42 



of the escarpment affords many excellent exposures of the 

 formations beneath; in the Niagara gorge the section ex- 

 tends down to the Richmond, and in Manitoulin island to 

 the Collingwood. The lower Ordovician formations are 

 best seen on the small islands north of Manitoulin. The 

 western peninsula affords numerous exposures of the upper 

 Silurian formations and the different members of the 

 Devonian series, but none of these are to be seen in the 

 Manitoulin islands. 



The following list indicates briefly the points at which 

 the various formations may be most conveniently studied: 



Chemung Kettle point. 



Hamilton Thedford. 



Onondaga Port Colborne, Pelee 



island. 



Monroe Amherstburg. 



Niagara Niagara, Manitowan- 



ing, Collingwood. 



Medina and Clinton. . . .Niagara. 



Cataract Manitoulin island, Col- 

 lingwood, Niag- 

 ara. 



Lorraine and Richmond . Clay cliff, Manitoulin 



island. Near Col- 

 lingwood. 



Collingwood and Utica. .Craigleith. 



Trenton Shore near Colling- 

 wood. 



Lowville, Black River 



and Trenton Islands north of Man- 

 itoulin. 



The relationship of the Cataract, Medina and Clinton 

 formations may be studied to better advantage at Hamilton 

 and at the forks of the Credit. (See Excursions B 3 and B 4). 

 An opportunity to examine the Guelph exposures is 

 presented by Excursion A12. 



The crystalline Pre-Cambrian rocks of the contin- 

 ental protaxis occupy the whole of the eastern shore of 

 Georgian bay and extend along the north shore of Lake 

 Huron. The subdivisions of the Pre-Cambrian recognized 

 within the area covered by the excursion are, in descending 

 order, as below: — 



