D. Bell — The Great Ice Age and Suhmergence. 353 



(2) But if any think otherwise, we revert to what we have already- 

 urged as to the limits of the deposit (which have been proved with 

 at least equal clearness) being a far greater objection to the theory 

 of a submergence. 



(3) We would also repeat that the objection drawn from the 

 extent of the *' bed " proceeds upon an assumption to which we are 

 by no means restricted, that the deposit was all transported by the 

 ice at once or en masse. 



At this stage we wish briefly to emphasize one of the points 

 alluded to in the minority's Note, viz. : the striking difference 

 between the composition of the shelly clay, and that of the " rough 

 gravel" below and the Boulder-clay above it. 



Be it remembered that the whole section rests on that belt of Old 

 Eed Sandstone which sweeps along the southern shore of the Moray 

 Firth, from Loch Ness to Fochabers and Buckie. It is surely a 

 remarkable fact that while the stony materials of the deposits 

 between which the shelly clay occurs, consist of from 70 to 80 

 per cent, of Old Red Sandstone, and only 20 to 30 per cent, of 

 the more ancient rocks (schists, gneisses, etc.) of the neighbour- 

 hood ; in the clay itself the proportions are nearly exactly 

 reversed — 70 to 80 per cent, of the more ancient rocks, and only 

 about 20 per cent, of the Old Red Sandstone ! The materials 

 forming the clay have thus been mainly derived from a greater 

 distance than those forming the rough gravel, or " Till," on either 

 side of it. The difference extends even to the sand taken from these 

 separate parts of the deposit. The sand above the shelly clay, and 

 that washed from the coarse gravel below it, is light in colour, 

 consisting mainly of "well-rounded particles of quartz derived 

 apparently from the adjacent Old Red Sandstone." But the sand 

 contained in the shelly clay itself is "dark or dark-grey in colour, 

 and contains much black mica apparently derived from the dis- 

 integration of gneissose rocks" (Report, p. 21). 



On the theory of a submergence, it seems impossible to explain 

 the sharp intercalation of a deposit of this kind, so thoroughly 

 different from its immediate surroundings. 



It has been suggested, indeed, by an esteemed member of 

 Committee, that as the submergence increased the Red Sandstone 

 of the district was all brought under water, and that then the 

 "blue shelly clay," resulting from the waste of the schistose and 

 gneissose rocks that remained exposed, was deposited. This, how- 

 ever, as far as we can see, will not hold good. The bottom of the 

 shelly clay is 487 feet, and its top 503 feet above the sea; whereas 

 the sandstone in the immediate neighbourhood reaches a height of 

 700 to 1000 feet, and further to the south-west it ascends to 1500 feet. 

 And from that direction the principal flow of sediment into the 

 supposed ocean basin would undoubtedly take place. Therefore, 

 long before the sandstone was completely submerged, — of which, by 

 the way, there is not the slightest independent evidence, — there 

 would be such a depth at Clava as is inconsistent with the pre- 

 vailing littoral character of the shells. Indeed, the limited extent 



DECADE IV. VOL. II. NO. VIII. 23 



