PH|iYSIC;AlL FEATiURES 113 



west from Blue Hawk lake, down the valley of the Burnt river, which 

 would give it a still larger area. Many other similar instances may be 

 observed in all parts of the area. 



TheXdrift, however, is comparatively thin everywhere, and the 

 depressions in its surface probably, in many cases, mark equivalent 

 depressions in the surface of the underlying gneiss, and thus a glance at 

 the map shows the remarkable influence which the strike of the rocks 

 underlying the area has had upon the distribution, position, and shape 

 of the lakes, and upon the course of the streams. In the southern por- 

 tion of the area the lakes lie very largely along the course of the bands of 

 Grenville limestone, while, in the granite region of the north, they form 

 a delicately etched pattern of the surface of the great plain of granitic 

 gneiss, occupying shallow depressions, whose course is determined 

 chiefly by the strike of the coimtry rock ; and, even when the lake 

 runs across the strike, the long arms and bays in its deeply indented 

 shore line will be found to follow the direction of the strike. 



The group of lakes in the townships of Nightingale, Clyde, Sabine, 

 and Lawrence show in a striking manner how the shape of the lakes is 

 determined by the complicated twisting of the strikes in that district. 



