SUPERFICIAL GEOLOGY OF DUNDAS VALLEY. I 25 



another time above the water, the waves washing over it caused a gra- 

 dual changing of the materials, and the formation of the beds of gravel 

 and sand dipping away from the lake. He also refers to the spit or 

 island lying in front of Toronto harbor. Davenport Ridge like Bur- 

 lington Heights- is underlaid by clay. 



The Beach at the head of the valley has already been referred 

 to, and it is therefore unnecessary to again refer to it beyond that its 

 elevation being about 560 feet above Lake Ontario, or 792 feet 

 above sea level, a height corresponding within a few feet of 790 of 

 Mr. Roy's table. 



From what has already been said concerning this beach, or 

 ridge, it might be inferred that this was the line of division between 

 the two lakes at some past period of the geography of the. district, as 

 at present it is the watershed of the two drainage systems of Lake 

 Erie and Lake Ontario. 



Concerning the other old beaches in the valley, little can be 

 said. Remains of two can, I think, be shown to exist in parts only. 

 I have not yet traced either of them sufficiently to be able to describe 

 them. 



The Geological survey * gives us information of two old 

 water margins in the vicinity of Dundas, thus : " to the west of the 

 town of Dundas is an old water margin at an elevation which seems 

 to coincide with the Burlington Heights, while on the north side of 

 the town another ridge of gravel and sand attaining a height ot 318 

 above the lake, occurs just under the escarpment of the Niagara for- 

 mation. In its eastward extension it recedes from the cliff and 

 diminishing in height disappears at the end of a mile. It approaches 

 the face of the escarpment on the east side of Spencer's ravine, on 

 the other side of which a still higher bank of sand and gravel con- 

 nects the escarpment and was probably at one time connected with 

 the gravel ridge, which would thus have formed a bar between the 

 former outlet of Flamboro' Creek and the waters which then filled 

 the Dundas valley." 



This gravel ridge is, I think, the end of the one found running 

 across the valley and forming the beach dividing the lower portion of 

 the valley proper from the upper one, on the Hamilton and Ancaster 

 road. At the road it is about 120 feet above lake level. 



* Geology of Canada, page 914. 



