1863.1 ]_g7 [Lesley. 



In these older instances of bitumen veins, we see small prototypes 

 of the large vein under consideration. 



The point of the phenomenon most interesting to structural geolo- 

 gists is this : Two opposite deductions are possible from the facts as 

 made known, on the one side in favor of the vast antiquity of the 

 coal oil, and on the other side in favor of the recent denudation of 

 the surface. If we have in this vein a deposit of coal oil hardened 

 by time and the absorption of oxygen, it is certain that the cutting 

 out of the ravines across which it lies, must have taken place subse- 

 quently ; for the outcrop rises to a height of nearly two hundred feet on 

 each side of the bottom of the ravine in which the shaft is sunk. I 

 do not learn from the report whether detached blocks or pieces of the 

 bitumen occur upon the surface, or in the alluvium of the vale below 

 the crossing of the vein. But that is of no consequence to the prin- 

 ciple. The valleys which it crosses must be younger than the vein, 

 if the vein was filled with fluid oil. Hunt shows plainly (see Sill. 

 Journ., March, I860, p. 107), that the oil wliich fills the fossil casts 

 of particular exceptional strata in the Lower Devonian Formation (as 

 in Bertee Township on the Niagara River opposite Buffalo), must 

 be an original deposit, and not a subsequent infiltration or exudation, 

 inasmuch as it has lined with oxidized bitumen the cavities of the 

 fossil casts in this stratum, and not those in similar strata above and 

 below. 



All that we know of the grooving of the surface of our palseozoic 

 areas consents to the great antiquity of the action, whatever that 

 action may have been. To demonstrate the antiquity of the Corni- 

 ferous coal oil, is merely to give more room for the antiquity of the 

 oil. Yet, the denudation, however ancient we may make it, must 

 still be kept more modern than the antecedent formation of the coal 

 oil and its change to bitumen. 



The date of the formation of the oil may be placed anywhere be- 

 yond the close of the Paleeozoic era, even as far back as the begin- 

 ning of the Devonian, or even in Lower Silurian times ; since the 

 Quebec Group is also the home of oil. The denudation of the sur- 

 face of the coal areas, cannot of course be put back beyond the uplift 

 of that area into the air. 



There remain two hypotheses for dating this denudation. One 

 class of geologists, the Cataclysmists, give the date of the uplift as the 

 date of the denudation ; make the two phenomena related and depen- 

 dent parts of one great action. The other class, the Secularists, re- 

 gard the present face of the country as but the latest phase of an 



