The Alpine Basement — Linkage Between Variscides and East-Mediterranean Mountain Belts

Abstract

The basement of eastern Mediterranean Alpine mountain belts and the extra-Alpine Variscides forms a collage of various tectonostratigraphic units which have been accreted and consolidated during the Variscan orogenic cycle. In consequence, most basement units of the entire Alpine-Mediterranean mountain belts, part of the southern, south-directed segment of the central to west European Variscan collisional belt, have an extension in extra-Alpine Variscides. The evolution of this segment of Variscides reflects processes of an active continental margin since late Precambrian time with both subduction and formation of back-arc basins, and accretion of suspected terranes along the northern Gondwanian margin. Final transpressional collision between crustal pieces of distinct Early Palaeozoic evolution occurred during Early to Late Carboniferous and is followed by molasse-like red bed sedimentation. Subsequent transgression of the Tethyan Sea along the southern margin of Variscides in Late Carboniferous to Permian was associated with dextral transtensive megashearing between Gondwana and Laurussia.