Looping the loop; geotectonics of the Alpine-Mediterranean region

Abstract

The Alpine-Mediterranean system consists of an African and a European orogenic belt which - with a few discontinuities - extend in great loops and bends between the Atlantic Ocean and the Middle East. The evolution and deformation of these belts or so-called oroclines is closely coupled to the relative movements of the African and European plates during the Mesozoic and Cenozoic. Oroclinal bending presupposes the evolution of relatively thick and rigid ribbon continents marginal to the African and European cratons. These ribbons are considered to have formed within the passive continental margins on either side of the Mediterranean while this seaway opened in a transtensional setting, starting in the Triassic. While the ribbons contorted the sedimentary basins in between were squeezed up and out in diapiric fashion to later be thrust (obducted) over their peripheries and to be emplaced as sedimentary and ophiolitic nappes. Orogenesis finished with the isostatic uplift of the oroclines and the subsidence of the deflated and denudated diapirs.