Les différents mécanismes à l'origine de la diversité des séismites, leur identification dans le Pliocène du Saïss de Fès et de Meknès (Maroc) et leur signification tectonique

Various synsedimentary structures (dish-structure, convolute bedding, loadcast, bedding dislocation and dissipation, sand intrusion) are interpreted as being due to seismic liquefaction and subsequent fluidization of marine and fluviatile sands. Their diversity is compared to the various deformation processes of seismites and related to the local influence of granulometry, diagenesis and slope. The two seismites horizons are referred to the end of the Middle Pliocene and the Late Pliocene and associated with tectonics to the south of the Rif orogenic belt.