THE LAURENTEDE MOUNTAINS. 



269 



THE LAURENTIAN SERIES. 



The origin of the name Laurentian and the cha- 

 racter of the rock series which compose this system is 

 described by Sir William Logan and Mr. Hunt in the 

 following extract from a " Sketch of the Geology of 

 Canada." 



THE LAURENTIDES.* 



" The province of Canada is traversed, through its 

 whole length, by a mountainous region dividing it into 

 two basins, which may be distinguished as the northern 

 and the southern basins. These mountains, which have 

 been named the Laurentides, form the north shore of the 

 St. Lawrence, from the gulf as far as Cape Tourmente, 

 near Quebec ; from which point they leave the river, and 

 while they follow its general direction become more and 

 more remote, until near Montreal, they are at a distance 

 of ten leagues from the St. Lawrence. Going further 

 westward, this mountainous region follows the line of the 

 Ottawa, and crosses this river near the Lac des Chats, 

 fifty leagues from Montreal. Thence taking a southward 

 direction, it reaches the St. Lawrence near the outlet of 

 Lake Ontario, and from this point running north-west- 

 ward, the southern limit of this formation, reaches the 

 south-eastern extremity of Lake Huron, at Matchedash 

 Bay, and forms the eastern shore of the lake as far as the 

 47th degree of latitude, where quitting this lake, the for- 

 mation gains Lake Superior, and extends in a north-west 

 direction to the Arctic Sea. 



" To the south of the St. Lawrence, this same region 



* A Sketch of the Geology of Canada, serving to explain the Geological 

 Map and Collection of Economic Materials sent to the Universal Exhibition 

 at Paris, 1855, by W. E. Logan, F.R.S., and T. Sterry Hunt, A.M. 



