AbstractFrost‐cracking and ice‐wedge growth are fundamental processes within the permafrost environment. Extensive areas of contemporary permafrost terrain are characterised by frost‐fissure polygons, formed by repeated thermal contraction‐cracking of the ground. The incremental growth of ice veins and wedges along the axes of contraction‐cracks contributes significantly to the volume of ground ice in near‐surface permafrost. In areas beyond the present limit of permafrost, the recognition of ice‐wedge pseudomorphs provides one of the few unambiguous indications of the former existence of permafrost conditions. An understanding of the processes of ice‐wedge growth and thaw transformation is essential if contemporary ice wedges are to be used as analogues for Pleistocene frost‐fissure structures, in palaeoenvironmenta