Sea-floor sedimentological and morphological mapping of Tremiti Islands (Adriatic Sea)

The Tremiti Islands are an isolated archipelago in the Adriatic Sea approximately 40 km east of Termoli and 20 km north of the Gargano Promontory. San Nicola, San Domino, Caprara and Cretaccio are the main islands belonging to this archipelago. In the frame of the C.N.R. Project Prisma 2 – Sottoprogetto 3, about 200 bottom sediments were collected during three oceanographic cruises (1997, 1998, 2001), between 5 and 100 m depth. The aim of this work is to provide some textural distributions of bottom sediments related to the sea-floor morphology. Sedimentological and textural maps of recent sediments are presented, adopting two different textural classifications: a ternary one (end-members: gravel, sand and mud) according to Folk (1965) and a binary one (end-members: sand and pelite) suggested by Nota (1958). The sediment textural patterns are strongly affected by wave motion and bottom currents in the northern side of the islands; conversely sedimentation processes are influenced by lower bottom energy at the sea-floor in the southern sector of the archipelago. In conclusion, it appears that the sea-floor sedimentation of this area, is better described by Folk’s classification because of gravel amount. The occurrence of this fraction outlines the numerous break slopes and steps characterising the complex morphology of the sea-floor due to Holocene sea-level rise and/or the tectonic uplift of the submerged body of the archipelago.