First-order similarities and differences between the Alps, Dinarides, Hellenides and the Anatolides-Taurides

We compiled a new map correlating tectonic units across several circum-Mediterranean orogen strands between Alps, Carpathians, Balkan Peninsula, the Aegean and Western Turkey, which allows discussing fundamental along-strike similarities and differences. One first-order difference is that Dinarides-Hellenides, Anatolides and Taurides represent orogens of opposite subduction polarity and age with respect to the Alps and Carpathians. The internal Dinarides are linked to the Alps and Western Carpathians along the Mid-Hungarian fault zone, a suspected former trench-trench transform fault, whose lithospheric root was obliterated during Neogene back-arc extension that formed the Pannonian Basin. Dinarides and Hellenides alike consist of far-travelled nappes detached from the Adriatic continental margin along decollement horizons in Paleozoic or younger stratigraphic levels during Cretaceous and Cenozoic orogeny. The more internal nappes (i.e. Drina-Ivanjica, Pelagonian units) are composite nappes whereby the allochthonous Adriatic margin sequences passively carry ophiolites (Western Vardar Ophiolitic Unit) obducted during the latest Jurassic-earliest Cretaceous. Hence, such obducted ophiolitic units root in one single Neotethys ocean that started to close with the initiation of obduction in the latest Jurassic; final suturing occurred during Cretaceous times, terminating with the formation of the Sava-Izmir-Ankara suture in the latest Cretaceous. Ophiolitic "massifs" found SW or S of the Sava-Izmir-Ankara suture zone do not mark oceanic sutures, nor do the Drina-Ivanjica and Pelagonian "massifs" represent independent continental fragments (terranes). The same logic applies to Western Turkey with the difference that the ophiolites overlying the Tavsanli zone, Ören-Afyon zone and the Lycian composite nappes were obducted in Late Cretaceous rather than Late Jurassic times. The widespread existence of obducted ophiolites between the Dinarides and Western Turkey thus represents another first-order difference to the Alps and Carpathians, where oceanic units occur invariably within accretionary prisms. Important lateral changes are also observed when comparing the present-day lithospheric configuration of the Dinarides with that of the Hellenides. While in the Dinarides the Adriatic lithospheric slab can only be traced down to a depth of c. 200 km, where its deeper parts broke off, an over 2100 km long slab is still preserved below the Aegean part of the Hellenides, indicating long-lasting subduction of a coherent lithospheric slab that initiated during the onset of closure of Neotethys (early Cretaceous?). According to crustal-scale retrodeformations, c. 1100 km of the total of 2200 km plate convergence since 120 Ma occurred after the closure of Neotethys and formation of the Sava-Izmir-Ankara suture zone some 65 Ma ago.