key sites

loch lomond stadial

periglacial landscapes

Holocene and perhaps modern slope deposits resting on soliflucted till

Channerwick

Significance: a rare coastal exposure that reveals organic sediments from the Windermere Interstadial 13 thousand years ago overlain by soliflucted till deposited under conditions of intense cold during the Loch Lomond Stadial

Peat covered by soliflucted till of probable Loch Lomond Stadial age and Holocene slope deposits

Coastal erosion has revealed a small fragment of the postglacial history of Shetland. After deglaciation, rapid warming allowed vegetation to colinise the newly exposed terrain. Conditions must have been moist, for peat development began swiftly. A reversion then took place to conditions of cold similar to those exposed in the full glacial phases of the Pleistocene. Tundra conditions prevailed on Shetland, perhaps with permafrost, for around a millennium between 11 and 10 ka. Seasonal thaw of the ground allowed soil flow - solifluction - down quite gentle slopes. Autumn freeze up led to the rotation of stones in the soil layer and up-freezing brought concentrations of stones to the surface, just as it does in cold winters today. The thick layer of colluvium is reworked soil material and probably reflects soil erosion in prehistoric and historic time.

Streetmap extract

Erected pebbles due to frost heave under the influence of ground ice