The effects of a Meso-Alpine collision event on the tectono-metamorphic evolution of the Peloritani mountain belt (eastern Sicily, southern Italy)

AbstractThe Peloritani Mountains, in the southern part of the Calabrian Terranes, southern Italy, have been classically interpreted as the product of the Paleogene brittle deformation of the European continental back-stop of the Neotethyan subduction complex. This reconstruction conflicts with the occurrence of an Alpine metamorphic overprint that affected portions of both the Variscan metamorphic units and part of the Mesozoic sedimentary covers of the mountain belt. New field data, integrated with petrographic, micro- and meso-structural analyses and stratigraphic investigation of the syn-tectonic terrigenous covers, well constrain a Paleogene collision event along the Africa–Nubia convergent margin that caused the exhumation of the Alpine metamorphic units of the Peloritani Mountains. The syn-collisional exhumation was associated with shearing along two major Africa-verging crustal thrusts arising from the positive tectonic inversion of the former European palaeomargin. Early tectonic motions occurred within the mountain belts and produced the exhumation of the external portions of the edifice. Later tectonic motions occurred along the sole-thrust of the entire edifice and caused the definitive exhumation of the entire mountain belt. The whole crustal thrusting lasted for a period ofc. 10 Ma, during the entire Oligocene. The definitive southwestward emplacement of the Peloritani Mountain Belt onto the Neotethyan accretionary wedge was followed by two Late Oligocene – Early Miocene NW–SE-oriented right lateral shear zones, replacing the previous crustal thrust. These two strike-slip belts are interpreted as the surface expression of the deep-seated suture zone between the colliding Africa and Europe continental crusts

Structure and morphology of an active conjugate relay zone, Messina Strait, southern Italy

Messina Strait is a narrow fault-bounded marine basin that separates the Calabrian peninsula from Sicily in southern Italy. It sits in a seismically active region where normal fault scarps and raised Quaternary marine terraces record ongoing extension driven by southeastward rollback of the Calabrian subduction zone. A review of published studies and new data shows that normal faults in the Messina Strait region define a conjugate relay zone where displacement is transferred along strike from NW-dipping normal faults in the northeast (southern Calabria) to the SE-dipping Messina-Taormina normal fault in the southwest (offshore eastern Sicily). The narrow marine strait is a graben undergoing active subsidence within the relay zone, where pronounced curvature of normal faults results from large strain gradients and clockwise rotations related to fault interactions. Based on regional fault geometries and published age constraints, we infer that normal faults in southern Calabria migrated northwest while normal faults in NE Sicily migrated southeast during the past ca. 2–2.5 Myr. This pattern has resulted in tectonic narrowing of the strait through time by inward migration of facing normal faults and rapid mantle-driven uplift

Slip on a mapped normal fault for the 28th December 1908 Messina earthquake (Mw 7.1) in Italy

The 28th December 1908 Messina earthquake (Mw 7.1), Italy, caused >80,000 deaths and transformed earthquake science by triggering the study of earthquake environmental effects worldwide, yet its source is still a matter of debate. To constrain the geometry and kinematics of the earthquake we use elastic half-space modelling on non-planar faults, constrained by the geology and geomorphology of the Messina Strait, to replicate levelling data from 1907 – 1909. The novelty of our approach is that we (a) recognise the similarity between the pattern of vertical motions and that of other normal faulting earthquakes, and (b) for the first time model the levelling data using the location and geometry of a well-known offshore capable fault. Our results indicate slip on the capable fault with a dip to the east of 70o and 5 m dip-slip at depth, with slip propagating to the surface on the sea bed. Our work emphasises that geological and geomorphological observations supporting maps of capable non-planar faults should not be ignored when attempting to identify the sources of major earthquakes

Geophysical Constraints to Reconstructing the Geometry of a Shallow Groundwater Body in Caronia (Sicily)

The characterization of a groundwater body involves the construction of a conceptual model that constitutes the base knowledge for monitoring programs, hydrogeological risk assessment, and correct management of water resources. In particular, a detailed geological and geophysical approach was applied to define the alluvial Caronia Groundwater Body (CGWB) and to reconstruct a hydrogeological flow model. The analysis of the CGWB, located in north-eastern Sicily, was initially approached through a reanalysis of previous stratigraphic (boreholes) and geophysical (vertical electrical soundings and seismic refraction profiles) data, subsequently integrated by new seismic acquisitions, such as Multichannel Analysis of Surface Waves (MASW) and horizontal-to-vertical seismic ratio (HVSR). The analysis and reinterpretation of geoelectrical data allowed the construction of a preliminary 3D resistivity model. This initial modeling was subsequently integrated by a geophysical data campaign in order to define the depth of the bottom of the shallow CGWB and the thickness of alluvial deposits. Finally, a preliminary mathematical model flow was generated in order to reconstruct the dynamics of underground water. The results show that integration of multidisciplinary data represent an indispensable tool for the characterization of complex physical systems

Universal newborn hearing screening in the italian region of sicily in 2018

Objectives. We have clarified the role of Universal Neonatal Hearing Screening (UNHS) for both early diagnosis and rapid treatment in order to improve the prognosis of the deaf child and reduce patient management costs. Although in Sicily UNHS has been progres-sively implemented, there is scarce data in the literature on this matter. Therefore, the main objective was to collect in the year 2018 the following data: number of newborns screened for hearing loss, number of infants “referred” to transiently evoked otoacoustic emissions (TEOAE), number of infants with pathologic auditory brainstem response (ABR) and number of infants affected by permanent hearing loss. Methods. UNHS monitoring was conducted through the collection of data through a ques-tionnaire, which was analysed evaluating the effectiveness and adherence to the screening program prepared by the Department for Health Activities and the Epidemiological Obser-vatory (DASOE). Results. In 2018, there were 40,243 newborns in Sicily. A total of 37,562 newborns were screened (93.3%). There were 1,328 “referred” infants with TEOAE (3.5%). On the 2nd lev-el, “referred” newborns examined were 1,080 of 1,328 expected (missing 248 “refer” new-borns, equal to 18.6%). The number of “referred” infants confirmed with TEOAE was 113 of 1,080, while “referred” infants confirmed with ABR were 71. On the 3rd level, 67 of 71 were infants examined: 28 infants were suffering from monolateral hearing loss (13 slight/ mild, 13 moderate, 1 severe and 1 profound) and 39 from bilateral hearing loss (1slight/ mild, 19 moderate, 13 severe and 7 profound). Excluding 7 infants from the NICU, 60 of 37,562 infants had hearing loss (1.5%). Conclusions. The monitoring of the UNHS in Sicily has allowed obtaining the data of individual centres, absent in the literature to date, to verify the effectiveness of the screening, according to JCIH criteria, to highlight some criticalities and, finally, to propose possible solutions

Last Interglacial sea-level proxies in the western Mediterranean

We describe a database of Last Interglacial (Marine Isotopic Stage 5) sea-level proxies for the western Mediterranean region. The database was compiled reviewing the information reported in 199 published studies and contains 396 sea-level data points (sea-level index points and marine- or terrestrial-limiting points) and 401 associated dated samples. The database follows the standardized WALIS template and is available as Cerrone et al. (2021b, 10.5281/zenodo.5341661)

Effect of the dynamic topology on the performance of PSO-2S algorithm for continuous optimization

International audiencePSO-2S is a multi-swarm PSO algorithm using charged particles in a partitioned search space for continuous optimization problems. In order to improve the performance of PSO-2S, this paper proposes a novel variant of this algorithm, called DPSO-2S, which uses the Dcluster neighborhood topologies to organize the communication networks between the particles. Experiments were conducted on a set of classical benchmark functions. The obtained results prove the effectiveness of the proposed algorithm

Introduction A Hellenic Modernism: Greek Theatre and Italian Fascism

The introduction to the special issue explores the central place of Greek theatre within the culture of Italian Fascism. Building on scholarship from the so-called cultural turn in the study of fascism, which variously identified fascism with a form of modernism, it demonstrates that a dialogue between modernism and classicism was fully at work in the performances of ancient drama occurring all over the Italian peninsula and in the colonies in North Africa. The term ‘Hellenic modernism’ is introduced here to underline the fusion of Greek theatre with distinctively modernist traits during the ventennio and provide an analytical tool for investigating the role of classical performances and spectacles within Fascism’s programme of cultural and national renewal

Submagmatic to Solid-State Deformation Microstructures Recorded in Cooling Granitoids during Exhumation of Late-Variscan Crust in North-Eastern Sicily

Late-Variscan granitoid rocks of trondhjemitic and granitic composition, intruded in migmatitic paragneisses in the north-eastern Peloritani Mountains (southern Italy) at ~310 Ma and ~300 Ma, respectively, exhibit a range of deformation microstructures developed under a shear regime at decreasing temperatures. Non-coaxial deformation is documented by sigmoidal feldspar porphyroclasts, mica fish, and asymmetric boudins affecting tiny andalusite crystals. Late-Variscan shearing during granitoid cooling is constrained by largely represented chessboard patterns in quartz and, especially, submagmatic fractures in plagioclase, indicating deformation at high-temperature conditions (T > 650 °C), in the presence of melt. Submagmatic deformation was extensively superseded by deformation at lower temperatures. Examples of solid state-high temperature deformation-related microstructures (T > 450 °C) include feldspar bulging, quartz grain boundary migration, and subgrain rotation recrystallization. Finally, low temperature subsolidus microstructures (T < 450 °C) consist of quartz bulging, mica kinks, and feldspar twinning and bending. A complete sequence of deformation, operating from submagmatic to low-temperature subsolidus conditions is recorded in both the older and younger granitoids, suggesting a duration of ~20 Ma for shear zone activity during post-collisional exhumation of the Variscan middle crust in southernmost Italy