Neotectonic implications of a lineament-coplanarity analysis in southern Calabria, Italy

Abstract

Abstract A synthesis of the geodynamical interpretations proposed in the literature shows that the respective role of different possible driving mechanisms in the Neogene and Quaternary tectonic evolution of southern Calabria is still under discussion. Owing to different methodological approaches and scales of observation, the same holds true for marine terrace levels recognized in the area of Reggio Calabria. Their number, elevation, spatial correlation and age, as well as their tectonic significance, are still debated, resulting in some uncertainty about the timing and rate of the regional uplift and its local variations. To complete the mapping of fault zones potentially dislocating the marine terraces, a three-dimensional (3D) morphometrical analysis of lineaments has been carried out. From a data-set composed of linear structures recognized on an illuminated digital elevation model (17 km × 18 km in size) centred on Reggio Calabria, the method aims at identifying lineaments pertaining to a single plane. Assuming that faults may be assimilated to planes at the local scale, the coplanar lineaments allow the 3D attitude and location of fault or fracture planes to be determined. The planes retained as tectonically significant (on the dip value and number of coplanar lineaments) have been successfully compared with the existing faults as well as with geomorphological data (long river profiles) of southern Calabria. Beyond mapping the main faults of the study area, the coplanarity analysis highlights the existence of conjugate faults within the NW-SE fault zone of Terreti-Monte Embrisi. It also locates some E-W striking faults which were previously known only at the outcrop scale.