A new concept of glaciation in Lewis and Harris, Outer Hebrides

• Published in: Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences
• Main Author: von Weymarn, J. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1979
• Subjects: General Medicine; Ice cap
• Online Access: http://dx.doi.org/10.1017/s0269727000012665; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0269727000012665

Synopsis Contrary to previous ideas, it is suggested that Harris and the major part of Lewis were covered by a large local ice cap during the last glacial phase. Local glaciers from central Lewis and the interior of North Lewis moving over the eastern fringe across the Eye peninsula and towards the north-west coast appear to have overridden and redistributed deposits from earlier glaciers of external origin. There is some evidence that the northern tip of Lewis and the Tolsta Head peninsula were also invaded by external ice during the final glacial phase. The application of a theoretical icesheet-surface profile substantiates the concept that Scottish mainland ice at its maximum advanced over northern parts of the island. According to the C-14 date of an organic layer beneath glacial till at Tolsta Head the last incidence of external and/or local ice in the island occurred after 27,300 years BP. Deglaciation phenomena at Uig, south-west Lewis, mark an earlier stage in the dissolution of the ice cap, while hummocky moraine in the mountain and submountain zone indicate the retention or renewed formation of valley glaciers during the late Devensian.