SEDIMENTOLOGIE DES FORMATIONS DE ...
SEDIMENTOLOGIE DES FORMATIONS DE MARTEAU, DU BOIS D'AUSSE ET DE LA PARTIE INFERIEURE DE LA FORMATION D'ACOZ (DEVONIEN INFERIEUR) DANS L'EST DE LA BELGIQUE, AU BORD NORD DU MASSIF DE STAVELOT
E. Goemaere, E. Catot, L. Dejonghe, L. Hance & P. SteemansMemoirs of the GSB n°42 - 1997
ABSTRACT.
The Lower Devonian Marteau and Bois d'Ausse Formations and the lowermost part of the Acoz Formation outcropping north of the Stavelot Massif in Eastern Belgium are the subject of detailed and well documented sedimentological and petrographical investigations. Continuous sections outcropping in the Helle and Gileppe valleys have been described bed by bed. Lithological characters, sedimentary structures and petrographical content are the basis for understanding the sedimentary evolution and paleoenvironments. In the lower part of the Marteau Formation, coarse-grained siliciclastic deposits are indicative of a braided-river system, evolving towards an alluvial plain of limited extent. Sediments from the upper part of the Marteau Formation reflect a more coastal alluvial plain setting, affected by intertidal influences. The littoral environment is obvious in the lower part of the Bois d'Ausse Formation with a sandy sedimentation resulting mainly from fluvial influx. Temporarily, a coastal alluvial plain develops, attested by intertidal influences. Barrier-beach conditions with fluvial influx characterize the upper part of the Bois d'Ausse Formation. It corresponds to the transgressive maximum for the Lower Devonian sea in the studied area. The return to a continental setting is rapid with the development of the red-coloured sediments which characterize the Acoz Formation.
