Geogr. Fis. Dinam. Quat. DOI 10.4461/GFDQ.2011.34.7 34 (2011), 65-74, 6 figg. PIERLUIGI BRANDOLINI (*), FRANCESCO FACCINI (*), ANDREA ROBBIANO (**) &FRANCESCA BULGARELLI (***) GEOMORPHOLOGY AND CULTURAL HERITAGE OF THE PONCI VALLEY (FINALESE KARSTIC AREA, LIGURIAN ALPS) ABSTRACT: BRANDOLINI P., FACCINI F., ROBBIANO A. & BULGARELLI This site has geomorphological, environmental, and archaeological F., Geomorphology and cultural heritage of the Ponci Valley (Finalese value and in all it can be acknowledged as a geosite of Mediterranean im- karstic area, Ligurian Alps). (IT ISSN 0391-9838, 2011). portance. Thereby it represents an asset of high cultural and landscape value for which protection and enhancement measures must be undertak- The Finalese is an area of great geomorphological and cultural value, en to preserve it and, at the same time, to promote sustainable tourism. with major scientific, landscape, socio-economic, and historical features that offer opportunities for investigating the relationships between issues KEY WORDS: Karstic phenomena, Stone georesources, Roman bridges concerning geodiversity and land use. remains, Geotourism, Ligurian Alps. This paper presents the geomorphological and environmental profile of the Ponci Valley, which is located in the Finale Ligure (Savona) hinter- land, and its relationship with the presence of some artefacts of Roman INTRODUCTION age (13-12 B.C.). The Ponci Valley, which is composed mainly of bioclastic limestones General interest in aspects of earth sciences associating and secondarily of underlying dolomitic limestones, is included in the the natural landscape with cultural heritage is growing: 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 concept of Cultural Geomorphology has been introduced was once more extensive than it is today and was later captured by the in this scenario with scientific explanations and innovative adjacent Sciusa and Corealto streams. research methodologies. According to current definitions The lithological features, geomorphological evolution, and morpho- (Panizza, 2001; Panizza & Piacente, 2003; Reynard, 2008) structural relationships between the outcropping lithotypes, through a this subject aims to investigate the geomorphological ele- marked infiltration of rainfall and an underground flow, caused the for- mation of karstic surface and underground phenomena whose evidence is ments of a region by considering it a natural landscape provided by the presence of cockpits, dolines, and uvalas as well as sever- asset and for its relationship with cultural assets of archi- al swallow-holes, springs, and caves; the latter are mainly located along tectural, historical and archaeological types. the contact between the dolomite and bioclastic limestones. The relationships between geomorphology and the cul- Along the Ponci Valley, five Roman bridges can be observed, three of them are still well-preserved, as well as embankment protection structures tural elements can be considered schematically according and some remains of road parts: these represent one of the best evidences to two reciprocally integrated viewpoints: i) geomorpholo- of the Via Iulia Augusta, a remarkable example of the ancient Roman gy meant as a component of a territory’s cultural heritage; roads system that can still be observed in western Liguria. Favourable cli- ii) the relationships between some cultural components of matic conditions throughout the year, together with the valuable land- a territory and the geomorphological context in which scape and environmental aspects, led to a growing interest in terms of tourism and sport and the consequent creation of hiking and mountain they are inserted (Panizza & Piacente, 2008; 2009; Rey- bike trails, in addition to the well-established caving and climbing. nard, 2009a; 2009b). This paper presents the geomorphological and cultural heritage of the Ponci Valley, which is located in western Liguria, in the Finalese area: this region plays an interna- (*) Dipartimento per lo Studio del Territorio e delle sue Risorse, Uni- tional geomorphological role with major scientific, land- versità degli Studi di Genova - [email protected] scape, socio-economic, and historic-environmental features (**) Consultant Geologist (Ph.D.). providing opportunities for an in-depth study of the scien- (***) Soprintendenza per i Beni Archeologici della Liguria. tific issues mainly concerning geodiversity and geoarchaeo- This text is derived from a lecture given at the 3rd Meeting of the Italian Association of Physical Geography and Geomorphology, held in Modena on logy (Panizza & Piacente, 2000; Gray, 2004; Panizza, 2005; September 13, 2009 in honour of Prof. Mario Panizza. Dowling & Newsome, 2006; Brandolini & alii, 2007). 65 The Finalese is one of the most charming areas of the GEOGRAPHICAL SETTING Mediterranean sector. Its geomorphological features are well-known, being characterized by a series of plateau The Ponci Valley is located in the province of Savona and ridge zones with a number of peaks of limited eleva- and includes the municipalities of Finale Ligure, Vezzi tion, but mainly representing rocky towers isolated by Portio, and Noli (fig. 1). This valley mainly runs N-S for deep canyons: Rocca di Perti (360 m), Rocca Cornei (357 about 3 km and is separated westward from the valley of m), Rocca degli Uccelli (332 m), and Bric dei Crovi (382 the Sciusa Stream by the ridge of the relieves Rocca del m). This area includes several karstic springs and is Corno (302 m), Rocca degli Uccelli (369 m), and Bric Carè crossed by a few water courses, some of which flow un- (482 m). It is bounded to the northeast by the Manie derground; terraced landforms, flood plains, and karstic plateau, the valleys of the Corealto and Noli streams, the depressions, swallow-holes, and caves are found here. Bric dei Monti (443 m), and a series of minor relieves ex- The high rocky coast between Capo Noli and Capo della tending as far as the Bric Briga (320 m). Caprazoppa exhibits small bays with pocket beaches. The Ponci Valley represents the northeast sector (5.9 The central part of this area features the Pietra di Finale km2) of the Sciusa Stream valley (26 km2), and its mouth is Auct., composed of bioclastic vacuolar limestones with to the east of the Finale Ligure town; the Ponci Stream has corals, typically white-rose coloured; the great layers of two main left-bank tributaries, the Landrazza and Armetta Dolomites of S. Pietro dei Monti outcrop around it, in- streams. tercalated by dolomitic limestones with small gastropods Since more than three decades ago, plans have been and quartzites. Except for small cultivated areas and iso- made to set up the Finalese Regional Park in this area, lated cores at the area margins on the Manie plateau and which belongs to the European ecological network Natu- valley floor connecting the «Rocche» (rock towers), the ra 2000, which was established to ensure the habitat pro- Mediterranean landscape has a very natural character de- tection of environmentally valuable areas including the spite the presence of abundant evidences of ancient hu- Sites of European Interest. The sector that has been stud- man settlements dating back to all the historic periods ied, among more than a hundred sites of the Ligurian re- until the Palaeolithic. gion, belongs to the Finalese-Capo Noli Site of European The Ponci Valley, in particular, is bounded by the Interest. Verzi mountains and the rocky spur of Rocca del Corno: Furthermore the Manie plateau is one of the 39 karst this is a relict valley, with the stream erosion being scarcely areas in Liguria (Manie/Capo Noli area), spreading over relevant nowadays. The waters that have incised it are almost 14 km2 and containing more than 2.5 km of the to- presently flowing underground owing to karstic phenome- tal length of surveyed caves. na and their blowout occurs at the Acquaviva spring in the With an annual mean rainfall of about 900 mm and an nearby Sciusa Valley. annual mean temperature of about 15 °C, this area shows The valley preserves the most relevant and monumen- the typical Mediterranean climate with dry summer and tal evidence of the Roman communications routes in Lig- rainy remaining periods, particularly in the autumn. uria: the ancient Via Iulia Augusta from Vado Ligure (Va- Climatic features can be described by using data col- da Sabatia) turned towards the hinterland to avoid haz- lected by the meteorological stations at Calice Ligure (at ardous active coastal cliffs, running behind Capo Noli, and 70 m a.s.l.), Manie (297 m), Rialto (376 m), Feglino (160 entered this valley from the north across the Magnone m), and Colle del Melogno (1028 m), which provided data Pass (Bulgarelli, 1996; Bulgarelli & Massabò, 2001). series in the period between 1950 and 1995. Vestiges of five huge bridges crossing the desiccated Precipitations rise linearly with altitude and range be- water course can still be observed today. These were tween about 900 mm/y along the coast (Pietra Ligure and built using the stone probably extracted from the quar- Capo Noli) and more than 1200 mm/y at Colle del Melog- ries that can be visited along the trail; after the Ponte del- no, which represents the saddle along the Tyrrhenian-Po l’Acqua, at Cà du Puncin, it is possible to climb up to the River ridge. Annual mean temperatures vary similarly, rang- Ciappa del Sale where, from the Mediterranean scrub, ing from about 16 °C along the coast to below 10 °C at there is a panoramic view of the coast and adjacent Mar- Colle del Melogno (fig. 2). itime Alps. If Calice Ligure is considered a typical station, precipi- The Ponci Valley is a tourist attraction for free-climbers, tations exhibit an absolute maximum in October (120 mm) who find several equipped rock walls, and speleologists; and a relative maximum in March (108 mm), whereas the however its trails are also frequented throughout the year minimum is recorded in July with values less than 30 mm.