SOME LOCAL DETAILS. 189 



To the eastward of the mouth of Trois Pistoles river, 

 the first terrace above mentioned is brought out to the 

 shore by a projecting point of rock. In proceeding west- 

 ward toward isle Verte, it recedes from the coast, leaving 

 a flat of considerable breadth, which represents the lowest 

 terrace seen on this part of the St. Lawrence, and is 

 elevated only a few feet above the sea. This flat is in 

 many places thickly strewn with large boulders, probably 

 left when it was excavated out of the clay. In proceeding 

 westward the first or railway terrace of Trois Pistoles, 

 inland of the flat above mentioned, is seen to consist of 

 boulder-clay, either in consequence of this part of the 

 deposit thickening in this direction, or of the Leda clay 

 passing into boulder-clay. It still, however, at isle Verte, 

 contains a few shells of Leda glacialis in tough reddish 

 clay holding boulders. 



Rivi&re-du-Loup and Cacouna. The country around 

 Cacouna and Riviere-du-Loup rests on the shales, sand- 

 stones, and conglomerates of the Quebec and Potsdam 

 groups of Sir W. E. Logan. As these rocks vary much in 

 hardness, and are also highly inclined and much disturbed, 

 the denudation to which they have been subjected . has 

 caused them to present a somewhat uneven surface. 

 They form long ridges running nearly parallel to the 

 coast, or north-east and south-west, with intervening 

 longitudinal valleys excavated in the softer beds. One of 

 these ridges forms the long reef off Cacouna, which is 

 bare only at low tide ; another, running close to the 

 shore, supports the village of Cacouna ; another forms the 

 point which is terminated by the pier ; a fourth rises into 

 Mount Pilote ; and a fifth stretches behind the town of 

 Riviere-du-Loup. 



