Abstract
The hypothesis that the obsequent scarplets on Ben Attow were formed by selective, perhaps glacial, erosion was considered by the authors but rejected for three main reasons. First, the slope is formed of Moinian Psammite and it would seem unlikely that scarplets could remain unscathed whilst glacial erosion scoured a trench across the slope immediately upslope of them. Second, up to twenty scarplets occur between the floor of Glen Licht and the crest of the slope. If the scarplets were formed by glacial erosion then their absence in the remainder of Glen Licht must be accounted for. Finally, (Fig. 1) of Holmes & Jarvis' (1985) paper shows some scarplets that strike at angles diagonal to the direction of the slope and, therefore, are discordant with the main trend of the scarplets. The varying orientations of these scarplets poses a further difficulty for the selective erosion hypothesis.
The upslope faces of the scarplets were examined for slickensides but none were observed, nor were glacial striae seen. This negative evidence may be due to the vegetation cover on many of the scarplets and the degradation of most of their upslope faces. Any slickensides or striae may have been lost. However, Bovis (1982) suggested that low normal stresses acting on steeply inclined discontinuities may have prevented the formation of slickensides at a rock slope topple that he investigated.
At Ben Attow and on other slopes studied by Holmes (1984) and Jarvis (1985) there is a relationship between obsequent scarplets and consequent failure scarps
