Mesozoic plate tectonic reconstruction of the Carpathian region
Abstract Palaeomagnetic, palaeobiogeographic and structural comparisons of different parts of the Alpine–Carpathian region suggest that four terranes comprise this area: the Alcapa, Tisza, Dacia and Adria terranes. These terranes are composed of different Mesozoic continental and oceanic fragments that were each assembled during a complex Late Jurassic–Cretaceous–Palaeogene history. Palaeomagnetic and tectonic data suggest that the Carpathians are built up by two major oroclinal bends. The Alcapa bend has the Meliata oceanic unit, correlated with the Dinaric Vardar ophiolite, in its core. It is composed of the Western Carpathians, Eastern Alps and Southern Alcapa units (Transdanubian Range, Bukk). This terrane finds its continuation in the High Karst margin of the Dinarides. Further elements of the Alcapa terrane are thought to be derived from collided microcontinents: Czorsztyn in the N and a carbonate unit (Tisza?) in the SE. The Tisza–Dacia bend has the Vardar oceanic unit in its core. It is composed of the Bihor and Getic microcontinents. This terrane finds its continuation in the Serbo–Macedonian Massif of the Balkans. The Bihor–Getic microcontinent originally laid east of the Western Carpathians and filled the present Carpathian embayment in the Late Palaeozoic–Early Mesozoic. The Vardar ocean occupied an intermediate position between the Western Carpathian–Austroalpine–Transdanubian–High Karst margin and the Bihor–Getic–Serbo–Macedonian microcontinent. The Vardar and Pindos oceans were opened in the heart of the Mediterranean–Adriatic microcontinent in the Late Permian–Middle Triassic. Vardar subducted by the end of Jurassic, causing the Bihor–Getic–Serbo–Macedonian microcontinent to collide with the internal Dinaric–Western Carpathian margin. An external Penninic–Vahic ocean tract began opening in the Early Jurassic, separating the Austroalpine–Western Carpathian microcontinent (and its fauna) from the European shelf. Further east, the Severin–Ceahlau–Magura also began opening in the Early Jurassic, but final separation of the Bihor–Getic ribbon (and its fauna) from the European shelf did not take place until the late Middle Jurassic. The Alcapa and the Tisza–Dacia were bending during the Albian–Maastrichtian. The two oroclinal bends were finally opposed and pushed into the gates of the Carpathian embayment during the Palaeogene and Neogene. At that time, the main N–S shortening in distant Alpine and Hellenic sectors was linked by a broader right-lateral shear zone along the former Vardar suture.