GNGTS 2014 - Atti del 33° Convegno Nazionale

88 GNGTS 2014 S essione 1.1 shells of Strombus Bubonius , have been found by Bonfiglio and Violanti (1983) at elevation of 85 m a.s.l. Toward the west, between Madonna dei Miracoli and Faro Superiore, terraces V and VI order with inner edges located at elevations from 140 m to 170 m a.s.l., respectively, discontinuously crop out. As regards the chronological attribution, the occurrence of Strombus Bubonius has allowed to correlate the terraces IV to the MIS 5.5 (125 ka) and to constrain the age of the terraces I, II, III, V and VI order, that can be correlated to the remaining marine high- stands occurred between the MIS 3.3 (60 ka) and the MIS 7.5 (240 ka). So, the I, II and III order terraces can be attributed to the MIS 3.3 (60 ka), to the MIS 5.1 (80 ka) and to the MIS 5.3 (100 ka), respectively, while the V and VI order terraces can be attributed to the MIS 7.1 (200 ka) and to the MIS 7.3-7.5 (215-240 ka). Uplift rates and fault activity. In the Calabrian side, the Cappuccini fault was characterized by sin-sedimentary activity during the upper Pliocene-lower Pleistocene (Monaco et al ., 1996), then it was sutured by the deposits of the VI terrace order, attributed to the 167 ka marine stand. The Pezzo-Scilla fault is considered still active in its north-eastern sector (Jacques et al ., 2001; Ferranti et al ., 2007; 2008), whereas on its western end it is sutured by the I order terrace, dated at 60 ka. The uplift rates change in time and space and represent the sum of the regional signal, homogeneous in the last 700 ka (Westaway, 1993) and the co-seismic vertical deformation induced by the fault activity around the main Quaternary faults (King et al. , 1988). These two components are added on footwall of the seismogenic faults, while on the hangingwall the co- seismic vertical movements are subtracted to the regional rate. The estimated uplift rates range from 0.8 mm/yr for the period 330-60 ka, on the downthrown block of the Pezzo-Scilla fault, to 2.0 mm/yr (twice the regional component of 1.0 mm/yr estimated byWestaway, 1993) for the period 330-200 ka, on the Campo Piale high. The constant elevation of the I order terrace suggests an uniform uplift rate of 1.4 mm/yr along the entire coastal area, and, consequently, a deactivation of the western sector of the Pezzo-Scilla fault in the last 60 ka, even though the offshore activity of segments belonging to the same system is not excluded (see Selli et al ., 1979; Ferranti et al ., 2008). However, it is considered still active in the north-east segments, since it is considered responsible of one of the sequence earthquakes on February-March 1783 (Monaco and Tortorici, 2000; Jacques et al. , 2001) and of the co- seismic uplifts of the coastal area between Scilla and Palmi area, situated on the footwall of the structure, in the last 5000 years (Ferranti et al ., 2007, 2008). As regards the Sicilian side, the terraced sequence is cut on structural high bounded by the Mortelle Fault to the north and by the Ganzirri Fault to the south. The tilting of ~10-15° toward south coud be related to the greater activity of the Mortelle Fault. The elevation of the inner edges of VI- II order terraces suggests an uplift rate slightly smaller than the regional component (Westaway, 1993) between 240 and 80 ka. This could be due to the late Quaternary activity of the Faro Superiore Fault (Fig. 1), being the terraced block located on its hanging wall. The uplift-rate has increased to 1.3 mm/yr in the last 60 ka, as indicated by the I order terrace elevation. Uplift rates of 1.3-1.4 mm/yr for the last 60 ka have been estimated on both side of the Straits by long-term (see above) and short-term Holocene markers (see Antonioli et al ., 2006; Scicchitano et al. , 2011). They are probably related to the current activity of offshore structures (Selli et al ., 1979; Guarnieri et al ., 2004; Ferranti et al ., 2008; Aloisi et al ., 2012). Acknowledgements. This work was partially funded by PRIN 2010–11 Project “Active and recent geodynamics of Calabrian Arc and accretionary complex in the IonianSea” (responsible C. Monaco). References Aloisi M., Bruno V., Cannavò F., Ferranti L., Mattia M., Monaco C. and Palano M.; 2012: Are the source models of the M 7.1 1908 Messina Straits earthquake reliable? Insights from a novel inversion and a sensitivity analysis of Loperfido (1909) levelling data . ����������� ������� �������������� ��� ������������������� Geophysical Journal International, DOI 10.1093/gji/ggs062.