An alternative model for the recent evolution of the Northern–Central Apennines (Italy)

Abstract

The aim of this paper is to propose an alternative model for the Pliocene-Quaternary to present evolution of the Northern–Central Apennines by combining geometrical requirements (Riedel shear system) with existing structural and geological geometries (fault systems and their tectonic associations). We define three sectors characterized by different geological, seismological, geodetic and geothermal signatures: the North-Western Sector (NWS), the Western Central Sector (WCS) and the Eastern Central Sector (ECS). According to GPS data derived from literature the three blocks move independently. In particular, the NWS is bound between the ECS/WCS and the Alps; this constraint leads to a stress accumulation responsible for a fragmentation into further several blocks, which move either to the NE or SW. The WCS is relatively stable; the ECS moves towards NE and is characterized by the presence of numerous releasing and restraining bends, which can be related to the action of a main NNW–SSE left-lateral shear zone. Accordingly, the recent and active tectonic setting of the Northern–Central Apennines is rather related to the dynamics of the introduced blocks, caused by the push of the African plate against Europe, than to subduction processes.