A. H, Green — Geology of Co. Donegal. 553 



forget that if really warm climates ever did supervene during inter- 

 Glacial times, every such warm period must have been followed by 

 temperate, cold-temperate, and Arctic conditions. And these last 

 would consequently be the most fully represented of the series. 



So far, then, as the Scottish Glacial drifts are concerned, there is 

 no evidence whatever to show that the inter-Glacial periods may not 

 have been warm enough at times to cause all the snow and ice to 

 disappear from the country. Whether we shall ever obtain any 

 decisive evidence on this head will probably depend upon the assi- 

 duity with which the inter-Glacial deposits are examined. The Till 

 was for many years looked upon as an Azoic deposit, and only a very 

 few hammerers continued, Micawber-like, to hope for " something 

 turning up." I believe that mammalian remains have been oftener 

 obtained from the beds in the Boulder-clay during shaft-sinking and 

 other mining operations than geologists are aware of. While carry- 

 ing on the Geological Survey of the Scottish Coal-fields, I have 

 frequently heard of "bones" and "horns" having been met with by 

 the workmen in sinking through the deep drifts. These relics, un- 

 fortunately, have almost invariably been lost or mislaid ; but there 

 can be little doubt, from the descriptions that were given to me by 

 intelligent overseers, that the relics were true fossils, and still less 

 doubt that these fossils were obtained, not in recent alluvial, but in 

 Glacial deposits.^ 



V. — Notes on the Geology of Part of Co. Donegal, Ireland. 

 By A. H. Green, M.A., F.G.S. 



IN the early part of this year I paid a visit to the north-western 

 part of Donegal. My stay was short and my time too much 

 taken up with other matters to allow of detailed geological work ; 

 but there were two things that at once attracted the attention of the 

 most casual observer, the bedded character of the granite, and the 

 traces of former wide-spread giaciation. To these I gave such time 

 as I could, and on my return threw my notes into a paper which was 

 read before the Geological Society of London. On seeing my paper, 

 Mr. E. H. Scott had the kindness to send me copies of two papers 

 of his own and of a report by himself. Sir E. Griffith, and Professor 

 Haughton, on the Donegal Granites, in which, among other matters, 

 the bedded character of these rocks was pointed out.^ 



^ Descriptions of inter-Glacial deposits will be found in " Glacial Drift of Scotland," 

 by A. Geikie, Glasgow Geol. Soc, vol. i., part ii. ; " On the Surface Geology of the 

 District round Glasgow," by James Bennie, Glasgow Geol. Soc, vol. iii., part i. ; 

 " On Two River Channels buried under Drift," etc., by James Croll, Edinburgh Geol. 

 Soc, vol. i., part iii.; "On the Discovery of a Sand Dyke," etc., by Robert Dick, 

 Edinburgh Geol. Soc, vol. i. part. iii. ; Explanation of Sheet 24, Geol. Survey of 

 Scotland, etc., etc 



2 On the Granitic Eocks of Donegal. By R. H. Scott, M.A. Dublin : Printed at 

 the University Press. Part 1, 1862 ; Part 2, 1863. — On the Chemical and Minera- 

 logical Constitution of the Granites of Donegal, and of the Rocks associated with 

 them. By a Committee, consisting of Robert H. Scott, Sir R. Griifith, Bart., and 

 the Rev. S. Haughton, M.D., F.R.S., appointed at the Manchester Meeting of the 

 British Association, 1861. 



