Palaeomagnetism and palaeogeography of Adria

Abstract

Abstract An ‘African’ Mesozoic apparent polar wander path (APWP) based on rotated North American data is compared with palaeomagnetic data from Adria and surrounding regions. The form of the APWPs from the Southern Alps, Umbria-Marche (Italy) and the Transdanubian Central Range (Hungary) is similar to that of the ‘African’ APWP. The Umbria-Marche and Transdanubian APWPs are rotated relative to the African APWP, and the rotation is best explained by local anticlockwise tectonic rotations of 20° and 30° for the NW Umbria-Marche and Transdanubian regions, respectively. Permian to Cretaceous palaeomagnetic poles from the Southern Alps are not distinguishable from the African APWP. The more recently derived Cretaceous poles from Istria, Cretaceous poles from Iblei (Sicily), Gargano and Apulia are all consistent, within the confidence limits of the data, with the African APWP. Rifting in the Ionian Sea/Eastern Mediterranean either predated the mainly Jurassic-Cretaceous palaeomagnetic dataset or did not produce recognizable rotation of Adria relative to Africa. The Northern Calcareous Alps are often considered to have been contiguous with the Southern Alps during the Mesozoic, however, the NCA (Liassic) poles are closer to coeval poles for Europe, and are rotated in excess of 80° clockwise relative to the African APWP. The Northern Calcareous Alps were probably detached from the Southern Alps during Late Triassic and Jurassic time, and did not undergo the ‘African’ rotation which affected Adria.