PART V. 



SYSTEMATIC OUTLINE OF THE GEOLOGY OF CEN- 

 TRAL CANADA, COMPRISING THE PROVINCES 

 OF ONTARIO AND QUEBEC. 



As explained in preceding sections of this work, the various rock- 

 formations which make up the outer portion or so-called crust of the 

 earth do not form a single unbroken series, but belong to various 

 epochs of formation. These epochs comprise five primary divisions 

 or ages : determined partly by the superposition of their rocks, and 

 partly by the fossilized organic bodies which many of these rocks 

 contain. The ages bhus recognized are as follows : 

 5. The Present or Existing Age. 

 4. The Cainozoic Age. 

 >. The Mesozoic Age. 

 2. The Palaeozoic Age. 

 1. The Archsean Age. 



These ages, although distinct in the main, offer, as in all historic 

 periods, a gradual passage from their older into their newer epochs. 

 The rocks by which they are made known to us are of three princi- 

 pal kinds : Sedimentary or Stratified rocks, represented by ordinary 

 sandstones and limestones, clay-slates, clays, sands, &c., many of 

 which contain the fossilized remains of plants and animals living on 

 the earth when the rocks in question were formed ; Foliated or 

 Stratiform-crystalline rocks, represented by gneiss, mica-schist, crys- 

 talline limestone, &c.; Eruptive rocks partly crystalline, as granites 

 and syenites ; partly compact or aphanitic in texture, as ordinary 

 traps and basalts ; partly scoriaceous, as ordinary lavas ; and partly 

 vitreous, as obsidian. 



In the Dominion of Canada, viewed in its entirety, examples occur 

 of all these rocks, and each of the five great geological ages is repre- 

 sented by rock-formations ; but in the separate Provinces of the 

 Dominion, the rock-representatives of some of the geological ages are 

 unknown. Thus within the boundaries of Ontario and Quebec there 

 are no known rock-formations of Mesozoic or Cainozoic age. Viewed 



