1870. | W. BLEASDELL—-MODERN GLACIAL ACTION. 669 
8. Oxsservations on Moprrn Guacrat Acrion in CANADA. 
By the Rev. W. Breaspett, M.A. 
(Communicated by Principal Dawson, F.R.S., F.G.S.) 
Sir Cartes Lyrrt, in his ‘ Principles of Geology,’ has drawn 
attention to the effects of glacial action in Canada in the trans- 
portation of large stones and boulders on the shores of the river St. 
Lawrence to new positions by the powerful agency there exercised, 
more or less, every winter. As this subject possesses much geolo- 
gical importance, I write down a few observations of this kind that 
may be of interest. 
There can be no doubt that in every portion. of the province 
where large rivers, streams, and lakes abound, the effects of ice may 
be seen a the removal of eravel, stones, and shingle from sites 
where they have remained since the Boulder-drift period. 
On that arm of Lake Ontario which commences at the outlet of 
the river Trent, at Trenton, and runs in a zig-zag direction for 
nearly 90 miles until it meets the main lake near Kingston, named 
the Bay of Quinte, the waters are frozen over every winter to a 
thickness of from 13 to 23 feet. Near the head of the bay (with 
which, from a residence of nearly twenty years, I am more especially 
conversant), and at some period during the season, a crack occurs 
right across from shore to shore. If this strikes a gravelly shore at 
either end (as it frequently does), the ice forming the crack being 
lifted up on each side, gravel, shingle, or stones may be seen im- 
bedded in the ice which has thus been lifted up. These have been 
taken from the shallows by the ice coming into contact with them. 
This shows the effect of such ice on a shallow gravelly shore where 
the water is not more than from 1 to 2 feet deep. And hence it 
may be concluded that, not only from such shores, but also from 
muddy ones, earth, sedge, and other matters are transported to new 
localities at the breaking up of the ice in the spring, when the 
waters rise by the melting of the snows; and thus we have a pre- 
sent geological agent acting powerfully every season in the removal 
of gravel, stones, boulders, and earthy matter to distant spots. 
In the rapids of the rivers in Canada loose cakes of ice, named 
flood-, anchor-, or pack ice are formed ; and in the river Trent these, 
being formed thus a short distance above the deep water of that 
river’s mouth, either pile up in a high mass on the solid ice below, or 
find their way under it, and, floating down to the bar near the 
mouth in the bay, there eventually dam up the waters more or 
less, and occasionally flood the banks. A large flood of this kind 
inundated the lower streets of the village of Trenton in January 
1867; and the water freezing forthwith, there was a layer or stra- 
tum of ice of over a foot in thickness there for the rest of the 
winter. A flood of this extent is of unfrequent occurrence, how- 
ever, and the ice barrier generally gives way before the waters rise 
to this level. From a similar cause the lower part of the city of 
Montreal was flooded by an accumulation of anchor-ice from the 
