34 THE OEYSTAL FALLS 1 RON-BE AEING DISTRICT. 



nieaiidering character of its cliamiel. This resemblance is still further 

 enhanced hj the presence of a remnant of a crescent-shaped cut-off, so 

 characteristic of the old age of rivers. Just opposite this cut-off is a lake, 

 which is of interest on account of its possessing two outlets, both leading 

 into the river. Unfortunately this fact was observed on the topographical 

 sheet too late to permit of a return to the field for the purpose of determining 

 the cause of the presence of the two outlets. 



Passing up the stream we soon reach the lakes, which farther on become 

 more numerous. The life history of these lakes is inseparably connected 

 with that of the river. They reached maturity during or at the close of the 

 Glacial epoch, and since that time their history is that of decline. This 

 part of the history of these lakes may be briefly stated as follows: As the 

 erosion continues, the areas of water are reduced and the surrounding swamp 

 areas are correspondingly increased. If a lake were large and considerable 

 inequalities existed in its bottom, two or more small lakes connected by the 

 stream flowing through them may be formed. The final stage is a swamp, 

 traversed by the slow-flowing river. 



The various stages in the history of the lakes are well illustrated on 

 the accompanying map, PL VIII, by the following series of lakes. In Nos. 

 1 and 2 the general character of such bodies of water, which may be con- 

 sidered essentially as mere expansions of streams, is seen. No. 3, and Deer 

 Lake, have long since reached maturity and are advancing rapidly to the 

 point where they will each be separated into two bodies of water. No. 4 

 has already reached this stage, and in the swamp marked A we have the 

 last stage, the swamp, with the stream flowing between peaty banks. 



On Light and Liver lakes, in the lower part of the Deer River, we may 

 see all Ijut the last of these stages illustrated. The lakes are attached to 

 the main river hj very short streams. The main river after leaving- the 

 rapids above, where it accumulates considerable detritus, enters a flat por- 

 tion of its course partly occupied by the two lakes in question. Here, its 

 ra^)idity being diminished, the stream deposits the detritus. Thus it has 

 gradually built a delta, now for the most part covered by swamp growth. 

 This tends to advance the shore line, and thus diminish the water area. 

 The rapid cutting down of the barrier immediately l)elow the lakes by the 

 swiftly-flowing stream tends to lower the lakes and thus diminish their 

 surface area still more. 



