Evoluzione geologica e tettonica plio-quaternaria dell'alta valle del F. Salto (Italia centrale): primi risultati derivanti dall'analisi delle superfici relitte e dei depositi continentali

Abstract

The studied area is located in the upper part of the River Salto basin in the portion delimited by Monti della Duchessa, the Malito Valley and the village of Coiiorso. Within this territory, there is the Corvaro basin, a small sub-triangular depression the northeastern margin of which being characterized by the presence of an important NW-SE trending normal fault coinciding with the southwestern slope of Monti della Duchessa group. The results obtained from a study of remnant landsurfaces and continental deposits allowed to hypothesise a possible geological and tectonic evolution of the area. In particular, two sectors have been distinguished, each of them characterised by the presence of a given number of orders of remnant landsurfaces with essentially homogeneous geometric relations between one another. One sector includes: the Monti della Duchessa group, the Amara Valley, the Mt S.Rocco-Mt Rotondo ridge and the whole Malito Valley. The other one includes the hills between Rosciolo and Marano to the SE and Borgorose, Coiiorso and Pescorocchiano to the NW. The boundary between the two sectors is the aforementioned tectonic structure at the foot of Monti della Duchessa and its NW continuation along the Mt Costa-Mt Castiglione alignment. It can thus be hypothesised that differences in landsurface successions may be linked to differential tectonic vertical movements in the two sectors. Recent geological surveys of Plio-Quaternary formations by the authors indicate a new evolutionary model suggesting that the most important displacements of the above mentioned structure occurred in the Middle Pleistocene.