474 



Canadian Record of Science. 



a complicated series of rocks of unknown origin, but com- 

 prising a considerable amount of intrusive material. He- 

 regards it as either 

 the remains of a 

 primitive crust pen- 

 etrated by much igne- 

 ous matter, or as a 

 series of altered rocks 

 older than the Gren- 

 ville Series, and 

 formed under differ- 

 ent conditions. In 

 any case it seems to- 

 wan t the evidences of 

 ordinary aqueous de- 

 position presented by 

 the limestones, iron- 

 stones, quartzite, and 

 schists of the Gren- 

 ville Series. Similar 

 views were advocated 

 in my address on the 

 " Geological History 

 of the Atlantic," be- 

 fore the British Asso- 

 ciation, in 1886. 1 



Fig. 1. — Distribution of Grenville Limestone in the district north of 

 Papineauville, with section showing arrangement of the beds. 

 Scale of map 7 miles to an inch. (See also Dr. Bonney's- 

 paper, Geological Magazine, July, 1895, p. 295. ) 

 Dotted area : Limestone. 



Horizontal lines : Upper gneiss (fourth gneiss of Logan.) 

 Vertical lines : Lower gneiss (third gneiss of Logan.) 

 Diagonal lines : Overlying Cambrian and Cambro-Siluriani 

 (Ordovician. ) 



The Upper Laurentian of Logan (Labradorite, Anortho- 

 site, or Norian Series), supposed by him to overlie the 



1 See also Museum Memoir on Eozoon, pp. 2 T 3. Montreal, 1888. 



