GNGTS 2017 - 36° Convegno Nazionale

140 GNGTS 2017 S essione 1.2 Fig. 1 - Geographic overview of mud vulcano in Sicily (red point) and of the Sicilian Basal Thrust (red line). been involved in the latest tectonic phases. The deeper stratigraphic formations belonging to the Tectonic Unit of the Chain (Tactonic Sicilid Units). Sicilian units occupy the most structurally elevated position in the Apennine- Maghreb System. They originated in the Paleogene as an development wedge following the collapse of sedimentary shells from the neotetical ocean floor due to the convergence that produced alpine orogenesis and subsequently were transported in full on the outer paleodomains. Among the terms of the Sicilian Units, in the nissena area emerge the group of the Argille Variegate and the Numidian Flysch (member of Nicosia). Deep geology. The study of deep geology has required the literature analysis of various geological sections. All these geological sections were realized through the analysis of seismic profiles and stratigraphies (Catalano et al. , 2013; Lentini and Carbone, 2014; Bello et al., 2000; Accaino et al. , 2011; Bianchi et al. , 1987; Lavecchia et al. , 2007). According to Lavecchia et al. (2007) it was possible to extrapolate the depth of the Moho and of the Sicilian Basal Thrust (SBT). From the sections realized by Catalano R. et al. (2013), structures and geological formations present in the Sicilian subsoil have been extrapolated. The seismic profiles of the SI.RI.PRO project were also re-interpreted. Geodetic characterization of the area. Normally the phenomenon of “ Maccalube ” shows distinct warning signs that in the past have never been detected through monitoring systems. The geodetic-topographic monitoring network consists of a GNSS benchmarks network in order to record the vertical and horizontal movements of this area. With the Working Group of the Catania University of Geodesy, a series of GNSS field measurement have been conducted since October 10, 2016. Two GNSS receivers (TOPCON HiPerV (L1 + L2)) have been used. For the post-processing phase of the data, the Magnet Tools software provided by the University of Catania, was used. For better estimation of parameters for each daily solution, calculated precise ephemeris IGS and IGL and ground rotation parameters provided by the International Earth Rotation Service have been used. In addition, during processing, the data of the RESU permanent station belonging to the RING network was included in the data process. Morphometric analysis and morphometric elements. The study area has been identified in a geological structural domain affected by fold and thrust deformations characterized by south verging NE-SW trending structures, according to a roughly N-S oriented regional contractional stress regime. The geometry of the main hydrological basin (Imera river) develops on a regional scale from N to S for 114 km and about 40 km towards E-O; affecting an area of 2000 km 2 . For the morphometric analysis, we elaborated all the DEM (Digital Elevation Modell) mask using the MICRODEM software and calculate the respective Strahler’s curves. The pattern of the hydrographic network can be ascribed to dendritic and trellis pattern; because the tributaries of southern Imera river are orthogonal both to the main and to the tectonic structures. It is possible to find out from the observation and interpretation of every single Straheler