The geological signature of a slab tear below the Aegean

Laurent Jolivet (1) , Armel Menant (1) , Pietro Sternai (1) , Aurélien Rabillard (1) , Laurent Arbaret (1) , Romain Augier (1) , Valentin Laurent (1) , Alexandre Beaudoin (1) , Bernhard Grasemann (2) , Benjamin Huet (2) , Loic Labrousse (3) , Laetitia Le Pourhiet (3)

1 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327
2 Structural Processes Group Vienna
3 iSTeP - Institut des Sciences de la Terre de Paris

In this paper we explore the geology of the Aegean region in the Miocene to identify the geological signature of a first-order slab tear observed in all tomographic models. From 15 to 8 Ma, the tear is associated, spatially and timely, with a fast clockwise rotation of the External Hellenides, alkaline volcanism, high-temperature metamorphic domes with a predominance of north-dipping detachments, south-westward migration of granitoids intrusions. These features suggest a warmer geodynamic environment during the rotation and the impact of a hot mantle flow associated with the tear. The ~ 8 Ma duration between the first high-temperature metamorphic domes in the centre of the archipelago and the beginning of the fast rotation may correspond to the time needed for the slab to bend, stretch and finally tear.

Mots clés: metamorphic core complexes; slab tear; Backarc extension; detachments; Aegean; Mediterranean

Domaines: Planète et Univers [physics]; Sciences de la Terre; Tectonique

Laurent Jolivet, Armel Menant, Pietro Sternai, Aurélien Rabillard, Laurent Arbaret, et al.. The geological signature of a slab tear below the Aegean. Tectonophysics, 2015, 659, pp.166-182. ⟨10.1016/j.tecto.2015.08.004⟩. ⟨insu-01187096⟩