Collapse of quick clay is shown on microscopic scale in these schematic cross sections. Undisturbed clay (left) is thought to possess a "house of cards" structure. The "cards" are flat bits of clay minerals. Irregular blobs represent sand grains and tiny sots are dissolve salt, which provide electrolytic "glue" for the structure. Water (colour) is being squeezed out as clay collapses (middle). Most of the salt was leached out before collapse. Remolded or collapsed clay (right) contains very little water (Kerr, P.F., 1963, Sci. Amer. Nov., p. 134).