GLACIAL GEOLOGY.* 



By Prof. James Geikie, F. R. S. 



The results obtained by geologists, who have been studying the pe- 

 rii)heral areas of the drift-covered regions of our continent, are such as 

 to SMtisfy us that the drifts of those regions are not iceberg-droppings, 

 as we used to snppose, but trne morainic matter and tiuvioghicial de- 

 tritus. Geologists have not Jumped to this conclusion ; they have only 

 accepted it after laborious investigations of the evidence. Since Dr. 

 < )tto Torell, in 1875, first stated his belief that the " diluvium" of north 

 Germany was of glacial origin a great literature on the subject has 

 sprung up, a perusal of which will show that with our German friends 

 glacial geology has passed through much the same succession of phases 

 as with us. At first icebergs are appealed to as explaining everything — 

 next we meet with sundry ingenious attempts at a compromise between 

 floating ice and a continuous ice-sheet. As observations multi[)ly, how- 

 ever, the element of floating ice is gradually eliminated, and all the 

 phenomena are explained by means of land ice and "schmelz-wasser" 

 alone. It is a remarkable fact that the iceberg hypothesis has always 

 been most strenuously upheld by geoloj^ists whose labors have been 

 largely confined to the peripheral areas of drift-covered countries. In 

 the upland and mountainous tracts, on the other hand, that hypothesis 

 has never been able to survive a moderate amount of accurate observa- 

 tion. - - - 



The notion of a general ice-sheet having covered a large part of 

 I']uroi)e, which a few years ago was looked upon as a wild dream, has 

 been amply justified by the labors of those who are so assiduously investi- 

 gating the peripheral area of the "great northern drift." And perhaps 

 I may be allowed to express my own belief that the drifts of middle and 

 southern England, which exhibit the same complexity as the "lower 

 diluvium" of the continent, will eventually be generally acknowledged to 

 have had a similar origin. 



I now pass on to review some of the general results obtained by con- 



* Presidential address before the Geological Section of the British Association Adv. 

 Sci. at Newcastle, September, IbS'J. (Report of the British Jtmociation, 18iHll,vol. Lix, 

 pp. 552-564.) 



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