Stratigraphy and tectonics offshore of Puglia (Italy, Southern Adriatic sea)

The structural and stratigraphic framework of Puglia offshore between the Gargano promontory and the town of Brindisi(southern Adriatic Sea) has been analysed based on 1700 km of multichannel seismic profiles and 10 exploratory wells.The area includes two different geodynamic settings: (1) part of the undeformed Apenninic foreland ("Apulian carbonatePlatform"), consisting mainly of shallow water Mesozoic carbonates, and (2) part of the southern Adriatic Basin, whichrepresents the foredeep of the Hellenic thrust system. A Mesozoic slope, buried by Tertiary clastics and corresponding to theedge of the Apulian carbonate platform, is observed on seismic data. The present physiography of the escarpment is the resultof an erosional retreat mainly developed during the Tertiary and related to the subsidence of the South Adriatic Basin; at thesame time carbonate facies belts, as evidenced by well data, seem to suggest that in some sectors of the margin the originalMesozoic physiography has been preserved and fossilized, Three seismostratigraphic units, separated by regional or localunconformities, have been distinguished in the Neogene clastic sequence of the South Adriatic Basin.Significant deformations in the sedimentary cover are represented by various antiforms. One of these antiforms, named the"Gondola" ridge, is an elongated, positive structure deforming the pre-Tertiary basement. The western sector of the Gondolaridge belongs to a major E-W strike-slip lineament extending on land in the Gargano promontory. In the eastern part of thearea in question some tectonic features, resembling "pop up"-like and thrust antiforms, are arranged along an arcuate patternnamed here "Grifone" trend. The Grifone trend structures indicate a post-Pliocene tectonism probably related to the latestages of the Dinaric-Hellenic orogenesis. The recent westward migration of the Hellenic fold and thrust belt can be demonstratedby the South Adriatic foredeep shift during the last 5-6 million years.