Accaino, F

ALBANESE, Cinzia

CATALANO, Raimondo

GASPARO MORTICELLI, Maurizio

Manzella, A

Naselli, G.

Nicolich, R

SULLI, Attilio

VALENTI, Vera

Archivio istituzionale della ricerca - Università di Palermo

Santa Caterina. Deformed Messinian carbonates and evaporites give a strong structural control; themorphoselection favours the development of NE-SW trending monoclinal ridges along the SE-ver-gent fold forelimb. Sector 3 - To the south of Caltanissetta the profile crosses Neogene to Pleistocene deposits thatrepresent the deformed sedimentary fill of a thrust top basins system developed above the youngestand outermost sector of the Sicilian Fold and Thrust Belt (Gela Thrust Wedge, Catalano et al., 1993;Lickorish et al., 1999). This is a complex sector of the chain in which the main structures, NE-SWoriented, are related to activation of thrusts (Caltanissetta, Pietraperzia area). The growth of thesestructures produced a tipical stratal pattern recognizable in Pleistocene basin infill (Capodarso cal-carenites, Vitale 1996).Thrusts and overturned isoclinal folds, NE-SW-oriented with NW-ward vergence, involve theMessinian to Pliocene deposits along shallow décollement surfaces located into the Tortonian clays(Ravanusa-Riesi). In its terminal portion the profile crosses the Gela Thrust Wedge; the dominantstructures are represented by NE-SW and locally EW trending folds relatable to N-dipping bothblind and outcropping thrust faults (e.g. Settefarine thrust, Lickorish et al. 1999).Conclusions. The described surface deformational setting of the Central Sicily N-S belt, crossedby the SIRIPRO crustal profile, calibrated by subsurface (seismic profiles and boreholes) data,reconstructs a tectonic edifice whose structural levels and geometries appear comparable to thoserecognized in western (Catalano et al., 2000) and eastern Sicily (Bello et al., 2000).ReferencesAvellone, G., Barchi, M. R., Catalano, R., Gasparo Morticelli, M. & Sulli, A.; 2010: Interference between shallow and deep-seatedstructures in the Sicilian fold and thrust belt, Italy. Journ. of the Geol. Society of London, 167, 109-126.Bello, M., Franchino, A. and Merlini, S.; 2000: Structural model of Eastern Sicily. Memorie Società Geologica It., 55, 61-70.Catalano, R. and D’Argenio, B.; 1978: An essay of palinspastic restoration across the western Sicily. Geologica Romana, 17, 145-159. Catalano, R., Franchino, A., Merlini, S., and Sulli, A.; 2000: Central western Sicily structural setting interpreted from seismicreflection profiles. Memorie Società Geologica It., 55, 5-16.Catalano, R., Infuso S. & Sulli, A.; 1993: The Pelagian foreland and its northward Foredeep. Plio-Pleistocene structural evolution,in Geological Development of the Sicilian-Tunisian Platform, edited by M.D. Max and P. Colantoni, UNESCO Rep. Mar. Sci.,58, 37-42,.Lickorish, W. H., M. Grasso, R. W. H. Butler, A. Argnani, and R. Maniscalco,; 1999: Structural styles and regional tectonic settingof the “Gela Nappe” and frontal part of the Maghrebian thrust belt in Sicily, Tectonics, 18, 655-668.Roure, F., Howell, D.G., Guellec, S., Casero, P.; 1990: Shallow structures induced by deep-seated thrusting. In: Petroleum andTectonics in Mobile belts. J. Letouzey (Editor) and Editions Technip, 15-30, Paris.Vitale, F.P.; 1996: I bacini plio-pleistocenici della Sicilia: un laboratorio naturale per lo studio delle interazioni tra tettonica e glacio-eustatismo. In: Colella, A. (Ed) Riunione del gruppo di sedimentologia del CNR. Guida alle escursioni. Catania, 10-14 ottobre1996, 61-113.THE SIRIPRO PROJECT: AN INTEGRATED APPROACH TO SICILY GEODYNAMICSETTING. THE GEOLOGICAL INTERPRETATION OF THE CENTRAL SICILY CRUSTALSEISMIC LINER. Catalano 1, A. Sulli 1, V. Valenti 1, C. Albanese 1, M. Gasparo Morticelli 1 (and the DGGWorking Group), F. Accaino 2 (and the OGS Working Group), R. Nicolich 3, A. Manzella 4 (andthe IGG Working Group), G. Naselli 5 (and the CRES Working Group)1 Dipartimento di Geologia e Geodesia, University of Palermo, Italy2 Istituto Nazionale di Oceanografia e Geofisica Sperimentale, Sgonico, TS, Italy3 Dipartimento di Ingegneria Civile e Ambientale, University of Trieste, Italy4 Istituto Nazionale di Geoscienze e Georisorse, CNR, Pisa, Italy5 CRES (Centro per la Ricerca Elettronica in Sicilia), Monreale, Palermo, ItalySicily is a sector of the Apenninic-Maghrebian chain whose building up is referred to the sub-duction of continental and oceanic crusts beneath a complex “european crust” (Calabrian Arc,562GNGTS 2010 SESSIONE 3.3Bonardi et al., 2001). A number of qualitative descriptions for the tectonic-sedimentary evolution ofthe collisional system point out that the subduction A system in Sicily and its offshore prolongationappears as an E- and SE-vergent chain, locally more than 15 km thick (Catalano & D’Argenio,1982; Roure et al., 1990; Lentini et al., 1994; Catalano et al., 1996; Bello et al., 2000; Catalano etal., 2000; Finetti et al., 2005). The tectonic wedge is superimposed on the Iblean-Pelagian foreland(Fig. 1). The aforementioned tectonic assemblage is the result of two Miocene-Pleistocene com-pressional tectonic events. In the growing chain, the simultaneous development of thrusts, back-thrusts, and lateral displacement and the occurrence of clockwise nappe rotations during Late563GNGTS 2010 SESSIONE 3.3Fig. 1 - Structural map of Sicily (modified from Catalano et al., 2000): 1) Iblean units; 2) shelf to pelagic carbonate(Trapanese–Saccense) units; 3) shelf to deep-water carbonate (Monte Genuardo) units; 4) deep-water carbonate(Sicanian) units; 5) shelf carbonate (Panormide) units; 6) slope to deep-water (Imerese–Panormide) units; 7)Miocene Flyschs; 8) Sicilide units; 9) Calabrian–Peloritani units; 10) Miocene–Pliocene syntectonic deposits; 11)Plio-Pleistocene syntectonic deposits; 12) Plio-Quaternary volcanic rocks; 13) Pleistocene deposits; a) Fossilizedsouthern margin of the Calabrian units; b) Maghrebian–Sicilian thrust front; c) Ionian accretionary wedge thrustfront; d) thrusts; e) faults with strike-slip component; f) hypothetic continental oceanic boundary (modified byCatalano et al., 2000; Chamot-Rooke et al., 2005). In white bold line the location of SIRIPRO profile. In the left-hand corner CMT (1977–2003) focal solutions from the area (after Pondrelli et al., 2004) are also shown.Hypocentral depth: < 50 km; Magnitudo > 4.0. Miocene-Early to Middle Pleistocene, originate syncline structures filled by Miocene-lower Pleis-tocene syntectonic deposits in the frame of a continuous forward migration. These published datawell illustrate the outcropping thrust wedge, even if they don’t give information about the crustalstructures in Sicily. The necessity to overcome the lacking knowledge of the crustal characteristicshas promoted the SIRIPRO project (scientific leader R. Catalano) recently granted by MIUR. The crustal seismic profile SIRIPRO 1 (Accaino et al., 2010) acquired together with refractionseismic, gravimetry and magnetotelluric data, has strongly improved the knowledge of the deepcrustal characters beneath the central Sicily between the Northern Sicilian coast and the Southernregion of Gela (Fig. 1). The paper deals with the geological interpretation of the seismic reflectionline crossing central Sicily. The preliminary geological profile (Fig. 2) reveals the main deepgeometries of the chain-foreland system and the crustal characters down to the mantle/crust discon-tinuity.Fig. 2 - Geological interpretation of the SIRIPRO crustal seismic line.Geological and geophysical parameters (field geology, commercial seismic lines calibrated byboreholes, seismic facies characters, wide-angle reflection/refraction seismic, velocity models) con-tributed to recognize some structural levels in the processed stacked section (from the top, Fig. 2):a) the Gela thrust wedge (Falda di Gela) with some Plio-Pleistocene thrust-top basins;b) the main fold and thrust belt;c) the foreland and its regional monocline;d) the crystalline basement;e) the crust/mantle boundary.The northern sector of the geological cross section shows the thicker part of the chain as formedby a 18 km thick platform and basinal carbonate, Numidian flysch and Sicilidi stack of northward-dipping imbricated thrusts. The wedge is well bounded at the bottom by a decoupling level at themagnetic basement/cover boundary. In the Sclafani Bagni-Valledolmo area (Fig. 2) the chain reachthe main culmination showing the Imerese carbonate thrust sheets at the surface. In the central sec-tor, the stack of folded and thrust rigid bodies (progressively thinning towards the southern Caltanis-setta depression) shows southeast-ward vergency. The deep seated carbonate and clastic south-verg-ing thrust sheets are overlaid by the Gela thrust wedge. The tectonic wedge, 5 km thick in its innerpart (Mazzarino-Riesi area, Fig. 2), is thinning progressively towards south-east. It has a commonbasal decollement enveloping the internal thrust units, to the north. In the southern sector is evident the impressively steep Iblean carbonate regional monocline,acting as foreland of the Sicilian-Maghrebian FTB. The Iblean unit is downwarped from the out-copping Iblei to the Caltanissetta area, with a north-ward strong immersion. The top of the carbon-ate body is the base of the Caltanissetta trough, now recognized at about 18 km. The buried mono-564GNGTS 2010 SESSIONE 3.3cline, 8-10 km thick at the southern end, appears variously deformed (more than previously known)but not unrooted from its basement. The top of the crystalline crust (lower and upper crust) is rec-ognized at a depth of about 20 km (8.5 s/TWT) in the northern sector; it reaches more than 20 kmin the Sclafani Bagni-Valledolmo area and is imaged at about 10 km in the Iblean region. Some reflections, calibrated by DSS refraction seismic, occurring at place are related to theMoho discontinuity. A depth of about 30-32 km is calculated in the northern sector of the profile,reaching the deepest location to the south of Villalba at a depth of about 35 km; from there, it pro-gressively shallows reaching the Iblean region at a depth of about 25 km. An alternative hypothesisabout the M occurrence in the northern part of the abovementioned transect is suggested. The loca-tion of the supposed M-discontinuity and the crystalline basement suggest the occurrence of a crys-talline crust thinner than previously believed as well a major thinning (?) beneath the Caltanissettadepression.Conclusion. Results from seismic reflection processing together with gravimetry, magnetotel-luric data (see different contributions) support the geolocial interpretation and are able to improveour knowledge about a) the location of the African/Thyrrhenian european boundary at depth; b) thepronounced crustal flexure in central Sicily; c) the architecture of the FTB foreland system; d) theinteraction of the basement and the FTB; e) the occurrence of shear zones and transversal lines.Finally, the results confirm the role of the SIRIPRO Project in defining an optimal explorationmethodology to integrate the obtained different types of data by means of a software Platform.ReferencesAccaino F., Catalano R., Di Marzo L., Giustiniani M., Tinivella U., Nicolich R., Sulli A., Valenti V. Manetti P.; 2010: A crustalseismic profile across Sicily. Tectonophysics (in press). doi:10.1016/j.tecto.2010.07.011Bello M., Franchino A. & Merlini S.; 2000: Structural model of Eastern Sicily. Mem. Soc. Geol. It., 55, 61-70.Bonardi, G., Cavazza, W., Perrone, V., Rossi, S.; 2001: Calabria–Peloritani terrane and northern Ionian Sea. In: Vai, G.B., Martini,I.P. (Eds.), Anatomy of a Mountain: the Apennines and Adjacent Mediterranean Basins, Kluwer Academic Publisher,Dordrecht, The Netherlands, pp. 287–306.Catalano, R., D’Argenio, B.; 1982: Schema geologico della Sicilia. In: Catalano, R., D’Argenio, B. (Eds.), Guida alla geologia dellaSicilia occidentale, Soc. Geol. It. Guide Geologiche Regionali, pp. 9–41.Catalano, R., Di Stefano, P., Sulli, A., Vitale, F.P.; 1996: Paleogeography and structure of the central Mediterranean: Sicily and itsoffshore area, Tectonophysiscs 260, 291–323.Catalano, R., Franchino, A., Merlini, S., Sulli, A.; 2000: A crustal section from North Algerian to the Ionian ocean (CentralMediterranean). Mem. Soc. Geol. It., 55, 71–85.Chamot-Rooke, N., Rangin, C., Le Pichon, X., DOTMED working group; 2005: DOTMED: a synthesis of deep marine data ineastern Mediterranean. Mèm. Soc. Gèeol. France, 177, 64 pp.Finetti, I.R.; 2005: CROP project: deep seismic exploration of the central Mediterranean and Italy. In: Finetti, I.R. (Ed.), Atlases inGeoscience 1, Elsevier, Amsterdam, pp. 1–794.Lentini, F., Carbone, S., Catalano, S.; 1994: Main structural domains of the central Mediterranean region and their Neogenetectonic evolution. Boll. Geofis. Teor. ed Appl., 36, 141–144.Pondrelli, S., Piromallo, C., Serpelloni, E.; 2004: Convergence vs. retreat in Southern Tyrrhenian Sea: insights from kinematics.Geophys. Res. Lett., 31, 1–4.Roure, F., Howell, D.G., Muller, C., Moretti, I.; 1990: Late Cenozoic subduction complex of Sicily. Journ. of Struct. Geology, 12,2, 259–266.THE SIRIPRO PLATFORM: DATA ANALYSIS AND INTEGRATION SOFTWARE E. Barbera 1, A. Maltese 2, G. Naselli 1, R. Catalano 31 CRES – Centro per la Ricerca Elettronica in Sicilia, Monreale (PA), Italy 2 Libero professionista, Palermo, Italy 3 Dipartimento di Geologia e Geodesia, Palermo, Italy The SIRIPRO. platform (SIsmica a RIflessione PROfonda - Deep reflection seismic exploration)is based on Java programming language. The technologic environment through which the softwarehas been developed includes the ICEfaces framework combining JSF with Ajax and a database565GNGTS 2010 SESSIONE 3.3

THE  SIRIPRO PROJECT: AN INTEGRATED APPROACH TO SICILY GEODYNAMIC SETTING. THE GEOLOGICAL INTERPRETATION OF THE CENTRAL SICILY CRUSTAL SEISMIC LINE

https://iris.unipa.it/retrieve/handle/10447/60739/37321/GNGTS_2010.pdf

THE SIRIPRO PROJECT: AN INTEGRATED APPROACH TO SICILY GEODYNAMIC SETTING. THE GEOLOGICAL INTERPRETATION OF THE CENTRAL SICILY CRUSTAL SEISMIC LINE

Abstract

Similar works

Full text

Available Versions

Archivio istituzionale della ricerca - Università di Palermo