Regional reflection seismic exploration of the Strait of Sicily

Abstract

A regional seismic reflection survey was performed by OGS in 1970 on the Sicily Channel, using multichannel digital techniques and flexotir source. Reflections up to about 5 s (two-way time) have been obtained. The analysis of the velocity functions and the correlations with the available geological data allowed to indicate the geological attribution of the most continuous and characteristic reflectors from Miocene to Trias, and to recognize a thick sedimentary platform sequence which dominates all the Strait without solution of continuity from Northern Africa to Southern Sicily. The distension phase followed to tertiary orogenesis (upper Miocene to Pliocene) has produced an extended fault system mainly constituted by direct, subvertical faults with prevalent NW-SE orientation on the Strait area, with small to consistent displacements (up to 1 s _ 1000 m). Some of these faults remained active until present. As a consequence, a structure and morphology with horsts and grabens is rather predominant, accompanied with gentle ondulation and tabular zones. These last ones are developed N to Tripolitania area. The Tertiary sequence (Miocene to Eocene) is mostly composed by sediments having interval velocities from 2000 to 3000 mis, interbedded by some higher velocity horizoni (3500 to 4000 m/s).