The structural and kinematic history of a complex fold-and-thrust belt: an example from western Basilicata, southern Italy

The repeated opening and closure of oceans along the same trends, and the consequent fragmentation and reassemblage of continents, has long led to the concept of a cyclical recurrence in orogenic events, and a certain cyclical pattern is commonly recognised in the evolution of fold-and-thrust belts. Orogenic cycles generally involve two extensional stages, namely pre- orogenic and post-orogenic extension, separated by an intervening stage of contraction. However, when seen in greater detail, the evolution of fold-and-thrust belts is generally more complex. In fact, numerous studies from both active and fossil orogenic belts outline that the inferred histories are punctuated by the superposition of kinematically different structures, thus making each example a specific, distinct case. Moreover, the complete history of a fold-and-thrust belt is usually inferred from numerous observations carried out at different localities. The area that extends between the Melandro and Agri valleys has recorded a complex history of superposed deformations, that correlates well with the evolution of the southern Apennines of western Lucania. Most structures described in this investigation can easily be related to well- constrained episodes that have long been reported in a wide regional literature, whereas others don’t appear to fit current tectonic models. The origin and development of the latter structures thus require an explanation in terms of their plausible geodynamic significance.