DRIFT IN CANADA. 



251 



of the last-named rock, together with more or less rolled 

 or worn masses of granite, gneiss, &c. 



The fragments from the Silurian shales often possess 

 sharp and well-defined edges, showing that they have not 

 been water worn or removed far from the rock from 

 which they originated. They are found not only a few 

 inches from the surface of the parent rock, but in nume- 

 rous instances from fifteen to twenty feet above it, im- 

 bedded in a peculiar manner in the blue clay. Some of 

 the larger fragments are scratched and grooved. 



A cursory inspection of the artificial cliffs, as they ex- 

 isted during the construction of the esplanade, was 

 sufficient to show that a considerable number of the 

 pebbles and imbedded masses of rock did not occupy the 

 position they would assume if they had not been sub- 

 jected to some other force besides that of gravity or 

 water in motion. The inclination of the subjacent rock 

 is so slight (thirty feet in the mile) that for all purposes 

 of the present inquiry it may be considered horizontal ; 

 and it may be further remarked, that there is no reason 

 to suppose that any material change in position has oc- 

 curred since or during the accumulation of the blue clay. 

 A large number of the fragments of rock seen in the blue 

 clay are symmetrically inclined at an angle of 60°, 70°, 

 and 80° to the horizon, and frequently lean towards the 

 east and north-east. 



What force has thus symmetrically arranged these frag- 

 ments of shale, &c. ? That they now preserve the po- 

 sition into which they were forced by pressure, or that 

 they were brought from a distance and left in that position, 

 is sufficiently evident, as we cannot entertain the opinion 

 that the rock on which the boulder drift rests has materi- 

 ally changed its inclination since or during the Drift epoch. 



