Late Pleistocene




Loch Lomond Stadial

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. For more background see here

Many questions remain about environments on Shetland 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 Shetland, there have been long-standing suggestions that small glaciers developed at Burn of Mail, Sandness and north of Ronas Hill but, whilst local glaciers certainly once existed at these locations, their moraines remain undated. 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, but the detailed record at Clettnadal points to at least three intervals when organic deposition resumed (Whittington et al, 2003; Robinson, 2004). Three incursions of warmer water to at least latitude 56N during the Loch Lomond Stadial were also 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 Shetland at this time. The relatively milder conditions might account for the apparently limited development of scree and solifluction deposits on Shetland.