300 F. Leverett — Correlation of Moraines, etc. 



and perhaps the whole of the Ontario basin aud the eastern 

 Erie basin. The only outlet remaining is through the Lake 

 Huron and Lake Michigan basins to the Chicago outlet. The 

 distance to which the ice-sheet had retreated in the Lake Erie 

 basin seems to warrant ns in believing that the Huron and 

 Michigan basins may have been so far cleared of ice as to 

 afford an outlet in this direction, either around the north end 

 of the Southern Peninsula or across it via Saginaw Bay and 

 Grand river valley. 



Summary and Conclusions. 



From the data above presented it appears that Lake Erie in 

 its earlier stages was but a small body of water, its size being- 

 conditioned by the position of the retreating ice-sheet and by 

 the height of the western rim of the basin it occupied. It at 

 first occupied only a portion of the district between the outlet 

 and the western end of the present lake, the remainder of the 

 basin, including the whole of the area of the present lake, 

 being occupied by the ice-sheet. Its south and north shores 

 were then at the Yan Wert ridge, while its eastern border was 

 at the Blanchard moraine. 



By a recession of the ice-sheet northeastward to about the 

 meridian of Cleveland, the lake became much expanded and 

 its level was lowered a few feet, though the outlet still con- 

 tinued down the Wabash. Its north and south shores then 

 occupied the second or Leipsic beach, while on the east the 

 waves beat against the ice front. The ice-sheet itself seems to 

 have broken into bergs at its margin, and to have formed no 

 terminal moraine at that time though its lateral moraine is 

 well developed. 



A subsequent recession resulted in the lowering of the lake 

 below the level of the Ft. Wayne outlet probably by opening 

 a passage to the Chicago outlet for no other outlets were open 

 to this lake at that time through the Huron and Michigan 

 basins. The north and south shores of the lake were then 

 occupjdng the Belmore beach, while the east shore was unre- 

 corded because the waves beat against a vanishing sheet of ice, 

 and the ice itself, as in the preceding stage seems to have 

 failed to form a terminal moraine, though its lateral moraine is 

 strong. 



From the })henomena attending the replacement of the 

 three beaches in Ohio by moraines we are led to suspect that 

 two later beaches which die away in southwestern New York 

 are there connected with moraines, and that similar moraines 

 will be found to connect with the beaches of Lake Ontario, at 



