Late Flandrian solifluction on the Fannich mountains, Ross-shire

Abstract

Synopsis Five radiocarbon dates obtained for samples from a soil horizon buried by the downslope advance of a 0.4 m thick solifluction lobe on a 14° slope at 840 m in the Fannich Mountains yielded ages that range from 890 ± 120 B.P. to 530 ± 90 B.P. These radiocarbon ages are statistically indistinguishable from that of 660 ± 70 B.P. obtained for a sample from the same soil horizon 0.6 m downslope of the lobe front. As contamination of the samples to produce such similarity in ages is highly improbable, this evidence indicates very rapid, very recent advance of the solifluction lobe over a distance of at least 3 m at a rate hitherto unsuspected for recent solifluction in upland Britain and as great (if not greater) than any reported for similar features in other periglacial environments. The rapidity of lobe movement appears to reflect greatly accelerated recent activity, probably triggered either by climatic deterioration during the ‘Little Ice Age’ or by vegetation degradation caused by overgrazing.