La tettonica quaternaria della Piana di Isernia nell'evoluzione strutturale del settore molisano

Abstract

New structural and geomorphological data on the Isernia plain (Molise, Italy), which are new constraints to the geodynamic reconstruction of the Upper Molise-Matese sector of the Apennines Chain are presented. The main result of the sudy is the definition of the deformational style of the plain Quaternary fill deposits. Two events governed the Quaternary evolution of the Isernia plain area, i.e.: 1) a strike-slip tectonic activity along a NE-SW maximum compression direction during Lower Pleistocene, which is responsible of the initial formation of the Isernia plain; and 2) an extensional tectonic activity along a NE-SW maximum extension direction starting in Middle Pleistocene times. This sequence of events explain well the shape of the Volturno River middle valley and that of the Boiano Basin, the complex shape of the Isernia plain, the reactivation of pre-existing strike-slip faults in Lower Pleistocene and present tectonic activity.