VOLCANISM OFFSHORE OF VESUVIUS VOLCANO IN NAPLES BAY

High-resolution seismic reflection data are used to identify structura l features in Naples Bay near Vesuvius Volcano. Several buried seismic units with reflection-free interiors are probably volcanic deposits e rupted during and since the formation of the breached crater of Monte Somma Volcano, which preceded the growth of Vesuvius, The presumed und ersea volcanic deposits are limited in extent; thus, stratigraphic rel ationships cannot be established among them. Other features revealed b y our data include (a) the warping of lowstand marine deposits by unde rsea cryptodomes located approximately 10 km from the summit of Vesuvi us, (b) a succession of normal step faults that record seaward collaps e of the volcano, and (c) a small undersea slump in the uppermost mari ne deposits of Naples Bay, which may be the result of nuee ardentes th at entered the sea during a major eruption of Vesuvius in 1631. Detect ion of these undersea features illustrates some capabilities of making detailed seismic reflection profiles across undersea volcanoes.