164: 



CANADIAN DRIFT. 



[Ch. XIL 



from them the inference that they indicated a more northern climate, 

 the shells agreeing in great part with those of Uddevalla in Sweden.* 

 The shelly beds attain at Beauport and the neighborhood a height of 

 200, 300, and sometimes 400 feet above the sea, and dispersed through 

 some of them are large boulders of granite, which could not have 

 been propelled by a violent current, because the accompanying fragile 

 shells are almost all entire. They seem, therefore, said Captain Bay- 

 field, writing in 1838, to have been dropped down from melting ice, 

 like similar stones which are now annually deposited in the St. Law- 

 rence.f I visited this locality in 1842, and made the annexed sec- 

 tion, fig. 138, which will give an idea of the general position of the 

 drift in Canada and the United States. I imagine that the whole of 



B 



K. Mr. Kyland's house. 



h. Clay and sand of higher grounds, with 



Saxicava, &c. 

 g. Gravel with boulders. 

 / Mass of Saxicava rugosa, 12 feet thick, 

 c. Sand and loam with Mya truncata, 



Scalaria Graznlandica, &c. 



d. Drift, with boulders of syenite, &c. 



c. Yellow sand. 



o. Laminated clay, 25 feet thick. 



A. Horizontal lower Silurian strata. 



B. Vallev re-excavated. 



the valley, B, was once filled up with the beds b, c, d, e, /, which 

 were deposited during a period of subsidence, and that subsequently 

 the higher country (h) was submerged and overspread with drift. 

 The partial reexcavation of B took place when this region was again 

 uplifted above the sea to its present height. Among the twenty-three 

 species of fossil shells collected by me from these beds at Beauport, 

 all were of recent northern species; the only supposed exception, 

 Astarte Laurentiana, being now considered by good conchologists as 

 a variety of the British A. compressa (see fig. 139). I also examined 



b & *- 



Astarte compressa, Flem. = A. Laurentiana. 

 a. Outside. o. Inside of right valve. c. Left valve. 



the same formation farther up the valley of the St. Lawrence, in the 

 suburbs of Montreal, where some of the beds of loam are filled with 



* Geol. Trans., 2d series, vol. vi. p. 135. Mr. Smith of Jordan Hill had arrived 

 at similar conclusions as to climate from the shells of the Scotch glacial drift, 

 f Proceedings of Geol. Soc, No. 63, p. 119. 



