yb J. G. GOODUHILD ON THE GLACIAL PHENOMENA OE THE 



15° to 30°, as are many in the Longwathby cuttings and elsewhere. 

 Nor will any other explanation yet given make it clear how these 

 laminated and exceedingly fine clays could be accumulated while big 

 and little stones were being dropped into the soft clays below to 

 such an extent that some of the gutta-percha clays gradually pass 

 into good characteristic till. 



It cannot be doubted that fragments of ice would now and then 

 fall into the soft drifts, contorting the beds some little distance 

 around, and that, as Sir Charles Lyell has remarked, the detritus 

 that accumulated around these lumps of ice would be thrown down 

 in great confusion when the ice melted. Add to this the occasional 

 local contortion caused by the falling of large boulders, the heaping 

 up of masses of coarse gravel upon unconsolidated beds of sand and 

 mud, the slipping forward of soft beds deposited on a slope, and 

 the occasional movement of the slowly melting sheet of ice, and we 

 can see that there is no occasion to call in the agency of floating ice 

 to account for any amount of local contortion which the beds may 

 have undergone. 



In the maritime districts beyond the edge of the ice it is not at 

 all unlikely that floating ice was at work contorting the beds ; but 

 as Mr. Geikie has lately remarked that the importance of floating 

 ice as a boulder-transporting agent has been greatly overestimated 

 in dealing with the JBritish drifts, it is not at all unlikely that what 

 has been set down unhesitatingly as contortion caused by floating 

 ice may, in a few cases, have been in reality due to some of the 

 causes enumerated above. 



In the higher parts of the valleys, where the quantity of water 

 flowing beneath the ice was less than elsewhere, there would be 

 little or no denudation or water-wearing of the drift going on ; so 

 that in such places the accumulation of till must have gone on 

 almost uninterruptedly until no more ice was left. In this way those 

 sloping banks and plains of till that occur high up near the water- 

 sheds must have been formed. 



The boulders in the upper parts of the ice, which in a great many 

 cases must have been those that had travelled furthest, would, as 

 Mr. Geikie has remarked, often be stranded at high levels as the 

 ice melted ; but if the theory here put forward be true, this deposi- 

 tion of the highest boulders must in the majority of cases have been 

 the last work of any given part of the ice-sheet ; so that while till 

 and gravel were being accumulated at low levels, the deposition of 

 the higher-lying boulders was going on ; and it was not until the ice 

 was nearly all melted, and therefore the greater part of the mounds 

 of till and of the eskers was heaped up, that the higher parts of the 

 ice-sheet, with their load of far-travelled and often angular boulders, 

 would be left as traces of the last work of the waning ice-sheet. 



It should, however, be mentioned that in the Eden valley and in 

 the Dale district there are no more boulders on the Eskers and 

 drumlins than occur in sections of those drifts of the same area ; in 

 other words, boulders are quite as common in the eskers as they are 

 on their outsides. 



