Mid-Silurian to Tournaisian of the Rabat-Tiflet Zone (northwestern Moroccan Meseta) – review and new data

This study refines the Wenlock–Tournaisian stratigraphy and facies history of the Rabat–Tiflet Zone using fossil, microfacies, and field data. It shows that sedimentation was controlled by sea-level changes, synsedimentary block faulting, slope tilting, and repeated seismic reworking. In the Rabat area, the Hosseine Formation records hypoxic black shales and organic-rich limestones with pelagic fauna, later affected by turbidites and slump deposits. Eastward, facies become shallower, with more crinoidal and neritic input from a nearby northern platform. A regression at the Lochkovian–Pragian boundary produced oxygenated limestones of the Bou Regreg and Tiflet formations with important conodont and trilobite faunas. During the early Emsian, the Oued Akrech and Safsaf formations reflect widespread crinoidal platform-margin deposition and temporary regional facies homogenization. Later Emsian to Eifelian deepening led to the formation of shale-rich units and the preservation of records of global events, such as the Daleje transgression. In the central zone, the Rechoua and Safsaf formations document an eastward-deepening slope and local continuation of carbonate deposition into the Eifelian. Givetian and younger deposits reveal renewed tectonism, slope instability, and major uplift, producing breccias, conglomerates, olistolites, and gravity-flow deposits of the Aïn-el-Klab Formation. These were followed by the Tournaisian Satour Formation, marking the end of major reworking and the development of shallow-water siliciclastic to carbonate environments.