226 THE CANADIAN NATURALIST- [Vol. X. 



•of about 400 feet above Lnke Onturio, thus showing the former 

 connection of the basins more than 100 feet below the rocky flows 

 which surround them. Even in this depressed area wells are 

 known to reach 60 feet in the drift without meeting with solid 

 rock. 



On the northern side of the Dundas valley the escarpment 

 •after reaching Copetown is buried by the drift. Although the 

 line of buried cliffs recedes somewhat to the northward of the 

 •Great Western Railway, yet there are occasional exposures, as at 

 Troy and other places in Beverly and Flamboro, where the under- 

 lying limestones come to the surface. At Hurrisburg the lime- 

 stones are known to be ab.^ent for a depth of more than 72 feet, 

 .as shown in a deep well in the drift. 



In the town of Paris one well came upon hard rock at 10 feet 

 below the surface, whilst another at 100 feet in depth, reached 

 BO farther than boulder clay. This last well mu^^t have been in 

 ■a buried channel of Nith's creek, as outcrops of gypsum bearing 

 beds of the Onondaga formation frequently occur near the summit 

 •of the hills. From what has just been written, it is easily seen that 

 tfhe Niacrara limestones are absent from -i more or less horizontal 

 floor (which is over 500 feet above the lake, on both the northern 

 and southern sides of the Dundas valley) which continues from 

 Dundas westward to near Harrisburg. when^ it meets a portion 

 of the Grand river valley. But almost immediately west of An- 

 •caster we find streams running northward at right angles to the 

 escarpment, and cutting through drift to the depth of almost 

 hundreds of feet. In fact, if we draw a line from Dundas to 

 northward of Harrisburg (a mile or two), and another from 

 Ancaster southward to the Grand river, we have two limits of a 

 region where the limestone floor has been cut away from an 

 •otherwise generally level region. The southern side of this 

 area is the southern margin of the Grand river valley, between 

 Seneca and Brantford, and the western boundary is composed of 

 •Onondaga rocks east of Paris (which perhaps forms an island of 

 rocks buried more or less in drift). 



Additional proofs may be cited. Ab^nit a mile south of Cope- 

 town a well was sunk to the depth of 100 feet before water was 

 •obtained. At two miles south-ea.st of the same village there is a 

 small pond only 240 feet above Lake Ontario, or more than 260 feet 

 below the neighboring escarpment. This is in drift. Again, at 

 a mile north of Jersey ville, the country has a height of 465 feet, 



