Triassic and Jurassic Oceanic/Paraoceanic Belts in the Carpathian-Pannonian Region and its Surroundings

Abstract

Mafic/ultramafic rocks and associated oceanic/ paraoceanic sediments of two ages occur in the Carpathian-Pannonian region. The older rocks indicate Middle Triassic rifting and spreading and occur in the Meliata unit of the Inner Carpathians, in the Transylvanides of the East Carpathians, and in the Vardar zone of the Dinarides and Hellenides. These localities can be united into a Middle Triassic-Late Jurassic Vardar ocean, forming the westernmost embayment of the Triassic Tethys ocean. The younger mafic/ultramafic rocks occur in the Penninic-Valais unit of the Alps, in the Pieniny Klippen Belt of the Carpathians, in the Bukk unit of the innermost West Carpathians, in the Mecsek unit of the Pannonian region, in the Mures ophiolite belt of Apuseni Mts., in the Black flysch nappe of the East Carpathians and in the Severin nappe of the South Carpathians. These indicate rifting and/or spreading starting in late Early Jurassic. Most of these localities can be united in a Middle Jurassic-Early Cretaceous “Penninic” oceanic zone. Consequently, in the Carpathian-Pannonian-Dinaride region the Jurassic “Penninic ocean” lay to the north of the Triassic Vardar ocean. Its opening was most likely caused by the interaction of the opening of the Atlantic and back-arc basin formation connected with Vardar subduction.