240 THE CARBONIFEROUS SYSTEM. 



locality — Hitchcock, Bailey, and Hind more especially — have adopted 

 the theory of a vein filled with bituminous matter. I regard therefore 

 this mode of occurrence, or the second of those above mentioned, as 

 established, and it only remains to consider whence the supphes of 

 liquid bitumen could have been obtained. I have no hesitation in 

 assigning them to the highly bituminous Lower Carboniferous shales. 

 These beds are manifestly of the same character with the so-called 

 "oil coals" of Nova Scotia, and the earthy bitumens of Scotland. 

 They must have been beds of mud charged with a great quantity of 

 finely comminuted vegetable matter, of the nature of peaty muck, 

 which has become perfectly bituminized, and which probably in an 

 earlier stage of its formation was more prone to ooze into fissures as 

 a Hquid petroleum than at present. The deposit of the Albert Mine 

 would thus be a vein or fissure constituting an ancient reservoir of 

 petroleum, which, by the loss of its more volatile parts and partial 

 oxidation, has been hardened into a coaly substance ; and the examples 

 of similar phenomena which I have seen in Canada induce me to believe 

 that the agency of internal heat would not be required to produce the 

 observed result. It is true that one able observer has supposed that 

 the supplies of petroleum from which the Albertite has been formed, 

 have been afforded by the underlying Devonian beds ; but no evidence 

 exists of the occurrence of bituminous matter in these rocks in New 

 Brunswick. The peculiar Corniferous limestone which is the reservoir 

 of petroleum in Canada, does not occur in New Brunswick, and the 

 Lower Carboniferous shales themselves contain abundance of the 

 material required. In this view, though the Albert shales are Lower 

 Carboniferous, the vein of Albertite must have been formed at a later 

 period, after the beds had begun to experience disturbance. In this 

 as in other respects the deposit of this curious mineral differs remark- 

 ably from ordinary coal, which always constitutes conformable beds 

 contemporaneous with the enclosing strata. 



With regard to the original formation of the shales, their lamination 

 and their great thickness, as well as the nature of their material, show 

 that their formation was gradual, and probably occupied a long period. 

 I do not regard the state of preservation of the fishes as any objection 

 to this. They may have been killed by occasional eruptions of mud 

 loaded with organic matter rendering the water unwholesome. When 

 once embedded in mud of this character, their parts could not be 

 separated, and even then - soft tissues might be preserved, as in modern 

 peat, for a long time. The swarms of cyprids which devoured dead 

 fishes in other parts of the Carboniferous areas do not seem to have 

 been present. Farther, though in some layers the fishes occur in a 



