SUPERFICIAL GEOLOGY OF DUNDAS VALLEY. IO7 



is composed chiefly of dark colored broken shale, having, where notice- 

 able, a western dip. This broken shale can be traced for nearly a mile 

 along the road leading into the village of Copetown. That these 

 two exposures (the one at Crysler's and the one at the 

 swamp) are on the opposite sides of the height of land is obvious, 

 both from the dip of the beds of sand and shale, as well as from the 

 course of the different streams having their rise in the district — all 

 the streams on the western side running in a southwestern direction 

 to the Grand River or Fairchild's Creek, while the eastern side sends 

 all its streams down the valley to the Dundas Marsh. This swamp lies 

 on the top ot the ridge, and its outlet (if outlet it can be called) is 

 through the gravel to the southwest.* The depth of 

 this swamp has never been properly ascertained, but it is 

 generally estimated to be somewhere between fifty and sixty feet. 

 From a series of measurements made by aneroid, I made this swamp 

 520 feet above the level of Lake Ontario. The hills around the 

 swamp rise to a considerable height above it. This ancient beach, 

 for it is without doubt an old beach, is flanked on both sides by 

 high, long shaped and rounded hills, of reddish sand, heaped up ap- 

 parently by glacier or water action, and showing no signs of stratifica- 

 tion, beyond that here and there the underlying sand assumes a 

 bluish tint. 



The belt of sand to the west of this ridge is much broader and is 

 less broken than that on the eastern side. On the west, the hills as 

 a general rule are long rolls stretching first in a southwesterly direction, 

 but to the westward, gradually assuming a more northerly and south- 

 erly position. The margin of this sand belt beginning to the west of 

 Jerseyville, passes easterly in a semicircular form around the height 

 of land, and borders a large district of stratified clay, On the east- 

 ern side the hills are in a great measure cone shaped and broken, 

 passing into clay mounds within a short distance down the valley. 

 In many places I have noticed these cone shaped hills to contain 

 conglomerate. In continuation of this ridge a broad belt of sand 

 and silt, more or less broken and rolling, passes towards the south- 

 east to the line between the townships of Ancaster and Glanford, 



* This outlet can only be of any effect when the swamp is swollen by the heavy rains of 

 Fall or Spring. 



