Definition: Cold period that occurred towards the end of the last (Devensian) glacial stage in Scotland, equivalent to the Younger Dryas of NW Europe. The event took place about 11000-10000 radiocarbon years BP. The period is named after the advance of ice from the SW Highlands to the southern shore of Loch Lomond.
Many questions remain about environments on Orkney during this cold interval. In Scotland, the Loch Lomond Stadial is a key interval in shaping of the landscape. In the mountains, glaciers reformed and advanced rapidly. In the lowlands, permafrost returned. Intense frost weathering generated screes and solifluction, the soil flow generated by flow of the active layer in summer, led to sludging of considerable thicknesses of glacial deposits to the base of slopes.
In Orkney, it has long been suspected that small corrie glaciers developed on Hoy. Records of organic sediments in lakes point to one or more periods cooling at around this time, with increased erosion in catchments and sediment supply to lakes. Three incursions of warmer water to at least latitude 56ºN during the Loch Lomond Stadial were detected by Kroon et al. (1997), in the offshore sedimentary sequence near north-west Scotland. It remains possible that a weak maritime influence prevented the development of permafrost over large parts of Orkney at this time. The relatively mild conditions might account for the apparently limited development of scree and solifluction deposits on Orkney.