithologic records and 43 check points obtained from 9 interpreted seismic sections, several 3D HTML models were constructed defining three stratigraphic units (Pre-Messinian, Messinian, and Post-Messinian). An overlap of the Post-Messinian top surface and an erosional truncation of the Messinian top surface toward the N were observed, together with a rising of the Pre-Messinian top surface in the northwestern area. This stratigraphic architecture may indicate differential subsidence and/or uplifting due to syn-sedimentary fault kinematics in the whole studied area. The 3D models with the stratigraphic unit boundary surfaces obtained with KNN interpolation (showing stepped and abrupt edges) allowed the interpretation in terms of structural architecture and syn-sedimentary fault kinematics. Three main sets of faults were deduced: N–S; NNW-SSE, and ENE-WSW. A minorly represented E-W set was added to the main sets. These faults generated a horsts-grabens structure, and in many cases a determinate set of faults caused a progressive lowering or rising of some areas with an “en echelon” arrangement. According to previous works, these deduced sets of faults (most of them strike-slip faults) have a good agreement with the general structural architecture and defined faults in the area.

Microbial dominated Ca‐carbonates in a giant Pliocene cold‐seep system (Crotone Basin – South Italy)

AbstractThe Pliocene cold‐seep carbonate of the Crotone Basin (South Italy) represents a key site for dimension, outcropping exposure and quality. These deposits form a large carbonate (calcite) body (350 m long, 100 m wide and 40 m thick), and are characterized by a conduit facies made of authigenic calcite interpreted as previously active gas/fluid escape pipes and by a pavement facies, depicted as the surrounding early calcite‐cemented bioclastic and siliciclastic sediments. Pavement facies are commonly colonized by chemosymbiotic and non‐chemosymbiotic macrofauna (Lucinid and Solemyid bivalves, gastropods and serpulids). The conduit microfacies is characterized by the inward accretion of dark micritic laminae alternating with whitish sparitic layers. The micritic laminae show a microbial peloidal to dendrolitic fabric, which commonly incorporates planktonic foraminifera and coprolites, whereas the crystalline layers consist of microsparitic and sparitic crusts of prismatic zoned calcite crystals. The pavement facies shows more variability, because it is typified by laminated microbial boundstones, chemosymbiotic–bivalves packstone, foraminiferal packstone/wackestone and hybrid arenites. The stratigraphic constraint coupled with the foraminiferal assemblage (planktonic taxa) suggest a deep‐water setting occasionally affected by siliciclastic sedimentary flows. The pavement facies also shows common brecciation features, suggesting the establishment of post‐depositional overpressure conditions due to the early cementation of the conduits, which triggered localized rock failure. Stable isotope analysis of the different facies reveals overall negative δ13C values (−6.8 to −37.4‰ Vienna PeeDee Belemnite), indicating the presence of a complex mixture of methane with other hydrocarbons consumed microbially via anaerobic oxidation of methane; whereas δ18O is relatively positive (0.0 to 3.4‰ Vienna PeeDee Belemnite) suggesting the possible dehydration of clay minerals and/or destabilization of gas hydrates. This study, besides helping in the definition of the migration pathways and modality of accumulation of hydrocarbon‐rich fluids, can also help in building more and more realistic models for the complex genesis of cold‐seep carbonates.

Tectonic evolution of the Crotone Basin (central Mediterranean): The important role of two strike-slip fault zones

The middle Miocene to Quaternary evolution of the Crotone Basin (CB), on the Ionian side of the Calabrian Arc (southern Italy), was strongly controlled by the activity of the NNW- to NW-striking Rossano-San Nicola (RSFZ) and Petilia-Sosti (PSFZ) fault zones. The integration of low frequency 2D seismic reflection profiles, boreholes and geological maps has allowed the discovery of a positive flower structure, which is part of the RSFZ. Such a positive flower structure was responsible for the emplacement of an allochthonous unit in the Late Tortonian and contributed to the onset of gravitational collapse in the Pliocene. Dextral transpressional tectonics related to the RSFZ led to the expulsion of a S-verging thrust controlling the emergence of the northern sector (Cirò area), and the development of an elongated E-W-oriented depocenter in the southern sector of the Crotone Basin (Crotone area), from the Late Tortonian to Late Messinian. In the Late Messinian, the offshore area of the basin turned into a structural high marked by overall exposure conditions, as a consequence of the RSFZ activity. Contractional/transpressional activity also took place at the transition between the Early and Late Pliocene, when the PSFZ governed the superimposition of the Messinian Unit in the Crotone area. Conversely, phases of extensional/transtensional tectonics are inferred to have been occurred along the PSFZ during the Messinian, by the development of a tectonic trough in the south Crotone area. This tectonic regime is also supposed to have persisted during the Early Pliocene and the Pleistocene in the offshore area, where the development of local depocenters took place.

Zanclean to gelasian high-frequency sequences of the crotone basin (southern Italy): Architectural variability and forcing mechanisms

The Zanclean Belvedere Formation and the Gelasian Strongoli Sandstone, cropping out in the Neogene to Quaternary Crotone Basin, southern Italy, exhibit a high-frequency cyclicity consisting of 10°–101 m sequences, which stack in an aggradational to progradational pattern. These high-frequency sequences are bounded by ravinement surfaces and are usually composed of transgressive and regressive deposits of similar thickness. In particular, the high-frequency sequences of the Belvedere Formation are composed of a transgressive systems tract and of a highstand systems tract, whereas those of the Strongoli Sandstone likely record also forced regression in their upper part. Due to the vertical repetition of the studied high-frequency sequences and their similar architecture despite the different tectonic settings in which the two formations accumulated, a climatic/glacio-eustatic control associated with earth-orbital parameters is very likely, as also documented in coeval successions worldwide. This contribution refines the correlation between shallow-marine sequences and their deep-water counterparts, which preserve a better record of the Milankovitch cyclicity.

The Rossano–San Nicola Fault Zone evolution impacts the burial and maturation histories of the Crotone Basin, Calabrian Arc, Italy

This work addresses the tectonic significance of a NW–SE-trending strike-slip fault zone in the Calabrian Arc of southern Italy, the Rossano–San Nicola Fault Zone (RSFZ). High-quality seismic reflection and 1D forward models of exploration boreholes and pseudo-wells show that the RSFZ experienced multiple Miocene phases of contractional/transpressional tectonics. These were followed by crustal extension during the Pliocene, which occurred in association with the oceanization of the Tyrrhenian Sea, Apennine orogenesis, and collision between the Calabrian Arc and adjacent tectonic plates. Such a setting had a profound influence on the Crotone Basin and its economic potential: (1) tectonic reactivation allowed reservoir units of the Crotone Basin to be charged by gas derived from Triassic/Lower Jurassic source rocks; and (2) source rocks reached their maximum depth and remained in the gas generation window after the emplacement of a large mass-transport complex in the Pliocene. In the surrounding areas, tectonic activity near the RSFZ contributed to source-rock maturation by enhancing local sedimentation rates, particularly during Langhian (Middle Miocene) and Zanclean (early Pliocene) tectonics. This work is important as it demonstrates that the tectonostratigraphic evolution of the Crotone Basin was closely related to the structural evolution of the RSFZ. Crucially, the study area reveals the first example of a gas field fully sealed by a large mass-transport complex. As a corollary, we tie the Late Cenozoic geological history of the Crotone Basin to the geodynamic evolution of the central Mediterranean region, namely the Ionian and Tyrrhenian seas. We identify new prospects in the Crotone Basin, and provide a time frame for gas generation and accumulation in southern Italy.

Fingerprints and energy budget of the earthquake cycle in shallow sediments

Earthquake cycle consists of alternating transient coseismic slip and long-lasting interseismic periods, covering a wide range of slip rates. Unveiling the deformational signature of earthquake cycles in major seismogenic fault systems is an essential component of seismic hazard evaluation. Here, we present a study combining field and microstructural data acquired from an extensional fault zone with ∼100 m displacement, developed in poorly lithified siliciclastic sediments of the Crotone Basin, South Italy. The maximum burial depth of faulted sediments did not exceed 500 m. Within the fault core a dense network of mutually cross-cutting dark gouges and deformation bands is hosted. Dark gouges and deformation bands display striking distinctive features (i.e., geometric arrangement, grain size distribution, displacement, fractal dimension and clast preferential orientation), suggesting their genesis occurred under different slip rates. Based on grain size distribution data, total surface energies required for dark gouge and deformation band development are in the order of 106 and 104 J/m2, respectively. These values are in accordance with literature fault scaling laws regarding moment magnitude-surface energy relationship. Our results support the genesis of deformation bands during inter-seismic, creeping fault activity periods, while dark gouges were produced during coseismic slip events.

Sandstone petrology of the Crotone Basin, Calabria (Italy) from well cores

Siliciclastic Serravallian–Tortonian strata of the Crotone Basin, and allochthonous Paleogene siliciclastic strata (Cariati Nappe) were studied in 8 well logs, both onshore and offshore. Compositional and stratigraphical variations along transects of 60 km (N-S) and 27 km (W-E) were undertaken. Modal analysis of buried sandstones testified four distinctive sandstone petrofacies: quartzolithic and quartzofeldspathic composition related to allochthonous terranes of the Cariati Nappe, quartzofeldspathic and quartzofeldspatolithic composition related to the Crotone Basin. Sandstones composition reveals a direct influence of the nearby crystalline (plutonic and metasedimentary rocks) and associated Mesozoic to early Miocene sedimentary source areas (Sila Unit). Detrital modes are intimately related to the tectonic setting evolution of the area. Comparison with southern Apennines regional petrofacies of the Sicilide Complex, and Crotone Basin outcrop petrofacies had shown analogies with buried sandstones, as a consequence of typical setting within foreland basin system.

Neogene cold seep carbonates in the Crotone Basin (South Italy)

A Neogene cold seep carbonate body crops out in the Crotone Basin and is characterized by a Conduit facies, made of authigenic carbonates filling the gas/ fluid escaping pipes and a Pavement facies made of early-cemented bioclastic and siliciclastic sediments colonized by a chemo-symbiotic fauna dominated by Lucinid bivalves. The conduit facies is composed of alternated mm-thick dark micritic and clear sparitic lamine rimming and inward accreting open fissures. Micrite exhibits microbial peloidal to dendrolitic fabrics, while sparry laminae shows prismatic-pyramidal to anhedral-subhedral crystals. The pavement facies is made of microbial boundstones, bioturbated mudstone/wackestones and packstone/grainstones passing into mixed arenites, all interbedded with syn- sedimentary breccias due to local overpressure conditions because of gas/fluid injections. Planktonic foraminifera are widespread and suggest a deep-water setting. Stable Isotopes analysis in all the facies shows 13C depletion (δ13C values between -6.8 and -38‰) and 18O enrichment (δ18O values between -0.04 to 3.4‰) reflecting destabilization of gas hydrates made of methane/crude oil mix.

Identification of maximum flooding surfaces at different scales: The case of the Piacenzian to Gelasian Cutro Clay and Strongoli Sandstone (Crotone Basin, southern Italy)

The Piacenzian to Gelasian deep- to shallow-marine succession cropping out in the NE part of the Crotone Basin, southern Italy, is ideal for applying integrated sedimentological and micropaleontological criteria to recognize cryptic surfaces of sequence stratigraphic significance, such as the maximum flooding surface (MFS), and other surfaces devoid of physical expression, such as the maximum water-depth surface (MWDS). The micropaleontological criteria consist in the calculation of parameters such as the % fragmentation of benthic foraminifera, the ratio between distal and proximal benthic foraminifera, and the plankton/benthos ratio. In any sequence, the offset between the lowest values of % fragmentation and the highest values of the distal/proximal ratio defines a relatively thin uncertainty interval in which the MFS should lie. Moreover, the MWDS is inferred to correspond to the peak of the plankton/benthos ratio, which may coincide with the MFS or it may be slightly above it. Notably, the method allows to recognize MFSs and MWDSs of different hierarchical ranks, and therefore it is effective in the study of sequences of any scale, including modern studies of high-resolution sequence stratigraphy.

Subsidence analysis by mean of DeGloT software: Application to the key-case of the Miocene-Quaternary Crotone Basin (Calabria, S. Italy)

The present work deals with the application of subsidence analysis to the Crotone Basin through the application of a software written ad-hoc by using the. NET framework. The application of this software called Decompaction Glorious Trend (DeGloT) has been tested on a case study along the Ionian coastal plain of Calabria, in the Crotone Basin, Southern Italy. The study area includes the stratigraphic infill of the Neogene to Quaternary Crotone Basin as an example of a thick stratigraphic succession deposited within a progressive changing nature of subsiding region. Because of regional tectonic events, this area is characterized by a complex geological and evolutionary history recorded in this sedimentary basin. The Crotone Basin experienced an alternation of uplift and subsiding processes. We used DeGloT software for the subsidence analysis, by using well controlled dataset from a large number of well log for hydrocarbon exploration and stratigraphic and structural architecture from both surface seismic profiles and outcrop occurrence.A description of the software logic and several examples of its usage are provided. The historical evolution of the subsidence analysis and the essential theorical information are summarized in order to understand the requested input and the resulting output of the software.Even if the software was designed for the Crotone Basin, it can be used for applicability to other sedimentary basins.

Interferences between natural and anthropic hazards in marine-coastal environments: Assessing transport from land to the offshore systems in the Crotone basin (Ionian Sea)

This paper is focused on the field-evidence of environmental hazard associated with flood events in highly contaminated marine coastal areas. The Crotone site (Ionian Sea), in the 1900s hosted a large industrial settlement (with the largest plant in Europe of zinc production, phosphorus manufacture, etc.) which left a severe legacy of environmental pollution. Here, we report the results of an investigation related to the distribution of heavy metals (Zn, Pb, Cd, Cu) in 230 sediment cores that allowed a detailed reconstruction of the contamination due to the discharge at sea of industrial wastes deriving from the Zn-sulphides leaching processes. High concentrations of heavy metals (e.g., Zn > 5000 mg kg−1) accumulated in sediments of the seabed along coastline, exposed to the fluvial and coastal dynamics, act as a potential long-term source of pollution for the marine ecosystem. Fingerprints of historically flash flood events evidenced in two 210Pb dated sediment cores suggest that these catastrophic events played a crucial role in the land-to-sea transferring (and sequent dispersing effects) of highly polluted sediments. Anomalous depositions of heavy metals-rich sediments in the offshore system (4–6 km from the coastline) testify secondary contamination due to mobilization and redistribution of old contaminated sediment due to flood events. These interactions between natural and anthropic hazards trigger cumulative mechanisms of multiple-pollution and transfer of contamination from polluted nearshore to offshore nearly pristine areas trough main canyon axes.

The Petilia-Sosti Shear Zone (Calabrian Arc, southern Italy): An onshore-offshore regional active structure

The integrated interpretation of different types of data, consisting of a detailed Digital Terrain Model, field structural and morphotectonic observations, high resolution seismic data, seismological and Synthetic Aperture Radar interferometry information (vertical and horizontal movements), associated with a review of the available literature, has allowed to analyze the shallow expression of the regional-scale Petilia-Sosti Shear Zone (PSSZ). It is one of the major NW-trending tectonic lineaments affecting the Calabrian Arc and is characterized by a present-day tectonic and gravity-driven deformation. This study investigated the portion of the PSSZ between the offshore Crotone Peninsula, located along the Ionian sea of Calabria, and the central part of the Sila Massif.A complex tectonic history is documented since middle Miocene onward for the PSSZ. It consists of an alternation of sinistral and dextral transpressional and transtensional tectonic phases correlated with the geodynamic events occurred during the SE migration of the Calabrian Arc.The shallow expression of the investigated part of the PSSZ consists of a roughly 14 km wide, ca. 80 km long NW-trending tectonic zone including synthetic NW- to NNW-trending faults and N-NE antithetic minor structures. The main identified NW-trending faults, which show a development between 30 and 50 km, are the Sila and Lakes faults in the Sila Massif, and the Marcedusa-Steccato, Fosso Umbro and Tacina faults located in the SW part of the Crotone Basin and in its offshore area. Currently, the fault segments of the Sila Massif exhibit a prevailing normal kinematics with a left-lateral component, whereas a more complex geological framework occurs in the south-western part of the onshore-offshore Crotone Basin. The latter is dominated by gravity-driven movements, associated with the SE migration of the Crotone Megalandslide and with the regional uplift of Calabria, whereas normal kinematics with a small left-lateral component of movement, locally replaced by reverse/transpressional tectonics, was observed along the southern coast in the late Pleistocene deposits of the Le Castella marine terrace.The seismological data highlight that some strong earthquakes occurred in 1638, 1744 and 1832, with magnitude Mw between 5.7 and 6.8, might be associated with the Lakes, Fosso Umbro and Tacina faults respectively. In this frame, the PSSZ is proposed as a new potential NW-oriented active composite seismogenic source for the central-northern Calabria.

Impact of sedimentation, climate and sea level on marine sedimentary pyrite sulfur isotopes: Insights from the Valle di Manche section (Lower-Middle Pleistocene, southern Italy)

Variations in the isotopic composition of sulfur in sedimentary pyrite (δ34Spyr) are often used to reconstruct global sulfur biogeochemical cycling and Earth's surface oxidation state over Earth history. Recent work, however, has shown that δ34Spyr is strongly impacted by local depositional conditions, which both confounds attempts to reconstruct global sulfur cycling and provides a new proxy for investigating local paleoenvironmental conditions. We present a chemostratigraphic record of δ34Spyr in a detailed paleoenvironmental and sequence stratigraphic framework spanning the Early-Mid Pleistocene transition from the Crotone Basin (Calabria, Southern Italy). Bulk δ34Spyr data parallel transgressive-regressive cycles and enable the differentiation of progradational and retrogradational stacking patterns, where δ34Spyr values decrease toward −50‰ in outer shelf deposits during late transgression and become more positive and variable in prograding sedimentary units accumulated in shallower environments. In parallel with the observed variations in δ34Spyr, complementary data on organic carbon abundance and isotopic composition and total nitrogen abundance document changes in terrestrial delivery of sediment to the basin, as a consequence of glacial-interglacial eustatic sea-level changes, regional climate and local tectonics. The chemostratigraphic record of δ34Spyr appears sensitive to variations in sedimentation rates and local erosional surfaces and therefore may represent a powerful tool to assess stratal stacking patterns for sequence stratigraphic interpretations of siliciclastic successions. These results highlight the role of local conditions in controlling sedimentary δ34Spyr records and illustrate how isotopic data can be used to reconstruct key parameters of the sedimentary environment that might not otherwise be accessible, especially in deep-time strata.

Recognizing maximum flooding surfaces in shallow-water deposits: An integrated sedimentological and micropaleontological approach (Crotone Basin, southern Italy)

The Pliocene and Pleistocene intervals of the Neogene to Quaternary succession of the Crotone Basin, southern Italy, offer good examples of shallow-marine high-frequency sequences (fourth-order or lower rank stratigraphic frameworks) composing higher-rank units. The analysis of some representative sections from this succession has allowed performing an integrated sedimentological and micropaleontological study aimed at defining new criteria to recognize high-frequency maximum flooding surfaces. In particular, field data have been compared with some parameters derived from the micropaleontological analysis, such as the abundance, diversity and % fragmentation of benthic foraminifera, as well as the ratio between distal and proximal benthic foraminifera species and the plankton/benthos ratio. This integrated study allows to define an uncertainty interval in the high-frequency sequences, in which the maximum flooding surface should lie. This uncertainty interval is usually characterized by lower values of the % fragmentation and higher values of the abundance, diversity and distal/proximal ratio, whereas the peak of the plankton/benthos ratio allows to define a surface of maximum water depth, placed above the maximum flooding surface. Usually, the greater the magnitude of the transgression, the thinner the uncertainty interval. These results highlight the cryptic nature of the maximum flooding surface within condensed sections, even in high-resolution outcrop studies, and allow to refine the criteria based on which the position of such surface can be approximated in the field and in sediment cores.

Displacement-dependent microstructural and petrophysical properties of deformation bands and gouges in poorly lithified sandstone deformed at shallow burial depth (Crotone Basin, Italy)

We present the results of meso-and micro-structural analyses performed on fault-related soft-sediment deformation structures affecting poorly lithified, high-porosity siliciclastic sediments in the Crotone Basin, Southern Italy. The investigated extensional fault zone has a total displacement of ~90 m and juxtaposes marine clayish sediments in the hanging wall against arkosic to lithic arkosic sandstone in the footwall. In the footwall damage zone, deformation is achieved by a network of conjugate deformation bands, whereas the foliated fault core hosts cm-thick gouges. Deformation bands and black gouges accommodated displacement between 0.2 and 20 cm. Microstructural observations and quantitative image analysis pointed out that particulate flow operated during the early stages of faulting, followed by cataclasis after significant porosity loss. Mineralogy of clasts controlled grain-scale deformation mechanism: following this, feldspar experienced extensive intragranular crushing, while quartz grains were deformed mainly by splitting and abrasion. Permeability of pristine sandstone spans from 5.4 × 104 to 1.4 × 105 mD, while inside deformation bands is reduced by 1-2 orders of magnitude, reaching 3-4 orders of magnitude within fault gouges. Permeability drop inside the fault zone is related to the accommodated displacement along each deformation structure, potentially leading to hydraulic compartmentalization of high-porosity sandstone reservoir.

Large-scale gravity-driven phenomena in the Crotone Basin, southern Italy

The aim of this study is to better define the scale, timing and driving mechanisms of a seaward-gliding landmass currently affecting the Crotone Basin, a forearc basin on the Ionian side of Calabria (southern Italy). An integrated approach of seismic, well and field data, together with literature information, have revealed that the slide includes an onshore updip extensional domain compatible with the presence of a curved seaward-dipping fault system to the NW, which is connected southward to an offshore downdip compressional domain through a buried detachment surface lying at a Messinian halite layer. The landmass, which involves Messinian-Pleistocene deposits, has started to slide since the Zanclean, and experienced a paroxysmal episode between late Zanclean and early Piacenzian linked to transpressional tectonics. After a phase of inactivity during the Calabrian, the gravitational collapse underwent a second reactivation since middle Pleistocene due to regional uplift, which seems to be restricted to the offshore sector, the Crotone peninsula and probably the eastern coastal area. • A better definition of the scale, timing and driving mechanisms of the Crotone Megalandslide is provided. • A first phase of activity started during the Zanclean and ended during the Gelasian, and involved the whole basin. • A second phase of activity persists since the middle Pleistocene and involved only the Crotone peninsula and the offshore area.

Sedimentary evolution of the Neogene-Quaternary Crotone Basin (southern Italy) and relationships with large-scale tectonics: A sequence stratigraphic approach

Abstract The Crotone Basin is a Neogene-Quaternary depocenter developed along the Ionian margin of Calabria, southern Italy. The basin opening was concomitant with the onset of spreading of the Tyrrhenian backarc Basin during late Serravallian and the subduction of the Ionian lithosphere below the Calabrian Arc. The adoption of modern sequence stratigraphic principles to subdivide the basin fill into stratigraphic sequences of different rank, bounded by subaerial unconformities, has allowed cycles of creation and loss of accommodation mainly related to tectonics to be recognized. In particular, an alternation between phases of basin subsidence, concomitant with spreading of the Tyrrhenian backarc Basin and forward migration of the Arc, and phases of compressional or transpressional tectonics, accompanied by basin uplift and stopping of Arc migration, are well recognizable in the basin fill, in particular for the late Messinian to late Pleistocene part of the succession. The present study highlights the effectiveness of the sequence stratigraphic method in basin analysis to decipher the effects of large-scale tectonic events on sedimentation and ultimately to reconstruct the geodynamic evolution of the central Mediterranean.