H. L. Fair child — Glacial Lakes in Central New York. 263 



cuse they have not been mapped, but another and lower water- 

 course may be seen from the Auburn branch of the New York 

 Central railroad, heading in a cataract west of Marcellus station 

 and followed by the railroad eastward to beyond Camillus. 



It is possible that one or more of the channels lower in ele- 

 vation than the Cedarvale channel may have established for a 

 short time an independent lake level, but such waters could 

 not have extended westward beyond the Ontario basin, as the 

 planes of these outlets are below that of Niagara. 



Upon the north sides of these channels the morainal drift is 

 heavy and the topography more irregular than shown by the 

 topographic sheets. 



Lake Iroquois. 



These latest glacial waters of the Ontario basin have been so 

 long known that extended description is unnecessary here. The 

 name was given by J. W. Spencer, and Mr. Gilbert correlated 

 the shorelines with the col and ancient outlet at Rome. This 

 large and important body of water had a long life, during 

 which it matured its western shorelines and expanded to an 

 area larger than that of the present Ontario, as its surface was 

 far higher than Ontario, although the retreating ice barrier 

 during most of the life of Iroquois held possession of some of 

 the northern or northeastern part of the basin. 



During the life of Iroquois the differential elevation toward 

 the north-northwest, or canting of the basin toward the south- 

 southwest, produced a shifting of the shorelines, a transgression 

 of the waters upon the southern shores and a recession from 

 the northern shores. This has been graphically shown by Dr. 

 Gilbert.* 



The Iroquois shoreline was not matured east of Sodus 

 although abundant evidence of the water-action exists. South 

 and east of Sodus Bay the map gives only the general or 

 hypothetical position of the water line. 



, The lake became extinct by the opening of the St. Lawrence 

 Yalley and lowering of the water below the Rome outlet. At 

 this time the altitude of the basin was such that the head of 

 the St. Lawrence channel, at the Thousand Islands, was below 

 sea-level, and a gulf of the ocean occupied the Ontario basin. 

 The differential uplift, however, soon barred the sea and 

 initiated the present lake and river. 



* "The History of the Niagara River," 6th Ann. Rept. Com. of State Res. of 

 Niagara, Albany, 1890. 



