V 

 Prof. E. Hull — Glacial Deposits of Aberdeenshire. 451 



difficulty, and suggests the washing and rounding process above 

 referred to ; but if this were carried on under the waters of the sea 

 it involves the recognition of submergence, a view borne out by the 

 presence of sea-shells. 



Next we have to consider the mode of formation of the Upper Red 

 Clay (No. 1) which is found overlying the gravel and sand deposit 

 (No. 2). Mr. Jamieson considers this to be undoubtedly the pro- 

 duct of submergence to a depth of some 30Q feet; but Mr. Bell 

 regards it as of purely glacial (or land-ice) origin. It is not sur- 

 prising that as Mr. Bell regards No. 2 as the product of land 

 glaciation, he should take a similar view with regard to the Upper 

 Red Clay with boulders. But again I ask — why, if all these three 

 deposits are the products of similar physical agencies, should they 

 assume such diversified forms as to be capable of, not only definition 

 under different terms, but of illustration along the line of a sea-cliff 

 under very different modes of representation, as Mr. Jamieson has 

 shown ? If they have originated from one and the same agency, 

 why should they not have been found as represented by a solid 

 mass of Boulder-clay from top to bottom ? The same or similar 

 conditions would, we may suppose, have produced similar results. 

 Instead of three deposits superimposed and each differing from the 

 other, we might have expected one solid ground-moraine formation 

 throughout. Then, in order to maintain the purely land-glacial 

 origin of No. 1, according to Mr. Bell, we have to explain in 

 some way (to myself unintelligible) the presence of marine forms, 

 enumei'ated by Mr. Jamieson,' consisting of shells, such as Astnrte 

 horealis. Cyprina islandica, Saxicava sulcata, etc. ; remains of fishes, 

 swimming birds (eider-duck), seals, starfishes (Ophiura). These 

 forms were not found, it should be observed, on or near the surface, 

 but sometimes imbedded deep in the clayey mass. No doubt Mr. 

 Bell would reply that their presence is to be accounted for by sup- 

 posing that these forms were carried from the sea to the land by the 

 glacier.- But if this be the explanation, I would observe that the 

 ice of the North Sea, whether derived from Scandinavia or Scotland 

 itself, was only forced over the land while the North Sea was 

 blocked by ice, in which there were neither shells, starfishes, nor 

 probably seals. On the whole it would seem that Mr. Jamieson 

 has on this point the preponderance of the evidence ; and if so, 

 considering the sub-glacial conditions under which the Upper 

 Boulder-cLiy was clearly deposited, it does not seem surprising that 

 in the waters " marine life was far from abundant." 



It seems to me that the confusion which has arisen amongst the 

 neo-glacialists regarding the glacial phenomena of the British Isles 

 is largely due to the practice of confounding aqueous with glacial 

 deposits. As long as deposits, such as No. 2 above, consisting of 



' Supra cit., p. 166. 



2 If it be the iutention of Mr. Bell to represent this by his map, I may observe 

 that on comparing the lines of the ice movement with the arrows given by Prof. 

 James Geikie in his map in the "Great Ice Age," they are almost always at right 

 angles : both cannot be correct. 



