A fourth level of Frasnian carbonate mounds along the south side of the Dinant Synclinorium (Belgium)

An additional level of Frasnian mounds has been recognized in the La Boverie quarry at Rochefort and in four boreholes drilled in the Nord quarry at Frasnes, on the south side of the Dinant Synclinorium. It occurs between the Arche and Lion Members belonging respectively to the Moulin Liénaux and Grands Breux Formations, in the middle part of the stage. The new name of La Boverie Member is introduced at the top of the Moulin Liénaux Formation, for the deposits lying between the Arche and Bieumont Members; the latter is the basement of the Lion mound. The same succession has been observed in the sections of Moulin Bayot close to Vodelée, in the southeastern part of the Philippeville Anticlinorium. The La Boverie Member starts with rather deep bioclastic sediments, after the collapse of the carbonate factory at the top of the Arche mound. In the upper part of the lithostratigraphic unit, there is a thin buildup characterized by relatively shallow facies. The solitary rugose corals Macgeea boveriensis n. sp., M. socialis SOSHKINA, 1939 and Sinodisphyllum posterum (IVANIA, 1965) collected in the lower part of the La Boverie Member are described in detail whereas the revision of S. kielcense (ROZKOWSKA, 1979) occurring in the Bieumont Member is also provided.