Spencer.] 



322 



[March IS, 



the lake, as that is the elevation of the divide between the upper waters of 

 these two rivers. 



The outlet of Lake Erie, indicated in this paper, is known at many places 

 along its route to have no rock-bed for a distance below the surface of the 

 higher lake, and to a probable depth shown below sufficiently great to 

 empty Lake Huron. 



Again, Mr. Carll has shown that the Allegheny drainage passed near 

 Dunkirk into the Erie basin at a place just opposite to its outlet, as indicated 

 by the present writer. 



Much of the Dundas valley is underlaid by stratified Erie clay, which is 

 known to extend to a depth of 60 feet below the surface of Lake Ontario, 

 according to Dr. Robert Bell. In the upper part of the vallej% streams 

 have exposed some deposits of unstratified clay filled with angular shingle, 



Fi^.Z. 



Fig. 2. — 1. Hudson River Formation ; 2. Medina shales; 3. Niagara and Clinton 

 dolomites with some shales. A, C, D, B, modern valley at meridian of Burling- 

 ton Heights ; a, C, D, b, modern valley at meridian of Dundas; a, e, d, e, b, sec- 

 tions across, deeply excavated in beds of streams in western part of the Dundas 

 valley; 4. Boulder clay filling ancient valley ; 5. Erie clay; 6. Talus from sides 

 of escarpment ; 7. Old beach, 108 feet above lake at Burlington Heights. G. Des- 

 jardin's canal leading from Dundas marsh to Burlington bay ; W, W, well at 

 Royal Hotel, Hamilton ; W, another well at Dundas; L. O, level of Lake On- 

 tario; L, E, level of Lake Erie, Horizontal scale, 2 miles to an inch ; vertical 

 scale, 40U feet to an inch. 



derived from the thin beds of limestone forming the upper portion of the 

 Niagara Formation, In the eastern portion of the valley, the Erie claj'- is 

 overlaid unconformably by brown Saugeen clay or loam (stratified). In 

 the upper portions of the valley the hills are capped by brown claj's or 



