A multidisciplinary study along the north-eastern and western borders of the Matese and Sannio Mts., respectively, has been devoted to decipher the Quaternary to Recent deformation of this sector of the Apenninic chain (MASCHIO, 2003). The mesostructural and geomorphologic analysis, supported by data from low-magnitude seismic sequences (MILANO et alii, 1999; VILARDO et alii, 2003) has allowed to: (1) map the distribution of Middle Pleistocene-Holocene normal fault systems; (2) assess geometry, kinematics and timing of deformation of the fault systems; (3) estimate averaged slip rates for the main tectonic structures, based on offsets of geomorphologic markers; (4) compare the fault kinematic and seismotectonic frame, (5) suggest a geometric model of the active deformation for this sector of the Apenninic chain, that helps clarify the relationships between exposed faults, historical and instrumental seismicity, and seismicity of boundary segments. In detail, the investigated fault systems present an articulated geometry and a complex kinematics in respect to the NE-SW direction of extension typically observed in the Southern Apennines. The tectonic control of inherited structures on active faulting plays a key role on the geometric arrangement of the arrays, formed by N-S and E-W segments which link each other to NW-SE striking, young deformation zones. Quaternary to Recent deformation appears to be accommodated by slip partitioning both on sub parallel structures and on variously striking but kinematically coordinated faults, active within a non-plane strain environment. The fact that slip is heterogeneously distributed in space is consistent with the focal mechanisms of the 1997-1998 low magnitude seismic sequences (MILANO et alii, 2001; VILARDO et alii, 2003). Inspection of the spatial distribution and differential elevation of remnants of sub-horizontal erosional and/or depositional surfaces, referred to various morphological events, has documented a migration of faulting during the Middle/Upper Pleistocene-Holocene and permitted to estimate vertical slip-rates for most of the segments of the fault systems. The main results are listed as follows: - a NE-dipping fault array in the Matese Mts. is active after 2 Ma (from Sassinoro to Guardiaregia to Roccamandolfi villages) and has a cumulate slip rate up to 0.31 mm/a; - most of the main fault systems of the northern border of the Matese Mts. and of the main antithetic ones of the southern border of the Montagnola di Frosolone are active after 0.7 Ma and have integrated slip rates up to 1.37 mm/a and to 0.33 mm/a, respectively; - range-bounding faults of the Matese and Sannio Mts., together with the N-S oriented Le Piane fault (DI BUCCI et alii, 2002), are active mostly after 0,12 Ma with cumulated slip rate of 1,0 mm/a. We suggest these fault systems are representative of an articulated, NE-dipping seismogenic structure, which is internally constituted of both E-W oriented inherited faults linking major NW-SE younger faults, and has NNW-SSE striking faults at its terminations (i.e. Le Piane and Castelpizzuto faults, towards north and Sassinoro, Collalto and Pescosardo faults, towards south). The cumulate slip rate estimates highlights that most of the strain accumulation is concentrated in the middle of the seismogenic structure, from Sepino-Guardiaregia to Castelpizzuto villages. Slip on the structure boundary can occur both during large earthquakes and low-energy seismic sequences.
Middle Pleistocene to Holocene tectonics of the Sannio-Matese Mts. boundary: Geometry, kinematics and fault activity / Maschio, L.; Ferranti, L.. - In: RENDICONTI DELLA SOCIETÀ GEOLOGICA ITALIANA. - ISSN 0392-3037. - 2:(2006), pp. 150-151.