Great Britain and Ireland

Great Britain and Ireland contain both lowland periglacial landscapes dominated by relict Pleistocene periglacial landforms, sediments and structures, and upland landscapes where Lateglacial and active periglacial landforms are developed on glaciated mountainous terrain. Lowland periglaciation is represented by weathering features (brecciated bedrock and periglacial karst), evidence for past permafrost (pseudomorphs of ice wedges and composite wedges, frost polygons, relict ground-ice features, relict active-layer phenomena and glacially-deformed past permafrost) and mass-movement structures, sediments and landforms (rockhead deformation structures, active-layer detachment shears, granular and clayey ‘head’ (gelifluctate) deposits, and cambered strata, gulls and valley bulges). Loess deposits cover extensive areas of south and east England, and coversands occur in a few areas. Periglacial fluvial activity has contributed to the formation of sediment-mantled dry valleys, and the development of flights of terraces flanking trunk valleys outside the limit of the last ice sheet. On uplands, the oldest periglacial features are pre-Devensian tors and blockfields. Lateglacial periglacial phenomena include large-scale sorted patterned ground, relict bouldery ‘stone-banked’ lobes and terraces, periglacial valley-fill deposits, relict talus accumulations and paraglacial rock-slope failures. Active (Holocene) features include small-scale sorted patterned ground, shallow solifluction lobes and terraces, and ploughing boulders, together with a range of high-altitude aeolian features (deflation surfaces, wind-patterned ground and (niveo-)aeolian sand accumulations); debris flows dominate present mass-movement activity on many hillslopes.