ACTIVE PATTERNED-GROUND AND CRYOTURBATION ON MUCKISH MOUNTAIN, CO DONEGAL, IRELAND

Active stony earth circles occur on the less coarse cells of relict so rted nets developed in quartzite debris above 600 m ASL on Muckish Mou ntain, north-west Ireland. The earth circles are underlain by deformed and truncated podzolic soil horizons that resemble cryoturbations pro duced by differential frost heave of adjacent sediments. Grain-size di stributions indicate that the soils are frost-susceptible and possess negative frost-susceptibility gradients. This infrequent association o f coarse quartzite debris and fine-grained frost-susceptible matrix pr obably arises from the weathering of thin inter-bedded pelites (schist s) within the quartzite. Recent activity may have been triggered by cl imatic deterioration during the Little Ice Age, although present clima te on Muckish appears capable of maintaining the surface morphology of the stony earth circles. These features, along with forms described p reviously, suggest that most if not all upland areas in Ireland above 600-700 m ASL possess climatic conditions favouring frost-related soil processes.