The mesoscopic response to positive tectonic inversion processes: an example from the Umbria-Marche Apennines, Italy

The Gola delle Fucicchie, near Pontericcioli, in the Umbria- Marche Apennines, provides an excellent opportunity to study the interaction between extensional and contractional structures result- ing from positive tectonic inversion. This outcrop is a classic site for investigations of the nature of folding in carbonates, and of the rela- tionships between mesoscopic and macroscopic folds. A metric-scale array of normal faults of Paleogene age is deformed by a late Mio- cene fold train. Observations on minor structures and their over- printing relationships within the fold train allow the recognition of several structural stages, including pre-folding layer-parallel exten- sion, layer-parallel shortening and folding. The inferred deformation history is similar to that reconstructed for larger structures in the Umbria-Marche belt, and both can be explained in terms of plate- tectonic models for the Alps-Apennine system. These results show the importance of integrating observations at different scales in the study of tectonic inversion processes.