SOMETHING ABOUT OIL. 289 



Kentucky. These wells, however, are bored through some 

 portion of the coal-measures or underlying conglomerate, 

 though it is not certain that any important supply has been 

 reached by any well which terminated within the range of 

 the coal-beds. 



In the lower portion of the Hamilton group is anothei 

 black shale, known in New York as the &quot; Marcellus Shale,&quot; 

 but assuming at the West so calcareous a character that it 

 has not been generally distinguished from the proper lime 

 stones of the Hamilton group. It presents itself in Mich 

 igan and Ontario as a mass of black, shaly limestone or cal 

 careous shale, overlaid by the thin-bedded and argillaceous 

 limestones of the Hamilton group proper. I am led to re 

 gard this formation as the chief source of petroleum in the 

 Enniskillen and Bothwell regions of Ontario. 



In the Cincinnati group is another&amp;gt;black shale which is 

 believed to supply the wells in the Burkesville region of 

 Southern Kentucky, and on Manitoulin Island of Lake Hu 

 ron. Not unlikely, some of the impure coals of the sub- 

 conglomerate series have afforded supplies to wells termi 

 nating in the conglomerate in West Virginia and the neigh 

 boring portion of Kentucky. The oil springs of California 

 are supplied from formations of much more recent date. 



No limestone is known to be the mother-rock of large 

 supplies of petroleum. It is true that the Corniferous lime 

 stone is saturated and blackened in many localities by the 

 presence of bituminous matters ; and it is true that this 

 formation lies beneath the productive oil regions of West 

 Virginia, Western Pennsylvania, and Enniskillen, in Onta 

 rio. It is due, also, to one of the most eminent authorities 

 in chemical geology to state that Dr. T. S. Hunt entertains 

 the opinion that the Corniferous limestone is probably the 

 source of petroleum in the several regions named, and es 

 pecially in Ontario. He has embraced numerous opportu- 



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