SUPERIFCIAL GEOLOGY OF DUNDAS VALLEY. I 29 



This elevation would, therefore, have to be compared with the eleva- 

 tion of the old channel at St. David's and at Queenstown. 



This may form an objection to the theory that Dundas valley is 

 an old river channel. From the nature of the Niagara beds in this 

 district, and from the frequency and extent of the fractures through- 

 out these beds, it may be that at the folding over of the anticlinal, a 

 fracture of considerable dimensions occurred and thus opened a 

 direct passage to the streams of the district and enabled them to 

 operate upon the softer shales lying underneath the limestones form 

 ing the surface. This theory receives some color from a large 

 fracture extending from the ravine at Albion Mills back into the 

 country for some miles. The fissure thus opened will gradually be 

 enlarged by the action of the water, the frosts in winter and other 

 atmospheric changes. At the opening of the first Glacial period this 

 gorge would present a natural pathway to the ice, and by the grind- 

 ing of the glacier along its sides would be enlarged to form an 

 opening of considerable extent. On the retiring of the glacier, the 

 stream would resume its sway until the return of the ice would still 

 further widen the gorge and on retiring close up the avenue com- 

 pletely and leave the country to the action of the lake, when the 

 upper beds would be gradually re-arranged into the form we now 

 find them. 



DRIFT FILLING UP THE VALLEY. 



Through the agency of the sections seen in the streams running 

 through the valley, we have a general knowledge of the upper beds 

 of the drift, while the records of well-borings give us a pretty fair 

 idea of what is to be found further down. 



What is the floor of the valley, and at what rate of inclination 

 does it go up the valley ? I think these questions can be answered 

 in a partially accurate manner. 



In Hamilton the hard rock of the Hudson river formation has 

 been reached at a depth of 227 feet below lake level, and near the 

 centre of the valley, on Lot 40, of the first concession of Ancaster, 

 at an elevation of 232 feet above lake level, a well 30 feet deep came 

 the sandstones of the Clinton formation. This rock would therefore 

 be 202 feet above lake level. These elevations would give a general 

 inclination of about 434 feet in seven miles, or about 62 feet to the mile. 



Although this is the approximate rate of inclination it cannot be 



