Sketch of the Geology of the Arctic Regions. 3 



The shores of Great Bear Lake are of primitive rocks, sometimes 

 rising into elevations of eight hmidred, or a thousand feet. Detach- 

 ed blocks and gravel, probably the debris of the hills, consisting of 

 quartzose sandstone, fragments of granite, and granite running into 

 gneiss, are found on the surface, and in the vallies. The north 

 shore of Bear Lake is formed by bowlders of limestone. Fort 

 Franklin stands on a bay of the West coast, and the bottom of the 

 bay, and the beach, are strewed with bowlders of primitive and other 

 rocks, of which the following are some of the varieties. Coarse 

 crystalline granite ; felspar, flesh red ; granite, with felspar paler ; 

 quartz in small quantity ; fine grained granite ; quartz and felspar, 

 white, with garnets. Granite, felspar brick red ; quartz and augite, 

 no mica. Porphyritic granite ; sienite ; porphyritic sienite ; reddish 

 brown horn stone porphyry ; crystalline greenstone ; porphyritic 

 greenstone ; pitchstone porphyry ; greenstone slate ; amygdaloidal 

 claystone porphyry ; dolomite ; limestone with corallines ; chert ; 

 white quartz ; coarse sandstone ; fine grained spotted sandstone ; 

 striped sandstone ; and dark red claystone. Some of the granite 

 bowlders were recognised as the same which occur at Fort Enter- 

 prize. 



The soil in the vicinity of Fort Franklin is sandy, or gravelly, 

 covering a bluish plastic, but not tenacious clay, of unknown depth, 

 and during a greater part of the year firmly frozen. Narrow precip- 

 itous ridges of limestone rise in the country west and north of Fort 

 Franklin, which is otherwise level as far as the eye can reach. 



Bear Lake R 



iver. 



Sandstone of a yellowish grey color, associated with beds of bluish 

 clay, forms the solid strata on the banks of the river. Imbedded in 

 them are concretions of various sizes and irregular shapes, of a pur- 

 plish ii'on brown, studded with crystals of sulphate of lime, and small 

 round grains of quartz. Salt springs yielding excellent common salt 

 fall into the river a little below the rapid, at that point where the Rocky 

 Mountains first appear in the distance. The walls of the rapid are 

 a hundred and twenty feet high, and three miles long, consisting of 

 horizontal strata of " earthy looking stone intermediate between clay 

 and sandstone." Lignite with impressions of fern appears in the 

 banks, also ammonites in a brown iron shot sandstone. The lime- 

 stone ridge below the rapid stands on a narrow base, and its general 



