364 H.. H. Howorth—A Great Post-Glacial Flood. 
forming either one broad belt or several narrower bands, broken by 
intervening beds of slate. This igneous zone is overlaid on the 
west by a thick bed of gravel, which for a space of about three 
miles broad and twenty-four miles long entirely conceals the beds 
lying next to the mountain chain. On the coast near Clynnog the 
gravel forms the entire cliffs, nearly 100 feet high; on the east of 
Caernarvon and Bangor it passes inland at some distance from the 
Menai Straits; it terminates northwards on the coast between Aber 
and Penmanmawr. It consists of rolled fragments of all sizes, 
from mere pebbles up to huge boulders, all apparently derived from 
the rocks of the Snowdon chain. The valley which contains this 
great drift deposit is the more remarkable when contrasted with the 
valleys on the east of the chain, which comparatively are free from 
eravel. There is, however, a similar accumulation of gravel in 
some of the lower parts of the south-west of Caernarvonshire.” 
(Sharpe, Journ. Geol. Soe. vol. ii. pp. 805, 306.) 
Let us again turn to those whom I have styled the Old Masters. 
This time we will appeal to Dr. Buckland, not Dr. Buckland at the 
time he published the Reliquiee Diluvianie, but Dr. Buckland when 
he had turned his back on his old self and had become the friend and 
champion of Agassiz and his Glacial theories and the President of 
the Geological Society. After describing the Glacial striz and 
rounded rocks in the valley of the Ogwyn, he adds, that he saw “no 
indications of undisturbed moraines in the valley of the Ogwyn, but 
that he was of opinion that they may have been obliterated by the 
rush of water which transported the northern drift, and effected a 
lodgment of it on Moel Faban at the end of the Glacial period” 
(Proceedings Geol. Soc. vol. iii. p. 581). Again, after showing in 
detail how in various places in North Wales traces of Glacial action 
are clearly discernible, he proceeded to consider the remodification of 
Glacial detritus by violent inundations, stating that the only two cases 
mentioned in his paper of deposits resembling moraines are both on 
the South-east side of the great mountain-chain, one at Pen Tre 
Voelas, high up in the valley of the Conway, the other in a high 
mountain valley near Llyn Ogwyn, showing that on that side of the 
chain there are no traces of those accumulations of far transported 
materials which occur on the North-west flank of Snowdonia and 
consist of pebbles of granite as well as other rocks derived from 
Anglesea, Cumberland, or Ireland, associated with fragments of 
existing species of marine shells and a tumultuous mass of other 
detritus. ‘‘ These drifted materials,” he says, ‘‘are found high up on 
the flanks of the mountains, namely, on Moel Tryfaen, at the height 
of 1392 feet, and at Moel Faban more than 1000 feet above the 
valley of the Ogwyn near Bethesda. From the former point they 
gradually descend to the plain which extends to the shore near 
Caernarvon, covering the whole of its surface,” and he concludes ‘that 
their position “ may be due to a great diluvial wave or marine current, 
advancing from the North and propelling before it the materials of 
which the drift is composed” (id. pp. 588 and 584). 
Dr. Buckland tells us further that Mr. W. E. Logan (now better 
