EISING OF THE LAND AROUND HUDSON BAY.^ 



By Egbert Bell, 



Of the Geological Sui'vey of Canada. 



In the Provinces of Ontario and Quebec it has been found from 

 actual levelings by Gilbert, Spencer, and Upham that the old shore 

 lines are not perfectly horizontal, but that they sloije upward in a 

 northeasterly direction at rates varyiug in different regions from a few 

 inches to a foot and even 2 feet per mile. If this upward slope were 

 continued in the same direction to the northeastern extremity of Lab- 

 rador, 1,300 miles from Lake Huron, the increase in the elevation might 

 there amount to 1,000 or 2,000 feet. It is scarcely probable that the 

 differential elevation is constant and regular for such a great distance. 

 Still, it is a fact that well-preserved shore lines are to be seen at great 

 heights in the northern parts of Labrador. In my Geological Survey 

 Eeport for 1884 I have mentioned ancient beaches at Nachvak, 140 

 miles south of Hudson Strait, which have an estimated altitude of 

 1,500 feet above the sea. 



The two sides of Hudson Bay present very different physical char- 

 acters. The eastern is formed mostly of crystalline rocks, and, as a 

 rule, is more or less elevated, with a broken surface sloping some- 

 what rapidly westward or toward the bay; while the western side 

 is mostly very low and much of it is underlaid by nearly horizontal 

 Silurian and Devonian strata. These low shores are accompanied by 

 shallow water extending far to seaward. The head of James Bay, 

 which forms the southern jDrolongation of Hudson Bay, is extremely 

 shallow, but the various rivers which flow into it have cut channels 

 through the soft shallows, and by means of these the land may be 

 approached with seagoing vessels. The whole of Hudson Bay may 

 be said to be shallow in proportion to its great area, as the soundings 

 show that it does not average more than 70 fathoms in depth. 



The shores of the bay everywhere afford abundant evidence that 

 there has been a comparatively rapid rise in the laud and that the ele- 

 vation is still going on. I have mentioned numerous proofs of this in 

 my various official reports on the geology of these regions from 1875 



1 Eead before the Geological Society of America, Philadelphia, December 27, 1895. 

 Abstract as printed in American Journal of Science, fourth series, Vol. I, March, 1896, 



359 



