KINEMATIC EVOLUTION OF THE CORSICA TRIPLE JUNCTION

The tectonic evolution of Alpine Corsica and surrounding areas is described through a series of 2-D and 3-D plate reconstructions from the onset of the Alpine convergence in the early Cretaceous (~120 Ma) to the early Miocene (~19 Ma). The southward subduction of Eurasian lithosphere beneath Adria and Iberia, and the subduction of Ligurian lithosphere beneath the eastern Iberian margin, led to the formation of a trench-trench-trench triple junction close to the northern tip of Corsica, whose kinematic evolution determined the structural complexity of eastern Corsica and the Ligurian accretionary prism. During a first phase, from the early Aptian (~120 Ma) to the late Maastrichtian (~68 Ma), the triple junction migrated eastward along the Alpine subduction zone, determining the juxtaposition of the Alpine and Ligurian accretionary prisms. A second phase, which started during the Eocene (~55 Ma) and terminated at the beginning of the Oligocene (~33 Ma), was characterized by the northeastern migration of the triple junction along the Alpine trench and by the overthrusting of the Alpine accretionary prism onto the eastern Iberian margin. During this time interval the Alpine and Ligurian subduction zones were linked by a left-lateral transform fault. Finally, from the early Oligocene (~33 Ma) to the early Miocene (~19 Ma), during the rotation of the Corsica and Sardinia blocks, slip partitioning along the southern part of the Alpine accretionary wedge determined the formation of a small sliver (Alpine Corsica) which migrated northwestward with respect to Corsica along a left-lateral transform fault.