No. 4.] CLAYPOLE — PRE-GLACIAL GEOGRAPHY. 213 



PRE-GLACIAL FORMATION OF THE BEDS OFj 

 THE GREAT AMERICAN LAKES. 



By Prof. E. W. Claypole, B.A., B.Sc. (Lond.) of Antioch Coll., Ohio. 



In a paper by the writer of these lines which appeared in the 

 Canadian Naturalist in April, 1877, under the title " Pre-Gla- 

 cial Geography of the Region of the Great Lakes," an attempt 

 was made to shew that the beds of those inland seas of North 

 America are not results of glacial erosion during the ice age, but 

 that they antedate the ice age altogether, and are due to the 

 action of fresh water streams which flowed in the region at an 

 earlier time, and when the laud, especially to the northward, 

 stood at a higher level compared with the sea than at present. 

 The beds of Lakes Huron, Erie and Ontario were attributed to 

 the action of a pre glacial Mohawk having its sources somewhere 

 in the basin of the first named lake, and flowing past Detroit, 

 where a deep channel is kaown to exist, into the basin of Lake 

 Erie, thence through a similar old and lost channel somewhere 

 near Niagara, into the Ontarian basin, and thence through a yet 

 deeper but now filled up passage near Syracuse and Lake Onon- 

 daga into the valley of the Mohawk, and through that and the 

 present Hudson into the Atlantic. In like manner it was main- 

 tained that the bed of Lake Michigan was a valley formed by 

 the upper waters of a river whose later course was through a 

 deep but buried channel running southward through Illinois, and 

 which has been traced as far as Bloomington, where it is at least 

 200 feet deep. The bed of Lake Superior, it was also suggested, 

 may be the valley formed or occupied by the head waters of a 

 river which flowed away at some point east of Marquette, and 

 traversed the State of Wisconsin along the lines of Lakes Winne- 

 bago and Horicon and Rock River, until it met the Mississippi 

 near where Rock Island now stands. 



Many of the facts upon which the opinions then expressed 

 were founded were derived from the Geological Survey of Ohio, 

 and the whole tenor of the paper was largely in accord with 

 many passages from Dr. Newberry's pen, though in some points 

 the writer was at issue with the distinguished director of the 

 Ohio Survey, and in others he went beyond any conclusions 

 reached in that work. Since the publication of the paper, Dr. 



