The geology of the Qued Sedjenane Area, Northern Tunisia and its bearing on the Numidian Flysch problem

Evidence from the Oued Sedjenane area, northern Tunisia, indicates that the Numidian Flysch Complex is allochthonous in the western Mogod Mountains. The complex consists of interlayered quartzose conglomerate, sandstone, and shale which were deposited by turbidity currents in the mid-fan region of a submarine fan complex on the northern margin of the African continent during Oligocène and lower Miocene times. The depth of deposition of the flysch was greater than 2 meters. Data support the hypothesis of Wezel (197b) that the source area for the Numidian sediments was to the south on the African craton. During middle Miocene time, the Numidian Complex was detached from its substratum and thrust southward over the Maestrichtian to Eocene limestone-marl sequence which underlay the thin, locally-preserved veneer of clastic rocks on the Miocene African shelf. Only the lower Miocene portion of the Numidian Complex was involved in the frontal part of the thrust sheet exposed in the map area. The displacement of the Numidian thrust sheet is a minimum of 25 kilometers. During and following the emplacement of the thrust sheet, diapiars of Triassic evaporite rising from the main decollment surface beneath the Tellian Atlas were injected along the thrust plane. A middle Miocene time of thrusting and contemporaneous internal deformatio