Palaeotectonic reconstruction of the central Alpine-Mediterranean belt for the Neogene

Abstract

The structural patterns of the central Alpine-Mediterranean belt ranging from the eastern Balearic Sea to the western Aegean Sea, have been reconstructed for 10 and 20 Ma B.P. They have been obtained in the frame of the Africa/Europe convergence through a step-by-step rigid-plastic reconstruction, using available geological and palaeomagnetic data. All domains outlined in the present situation are shown in the palaeotectonic reconstructions. While the structural pattern at 10 Ma B.P. is similar to that of the present, except for the Tyrrhenian region, that at 20 Ma B.P. differs from it in most areas. The well-known Adriatic promontory of the African plate is recognizable in both pictures, and at 20 Ma its original boundaries are revealed as strongly deformed flysch belts. The Adriatic promontory was broken up in the Early or Middle Miocene into two microplates of comparable sizes. The norther one is the Adriatic microplate (s.S.), which suffered counter-clockwise rotation by 20° relative to Africa around the Alpine-Apenninic whirl centre. The southern one is the Apulian microplate, first outlined in the present work including the South Apenninic and the Apulian (s.S., south of the Gargano Peninsula) platforms, which suffered no rotations relative to Africa but which moved towards the northeast of it. The primary reason for the break-up of the Adriatic promontory was, most probably, the opening of the Balearic-Ligurian Sea. Since 10 Ma, the Adriatic and Apulian microplates were again integral with Africa or, perhaps, they moved towards the west relative to Africa, pushed by the Turkish microplate. The orogeny in the area discussed is mostly linked with collisional processes on the boundaries of the Adriatic-Apulian unit.