GNGTS 2014 - Atti del 33° Convegno Nazionale

44 GNGTS 2014 S essione 1.1 10 My due to the SE-ward roll-back of the Ionian slab (Faccenna et al., 2005; Zecchin et al. , 2012). The latter has partially or completely undergone detachment (Neri et al. , 2009; Guarnieri et al. , 2006; Wortel and Spakman, 1992), and the whole subduction system experienced a tectonic rebound (uplift) when the propagating tear passes underneath the plate margin segment (Wortel and Spakman, 2000). The study area is influenced by different NW- SE major transcurrent faults and their antithetic lineaments that show alternating episodes of transtensional and transpressional activity. These structures belong to a larger fault system (i.e., Lamezia-Catanzaro Fault) which partly corresponds to the sinuous NW-SE trending transcurrent fault previously recognized by Van Dijk et al. ������� ����� ������� �������� �� � (2000). These faults, arranged in a right-hand en echelon pattern, dissected the Oligocene-Early Miocene orogenic belt made of Alpine nappes overthrusting the Apennine Chain (Tansi et al. , 2007). The Pliocene-Pleistocene basin-fill succession unconformably overlies the Messinian deposits (Fig. 2). ��� ��������� �������� �� ����������� The lowermost interval is represented by ~300 m thick limestone-marl alternations, matching the so-called Trubi Formation (Zanclean) (Fig. 2). This succession is overlain by Lower Pleistocene interval, which consists of mixed silici-bioclastic sands (Longhitano et al. , in press). ����� ��� ������ ������������ �� ������� Since the Middle Pleistocene, an intense ESE-WNW oriented regional extensional phase occurred. ������ ���������� ����� ��� �������� During Quaternary time, the Calabria block experienced a rigional intense uplift witnessed by the occurrence of spectacular flight of marine terraces, mainly developed along the western Calabria coastline (Capo Vaticano promontory, the S. Eufemia Plain, and the Coastal Range). The terraces record also Quaternary cyclic sea-level changes (Tortorici et al. , ������ 2002). Structural features of Catanzaro Trough. The Catanzaro Trough is bounded by different fault sets controlling the morpho-tectonic evolution (Fig. 3a). The preliminary structural data analysis allow us to identify a transtensional/transpressional phase that has characterized the study area during the Middle Miocene - Lower Pleistocene time. ���� ������ ������ ��� ���� �������� �� � ����� ������ �������� ������� ���� �� ������� This faults system has been replaced by a NE-SW normal faulting related with an overall WNW-ESE extension, likely due to the development of the Tyrrhenian Rift Zone. These two important phases include a number of different fault systems. The WNW-ESE trending fault zones (Fig. 3b), corresponding to the Lamezia-Catanzaro Fault ( sensu Tansi et al. , 2007; Fig. 3a), border the northern side of the Catanzaro Trough. This system show firstly transcurrent kinematics, while at a later stage this trend was overprinted by normal and oblique faulting (Fig. 3c). Galli and Bosi (2003) mapped the trace of this faults system and they tentatively attributed it one of the 1638 shocks (March 28, Mw=6.6). The southern side of Catanzaro Basin, which is limited discontinuously by the Stalettì- Squillace-Maida fault system (Fig. 3a; Ghisetti, 1981), is the epicentral area of other strong Fig. 2 – Stratigraphy of Pliocene-Pleistocene Catanzaro Trough basin. The Catanzaro Trough is infilled by a Neogene-Quaternary sedimentary succession showing several unconformities.