Lithological, magnetic and geochemical data do not allow distinguishing the homogenous, green cleaved mudstone at Rebecq (Senne Valley), defined as the Upper Ordovician Hospice de Rebecq Formation by Herbosch (2005), from those of the Asquempont Member of the Lower to lower Middle Cambrian Oisquercq Formation. Moreover, structural geological considerations and new mapping show that the geology of the Rebecq area is better explained by re-considering the homogenous, green cleaved mudstone at Rebecq as a local resurfacing of the Asquempont Member of the Oisquercq Formation in the footwall of the Asquempont Detachment System. Using this idea, a new geological map is presented of the Rebecq area. As the rocks at Rebecq, in the type locality of the Hospice de Rebecq Formation, are better re-considered as belonging to the Asquempont Member of the Oisquercq Formation, the name Hospice de Rebecq Formation should be abandoned. This, in turn, implies that also the green rocks of the Grand-Manil area (Orneau Valley), previously considered as belonging to the Hospice de Rebecq Formation, should be renamed. For the latter, we propose the name Cimetière de Grand-Manil Formation. ; info:eu-repo/semantics/published