Original paper

Fluvial terraces of the Ambleve: a marker of the Quaternary river incision in the NE Ardennes massif (Western Europe)

Rixhon, Gilles; Demoulin, Alain

Abstract

The geomorphological analysis of the terraces of the Amblève, an Ardennian subtributary of the Meuse, allows us to reconstruct eleven distinct levels (T1 to T11). Like those of most rivers draining the Ardennes massif, the Amblève terrace profiles also converge in the upstream direction. Moreover, the “Main Terrace” complex, widely recognized in the Rhine and Meuse systems (including their major tributaries draining the Ardennes-Eifel massif), has also been identified in the Amblève valley. However, the lack of terrace remnants in the ∼ 10km-long reach of the Quarreux gorge, combined with the knickpoint observed in the presentday long profile in this reach, leaves some uncertainty in the overall profile reconstruction. Despite the presence of a paleokarst filled by alluvial material in the lower Amblève and diversely dated between ∼ 0,5 and ∼ 1 Ma, firm chronological data about the Quaternary evolution of the Amblève are still lacking. Therefore, we base our discussion of the temporal evolution of the Amblève incision on geometrical correlations with dated terraces of the Meuse downstream of Liège.