30 



The Ottawa Naturallst. [April 



great numbers of these loose rocks can be seen, one of which 

 measures 20 feet by 15 feet and is 4 feet out of the ground. 



Among channels of more recent date but which are now 

 closed except at periods of high water on the river, two at least 

 may be mentioned. East from Coulonge village a depression 

 in the surface extends to the Ottawa at the north west angle 

 of Calumet Island. The eastern portion of the depression to the 

 west of the river is known as the Grand Marais or Big marsh; 

 and while at ordinary stages of water in the Ottawa much 

 of this is comparatively dry, in the spring it becomes a regular 

 water-course cutting off the great point which extends south-west 

 from Coulonge village to La Passe. 



Further east below Ottawa at the mouth of the Nation river 

 a depression also occurs forming the bay in front of the villnge of 

 Papineauville, and separating that place from what is known as 

 the Presqu'ile. This latter is a long ridge or tongue of gravel 

 and sand which extends east from the mouth of the North Nation 

 River for about six miles. At high water stages the current passes 

 over the narrow barrier at the west end of the Presqu'ile Bay and 

 flows directly past the village. It is quite possible that close 

 investigation in the Ottawa basin would disclose other channels 

 which are now partly filled. 



In this paper it has been the intention to indicate only the 

 most prominent of these old channels. That the submergence of 

 the whole basin has been sufficient to cause the waters of James 

 Bay to unite with those of the Ottawa basin is indicated by the 

 presena of well defined terraces and clay deposits at elevations 

 greater than the present height of land north of Lake Temiscaming. 

 It is probably due to this great spread of inland or ocean waters 

 over this area that the sands and gravels which have been so 

 instrumental in choking up the ancient valley of the river are so 

 widely distributed. That these upper level deposits of clay and sand 

 have not yielded organic remains is only negative evidence against 

 this theory. On similar grounds much of the typical marine clay 

 of the Ottawa and St. Lawrence basins would not be of marine 

 origin since inthe whole stretch north and west of Ottawa city 

 they yield marine fossils only in very lare cases. 





