Geomorphology and cultural heritage of the Ponci Valley (Finalese karstic area, Ligurian Alps)

Abstract

The Finalese is an area of great geomorphological and cultural value, with major scientific, landscape, socio-economic, and historical features that offer opportunities for investigating the relationships between issues concerning geodiversity and land use. This paper presents the geomorphological and environmental profile of the Ponci Valley, which is located in the Finale Ligure (Savona) hinterland, and its relationship with the presence of some artefacts of Roman age (13-12 B.C.). The Ponci Valley, which is composed mainly of bioclastic limestones and secondarily of underlying dolomitic limestones, is included in the more extensive Finalese karstic area including several plateaus (i.e. Manie, Camporiundu, and Bric dei Frati). The Ponci Valley is a relict valley that was once more extensive than it is today and was later captured by the adjacent Sciusa and Corealto streams. The lithological features, geomorphological evolution, and morphostructural relationships between the outcropping lithotypes, through a marked infiltration of rainfall and an underground flow, caused the formation of karstic surface and underground phenomena whose evidence is provided by the presence of cockpits, dolines, and uvalas as well as several swallow-holes, springs, and caves; the latter are mainly located along the contact between the dolomite and bioclastic limestones. Along the Ponci Valley, five Roman bridges can be observed, three of them are still well-preserved, as well as embankment protection structures and some remains of road parts: these represent one of the best evidences of the Via Iulia Augusta, a remarkable example of the ancient Roman roads system that can still be observed in western Liguria. Favourable climatic conditions throughout the year, together with the valuable landscape and environmental aspects, led to a growing interest in terms of tourism and sport and the consequent creation of hiking and mountain bike trails, in addition to the well-established caving and climbing