Vol. 51.] AND GRAVELS OF ABERDEENSHIRE. 477 



haven, it still invested the sea-bed and blocked the passage ? 

 Would it not be thinnest and ' less heavily developed ' to the 

 south, and therefore first give way there ? Thus it would keep 

 receding gradually northward, the sea becoming more and more 

 open to the south as it withdrew. Accordingly, before — probably 

 loog before — it was deep open sea at Peterhead and Fraserburgh, it 

 would be deep open sea in the neighbourhood of Stonehaven, and 

 the ice ceasing, as we have said, to go north, there would be no 

 fine red mud carried thither for deposition in the deep still water 

 when that came. The two conditions thus seem incompatible — the 

 northward-moving ice-sheet excludes the deep water, and the 

 deep water excludes, or precludes, the northward-moving ice- 

 sheet. 



Besides, could sea-water afford the tranquillity which seems to 

 have been required for the deposition of this fine mud ? Would 

 not waves, and tides, and currents play their part, especially so 

 near the coast, and prevent anything like so fine and, in parts, 

 so ' delicately laminated ' a deposit ? 



Again, why is this deposit, if marine, so ' remarkably devoid of 

 remains of animal and vegetable life ?' It is rare to find shells in 

 it, and when they do occur they are very scanty and usually in 

 broken fragments. 'For a marine deposit,' Mr. Jamieson con- 

 tinues, ' the scantiness of fossils is surprising ; for the greater part 

 of it seems absolutely barren/ The only explanation he can give 

 is that this extreme sparseness of organic remains ' seems to point 

 to a sea in which marine life was far from abundant.' 



Sir Charles Lyell has stated that he once thought ' the absence 

 of signs of organic life in the Scotch drift might be connected with 

 the severity of the cold, and also in some places with the depth of 

 the sea during the period of extreme submergence ; but,' he adds, 

 x my faith in such an hypothesis has been shaken by modern in- 

 vestigations, an exuberance of life having been observed both in 

 Arctic and Antarctic seas of great depth, and where floating ice 

 abounds. ' 1 So that the supposition of a sea in which marine life 

 only sparingly existed does not seem very satisfactory. 



These being some of the difficulties, one is disposed to ask 

 whether it is necessary to assume that this Red Clay was laid down 

 in the sea at all. It contains marine remains, truly, ' very scantily 

 and in fragments ' ; — is there not every reason to believe that these 

 have been brought along with the Eed Clay and the fragments of rocks 

 from a distance, by the ice which moved northward along the 

 coast ? And if ' still water ' were required for the deposition of 

 the clay (which, by the way, occurs most abundantly, as might be 

 expected, in the hollows and depressions and little valleys of the 

 district), would not that condition most likely be furnished by the 

 ice which passed northward along the coast, blocking the drainage 

 of the adjacent country, and causing ' extra-glacial lakes ' here and 

 there along its margin ? It seems inevitable that such effects would 



1 ' Student's Elements of Geology,' 1871, p. 154. 



