'2G8 ASSINNIBOINE AND SASKATCHEWAN EXPEDITION. 



CHAP. XXXVII. 



THE LAURENTIAN AND HURONIAN SERIES. 



Distribution of Formations. — The Laurentides. The Lattkentian 



System. — Description of Laurentian Rocks. — Lime and Soda Felspar. — 

 Titanic Iron-ore. — Crystalline Limestones. — Mineral Species in the 

 Limestones. — Intrusive Rocks. — Economic Materials. — Separation of 

 Laurentian Rocks into two Groups. — Extent of the Limestones in this 

 System. — Area of Laurentian Rocks in the Basin of Lake Winnipeg. — 

 Intrusive Rocks. — Character of the Dividing Ridge. — From Milles Lacs 

 to Rainy Lake. — From Rainy Lake to the Lake of the Woods. — From 

 the Lake of the Woods to the Winnipeg. — The Coast of Lake Winnipeg. 

 — Fundamental Gneiss of Scotland, the Equivalent of the Laurentian 

 Series in Canada. — Adoption of the name Laurentian in British Geology 

 by Sir Roderick Murchison, to represent the Oldest or Fundamental 

 Gneiss of Scotland. — The Huronian Series. — Description of Huronian 

 Rocks. 



DISTRIBUTION OF FORMATIONS. 



The distribution of series of formations in the order of 

 their occurrence from east to west in the basin of Lake 

 Winnipeg is as follows : — 



1. Laurentian Series. 



2. Silurian „• 



3. Devonian „ 



4. Carboniferous* „ 



5. Cretaceous „ 



6. Tertiary „ 



* Although this series has not been recognized on the east side of the 

 fossiliferous rocks in the Basin of Lake Winnipeg, yet the occurrence of 

 a Productus in a boulder in the bed of Red River affords presumptive evi- 

 dence that the series is represented there. I have therefore placed it pro- 

 visionally in the enumeration given above. 



