Geological map of the Mt. Vettoretto–Capodacqua area (Central Apennines, Italy) and cross-cutting relationships between Sibillini Mts. Thrust and Mt. Vettore normal faults system

Abstract

Geological map of the Mt. Vettoretto–Capodacqua area (Central Apennines, Italy) and cross-cutting relationships between Sibillini Mts. Thrust and Mt. Vettore normal faults system Abstract We present the results of a geological mapping project performed in the southern portion of the Sibillini Mts., aimed at defining the structural relationships between the Sibillini Mts. Thrust front and the Mt. Vettore normal fault system, reactivated during the 2016-2017 central Italy seismic sequence. The Sibillini Mts. Thrust is characterised by a hanging wall where the Meso-Cenozoic Umbria-Marche succession crops out, while the footwall is represented by the Messinian Laga foredeep unit. The Mt. Vettore extensional fault system is formed by two main normal faults, the “Castelluccio Plain” and “Mt. Vettoretto” faults. Being the cross-cutting relationships between the structural elements hidden by a thick debris cover, they have been reconstructed analyzing the geometries of the hanging wall anticline of the Sibillini Mts. Thrust and other field constrains. This allowed us to conclude that the Sibillini Mts. Thrust was displaced by the Castelluccio Plain normal fault with a max throw of ~ 250 m. Both the Castelluccio Plain normal fault and the Sibillini Mts. Thrust are subsequently cut by the Mt. Vettoretto fault, which is inferred to reuse in part the inverted Sibillini Mts. Thrust plane.