ice wedge A tapering, vertically layered mass of ice, about a metre wide at the top and extending downward for some 3–7 m. It results from contraction cracking of the ground during extreme cold, followed by water penetration from the active layer and subsequent freezing. It is characteristic of uniform sediment, such as river alluvium, under periglacial conditions.

ice wedge Tapering, vertically layered mass of ice, about a metre wide at the top and extending downward for some 3–7 m. It results from contraction cracking of the ground during extreme cold, followed by water penetration from the active layer and subsequent freezing. It is characteristic of uniform sediment, such as river alluvium, under periglacial conditions.