MICHIGAN ACADEMY OF SCIENCE. 



183 



The Geology of the Western End of Lake Erie does not appear to have been 

 very well worked out by either Michigan, Ohio, or Ontario. It is therefore 

 with some diffidence that I advance an opinion. I am, however, convinced 

 that those forces which gave rise to unconformity between the Silurian and 

 the Devonian strata, caused an expansion of the Devonian sea southward 

 and southeastward. In proof of this let it be stated that the rock outcropping 

 on Pelee Island, and (as I am told) on Middle Island and Kelley's Island, 

 in Lake Erie, is the same as that in the Amherstburg Quarries in Anderdon 

 Township. The approximate limit of deposit of the Devonian westward 

 corresponds, very probably, as nearly as may be, with the international 

 boundary line until it passes North Bass Island, thence curving southward 

 till it passes the west side of Kelley's Island. If this be (as I believe it to 

 be), the delimitation of the Devonian in this direction, it follows that the 

 Corniferous strata rest unconformably upon the earlier deposits of the upper 

 Silurian at the west end of Lake Erie. 



The surface extension over the entire upland of Pelee Island is the same 

 thin-bedded limestone as lies over the heavy bedded stone in the Amherst- 

 burg Quarries. At the north end of the island the rock has faulted, leaving 



Showing the heavy beds from which the block stone was quarried for tlie Canadian Sault canal 

 locks, and for the old locks at the American Sault. The same quality of stone was taken from 

 Pelee Island to build the locks at Port Colborne, on the Welland canal. 



a bluff, with north exjjosure of the thin and heavy bedded lime. About the 

 middle of the island on the west side, is another similar elevation of 598 

 feet to 608 feet, or thereabout, breaking off eastward at an angle with the 

 north and south faces of the ridge. But at no place on the Island is there 

 an exposure deep enough to show the high grade limestone that underlies 

 the heavy beds. 



The siliceous strata occurring in the Sibley quarry, near Trenton, Wayne 



