Timing of rotation and kinematic evolution of the Albano-Hellenides within the Aegean orocline

The Aegean arc represents the most prominent salient in the Mediterranean region and is characterized by large vertical-axis rotations along its limbs. Paleomagnetic studies along its western limb indicate that the external Ionian and Kruja zones of the Albano-Hellenides experienced ~40° of clockwise (CW) rotation relative to Africa/Adria, yet the timing of this rotation remains controversial. Previous interpretations have proposed either two (Miocene and Plio–Pleistocene) rotation episodes, or a single post mid-Miocene rotation accelerating along time. These uncertainties partly reflect the contribution of local thrust tectonics and/or strike-slip faults biasing the regional rotational trend.
We present new paleomagnetic data from 41 sites located in the virtually continuous Eocene-Early Pliocene sedimentary succession of the Tragjasi thrust sheet (Ionian zone, SW Albania). Sampled layers lie on the backlimb of a 50 km-long anticline subparallel to the regional orogenic trend and located away from major strike-slip faults. Eocene to early Early Pliocene sediments consistently record a 35°±9° CW rotation, demonstrating that rotation in the external Albanides began not earlier than the late Early Pliocene (~4 Ma).
Such new timing constraints were integrated into a quantitative kinematic reconstruction of the Aegean orocline over the last 20 Myr, developed in GPlates by combining paleomagnetic rotations with published kinematic models of the Peloponnese–Aegean domain. The reconstruction further integrates geophysical constraints on slab geometry and the amount of subducted oceanic lithosphere, allowing us to propose an updated kinematic evolution of the Aegean orocline.
Our results show that the post-Messinian tectonic evolution was characterized by synchronous CW rotation of the Albano-Hellenides and the Peloponnese, accompanied by a marked acceleration of subduction rates. We interpret this kinematic reorganization as due to multiple geodynamic processes, including (i) enhanced slab pull driven by the subduction of ~150 km of negatively buoyant Ionian (Neo-Tethys) oceanic lithosphere, (ii) mechanical coupling across the Kefalonia-Lefkada Fault, (iii) westward propagation of the North Anatolian Fault into the Aegean region, and (iv) the progressive development of a slab tear beneath the southern Dinarides. Together, these results highlight the tight coupling between slab dynamics and oroclinal bending in the late Cenozoic evolution of the Aegean orocline.