GNGTS 2013 - Atti del 32° Convegno Nazionale

the continental shelf, between the coastline and the 140-150 m (200 m in some cases) isobaths. The domain C includes the upper continental slope, located between the platform margin and the 650 m isobaths. The domain D is the lower continental slope, deeper than 650 m in depth. These physiographic domains include several morphological elements, each representing tectonic or sedimentary processes or volcanic events. On the continental shelf, as well as at greater depths, abrasional and/or depositional terraces, relict volcanic edifices, canyons and gullies can be recognized. The increase of dip angles in the lower portion of the A physiographic unit is due to basal normal faulting of the Epomeo resurgent block. The submarine canyons occur on the A and C physiographic units, acting as morphological and depositional links between physiographic ranges. The slope instability on the flanks of the volcanoes is a well-known geological process, mainly controlled by mechanisms of volcanic emplacement, hydrothermal vents, fast accretion of volcanic edifices and different erosional rates, as controlled by different lithologies of slope deposits (Thouret, 1999). Classical morpho-tectonic studies include the statistical analysis of the geometry of drainage patterns and stream direction controlled by tectonics and the identification of morpho-tectonic features. The main morphological characters of volcanic complexes of Latium in Italy are strongly controlled by four prevailing tectonic directions for Vulsini and three for Sabatini and Colli Albani volcanoes (Buonasorte et al. , 1993; Trigila, 1995). The structural setting of sedimentary units and the recent tectonic activity strongly controlled the location and the shape of the calderas. The influence of structural framework on the shape and the formation of large caldera complexes has been inferred from remote sensing and ground-based structural analyses. Fig. 2 – Composite map, respectively showing the DEM of the Naples Bay and Ischia island (A), the shaded relief map of the Naples Bay and Ischia island (B), the slope map of the Naples Bay and Ischia island (C) and the location map of the study area (D). 229 GNGTS 2013 S essione 1.3