584 
Carnarvon, covering the whole of its surface; and Dr. Buckland is of 
opinion that their position may be due to a great diluvial wave or ma- 
rine current, advancing from the north and propelling before it the 
materials of which the drift is composed. Similar detritus exists also on 
many of the lowersea-cliffs on various parts of the coasts of Carnarvon- 
shire, Cardiganshire*, Denbighshire and Cheshire ; likewise in the 
vale of Clwyd, where the author, in 1836, found, on the property of Mr. 
Lloyd, near the Cefn Cave, fragments of marine shells associated with 
the usual detritus}; and he infers, from the fact of Mr. Trimmer and 
Dr. Scouler having discovered recent marine shells and drifted pebbles 
over the bones in the cave, and from the admixture of the bones of 
mammifers with diluvium in Kirkdale, Torquay, and other caverns, 
either that those caves were submerged subsequently to their having 
been inhabited, and again raised above the level of the sea, or that 
vast irruptions of water, apparently loaded with icebergs, had over- 
whelmed the country. Dr. Buckland also calls attention to accumu- 
lations of similar detritus spread over the plains of Cheshiret, Staf- 
fordshire, Shropshire§, &c.; also to a hill of diluvium about six miles 
south-west of Carnarvon, crowned by the camp of Dinas Dindle, 
pointed out to him by Mr. Trimmer in 1836. ‘The beds of gravel 
and clay composing the hill are strangely contorted, and though 
their phenomena were inexplicable to him at the time he examined 
the spot, he is now disposed to think that the curvatures are due to 
the lateral pressure of icebergs, after the manner suggested by Mr. 
Lyell in a paper on the cliffs of the Norfolls coast]. 
In conclusion, Dr. Buckland says, he must refram from entering 
on the general subject of Diluvium and Drift, a sufficient number of 
facts not having been accumulated to admit of final conclusions. 
His present object has been only to bring forward new evidence of 
the action of glaciers and bodies of driftmg water in the highest 
mountain-passes of Snowdonia and the subjacent valleys, and to 
show that there, as in the mountain groups of Cumberland and 
Scotland, if it be admitted that both glaciers, moving upon dry 
land, and icebergs, floating on water, have produced deep and last- 
ing impressions, by friction, upon the surface of the hardest rocks 
over which they passed, and that both have also transported detritus 
and erratic blocks to regions distant from their native source, to 
each of these causes may be assigned its proper function, without 
assuming the exclusive agency of either of them. 
* Mr. W. E. Logan has called Dr. Buckland’s attention to the occurrence 
of chalk flints in drifted gravel near Cardigan, over a space of twenty-four 
square miles. Some of the mounds of gravel are from 80 to 100 feet high. 
Mr. Logan attributes the origin of these chalk flints to a current from the 
north. ; 
t For accounts of the diluvial phenomena of this district, see vol, i. p. 
402; also Reports of British Association, vols. v. and viii., and Jameson’s 
Edinb, Journ. vol. xxiv. p. 423. 
t Notices of Sir P. Egerton’s papers, vol. ii. pp. 189, 415. 
§ Abstracts of Mr. Murchison’s paper, vol. ii. pp. 77, 230 ; also Silur, Syst., 
chap. xxxvii. 
|| Ante, vol. iii. p. 171. q Ibid, pp. 332, 345, 
