\ 

 D. Bell — The Great Ice Age and Submergence. 349 



accumulate debris. Tims Dr. Geikie goes on to say — "I do not 

 believe it was necessary for the pi'eservation of intercalated deposits 

 that tliey should always have occupied a hollow or depression 

 sheltered from the full sweep of the ice-flow. The great thickness 

 attained by the Till in broad open lowland districts " [this is 

 diiferent from the " narrow belt of coast-land " formerly spoken 

 of] "shows that over such areas there was a tendency for the Till 

 to accumulate, probably owing to a diminished rate of ice-flow. . . . 

 Wherever the flow of the ice-sheet slackened, there would necessarily 

 be less erosive action, and therefore a good chance of pre-Glacial 

 and inter-Glacial beds being preserved" (p. 112; see also pp. 74-5). 



We leave Dr. Geikie to reconcile these clear and distinct state- 

 ments with his arguments for the complete erosion and removal of 

 the marine sediments by the " second glaciation." How could the 

 ice-sheets of that period, while thus largely sparing the " Lower 

 Till " and the overlying fresh-water deposits, pick out and carry 

 away so completely, and from all the low-lying and most sheltered 

 positions in the country, every ti-ace of the marine deposits, 

 " prolific " in organic remains, which must have been there 

 had the sea reached the level, or anything like it, which he 

 contends for ? Does he not require far more of the ice than 

 we do? We suggested that it may have transported some portions 

 of marine clay and sand a few miles inland from the sea ; he 

 supposes that it may have removed hundreds of square miles of the 

 same materials into the sea, sometimes over great distances and 

 across every inequality of ground, and left scarcely " a wrack 

 behind"! Truly we may say, "glacier-ice has played many strange 

 freaks, but one may be excused for doubting whether it is equal 

 to this remarkable performance" (p. 141). 



Indeed, we do not require to go beyond this individual section at 

 Clava to show how untenable Dr. Geikie's position is. Here, in 

 this upland valley of the Nairn — where, be it noted, there is every 

 evidence that the action of the ice was along the valley, and not 

 across it,^ — here are some 36 feet of partly stratified deposits overlaid 

 by a great thickness of Boulder-clay. The " second glaciation " must 

 evidently have been in great force here, to have laid down more 

 than 40 feet of this "Upper Till." Yet it did not wholly "clear 

 out " or " sweep away " the previously existing beds of " fine sand " 

 and " blue clay " ; it merely covered them up — at least SG feet of 

 them — and passed on ! What ground is there for saying that it 

 would do otherwise in hundreds of similar, or far more sheltered, 

 localities all over the country ? 



But if we wish another instance to confirm the view which we 

 are now maintaining, it is furnished to our hand in that immediately 

 afterwards referred to by Dr. Geikie (p. 142), viz. — 



The Strathendriclc Shelly Till, which was described by Mr. Jack, 

 of the Geological Survey, a good many years ago, as occurring 



^ "The Eiver Nairn runs in a north-easterly direction, and the ice-markings 

 on the floor of the valley indicate that the later ice-flow adhered pretty closely to 

 the direction in which the river now flows" (Trans. Inverness Sci. Soc, vol. ii). 



