Evidence of positive tectonic inversion in the north-central sector of the Sicily Channel (Central Mediterranean)

Abstract

In order to unravel the tectonic evolution of the north-central sector of the Sicily Channel (Central Mediterranean), a seismo-stratigraphic analysis of single-and multichannel seismic reflection profiles has been carried out. This allowed to identify, between 20 and 50 km offshore the central-southern coast of Sicily, a *80-km-long deformation belt, characterized by a set of WNW-ESE to NW-SE fault segments showing a polyphasic activity. Within this belt, we observed: i) Miocene normal faults reactivated during Zanclean-Piacenzian time by dextral strike-slip motion, as a consequence of the AfricaEurope convergence; ii) releasing and restraining bend geometries forming well-developed pull-apart basins and compressive structures. In the central and western sectors of the belt, we identified local transpressional reactivations of Piacenzian time, attested by well-defined compressive features like push-up structures and fault-bend anticlines. The reconstruction of timing and style of tectonic deformation suggest a strike-slip reactivation of inherited normal faults and the local subsequent positive tectonic inversion, often documented along oblique thrust ramps. This pattern represents a key for an improved knowledge of the structural style of foreland fold-and-thrust belts propagating in a preexisting extensional domain. With regard to active tectonics and seismic hazards, recent GPS data and local seismicity events suggest that this deformation process could be still active and accomplished through deep-buried structures; moreover, several normal faults showing moderate displacements have been identified on top of the Madrepore Bank and Malta High, offsetting the Late Quaternary deposits. Finally, inside the northern part of the

Crustal deformation, active tectonics and seismic potential in the Sicily Channel (Central Mediterranean), along the Nubia–Eurasia plate boundary

“…Based on the interpretation of marine geophysical data combined with the well-log stratigraphy of the ViDEPI project (https ://www.videp i.com/videp i/videp i.asp), numerous papers have described tectonic structures accommodating multiphase crustal deformations in the Sicily Channel 23,[38][39][40][41][42][43][44][45] . All Figure 2.…”

What seismicity offshore Sicily suggests about lithosphere dynamics and microplate fragmentation models in the Central Mediterranean

“…However, this latter result 379 must be considered as uncertain or highly preliminary because the number of data available in the 380 0-30 km and 30-70 km depth ranges is 15 and 12, respectively, then lower than the threshold of 20 381 adopted in this work for stress inversion. We do not report these latter results in graphical and 382 numerical form, we wait for future analyses with more data before drawing conclusions on the 383 depth variation of stress in the rifting zone of Polonia et al (2017). We conclude our discussion on 384 stress inversion results by remarking that partitioning of the dataset according to earthquake 385 magnitude has not evidenced any relevant change of stress or variation of heterogeneity level 386 among subsets.…”

The Graham Volcanic Field Offshore Southwestern Sicily (Italy) Revealed by High-Resolution Seafloor Mapping and ROV Images

“…The northern side of the Sicily Channel is characterized by a very uneven bathymetry, being a composite array of shallow continental shelves (the Siculo-Maltese Shelf and the Adventure, and Malta plateau), deep depressions, such the faultcontrolled Pantelleria, Linosa, and Malta grabens and a foredeep depocenter (the Gela Basin), and topographic highs, such us several small-to middle-scale banks of sedimentary origin (e.g., the Nerita, Terribile, Nameless, and Madrepore banks) (Colantoni, 1975;Calanchi et al, 1989;Cavallaro et al, 2017; Figure 1). Within the Sicily Channel, a widespread and scattered volcanism is known to have occurred during Upper Miocene to Pleistocene times, building up the alkaline volcanic islands of Linosa and Pantelleria and several other volcanic centers (e.g., Anfitrite, Tetide Galatea, Cimotoe banks) (Beccaluva et al, 1981;Calanchi et al, 1989;Rotolo et al, 2006;Civile et al, 2008Civile et al, , 2015Lodolo et al, 2012Lodolo et al, , 2019aPensa et al, 2019; Figure 1).…”

“…This belt was related to a lithospheric-scale transpressive transfer zone (the Capo Granitola-Sciacca Fault Zone, CGSFZ; see inset in Figure 1) between the western and eastern sectors of the Sicily Channel Rift Zone, characterized by different amount of rifting (Argnani, 1990;Civile et al, 2014Civile et al, , 2018. The CGSFZ is also positioned between two tectonically independent sectors of the offshore part of the Sicilian-Maghrebian Chain, characterized by different deformation ages, structural trends and tectonic evolution, playing a key role in the Neogene-Quaternary geodynamic evolution of the region (Argnani, 1990;Corti et al, 2006;Civile et al, 2008Civile et al, , 2014Civile et al, , 2018Ghisetti et al, 2009;Calò and Parisi, 2014;Cavallaro et al, 2017;Fedorik et al, 2018;Ferranti et al, 2019). The CGSFZ is composed of two major leftlateral strike-slip systems: the Capo Granitola fault system (CGFS) to the west, which affects the GVF area, and the Sciacca fault system (SFS) to the east (Figure 1), which bounds the eastern extent of the Nerita and Terribile banks (Civile et al, 2018;Fedorik et al, 2018;Ferranti et al, 2019).…”