Age and significance of former low-altitude corrie glaciers on Hoy, Orkney Islands
Authors: Ballantyne, Colin K.1; Hall, Adrian M.; Phillips, William2; Binnie, Steven3; Kubik, Peter W.4
Source: Scottish Journal of Geology, Volume 43, Number 2, 2007 , pp. 107-114(8)
Publisher: Geological Society Publishing House
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Abstract:
SynopsisGeomorphological mapping provides evidence for two former low-level corrie glaciers on Hoy, both defined by end moraines. Five 10Be exposure ages obtained from sandstone boulders on moraine crests fall within the range 12.4±1.5 ka to 10.4±1.7 ka (weighted mean 11.7±0.6 ka), confirming that these glaciers developed during the Loch Lomond (Younger Dryas) Stade (LLS) of 12.9-11.5 cal. ka bp, and demonstrate the feasibility of using this approach to establish the age of LLS glacier limits. The equilibrium line altitude (ELA) of one of the glaciers (99 m) is the lowest recorded for any LLS glacier, and the area-weighted mean ELA for both (141 m) is consistent with a general northward ELA decrease along the west coast of Britain. The size of moraines fronting these small (≤0.75 km2) glaciers implies that glacier termini remained at or close to their limits for a prolonged period. The apparent restriction of LLS glaciers to only two sites on Hoy probably reflects topographic favourability, and particularly the extent of snow-contributing areas.Document Type: Miscellaneous
DOI: 10.1144/0036-9276/01-331
Affiliations: 1: School of Geography and Geosciences, University of St Andrews, Fife, KY16 9AL, UK 2: Idaho Geological Survey, University of Idaho, Moscow, ID 83844-3014, USA 3: Institute of Geography, University of Edinburgh, Edinburgh, EH8 9XP, UK 4: Paul Scherrer Institute, c/o Institute of Particle Physics, ETH Zurich, 8093 Zurich, Switzerland
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