Neogene tectono-sedimentary interaction between the Calabrian Accretionary Wedge and the Apulian Foreland in the northern Ionian Sea

The structural setting of the northern Ionian Sea is the result of the collision between the CalabrianAccretionary Wedge (CAW) and the adjacent foreland, i.e. the Apulian Carbonate Platform. The CAWrepresents a sector of the Apennine accretionary system extending in the Ionian Sea, bounded to thewest by the Malta Escarpment and to the east by the Apulia Escarpment. This work presents the resultsof the interpretation of new seismic and bathymetric data acquired on the north-eastern edge of theCAW, in the N-Ionian Sea. The data interpretation has identified four main structural domains from NE toSW: 1. The Apulian carbonate Platform consisting of foreland shelf and transitional Mesozoic-Cenozoiccarbonate deposits; 2. A narrow foredeep basin, filled by a very thick Plio-Quaternary succession; 3. Adeformed domain, at the front of the CAW, incorporating thrusted foredeep sequences and a carbonateblock of the Apulian Platform (Transpressed Apulian Block, TAB); 4. A highly deformed pre-Plioceneaccretionary wedge. A mid-Pliocene unconformity interpreted on both the CAW and Apulian Forelandsuggests that a regional tectonic event occurred at that time, related to the evolution of Calabrian Arc,moving on the subducting oceanic Ionian slab before the collision. This event would correspond to amain tilting and faulting phase of the Apulian Foreland during the diachronous oblique collision with theCAW. The collision and the presence of a remnant of Ionian foreland at the southern front of theaccretionary prism, caused a gradual transition to a transpressional tectonics which produced the upliftof the TAB. The TAB would be the south-east continuation of the Amendolara ridge transpressedstructure, which forms the offshore extension of the Pollino range. This transpressed shear zoneinvolving the Apulian Foreland developed above the transition between the Adriatic continental crustand the subducting Ionian oceanic crust.