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L'analyse biostratigraphique et sédimentaire d'une série réduite du J. Serj (Tunisie), rapportée au Campanien-Maastrichtien, nous a permis de caractériser, pour la première fois, par la composition de la biophase, deux épisodes de remaniements sousmarins en milieu distal, qui sont successivement d'âge anté-Maastrichtien supérieur (zone à Rosita contusa) et anté-Paléocène supérieur (zone à Morozovella velascoensis). Ainsi, nous avons distingué deux surfaces de type LS 1 , délimitant trois intervalles stratigraphiques apparemment continus (Campanien inférieur, Maastrichtien supérieur et Paléocène supérieur) et une autre limite au sein du Campanien inférieur de type LS2, qui coïncide avec une surface bioturbée. Cela marque une activité tectonique synsédimentaire, dont témoignent latéralement des dépôts de gravité (conglomérats, slumps).

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The Jebel Oust region (north-eastern Tunisia) recorded two levels of marine black shale in the Lower Cretaceous marly series. Geodynamic evolution, biostratigraphic and Rock–Eval analysies allow classifying those black shales as unconventional shale oil resource systems that were deposited during two oceanic anoxic events: the Middel Barremian Event "MBE" and the Early Aptian Event "OAE1a". Paleogeographic evolution highlights two transgressive–regressive cycles: the first one is Valanginian-Early Barremian, and the second is Late Barremian–Early Aptian. Each black shale deposit occurs at the end of the transgression that coincides with the highest sea level. During the Barreman–Aptian interval, sedimentation was controlled by extensional faults in a system of tilted fault blocks which were reactivated several times. Kerogen is of type I, II origin in black shales and of type III origin in marls. Tmax values indicate "oil window" stage. Average transformation ratio is around 67% and 82%, respectively, in the Lower Aptian and Middel Barremian source rock related to the relatively high thermal maturity degree due to the deep burial of the later. Estimated initial hydrocarbon generation potential is moderate to high. Oil saturation index records an "oil crossover" indicating expelled and migrated hydrocarbons from the organic-rich to the organic-poor facies. The petroleum system of the two mature source rocks with a high hydrocarbon generation potential enclose all elements characterizing a "shale oil hybrid system with a combination of juxtaposed organic-rich and organic-lean facies associated with open fractures".