Vol. 51.] AND GRAVELS OF ABERDEENSHIRE. 475 



ments mixed through' them. 1 This seems a very insufficient 

 reason for having recourse to the expedient of a submergence. 

 And to adduce the upper limit of these gravels, even where no 

 shells have been found in them, as proving submergence to that 

 extent, is exactly the mode in which a submergence of 2000 feet 

 was at one time thought to be made out by certain high-level un- 

 fossiliferous gravels in "Wales which are now admitted not to be 

 marine at all. The writer of the Survey memoir says, ' It may 

 be presumed that the interglacial beds here described were accumu- 

 lated during the same submergence that introduced the shells into 

 the interglacial clays of King Edward and Clava. At the latter 

 place a submergence of 520 feet above present high-water mark is 

 necessary to account for the present position of the shells.' 2 This 

 is surely a somewhat hastily drawn conclusion. Every case must 

 be judged upon its own evidence, and must be clearly proved before, 

 it can be made a means of proving others. King Edward and 

 Clava have enough to do to answer for themselves. 3 Considered 

 as evidences of submergence they may both be said to be in a 

 'parlous state.' To take them as proved and admitted marine 

 deposits in order to strengthen the case for submergence elsewhere 

 is hardly admissible. 



Further, the Survey officers differ from Mr. Jamieson in con- 

 sidering the Red Clay simply as an ' upper Boulder Clay ' due to the 

 later glaciation. They say nothing about submergence in connexion 

 with it, nor do they take any notice of the marine remains in it, 

 thereby quashing the evidence for submergence on which Mr. 

 Jamieson chiefly relied. The question occurs, why should frag- 

 ments of shells in the intermediate, ' morainic,' ' false-bedded ' sands 

 and gravels be taken as proving submergence, and those in the .Red 

 Clay be quietly passed over ? 



Briefly, Mr. Jamieson took the intermediate sands and gravels as 

 purely glacial, saying nothing about submergence in connexion with 

 them, but thought that the Red Clay did indicate submergence. 

 The Survey officers reverse the finding in these respects ; they 

 interpret the sands and gravels as evidences of an interglacial sub- 

 mergence, and consider the Bed Clay as purely glacial. 



By this diversity of opinion I feel emboldened to state, with all 

 deference, my own view, which is that both the deposits in question 

 are due to the same cause, — the one to an earlier and the other to 

 a later stage of the same glacial conditions, and that submergence 

 is not indicated, far less proved, by either of them. 



We have already seen how weak is the case for submergence as 

 inferred from the intermediate sands and gravels. Let us now 

 turn to that which has been made out from the Bed Clay. 



Having clearly shown, by the facts which we have summarized, 

 the glacial origin of this clay, — that it was due to a great sheet of 

 land-ice moving northward along the coast, — and also stated the 



1 Op. cit. p. 22. 2 Ibid. p. 23. 



3 The shelly clay at King Edward is only about 150 feet above the sea, and 

 so, in any ease, cannot help us much in a question of 520 feet. 



