No. 5.] SPENCER — SURFACE GEOLOGY. 281 



luay be seen — at the Garrison Commons, just west of Toronto, 

 where the stiflF chiy contains angular fragments and slabs of shales 

 and harder rocks of the Hudson river formation, together with 

 well-rounded and scratched Lauren tian boulderi--. 



The Erie Clay in the Dundas Valley^ is essentially of mode- 

 rately deep-water origin, with only the upper portion of the 

 deposit exposed, and rather free from pebbles. An interesting- 

 characteristic of this clay is that it burns to form buff-colored 

 bricks (popularly white bricks), while the overlying clay burns to 

 red bricks (Dr. Bell). It is finely stratified with frequently thin 

 seams of sand. In the Dundas valley, the best exposures are on 

 the sides of the branch of the Dundas marsh, which passes up to 

 Beasley's hollow, west of Hamilton. It is especially well shown 

 along the side of the marsh between the Protestant and Catholic 

 cemeteries. There is here an exposure about 30 feet thick. A 

 considerable portion of the terrace which extends from Dundas to 

 Hamilton, at a height of about 70 feet above the lake, has its 

 margin, bordering on the Dundas marsh, underlaid by Erie clay 

 for about the lower 30 feet of exposure. The upper portion of 

 the terrace is made up of a highly arenaceous clay of yellowish 

 brown color, resting unconformably on the surface of the Erie 

 clay, which had been denuded, and in places removed by streams 

 before the deposition of the clay, which when wet resembles a bed 

 of sand in strata from one to three inches thick. This latter clay 

 is probably the representative of the Saugeen days, and is best 

 shown in section along the Hamilton and Dundas street railway. 

 An unconformable junction is exposed just near the " basin " of 

 the Desjardins canal at Dundas. This latter clay forms the 

 loamy soil of one of the finest pieces of farming land in Canada. 

 At the cutting of the Hamilton and Dundas railway, between 

 the Half Way house and marsh, there is associated with the latter 

 depo>it a bed of very fine gravel where the pebbles are less than 

 an inch in diameter. This may possibly be of more recent origin. 

 In Be;isley's hollow, near Ainsley wood, these clays rest on the 

 Mtdiiui shale, and are represented by only a few feet exposed. 

 According to Dr. Bell (as we have noticed before), the Erie clays 

 extend to at least 60 feet below the surface of Lake Ontario, in 

 the Dundas valley. To what depth it extends I cannot say, but 

 it i> underlaid by a Till to a depth of about 227 feet below the 

 lake, near the margin of the ancient valley described in former 

 pa^>: . The '•'■Brown clays^^ are also exposed on the northern 

 Vo„. X. s No. 5. 



