226 A. W. G. WILSON — TRENT river system 



The discharge from Cameron lake, past the village of Fenelon falls, 

 is through a new channel at the bottom of an older broad valley, with 

 fresh cut canyon walls and a falls about 20 feet over bedrock into Stur- 

 geon lake (plate 6). The distance between the lakes is a little over 2 

 miles. The depression in which the waters expand just below Fenelon 

 falls marks a portion of one of the smaller valleys of the second type, 

 tributary to the main valle}', that occupied by Sturgeon lake proper. 

 The Sturgeon Lake depression is the broadest and longest of the entire 

 system. It lies wholly on limestone rock, Black river, at the northeast 

 end, but chiefly Trenton. It is a valley of the second type, however, 

 having no ancient opening toward the Archean. Northwest of the 

 lake the basset edges of the limestone are found occasionally in the 

 valley side. For the most part, however, near the depression at least, 

 they are obscured by drift deposits. To the southeast the edges of the 

 Trenton limestone may be found at the lake shore in a few places and 

 in various places away from the lake. A low but well marked escarp- 

 ment, with a cliff front in places, marks the southern edge of the valley 

 and lies nearly 5 miles south of the lake. The extreme breadth of the 

 valley is nearly 11 miles. The sides of the valley are usually evenly 

 graded and covered with drift, and it is only in a few localities that the 

 bed-rock outcrops. Following the depression toward the southwest 

 both valley sides may be easily traced for over 36 miles from the dis- 

 charge point of the lake. The southwest part of the valley is occupied 

 by lake Scugog, and the river Scugog, which enters Sturgeon lake below 

 Lindsay, flows along the bottom of the valley. The depression continues 

 about 4 miles southwest of lake Scugog, where it is obscured by the mo- 

 rainic deposits which form the main topographic divide of Central Ontario. 

 In the vicinity of Scugog lake the valley in its present attitude is very 

 broad and flat-bottomed, and the bed-rock is completely drift-covered. 

 The nearest outcrop which the writer has seen is at Lindsay, about half 

 way between lake Scugog and Sturgeon lake. Another outcrop is known 

 to occur some miles to the west of the lake and at a slightly higher level. 

 The similarity of form between the valley sides of the Scugog depression 

 and the Sturgeon Lake depression, where much bed-rock can be found, 

 together with the perfect continuity of the two very strongly marked 

 depressions, makes it highly probable that bed-rock lies not far below 

 the surface anywhere in the vicinity of lake Scugog. The outlet stream 

 from the northeast end of Sturgeon lake passes through a narrow young 

 gorge cut in heavy-bedded Black River limestone to the depression 

 occupied by Pigeon lake. 



Pigeon lake is a slightly complex rock valley partly submerged. 

 From the north there enters a small stream which rises on the Archean 



