L'évolution des falaises argilo-crayeuses et limoneuses du nord du Boulonnais (Strouanne, Sangatte, France) / Evolution of the clay-chalk and silt cliffs in northern Boulonnais (Strouanne, Sangatte, France)

Abstract

L'évolution des falaises argilo-crayeuses et limoneuses du nord du Boulonnais (Strouanne, Sangatte, France) / Evolution of the clay-chalk and silt cliffs in northern Boulonnais (Strouanne,

The role of groundwater in cliff instability: an example at Cape Blanc‐Nez (Pas‐de‐Calais, France)

“…At Folkestone Warren (UK), Hutchinson (1969) demonstrated that there is no relationship between the majority of the groundwater in the Gault slipped masses and that of the inland chalk aquifer. Actually, variation of the liquid limit in the Gault and mass movements at Strouanne (Figure 2(C)) are the result of the infiltration of rain water on the cliff face where the Gault outcrops (Pierre and Lahousse, 2004). Groundwater action on weakly cemented clastics (Norris, 1990) is well illustrated by the processes observed in the bedded deposits of the Sangatte cliff.…”