Notices of Memoirs — Old Red Sandstone, Kiltorcan. 469 



the erratics generally diminish in number and in size. Boulders of 

 local rocks, often obviously transported and uplifted beyond their 

 parent outcrops, become relatively more abundant towards the limit 

 of the foreign drift, and generally form a spread of drift extending 

 beyond it and passing insensibly into the driftless area. 



Great lakes were held up by the ice barrier some time after it 

 commenced to retreat from the western slopes of the Pennines. 

 During early stages in this retreat the drainage from the lakes in and 

 north of the Etherow Valley escaped northwards, and ultimately 

 passed through the Walsden Gap into the Calder. When the ice 

 barrier east of Manchester fell below 600 feet above O.D., this drainage 

 followed the course of that south of the Etherow Valley and escaped 

 southwards. 



The action of the ice-sheet with its associated streams of water, 

 together with the marginal water derived from melting ice and 

 draining from the region beyond the ice-sheet, assisted by the action 

 of post-glacial streams, in depositing the original drift, in cutting 

 new channels through rock and drift, and in resorting and redepositing 

 the debris, seems quite sufficient to account for the complicated super- 

 ficial deposits in this area. 



No evidence has been found of more than one period of glaciation 

 nor of any local glacier system. There are, however, curious corrie- 

 or cirque-like features, e.g. on Shelf Moor, Glossop. Moreover, 

 although the Pennines are on the whole much lower north of the 

 Etherow Basin than further south, the overflow channels of glacier 

 lakes can be found at higher altitudes in the former than in the latter 

 region. This is the reverse of what might be expected if the higher 

 ground were ice-free. It may be, therefore, that at and near the 

 time when the ice-sheet attained its maximum development the snow- 

 line actually descended below the altitude of the higher Pennine 

 hills, and, without bringing about a definite local glaciation, 

 temporarily filled the higher hollows with snow up to the general 

 level of the ridge. Thus, instead of the margin of the ice-sheet at 

 that stage melting away rapidly, melting might be considerably 

 reduced and even temporarily suspended, and the ice-sheet reinforced 

 by the local snowfall. Such conditions would tend to depress the 

 limit of distribution of erratics immediately west of the highest 

 ground, but where an ice-stream carrying erratics actually crossed 

 the watershed they might lead to the distribution of those erratics 

 further and more widely than otherwise might have been possible. 



(4) The Old Bed Sandstone Bocks of Kiltorcan, Ireland. 

 Beport of the Committee, consisting of Professor Grenvjlle 

 Cole (Chairman), Professor T; Johnson (Secretary), Dr. J. W. 

 Evans, Dr. B. Kidston, and Dr. A. Smith Woodward. 



THE Committee has spent the sum of £5 from the unex- 

 pended balance of the grant made in 1913, and has returned 

 the remaining balance to the General Treasurer. The grant of £10 

 made in 1914 was not called on, since the work for which it was 



