Geomorphological Analysis of Karst Landforms at the Masso della Vecchia geosite (Salento Peninsula, Italy)

Abstract

The presence of a pedestal rock, locally named Masso della Vecchia, marks a site of relevant geological interest (geosite) in the surrounding of Giuggianello village (Salento Peninsula, Apulia region, Italy). This unusual natural landform and similar others occurring in the same area gave birth to myths and legends. A detailed geomorphological analysis of Masso della Vecchia area has been carried out. The site is placed at about 100 m of altitude on a lower Pleistocene abrasion surface which constitutes the top of the Serra di Poggiardo morphostructural ridge. Locally, the Miocene Pietra Leccese Formation crops out. It is constituted by poorly consolidated, bioturbated, yellowish biomicrites at lower levels rapidly grading upward in massive grainstones rich in glauconite minerals. The entire sequence gently dips northeastward. The geomorphological analysis revealed that the Masso della Vecchia and similar landforms occurring in the area are karstic features produced under a soil cover. Pinnacles, channels, notches, subsoil scallops, half-bells and other typical features have been recognized. The peculiar assemblage of subsoil karst features can be explained taking into account the geological structure, subsoil karst processes and the geomorphological evolution of this area during the Late Pleistocene.
Key words: subsoil karren, geoheritage, Salento, Italy.