Upper intertidal rhythmites in the Mont-Saint-Michel Bay (NW France): Perspectives for paleoreconstruction

摘要: Abstract The Mont-Saint-Michel Bay constitutes a good present-day example of sedimentation and facies in an upper intertidal domain. tangue , specific sediment this area, displays alternated structure sandy silty-muddy beds generated by the dynamics tidal currents. This bedding is frequently characterized vertical organization determined cyclic evolution energy during neap/spring cycle. organisation mainly consists thickness variation successive sand/mud couplets which represent deposit each semi-diurnal record cyclicity can be observed wide range from planar to climbing ripple bedding. investigations performed allowed clarify conditions deposition short-term preservation these rhythmites. Most well recorded cycles develop within protected environments necessarily require high suspended concentrations. Characteristic features modern rhythmites, such as number event per cycle, are discussed order select criteria for recognition ancient sediments. use should constitute way discriminate subtidal deposits propose paleogeographic reconstructions.