130 SUPERFICIAL GEOLOGY OF DUNDAS VALLEY. 



the true level of the old floor. This inclination would, at Dundas, 

 five miles up the valley, give the Clinton formation an elevation of 

 about 80 feet above lake level. The clays in the same neighborhood 

 have, however, been pierced to a depth of 60 feet below lake level 

 without touching rock. Now, by adding these two — 80 feet above, 

 and 60 feet below lake level — we may arrive at the conclusion that 

 between the place where the rock has been found ar 202 feet above 

 the lake and Dundas a break of 140 feet occurs. Professor Spencer 

 estimates the depth of Burlington Bay, from water level to rock, to 

 be 70 fathoms, or 83 feet below the bottom of the boring in Hamil- 

 ton. This 83 feet would therefore have to be added to the break of 

 140 feet we have seen to be above Dundas, making a total break of 

 223 feet. Niagara Falls are 160 feet, and if these measurements are 

 of any value, the pre-glacial age of Dundas valley witnessed a fall of 

 63 feet higher than the present age has the pleasure of beholding. 



The streams running through the valley have cut channels at 

 various depths, many of them piercing the underlying blue clay. 

 The sections of many of these channels, show the clays banded with 

 alternate layers of red and blue clays. 



A section has already been given of the stream in Beasley's 

 Hollow. Further up in the cutting, near Robinson street, the 

 section is : — 



FEET. INCHES 



Red clay, visible 1 6 



Blue clay (almost hard as slate) 1 



Red clay 4 



Blue clay (almost hard as slate) 1 3 



Red clay 5 



Total 12 9 



This is overlaid with reddish yellow clay, covered by a thin 

 layer of gravelly soil. The clays of some parts of the north eastern 

 side of the valley have the same banded appearance. 



On the stream near ths Red Mills, on the Ancaster and Dun- 

 das road, the blue clay, comparatively free from stones, is visible 

 several feet above the stream bed, and is surmounted by heavy 

 beds of a whitish clay. Further up the valley this stream runs upon 

 the top of the blue clay, between high banks of this whitish clay. 



