306 



light growth of the sandy openings very nearly corresponds with the 

 course of the ridge. 



The elevation of the ridge, its uniformity, and the gravel of which it 

 is composed, admirably adapt it for a highway. Roads have conse- 

 quently been run upon it through a large part of its course in Wayne 

 county, bearing northeast and southwest, from the village of Plymouth, 

 and also through town of York, in Washtenaw county, to Ridgeway, in 

 Lenawee. 



Divergences sometimes occur in this ridge, like those described by 

 Mr. Hall, in the Geological Report of New York, for 1838, and the 

 branches again unite ; or, after being diverted by the valleys of enter- 

 ing streams, it again i-esumes its former general parallelism to the pre- 

 sent shore of the lake. 



The State Topographer of Ohio, Col. Whittlesy, mentions the fact 

 of a "succession of low, gentle undulations, like a broad turnpike or 

 wave, running parallel to the shore" of Lake Erie, in that State. He 

 says they vary in number from one to three, and are distant from the 

 shore from half a mile to five miles, and he supposes they differ in 

 height from ninety to one hundred and twenty feet above the lake. 



" External appearances," he remarks, " certainly indicate that the wa- 

 ters of Lake Erie once stood a hundred feet higher than at present ; but 

 there is not as yet, evidence enough to decide this interesting question. 

 It would be diflicult to find natural barriers for a sea which should have 

 elevated itself to that height." 



From a series of levels, taken during the surveys of the public works 

 of Michigan, I have ascertained the ridge to have here a unifonn ele- 

 ration of one hundred and seven or one hundi-ed and eight feet above 

 Lake Erie, which, it will be perceived, agrees nearly with the estimate 

 of Mr. Whittlesy. The uniformity of this elevation furnishes an addi- 

 tional proof of its having once been coincident with the level of the 

 lake waters. 



The proofe of a former submergence of this whole countiy, are so 

 abundant that the general fact seems well established. It is also plain, 

 that this ridge could not have been formed during that turbulent state 

 ■^f waters which brought upon the rock-covered surface of the country 

 pense deposit of diluvium, but must have resulted from a quiescent 

 the waters. 



