The Jurassic-Cretaceous transition of Izzarene area, located north of Ouezzane, is characterized by retrograding redeposited carbonates (lower member), Tithonian-Lower Berriasian in age, and marly limestones (upper member), Berriasian-Valanginian in age. The most abundant reworked material of the lower member are lithoclastic grainstone and packstone with sedimentary structures indicating a wide range of transport mechanisms from debris flow to turbidity currents. Within this formation, three facies associations are organized in a submarine fan fashion according to the system II of Mutti [1985] and the suprafan of Normark [1972]. Flutecasts and imbricated conglomerates indicate flows towards the east. When taking into account the torsion of the External Riffian chain, during the Tertiary, one can envisage transport from south to north. The sediments are derived from a southern shelf equivalent to the platform of the eastern foreland. The allodapic formation is limited at the bottom and at the top by two discontinuities (erosional and/or by lack of deposit). It is possible to correlate this formation, Tithonian-Lower Berriasian in age, with the LZB 1-3 eustatic cycle of Vail et al. [1987]. Nevertheless, during this period, some tectonics events are recorded by the North African Tethyan continental margin. Near Had M'Sila, in the Preriffian zone, blocks faulting and differential subsidence affected the carbonate platform of the same age.
