Classification of Rocks, 53 



Oxford, Perth, Elgin, Middlesex, and portions of several other counties 

 adjoining these. Further west, it occurs in the counties of Kent and Essex. 



Hamilton Shales. 



This formation is a great mass of dull olive, blue, or black argillaceous? 

 tind bituminous shales, 1,000 feet in thickness in New York, but probably 

 not so thick in Canada. It occupies portions of Kent, Essex, and Lamb- 

 ton. 



Chemung and Portage Grolts. 



These rocks, or those of the same age, only touch this province on the 

 north side of the Bay of Chaleur, in Gaspe, where they are overlaid by the 

 lower part of the coal formation. They consist of sandstones, and are the 

 ■equivalents of the Devonian or Old Eed Sandstone Group. In Gaspe, they 

 are said to be 7,000 feet in thickness, and constitute the highest rocks of the 

 Geological series in Canada. 



In the Tables which follow, an attempt has been made to exhibit in a 

 form convenient for reference all the formations which may be expected to 

 occur in each of the counties of Upper and Lower Canada. We are well 

 aware that there is a probability of its not being correct in some of the par- 

 ticulars it contains. It must be borne in mind that there is no correct Geolo- 

 gical Map of the whole Province yet published, and it is almost impossible 

 to arrive at all the meanderings of these belts of rock with the materials for 

 compilation at present extant. The tables, however, will be of use as a 

 guide to the principal localities in a general way, and each reader can fill up 

 with further details from his own district at his leisure. In Lower Canada, 

 the country lying on the south side of the St. Lawrence, below Montreal, has 

 t)een greatly disturbed by ancient convulsions of nature, and much difficulty 

 will be experienced in ascertaining the boundaries of the tracts occupied by 

 each formation. The whole of this region is Silurian, with the exception of 

 the Devonian rocks in Gaspe, and the Lower Silurian lies next the St. Law- 

 rence, the Upper being inland near and upon the boundary line between 

 -Canada and the United States. 



The above are the only solid rocks to be seen over nearly all the Pro- 

 vince of Canada. In the neighbourhood of Lakes Huron and Superior, 

 what are called trap rocks, are of frequent occurrence. These are considered 

 to have originated during the phenomena of ancient volcanoes. Where the 

 •earth has cracked open and the melted matter from the interior has oozed 

 up to the surface and there solidified these trap rocks have resulted. They 

 are also found in Lower Canada. The mountain at Montreal, and others 

 which will be hereafter examined, are examples of trap hills. 



