108 W. B. Wright— Preglacial Shoreline, W. Ides of Scotland. 



evidence for this second preglacial platform, to which reference 

 has been made above (Section II), cannot, however, at present be 

 regarded as at all satisfactory, and unless its existence is confirmed 

 by evidence in other districts it need not be taken into account 

 theoretically. 



In Southern Britain the deposits'of the preglacial raised beach are 

 overlain by 'head' or 'rubble-drift', and a conspicuous feature of the 

 preglacial shoreline is the rounding off of the old sea-cliff owing to 

 atmospheric degradation at the time of formation of this head. 

 It is worthy of note that where the preglacial cliff of the Western 

 Isles is best preserved, as in Mull and parts of Colonsay, no such 



TRESHNISH . „. „ 

 ISLANDS •'"j&rv 



&* 100 



ARDMEANACH 

 ,115 

 I0NA 



COLONSAY 



ORONSAY < y 12 o / !' 



FlG. 4. Sketch-map on the scale 25 miles to the inch, showing the known 

 localities and heights of the preglacial raised beach of the Western Isles of 

 Scotland. The preglacial beach is shown by a black line, and the figures 

 give its observed heights in the different localities. 



rounding is observable. Some allowance must no doubt be made for 

 the nature of the rocks of which the cliff is formed, but, taking 

 everything into account, there is a distinct suggestion that the 

 Scottish cliff was never exposed to the same process of degradation 

 as that of the south. It may possibly have been below sea-level, but 

 it is more likely that it was already buried in ice long before the 



