Search results for " fault"
showing 10 items of 239 documents
Geometry and modeling of an active offshore thrust-related fold system: The Amendolara Ridge, Ionian Sea, southern Italy
2012
On the Ionian Sea coast of southern Italy, spanning the transition from the Calabrian Arc to the Apennines, NE-directed motion of the thin-skinned frontal thrust belt of the Apennines toward the Apulian foreland reportedly ceased during the Early-Middle Pleistocene (PATACCA & SCANDONE, 2007). Deformation since then was dominated by the regional uplift of the Calabrian Arc (WESTAWAY, 1993; CUCCI & CINTI, 1998). However, detailed structural and geomorphologic analysis has revealed that uplift of Middle Pleistocene and younger marine terraces not only ensues from a regional-scale process, but also reflects a smaller-wavelength component of shortening which is attributed to recent, deeper activ…
Seismotectonics of the active thrust front in southwestern Sicily: hints on the Belice and Selinunte seismogenic sources
2014
We present a seismotectonic model of the active thrust front in western Sicily, which includes the area hit by the 1968 Belice earthquake sequence. The ~40 km long South-WEstern Sicilian Thrust (SWEST) is formed by two aligned albeit non-parallel fault arrays, the Granitola-Castelevetrano Thrust System (GCTS) in the west and the Partanna- Poggioreale Thrust System (PPTS) in the east. The ~NE-SW trending, NW-dipping GCTS straddles from the Pelagian coastline to Castelvetrano, is ~18 km long and composed of two segments, with the northern, ~12 km long one showing geodetic and geologic evidence of active deformation (Barreca et al., 2014). The segment is marked by a sharp gradient in Different…
Geology of the Kumeta-Pizzuta ridges (NW Sicily)
2016
We present a 1:25.000 scale geological map of the Kumeta-Pizzuta ridge in north western Sicily (Italy), which was achieved by integrating stratigraphic, structural and geophysical data. In this area the tectonic edifice results from the piling-up of deep water-, carbonate platform- and pelagic platformderived tectonic units (Imerese and Sicilide, Panormide and Trapanese domains respectively) originated by deformations of former southern Tethyan continental margin. The structural setting shows interference of subsequent tectonic events, different type of structural styles, and different-scale deformational patterns. Early overthrust of the Imerese on the Trapanese units (since late Serravall…
Understanding paleomagnetic rotations in Sicily: thrust vs. strike-slipe tectonics
2018
The paleomagnetic investigation of the western Sicily Maghrebian belt has revealed since the 1970s that large clockwise (CW) rotations up to 140° with respect to the Hyblean-African foreland occurred synchronous with Tertiary shortening of the chain. The observation that rotations decrease stepwise from internal to external tectono-stratigraphic units led in the 1990s to a widely accepted model postulating that rotational thrust-sheet emplaced during forward orogenic propagation. More recently, other authors suggested that CW rotations from Sicily are conversely the result of late orogenic dextral strike-slip tectonics. Here we report on a paleomagnetic investigation of 30 Jurassic-Eocene s…
PRIN Project 2010-11 “Active and recent geodynamics of Calabrian Arc and accretionary complex in the Ionian Sea”: new constraints from geological, ge…
2014
This contribution illustrates the preliminary results of our Research Unit in the PRIN Project 2010-11, which focuses on active and recent geodynamics of Calabrian Arc. The integration of the new geological, geodetic and seismological data supports the inferred recent plate boundary reorganization in the central-southern Mediterranean, where the regional GNNS velocity fields point to a deceleration or cessation of Calabrian Arc migration, and to extension along the axis of the Calabrian Arc, accommodated by normal faulting (e.g. Capo Vaticano and Messina Straits (Aloisi et al., 2012; Pepe et al., 2014; Spampinato et al., 2014). The study of the lateral borders of the Arc revealed that obliq…
Long-term earthquake potential of active faults by using coastal and off-shore geological and morphological indicators
2017
Seismogenic fault models and active deformation ones coupled with models of both earthquake rate and earthquake probability were recently used in a time-independent modelling. The integration of models allows to estimates the magnitude, location, and likelihood of potentially damaging earthquake ruptures in regions with high natural seismic hazard. Improvements of these models imply the recognition of the spatial geometry of the larger, active faults, deemed to be the source of the most damaging future earthquakes. However, identifying active faults and calculating their geologic slip rates for deriving earthquake rates are not easy tasks in regions inaccessible to direct field studies like…
The use and beauty of ultra-high-resolution seismic reflection imaging in Late Quaternary marine volcaniclastic settings, Napoli Bay, Italy
2019
A Nápolyi-öbölben felvett ultra nagy felbontású egycsatornás (IKB-Seistec™) reflexiós szeizmikus szelvények korábbi geológiai és geofizikai vizsgálatok eredményeivel együtt kivételes, eddig soha nem látott felbontású szeizmikus leképezését nyújtják a Flegrei-mezők és a Somma-Vezúv felszín alá süllyedt késő-pleisztocén–holocén rétegtani felépí - tésének. A szeizmikus szelvényeken látott geometria és gravitációs magvevővel nyert üledékek adatainak összevetéséből Campania partközeli kontinentális talapzatán számos olyan üledékes és vulkáni szerkezet, valamint hidrotermális jelenség került leképezésre, melyek a legutolsó glaciális maximum (kb. 18 000 év) óta keletkeztek. A Pozzuoli-öbölben mért…
On the relationships between tectonics and volcanism in the offshore capo vaticano, se tyrrhenian sea, during the plio-pleistocene.
2014
High-resolution bathymetry and a grid of single-channel reflection seismic profiles (Sparker and Chirp) were recently recorded in a sector of the upper slope of Capo Vaticano (CV) promontory (Tyrrhenian coast, W Calabria) where forward and inverse modeling of previously acquired aeromagnetic data highlight the presence of a WNW©\ESE elongated, 20 km long and 3¨C5 km wide, magnetized body extending from sea floor to about 3 km below sea level. Magnetic properties of this body are consistent with those of the medium to highly evolved volcanic rocks of the Aeolian Arc (De Ritis et al., 2010). Forthwith offshore promontory, the bathymetry highlights a complex-shape seamount that develops along …
Understanding paleomagnetic rotations in Sicily: Thrust vs. transpressive structures
2016
Since the 1970s, paleomagnetic data collected in Sicily have documented large magnitude clockwise (CW) rotations around vertical axis with respect to Africa and the Hyblean foreland. Many Authors argued that rotations arise from rotational thrusting of large coherent nappes coinciding with paleogeographic units. In the forward thrust propagation process, each nappe rotates the overlying nappe stack. This would explain the stepwise decrease of rotation magnitudes from the internal Panormide unit (90°-140°) to the external Saccense unit, yielding no rotation. However, other Authors later proposed that rotations of Sicily are the consequence of dextral shear occurring since late Miocene times …
An active oblique-contractional belt at the transition between the Southern Apennines and Calabrian Arc: The Amendolara Ridge, Ionian Sea, Italy
2014
High-resolution, single-channel seismic and multibeam bathymetry data collected at the Amendolara Ridge, a key submarine area marking the junction between the Apennine collision belt and the Calabrian subduction forearc, reveal active deformation in a supposedly stable crustal sector. New data, integrated with existing multichannel seismic profiles calibrated with oil-exploratory wells, show that middle to late Pleistocene sediments are deformed in growth folds above blind oblique-reverse faults that bound a regional pop-up. Data analysis indicates that similar to 10 to 20km long banks that top the similar to 80km long, NW-SE trending ridge are structural culminations above en echelon fault…