SOME LOCAL DETAILS. 



199 



toward the mountain. On the glaciated surface lies 

 boulder clay holding local and travelled boulders. Above 

 this is clay and sand in layers, with numerous shells of 



many species, capped by sand 

 and gravel filled with Saxicava. 

 On the surface are here and 

 there groups of Laurentian 

 boulders. A few years ago all 

 these appearances were well 

 seen, but at present the quarry- 

 ing operations have been carried 

 toward the S. E. side of the 

 ridge where the eroded surface 

 of the limestone is covered only 

 with a little soil. Farther open- 

 ing to the eastward may again 

 expose the glacial deposits. The 

 appearances at this place are, 

 I think, conclusive as to the 

 action of floating ice drifting 

 ^ g up the river valley from the 

 N.E. The direction of stria tion 

 and of movement of material 

 and the marine character of 

 the deposits all testify to this. 

 We have already seen that 





beaches holding littoral shells 

 occur at Montreal mountain 

 south-west of this limestone 



plateau up to a height of 470 feet, and at one place in the 

 mountain toward its northern side there is a small plain, 

 in the subsoil of which there occur shallow-water shells 



