The carbonate sedimentation of the Dinant Synclinorium givetian platform is controlled by moderate but steady subsidence. More than four hundred meters of shallow-water limestones were accumulated. Most of these are semi-restricted to restricted and are the lateral equivalents of bioconstructions. Carbonate production, mainly in the lagoons, is linked to algal proliferation. Forty-six genera are recognized among spongiostromids, porostromids. codiaceans, udoteaceans, phylloids?, dasyclads, solenoporids, coccoids, charophytes, umbellinids, calcispheres and incertae sedis. Bevocastria is the most prolific alga. Carbonate build-ups are erected by phylloids?, giant dasyclads and Sphaerocodium . The widespread occurrence of rudstone sheets is due to the scarcity of stabilizing solenoporids.