Section IV., 1896. [ 137 ] Trans. R. S. C. 



VIII. — Paloiozoic Outliers in the Ottmca River Basin. 



By E. W. Ells, LL.D. 



(Read May 21, 1896.) 



The presence of fossiliferous sediments at various points throughout 

 the valley of the Ottawa has been known for many j^ears, and some of 

 these have been described in considerable detail in the earlier reports of 

 the Geological Survey. Important and extensive collections of the con- 

 tained fossils have been made from time to time, both by otïicers of the 

 Survey'and by others interested in the subject, and the horizon of most 

 of these outliers has thus been ascertained. JSTo regularly arranged tables 

 of these fossils have, however, hitherto been made and published.^ 



The formations recognized embrace the whole range of the Cambro- 

 Silurian (Ordovician) system from the Potsdam sandstone to the Lorraine 

 shales, both inclusive, while certain areas of newer strata, found at widely 

 separated points, show that the Medina and Niagara formations of the 

 Upj)er Silurian are also represented. 



The basin of the Ottawa River, as determined by its tributaries, is 

 extensive, the drainage area probably comprising not far from 130,000 

 square miles. The Ottawa itself follows a somewhat peculiar course, the 

 upper part for nearly three hundred miles flowing westward from its 

 source near the upper waters of the Gatineau, one of its principal tribu- 

 taries from the north, to the head of Lake Temiscaming, while the lower 

 portion flows in a nearly opposite or southeasterly direction to its junc- 

 tion with the St. Lawrence, a distance in a direct line from the head of 

 Temiscaming Lake of about four hundred and fifty miles. 



The height of land which sepai'ates the drainage basin of the Ottawa 

 from that of James Bay is found a short distance to the north of the 

 upper stretch of the river. That part of the basin between the main or 

 lower portion of the Ottawa and the northern divide is occupied for the 

 most part, in so far at least as is now known, by crystalline rocks com- 

 prising limestones, gneisses, granites, etc., of Archaean age, which have 

 alwaj^s been regarded as belonging to the Laurentian system. To the 

 north of Ottawa city the height of land is about two hundred and thirty 

 miles distant, and the eastern limit of the drainage area is marked by 

 the Eiver du Nord, which after a somewhat irregular course to the 

 northwest of Montreal enters the Ottawa Eiver about thirty miles west 

 of its junction with the St. Lawrence. To the west of Lake Temiscaming, 

 the line dividing the Ottawa waters from those of Lake Huron on the 



1 The publication of these lists is for the present deferred, owing to the large 

 amount of material therein contained. They will, however, shortly appear in the 

 report of the Geological Survey on the areas adjacent to the Ottawa River. 



