PLEISTOCENE STRIKE-SLIP TECTONICS IN THE LUCANIAN APENNINE (SOUTHERN ITALY)

Structural studies carried out in the Lucanian Apennines (Southern Ita ly) show that strike-slip faulting was the principal mode of deformati on of this area during middle-upper Pleistocene time. W-NW to E-SE tre nding left strike-slip fault systems dissect the entire Apennine mount ain belt and affect the preexisting thrust geometry. Strike-slip fault s, activated by a roughly E-W shortening, are characterized by differe nt geometries representing the surface response to lateral motion occu rring along deep-seated structures. The occurrence of different struct ural patterns which characterize different segments of strike-slip sys tem is related to (1) the depth of a major decoupling surface which se parates the upper tectonic multilayered horizon (Apennines thrust belt system) from the lower rigid horizon (Apulian belt) in which strike-s lip structures have originated and (2) the geometric relationships bet ween the strike-slip faults and the thrust belt pattern which characte rize the upper horizon. The different segments of the strike-slip syst em are interpreted as internal deformation developed within a crustal shear zone. This zone, which corresponds to the boundary between the A pulian block and the Apennine chain, is characterized by sinistral mov ement as a response to the northwesterly convergent motion of the Afri can plate with respect to Europe.