PBTEOLBUM IN ONTAEIO. 103 



running west-north-west, or parallel to the longer axis of the Petrolia area, but the general 

 bearing of all these together would be north-west and south-east, or in the direction of 

 the Bothwell area already alluded to. 



The petroleum of the Euuiskillen region was early conceived by Logan and Hunt to 

 occur on the course of the great Cincinnati anticlinal, which was, however, thought to be 

 connected with the anticlinal of the head of Lake Ontario ; and, following up this view, 

 maps were published, and much was written by others, tracing the supposed position of 

 the anticlinal, and shewing where oil might be looked for along its course. In the 

 " Geology of Canada " (p. 379) Sir William Logan says : " The general course of the main 

 anticlinal can be readily traced by means of the distribution of the formations. It would 

 appear that the crown of the arch runs in a gentle curve from the western extremity of 

 Lake Ontario by Woodstock, in the neighbourhood of which the base of the Corniferous 

 folds over it. Proceeding thence by the Thames in the general course of the Great Western 

 Railway, it would reach the town of Chatham, and then pass to Pigeon Bay, on Lake 

 Erie. The springs of Euniskillen would appear to lie north of this axis, and they may 

 probably be on a subordinate one, parallel with it ; which may be connected with the 

 undulation that has been already mentioned as aflecting the outcrop of the Guelph form- 

 ation at Rockwood." It is stated ("Geology," p. 363), that " a belt of higher Devonian 

 rocks crosses the country from Lake Huron to Lake Erie, and divides the region into two 

 areas. These newer strata occupy a saddle-shaped depression on the great Cincinnati anti- 

 clinal, which runs nearly east and west through the peninsula ; while the course of this 

 depression or synclinal is nearly north and south from Plympton on Lake Huron to 

 Orford on Lake Erie." 



There seems to be no doubt that the occurrence of petroleum in Enniskillen is 

 connected with the Cincinnati anticlinal, but the writer, after having done a considerable 

 amount of geological work in Western Canada at various times since 1859, and having 

 carefully studied the question, has come to the conclusion that this anticlinal, coming up 

 from Ohio, does not run eastward, as Logan supposed, into Lake Ontario, but that it main- 

 tains its northward course, and runs into the southern extremity of Lake Huron. This 

 geological axis is not marked by a conspicuously visible fold in the strata, as in narrower 

 and sharper anticlinals, but it nevertheless constitutes a remarkable feature in the geology 

 of North America. Southward of Lake Erie, in the form of a long, wide swell, it is plainly 

 traceable by the geological distribution of the formations through Ohio and Kentucky, 

 and again, in Tennessee and even in Northern Alabama. It separates the Pennsylvania 

 from the Illinois and Michigan coal fields. Northward of Lake Erie, an impartial study 

 of what is actually known of the geographical structure, as well as of the distribution of 

 the formations, indicates that its axis, after crossing the lake, continues on, as we should 

 naturally expect it would, in the same general north-north-eastward bearing through the 

 counties of Essex, Bothwell and Lambton, from about Little's Point on Lake Erie, to about 

 Kettle Point on Lake Huron, from which it probably continues in the same course under 

 the latter lake, and parallel to its eastern shore, to a point opposite Southampton, where, 

 turning a little more to the north-east, it would cross the Indian Peninsula parallel to 

 another anticlinal, that seems to run through Saginaw Bay and the gap between the 

 extremity of this peninsula and Grand Manitoulin Island. 



Following the line of axis above indicated, northward from Kentucky, where the 



Sec. iv, 1887. 14. 



