GEOLOGY 231 
tude 81 30', having marked mineralogical characters by which 
the identity of some garnets from Tiskernaces was established. 
Drawing a conclusion from such observations, it became evident 
that the main line of the drift, indicating the direction of its 
motion, runs from south to north." ' 
Dr. Bell in his report on the geology of Hudson bay and 
Hudson strait, 1885, draws attention to the flow of the ice from 
the land on both sides of the strait into that body of water, 
while the striae on the islands in the strait show that a great 
stream of ice passed eastward through the strait from Hudson 
bay into the north Atlantic. These observations have since 
been confirmed by observations of the striae on other islands of 
the strait. 
Tyrrell's observations on the glacial phenomena of the bar- 
ren-land region west of Hudson bay show that the country was 
intensely glaciated; that the centre of glaciation was on a nearly 
level plain now elevated some 400 or 500 feet above sea-level, 
there being no evidence to show that it was much more elevated 
during the period of glaciation. The centre of ice distribution 
was situated close to the western shores of Hudson bay, and the 
moisture sufficient to allow of such an accumulation of ice was 
probably derived from an open Arctic sea. The glacier moved 
south and southwest from this centre up a gradual grade to 
Manitoba, where morainic accumulations are found on the sum- 
mits of the Duck mountains at elevations from 1,800 to 2,400 
feet above present sea-level. Striae evidently formed by moving 
ice from this centre have been found by Dr. Barlow and the 
writer on the branches of the Moose river to the south of James 
bay, where the movement was from the northwest. 
There is little doubt that the ice also moved northward from 
the centre of glaciation, and that the evidence quoted above of 
the erratics found in the western Arctic islands is proof of 
 
