OF THE PARALLEL ROADS OF LOOHABER. 
691 
sea-bed at the entrance to the Irish Channel is strewed in places with fragments of 
granite, while on the slopes of the Little Sole there occurs a debris of “ large angular 
and rounded granite.” Supposing that one section of the great North British glaciers 
or ice-sheet descended the bed of the Irish Channel, is it possible that it may have 
extended so far as lat. 49 c N. and long. 10° W., and that this angular granite may be 
old glacial debris, or that in the Little Sole and adjacent banks we have remaining the 
moraine heaps of the old ice mantle ? 
The wide range of the ice-flow from the Scotch and North of England mountains 
as centres would also seem to indicate that the elevation of those areas was then 
relatively greater than at present to the surrounding areas. 
There is, therefore, some reason to believe that at the inset.of the glacial period 
the land of Scotland may have stood not less than from 1,000 to 1,200 feet higher than 
now, and, for all indications to the contrary, that height might even have been con¬ 
siderably more. 
If, however, the extent of the elevation of the land at the commencement of the 
glacial period be somewhat uncertain, owing to the difficulty of precise proof in such 
cases, there is no such uncertainty respecting the submergence that succeeded the first 
period of glaciation, the extent of which we are enabled, in consequence of the different 
nature of the proofs, to measure with some degree of certainty. 
§ 10. The Effects of the Subsequent Submergence on the Climate and on the Ice-sheet. 
It has been clearly established, on the evidence of fossiliferous marine beds, that 
after the first great glaciation of the country, the south of Scotland was submerged to 
the extent of 500 to 600 feet or more ; while in northern and central England, 
Wales, and Ireland the submergence is proved, on the same evidence, to have been 
not less than 1,300 to 1,500 feet. There is, however, no similar proof of the submer¬ 
gence having been of like importance in the north of Scotland or in the south of 
England. In Aberdeenshire'"' Mr. Jamieson has shown that the beds of this period of 
submergence do not extend higher than 300 feet. In Banflshiret I have found them 
at a height of about 250 feet; while in the district between the latter place and 
Lochaber they have not been recognised at greater elevations than about 100 feet— 
viz. : at Ardersier, near Fort George.| Still further north, in Caithness, a shelly 
boulder clay extends to a height of 200 feet, but there is yet some difference of opinion 
as to its origin. On the west coast marine clays of this age have been described by 
Mr. B. B. Watson in Arran § at an elevation of 320 feet ; in Bute they are formed no 
higher than 40 feet; while on the coast of the northern Highlands none have been 
* Quart. Journ. Geol. Soc., vol. xxi., p. 170. 
t Trans. Geol. Soc., 2nd ser., vol. v., p. 146. 
X Jamieson, Quart. Journ. Geol. Soc., vol. xxx., p. 321. Height not mentioned. In ‘ The Abstracts 
of Spirit-Levelling of Scotland ’ the height of the Ardersier Church above the sea-level is given at 87 feet. 
§ Trans. Roy. Soc. Edin., vol. xxiii., p. 526. 
