Active tectonics, sedimentation history and geomorphological features in the northern Sicily continental margin: implications for the marine geohazard assessment

Starting from the assumption that seismic events in the active margins are accompanied by evidence of a depositional, geomorphologic and structural type, which constitutes the geological record of their activity, we analysed different features of the Northern Sicily continental margin (NSCM) to reconstruct the deformational field and related stress field in the Southern Tyrrhenian sea. As an outcome of this project we were going to obtain seismotectonic setting and mapping to provide a powerful tool in managing and assessing the marine geological hazards. The study area extends from the San Vito Peninsula to the Termini Gulf along the NSCM, including the Ustica island, and is located in a t…

Hinterland-verging thrusting in the northern Sicily continental margin: a late collisional stage of the Sicilian Fold and Thrust Belt?

Backthrusting, nappe refolding, and normal faulting frequently characterize late collisional stage of an orogen. Shortening driven by backthrusting is widely reported in the Alpine orogen, and it has been proposed to be responsible for the increase of subsidence (Roure et al., 1990). Moreover delamination and backthrusting has been considered as related to subcritical condition of a Coulomb-type accretional wedge (Torres Carbonell et al., 2011). The Sicilian Fold and Thrust Belt (SFTB) was characterized by a three-stage evolution during the last 15 My: two main shortening events generated and developed at different structural levels (shallow- and deep-seated thrusts in thin-skinned thrust-m…

Active north-vergent thrusting in the northern Sicily continental margin in the frame of the quaternary evolution of the Sicilian collisional system

Abstract A three-stage evolution has characterized the Sicilian Fold and Thrust Belt (SFTB) during the last 15 My: two main thin-skinned shortening events involving mainly Meso-Cenozoic carbonate units, followed by thick-skinned thrusting involving Plio-Pleistocene deposits in the frontal area as well as the crystalline basement in the inner and deeper sector of the chain. We investigated the northern Sicily continental margin, by using differently-penetrative seismic reflection data and new field surveys, which revealed, both offshore and onshore, north-vergent compressional structures that affected the tectonic edifice during Quaternary time. These structures, correlated with the kinemati…

A scenario-based assessment of the tsunami hazard in Palermo, northern Sicily, and the southern Tyrrhenian Sea

Potential Cyclic Steps in a Gully System of the Gulf of Palermo (Southern Tyrrhenian Sea)

Multibeam bathymetric data revealed the occurrence of atrain of bedforms along a gully system in the Gulf of Palermo, Southern Tyrrhenian Sea. The observed gullies, located in the westernmost sector of the Gulf of Palermo, incise the outer shelf at a depth of 120 m and converge at the Zafferano Canyon, connecting to the Palermo Basin at a the depth of 1300 m. Bedforms develop along these gullies and along the thalweg of the canyon, displaying an average wavelength of 200 m, with maximum values of 340 m. Their gully floor location combined with their wave length, upslope asymmetry and crescent shape point to a possible cyclic steporigin of these bedforms. Preliminary numerical modeling sugge…

Comparing methods for computation of run-up heights of landslide-generated tsunami in the Northern Sicily continental margin

The North Sicily continental margin is a very active region located in the Central Mediterranean. Strong seismicity, active tectonics and volcanism, fluid escape, high sediment supply, and widespread mass movements historically have exposed this region to marine geohazards, with a potential for tsunami generation. Morpho-bathymetric analysis revealed that one of the most common mechanisms associated with marine geohazards is due to submarine mass failure processes, genetically linked to the other processes active in this margin. With the aim to assess the risks associated with landslide-generated anomalous waves, we selected two sectors of this margin, Gulf of Palermo to the west and Patti …

Geo-hazards of the San Vito peninsula offshore (southwestern Tyrrhenian Sea)

Geomorphological Tools for Mapping Natural Hazards.-- 12 pages, 7 figures, supplemental material https://doi.org/10.1080/17445647.2020.1866703.-- Software: The geomorphological main map and the Figures in the text were compiled using GLOBAL MAPPER, Surfer and Quantum-G GIS Software and redesigned to print with Adobe Illustrator

Late Quaternary palaeoenvironmental reconstruction of sediment drift accumulation in the Malta Graben (central Mediterranean Sea)

The Malta Graben is a deep tectonic depression in the Sicily Channel, bounded by NW-SE normal faults and filled by thick Pliocene-Quaternary deposits. A previous analysis of a giant piston core (LC09) from the Malta Graben had revealed a wide range of sedimentary features (carbonate turbidites, bioturbated mud and scours), although the chronostratigraphic constraint of the stacking pattern has remained elusive. After establishing a reliable chronological framework based on seven radiocarbon dates for a shorter core from the Malta Graben (ANSIC03-735), a down-core analysis of planktonic foraminifer and coccolith abundance, stable isotopes and sediment grain size was carried out. Since the la…

Hinterland-Verging Thrusting in the Northern Sicily Continental Margin: Evidences for a Late Collisional Stage of the Sicilian Fold and Thrust Belt?

The Sicilian Fold and Thrust Belt developed during Neogene-Quaternary times characterized by main African-wards tectonic transport direction. Recent investigations highlighted extensive hinterland-verging tectonic structures active during late Pliocene-Pleistocene time suggesting a late collisional stage of the Sicilian Fold and Thrust Belt that could be a precursor of a change in the subduction polarity in the central belt of Mediterranean.

Growth and geomorphic evolution of the Ustica volcanic complex at the Africa-Europe plate margin (Tyrrhenian Sea)

18 pages, 13 figures, 1 table