The opening of Sirte basin: Result of slab avalanching?

North Africa Sirte basin opening is an enigmatic feature in the complex Meso-Cenozoic rearrangement of Mediterranean tectonics. New borehole data inversion constrains its deformation history showing a 26 stretching event starting ~70 Ma and terminating in a further abrupt increase at ~50 Ma, rapidly fading. The 27 timing of this event hardly reconciles with the Mesozoic major plates rearrangement following the spreading 28 of the Atlantic, and the Neogene Central Mediterranean tectonics, active at different times. Here, we propose 29 that Sirte rifting could have been driven by the pull exerted by the Hellenic subduction. Reconstructions of 30 Hellenic convergence and slab deep subduction, as constrained by plate kinematics and tomography, show 31 that large slab mass accumulates in the upper mantle by late Cretaceous–Paleogene, eventually forcing 32 further sinking in the lower mantle, coeval to the growing strain evolution recorded in Sirte. Furthermore, 33 the ~20 m.y. phase of large pull here recorded, the consequent rapid growth over ~10 m.y. and following 34 decay are compatible with the dynamics of slab avalanche as revealed by numerical models, showing that the 35 Sirte basin opened in response to the large pull force developed during the mass flush, and transferred from deep slab to surface.