# Plio-Quaternary Tectonic Activity in the Northern Nubian Belts: The Main Driving Forces
## 1 Introduction
Decoupling of Adria also occurred from its northwestern edge (Padanian) through the reactivation of an old fault zone (Schio-Vicenza e.g., [8; 9; 11; 66; 67; 68; 69]). Following these decouplings, the Adria plate underwent a clockwise rotation and a minor north-northwestward motion (Figure 2b). The westward motion of southern Adria induced a strong E-W compression in the Hyblean-Pelagian domain and along the northern Nubian margin. The consequent shortening of the Hyblean-Pelagian domain was mainly accommodated by the northward extrusion of the Adventure wedge and the displacement of the easternmost Maghrebian sector. The northward indentation of these structures into the Alpine-Apennine material lying east of Sardinia caused the east to southeastward escape of wedges (southern Apennine and Calabrian units), at the expense of the Tethys oceanic remnants and the thinned margin of Adria [9; 10; 70; 71]. The extensional deformation that developed in the wake of the migrating Apennine and Calabrian units, generated the central and southern Tyrrhenian basins, while new accretionary belts developed along the fronts of the migrating wedges [7; 8; 9; 10; 11]. Figure 2: Neogenic evolution of the central and western Mediterranean regions. (**a**) Late Miocene, NT = northern Tyrrhenian. (**b**) Middle–Late Pliocene. Eg = Egadi fault, Ja = Jarrafa fault, LP = Libyan promoratory, NAP = northern Apennines, SAP = southern Apennines, Sc = Sciacca fault, SCH = Sicily channel, SR = Scichi-Ragusa fault, SV = Schio-Vicenza fault, Tr = Trippilotana fault, Va = Vavilov basin, VHM = Victor Hensen–Medina fault. (**c**) Pleistocene. Au = Aures, CP = Calabria–Peloritani wedge, GK = Greater Kalylia, HA = High Atlas, HP = High Plateau, LK = Lesser Kalylia, Ma = Marsili basin, MR = Mediterranean rairage, Pa = Palinuro fault, SA = Saharan Atlas, TA = Tunisian Atlas, Ta = Taormina fault, TTS = Transmoroccan fault system. See the text for explanations. Arrows indicate the long-term kinematic pattern [9; 11; 72]. Colors, symbols and other abbreviations as in Figure 1.  
The northward indentation of the Adventure wedge and the Maghrebian units also stressed the eastern Corsica-Sardinia block, leading to the formation of the Campidano graben in Sardinia [8; 9; 11; 73; 74; 75], a tectonic event that can hardly be attributed to alternative driving forces. In the northern Nubian margin, the westward push of the southern Adria plate caused oroclinal bending, thrusting and uplifting in the Tell and Atlas belts (Figure 3). The eastern sector of these chains (Tunisia) experienced the most significant deformation, including the formation of several SW-NE anticlines in the Aures zone (Figure 3b,c, e.g., [2; 18; 24; 76; 77; 78]). It can be noted that these features are perpendicular to the combined motions of the Nubian plate (north-northeastward) and of the Pelagian domain (westward). The deformation of the Aures zone also involved the development of several NW-SE oriented troughs (e.g., [2], Figure 2c). This deformation can be attributed to the SW-NE extension that occurred in the wake of the Maghrebian belt sector, which was pushed northward by the Adventure wedge (Figures 2c and 3b). The intense deformation that the easternmost Atlas sector underwent during this phase may explain why that chain is now very close to the Tell belt. This hypothesis is supported by paleogeographic studies, which suggest that a platform existed between the Atlas basin and the Tell passive margin ([2] and references therein). This platform, referred to as the \"Neritic Constantine units\" [79] in Algeria and the \"folded foreland\" in Tunisia [80], is now allochthonous and has been integrated into the Tell thrust belt [79]. Immediately south of this shelf, the Atlas Meso-Cenozoic basin was particularly deep in the Aures and the Tunisia trough [2], constituting a zone of crustal weakness, which has been affected by tectonic inversion since the Pliocene [76; 81; 82].