HIGH-RESOLUTION SEISMIC SURVEY IN THE WESTERN CALABRIA AND EASTERN SICILY OFFSHORE: IMPLICATIONS WITH VERTICAL TECTONICS

High-resolution seismic data acquired along the continental shelf/upper slope offshore of Capo Vaticano (western Calabria), Milazzo Promontory and Mt. Etna (eastern Sicily) allow to provide new insights on vertical mobility related to active tectonics. A number of depositional sequences bounded by unconformities or correlative para-conformities were recognized on Sparker profiles in the first 200-300 m below the sea-floor. The most recent sequence overlays a widespread erosional surface that ostensibly formed during the sea level stillstand of the Last Glacial Maximum (LGM), whereas a stack of depositional sequences, which are interpreted as representing the falling and low-stand systems tracts, records older Middle-Late Pleistocene eustatic cycles. In high-resolution seismic profiles the most recent sequence is expressed by well-stratified, laterally continuous, high-amplitude reflectors with typical thickness of 30-40 m. This stacking pattern is typically observed in the central Mediterranean shelf and upper slope affected by vertical tectonic movements (Fraccascia et al., 2013). The magnitude and rate of Late Pleistocene Holocene vertical tectonic movements have been measured on the basis of the present day depth variations of the edges of submerged depositional terraces (and associated abrasion platforms) that formed below the storm-wave base, during the sea level stillstand of the Last Glacial Maximum (LGM). These depositional features, represented by submerged prograding wedges and an associated terrace-shaped upper boundary, identified in the high-resolution seismic reflection, are referred to in this study as “Lowstand Infralittoral Prograding Wedges (LIPWs)” (Pepe et al., 2014). Our new data and methods provide evidence that LIPWs can be used as geomorphological indicators of vertical movements in offshore settings with well controlled uncertainty. Depending on geodynamic and structural setting, deformation can be related to regional and/or local contribution.