62 



Glacial grooving of a most pronounced and interesting 

 character is shown at both the north and south extremities 

 of the island; while, in the interior, long ridges of rock 

 mark the path of the glacier. These ridges, modified by 

 post-glacial weathering, present some very fine residual 

 features. 



-^ 



Glacial grooving in Onondaga limestone; south end of Pelee island, Lake Erie, 

 Ontario. 



Pelee island is the most southerly part of Canada, 

 and was formerly a centre of the grape and wine industries ; 

 but, at the present time, it is largely given up to the 

 culture of tobacco and corn. 



Monroe Formation — The extreme western part of 



the province is so heavily 



covered by drift that exposures are rare. The upper rock 



belongs to the Onondaga and is comparable with that of 



Pelee island. In the Detroit river, however, and in the 



