476 MR. D. BELL ON THE SHELLY CLAYS [Aug. I?95, 



reason why the ice moved in that direction, Mr. Jamieson unex- 

 pectedly proceeds to consider the ' progress of the submergence.' 1 

 What submergence ? The facts which have just been mentioned — ■ 

 the ice-blocked condition of the North Sea, and a great glacier from 

 the mountainous region to the south creeping up along the coast — 

 seem far from justifying any such hypothesis. 



I am rather inclined to think that a submergence of 500 feet or 

 more being at the time he wrote generally accepted, Mr. Jamieson 

 ■ — to whom I would invariably refer with the greatest respect — 

 simply admitted it among his facts, not deducing it from them. 

 Having observed that ' the fine red mud implies deep, or at least 

 quiet water,' he adopted the submergence as furnishing what was 

 required. The first fact, however, which he mentions in connexion 

 with it presents a difficulty. ' There is no evidence at the bottom 

 of the clay of littoral mollusca, such as would indicate shore-con- 

 ditions at the commencement of the submergence As a rule, 



it [the fine red mud] lies immediately on the top of the grey Boulder 

 Clay without the intervention of any beach-gravel or sand between 

 them, as if still water of some depth had at once taken the place 

 of the glacier.' To explain this, Mr. Jamieson supposes that the 

 glacier did not break up till a considerable amount of submergence 

 had occurred. ' In this way deep water would take the place of 

 the ice as soon as it floated off the bottom, and the red mud would 

 then settle down on the exposed surface of the grey Boulder Clay.' 

 Then, as the submergence proceeded, the glacier gradually retired, 

 sending out red mud all along its margin. And this process, Mr. 

 Jamieson conceives, would begin at the N.E. corner of the country, 

 where the ice was ' less heavily developed ' than elsewhere ; the 

 thinnest ice would yield soonest, and the sea-water would thus first 

 establish itself, say, ' in the neighbourhood of Peterhead and Fraser- 

 burgh, and thence creep south and west along the coast as the ice 

 gradually broke up.' 2 



Now, there seem to be several difficulties in the way of Mr. 

 Jamieson's theory. The chief and most obvious is this : — It was 

 the ice-blocked condition of the North Sea which compelled the 

 land-ice from Kincardine and Forfar to turn northward along the 

 coast, as it clearly appears to have done. As soon as that condition 

 began to give way, and in proportion as it approached an end, the 

 ice would undoubtedly cease to take that direction and would pro- 

 ceed out eastward to the more or less open sea. The compelling 

 cause of its turning northward being removed, and a more direct 

 exit at the same time set before it, of course it would turn northward 

 no longer. The ice in the North Sea being thus the domi- 

 nating factor in the case, the question arises, where would it most 

 likely give way first ? Be it remembered that it was land-ice, 

 chiefly from Scandinavia, occupying as a solid mass the bed of the 

 North Sea. Can we imagine that in the north, at Peterhead and 

 beyond, that ice had melted away, while in the south, at Stone- 



1 Quart. Journ. Geol. Soc. vol. xxxviii. (1882) p. 168. 



2 Ibid. p. 168. 



