212 A. \V. G. WILSON — TRENT RIVER SYSTEM 



a paper published three years ago the writer very briefly outlined some 

 of the facts and conclusions given herein more detail.* The important 

 bearing which the studies then made appeared to have on the origin of 

 the Saint Lawrence outlet from lake Ontario led him to delay fuller pub- 

 lication until he had been able to continue and extend the field work 

 begun at that time. During the past two summers every locality men- 

 tioned in the context has been visited, and in many cases the writer has 

 been able to revisit (in a few instances several times) critical points after 

 the first draft of this paper was prepared. The absence of good maps of 

 any kind for the province of Ontario, except some old county maps of 

 the eastern portion of the province, has greatly hampered the work and 

 necessitated longer and more detailed work in the field than would 

 otherwise have been necessary. 



The published sheets of the topographic map of the adjacent parts of 

 New York state have proved of great assistance. As might be expected, 

 the topography on the Canadian side of the Saint Lawrence is very sim- 

 ilar to that across the boundary. One of the maps, which accompanies 

 this paper (plate 8), prepared from the New York topographic map of a 

 portion of this area, will thus serve to illustrate the type of bed-rock 

 topography that is characteristic of the whole region under discussion. 

 The writer is indebted to Dr F. J. H. Merrill, State Geologist of New 

 York, for copies of the Saint Lawrence sheet of the geologic map of New 

 York state, and to Lieutenant Colonel Anderson, Chief Engineer, De- 

 partment of Marine and Fisheries, Ottawa, for very detailed profiles from 

 which the sections across the bay of Quinte were prepared. Above 

 water-level the sections were surveyed by the writer. The other maps 

 which accompany this paper were prepared from the admiralty charts 

 of the bay of Quinte, the charts of lake Ontario and the Saint Lawrence 

 river, published by the War Department, Washington, and from county 

 maps. 



The discussion deals with the topographic features of that portion of 

 the province of Ontario which lies east of lake Simcoe and north of lake 

 Ontario, together with that portion of New York state which borders on 

 the eastern end of lake Ontario. The eastern limit of the area is the 

 Thousand Island group. 



Geology of the Area under Discussion 

 the bedrock geology 

 As is well known, Saint Lawrence river, in the vicinity of the Thousand 



* A. W. G. Wilson : Physical Geology of Central Ontario. Trans. Can. Inst., vol. vii, 1900-'01, p. 168 

 et seq. 



