The Normandy chalk is highly fissured and shattered within 3–8 m. of its ground surface. The author suggests that this structure has resulted from frost-heaving during Quaternary glaciation.
There is little doubt that English chalk was mainly fissured at the surface in the same way. The old solifluction is well known, and during the 1946–47 winter frost-heaving was encountered on the chalk downs to a depth of 30 cm. Chalk is particularly susceptible to frost-heaving (see photograph on p. 176).
