La Statte inférieure: reconnaissance pionnière de l'évolution de la vallée

In the Cambro-Ordovician Stavelot-Venn Massif (Eastern Belgium), the valley of the Statte, which collects the waters of part of the Plateau des Hautes Fagnes, is very narrow in its crossing of the Cambrian quartzites of the Formation of La Venne. Downstream of the Rocher de Bilisse, it opens widely in the black shales of the La Gleize Formation (Cambrian summit). Deposits that are part of periglacial processes have accumulated in a terrace level that contains Rocourt's crypto-tephra. In one site, sphenes confirm the presence of another cryto-tephra whose existence was previously suspected in the cores of boreholes carried out for the construction of the motorway bridge (A27-E42) of Bernister which crosses the valley of the Eau Rouge; the name Tephra of Solwaster is attributed to him.