45 



This irregularity in the height of the cliffs, is, of course, 

 produced by erosion, which has swept away the rocks in 

 some places, and left them in others. In general terms, the 

 sections as seen on the lake shore represent a profile of the 

 topography, which was impressed upon the country during 

 long cycles of preglacial erosion. The low drift-filled portions, 

 where no rock is exposed, probably in all cases represent 

 broad valleys cut out by some preglacial stream. Some of the 

 irregularities in height, however, are only apparent, and due 

 to the varying directions in which the sections are cut. To 

 this latter cause must also be attributed the varying dips 

 observed in different parts of the sections, as these sections 

 sometimes extend in the direction of the strike of the strata, 

 or again obliquely across it. In no portion of the sections is 

 the true dip exposed, which, as was noted in Chapter I., is 

 to the south-east. 



The shore of Lake Erie presents a succession of crescents, 

 the projecting points usually being headlands of rock, 

 which frequently extend into the water, and so form an 

 obstacle to walking on the beach. Excepting such in- 

 stances however, the beach is of a character, which allows 

 easy travelling on it. Wherever it is sandy, it is usually 

 much compacted and firm, and will even permit the advan- 

 tageous use of a bicycle. But when the beach is composed 

 of shingle, as on the more exposed portions of the shore, the 

 case is different, for the pebbles are usually smooth flat 

 shale fragments, which slip over each other, and make 

 walking a rather tiresome undertaking, while the use of a 

 bicycle is impossible. 



In the following descriptions of the sections on the Lake 

 Shore, the names applied to them are those by which they 

 are designated in the paper on the 'Faunas of the Hamilton 

 Group" of this region, to which the student is referred for 

 many points not here discussed. If access to the volume on 

 the Geology of the Fourth District can be had, a thorough 

 study of the sections as given on Plate V., should be made. 



