130 JOURNAL AND PROCEEDINGS 



five or six streams of the Saugeen river. Of these one, the central 

 or Big Saugeen, deserves especial notice, for its valley in some places 

 exceeds a mile and-a-half to two miles in width and over a hundred 

 feet in depth, its banks being ridges of stratified gravel. Here and 

 there in its bed the rock reaches the surface ; but while exposures 

 are abundant on the more northern tributaries that flow through 

 Durham and the Rocky Saugeen further north, as a rule these rock 

 exposures are absent from the main stream, until Ayton is reached 

 in Grey County and Walkerton in the adjacent County of Bruce. 

 The valley of the branch in which Durham is situated is in like 

 manner over two miles in width from mouth to mouth, and in depth 

 over a hundred feet. 



Returning to the escarpment's edge, the next valley of import- 

 ance is that of the Credit in Caledon Township. This presents a 

 great resemblance to the valley known as Glen Spencer, Dundas, 

 but exceeds this both in breadth and depth. It is evidently a valley 

 of erosion, the Credit having cut its way down through three hun- 

 dred feet to the lower beds of the Medina rock, and in so doing 

 formed a romantic fir and pine-clad glen of half a mile to a mile in 

 width. From the fact that the superficial deposits seem, so far as 

 noticed, to occur only sparingly, it would seem that in the Credit 

 we have an ancient river, re-cutting its bed to a lower level. 



The Grand River, with its tributaries, the Irvine, the Speed, 

 and the Canestoga, presents picturesque valleys, especially the 

 canyon of the Irvine at Elora, north of Guelph. There the river 

 Irvine has excavated a narrow gorge to the depth of nearly a hun 

 dred feet in Guelph limestone, and from the fact that no recent 

 deposits are found on the sides, one may infer that the gorge is of 

 modern formation. Other picturesque valleys occur at various 

 points along the line of the main stream, especially at Gait, where 

 the ancient river-valley is plainly visible, and where the present 

 diminished stream wanders through flats of its own making. 



Again, coming eastward to the edge of the escarpment, the 

 valleys of the Twelve and Sixteen Mile Creeks of Halton county are 

 worthy of a brief notice. Deep and wide glens, wooded to their 

 tops, visible from a long distance, both of lake and of land, break 

 the uneven outline of the summit. Like the Sydenham, the Beaver 

 and the Credit, too, the streams wander on through deep gorges cut 

 far into the plains ; that of the Sixteen Mile Creek being remarkable 



