PROCEEDINGS. 
507 
or bowlders. In the deposits of the ridge native copper has been found ; 
consequently the drift-carrying agent moved southeastward down Georgian 
bay to the western end of the Oak Ridge and probably throughout its 
whole length. North and east of Belleville there are many lower and 
fragmentary ridges, having a trend somewhat across that of the Oak 
Ridge. The glaciation of the region adds great difficulties to the expla¬ 
nation of the phenomena. The striation in the Ottawa valley, from Lake 
Tamiscamang to near the junction with the St. Lawrence, is to the south¬ 
eastward with very rare local exceptions. On the Niagara escarpment, 
between Georgian bay and Lake Ontario, from 1,600 down to 700 feet 
above the sea, the striae are also to the southeast; but between these 
widely separated regions the surface markings of the rocks to the south 
and west are obscured to the west and south by drift, and to the north 
and east absent or rarely seen, although the crystalline rocks are com¬ 
monly rounded or very rarely polished—an absence that can only in 
part be accounted for by subsequent atmospheric erosion. About the St. 
Lawrence and Lake Ontario the striations are to the west and more par¬ 
ticularly to the southwest. Between the Ottawa river and Georgian bay 
there is a high prominence which divided the drift-bearing currents; but 
north of Lake Huron the glaciation is very strongly marked and to the 
southwest, with very rare local variations. 
All the lobes of glaciation about the lakes, from Superior to the Ottawa 
valley, radiate backward to the broad and open but low basin of James 
(Hudson’s) bay. The watershed between the lakes and Hudson’s bay 
during the epoch of the formation of the drift was several hundred feet 
lower than now—it is about 1,600 feet at present—as shown by the 
differential elevation of the beaches. For these conflicting phenomena of 
the drift no explanation was offered, but one was rather sought for. 
Air. C. A. Kenaston presented a paper on the Physical Features 
of a Portion of the British Northwest. 
316th Meeting. March 17, 1S88. 
The President in the chair. 
Fifty members and guests present. 
Air. John AIurdoch presented a communication on An Arch 
of Ice Formed by Horizontal Pressure. 
[Abstract.] 
On February 17,1883, the heavy ice-pack off Point Barrow moved in 
with great violence before a westerly gale, which blew with a velocity of 
sixty miles an hour, and by forcing the grounder “ lava flow ” against the 
