106 DE- EOBEET BELL ON 



Trentou limestone forms the surface, the diiferent geological formations become success- 

 ively more and more deeply buried as they fold over this line, one after another, each 

 forming a long curve or " nose " to the north. Judging by the records of the borings, the 

 northern point of the Niagara formation, where it curves round this axis, may touch the 

 north shore of Lake Erie, while the Onondaga formation probably occupies a great part of 

 the county of Essex, and is in turn followed by the Corniferous, Hamilton, and the 

 Portage and Chemirng, in Lambton. Northward of Plympton and Bosanquet the axis of 

 the anticlinal gradually rises, and in following it on in the same direction, the order of 

 the reappearance of the formations in succession along it becomes, of course, the reverse 

 of what it had been to the south of that region, and we get the Corniferous in the cou.nty 

 of Huron, followed by the Onondaga, G-uelph and Niagara in that of Bruce. The south- 

 west course of the Onondaga formation, on the east side of Lake Huron, first pointed out 

 by the writer in 1861, proves the existence of an anticlinal to the west under the 

 lake. Owing to the existence of the synclinal or belt of higher Devonian rocks, which 

 Sir William describes as crossing the country in a nearly north and south course from 

 Lake Huron to Lake Erie, shewing that the strike is really in that direction, it would 

 necessarily follow, from structural considerations, that there must be an accompanying 

 anticlinal to the west of it, and we have just seen that this brings to the surface the older 

 Devonian rocks under the drift in the Enuiskillen region, and that it is, in fact, the 

 Cincinnati anticlinal. 



Prof Edward Ortou, State Geologist of Ohio, has published a valuable report on the 

 recent discoveries of petroleum and inflammable gas in the north-western part of that 

 State. He thinks the Trentou limestone received its low arched form along the Cincinnati 

 anticlinal in that region before the next formation was deposited upon it, which would 

 indicate extensive movement at a very early geological time. He says : " There is a smaller 

 measure for these shales by 200 feet in the central region than there is immediately to the 

 eastward. In other words, there is an arch in the underlying Trenton, revealed by the 

 drillers, of which no hint whatever could be obtained by the surface exposures " (p. 29). A 

 further upward movement of the anticlinal may have taken place in Ontario after the 

 formation of the Corniferous limestone, and before the deposition of the Hamilton shales 

 upon it, for in certain parts we find the Marcellus shale eastward and westward of the 

 axis, but not directly ujpon it. 



The Onondaga formation is shewn by borings to carry important beds of salt near its 

 base, and to be greatly augmented in volume in Western Ontario along a belt to the east 

 of the anticlinal, and apparently parallel to its axis, all the way from the county of 

 Huron to Essex ; and it is possible that the shallow sea or bay in which these deposits 

 took place had the same general drection, and that it was held in position by the arched 

 form of the older strata, the successive beds of salt being formed as slight changes in the 

 sea level took place from time to time. Beds of salt of considerable thickness are found 

 again westward of the axis, along St. Clair River. 



t The cause which produced the Cincinnati anticlinal mrrst have begun at a very early 

 geological period, and appears to have been of continental extent. It is worthy of notice 

 in this connection that, if its general course were prolonged northward in the vast 

 regions of the more ancient rocks, it would pass through the central and clearly volcanic 

 portion of the great Huronian trough of the Abittibi region, and further on would follow 



