Subduction Evolution of the Dinarides and the Cretaceous Orogeny in the Eastern Alps: Hints From a New Paleotectonic Interpretation

Abstract

AbstractThe geological evolution of the Dinarides and Eastern Alps is reconsidered taking into account the constraints from a new paleotectonic interpretation for the central Mediterranean. The geological record of the Dinarides suggests that more than one ocean existed between Africa and Europe in Late Triassic‐Late Jurassic. Besides the large Vardar ocean, it is inferred that the basin located to the west of the Pelagonian domain is floored by oceanic‐like lithosphere. Following the Late Jurassic‐Early Cretaceous westward obduction of the Vardar ophiolite onto Pelagonia, subduction resumed close to the European margin and continued until early Paleogene, when the Vardar oceanic basin was consumed. Subsequently, the substrate of the narrow Pindos ocean‐like basin was subducted to the east, accommodating a few hundreds of kilometers of Adria‐Eurasia convergence. Plate kinematics indicate that N‐S convergence between Africa and Europe initiated only after the Cenomanian, well after ophiolite obduction occurred in the Dinarides‐Hellenides. In the Eastern Alps, however, an early Late Cretaceous orogeny has been recorded, separated from the tectonic evolution of the Alps sensu strictu. This Cretaceous orogeny of the Eastern Alps has not been fully understood. The new reconstructions suggest that the Pindos and Vardar oceans merged north of Pelagonia and were confined by a transform fault bounding to the south the Austroalpine domain. Within this frame, where the occurrence of wider oceanic domains is considered, the Cretaceous orogeny of the Eastern Alps can be linked to different episodes of ophiolite obduction and a subsequent shift of tectonic activity that has been recorded in the Dinarides.