234 II. P. IT. BKUMELL — GAS AND PETROLEUM IN ONTARIO. 



Many other records of wells bored into or through this formation are 

 at hand, which go to show that it varies locally as to thickness, yet con- 

 stantly diminishes toward the north. Of the formation in the western 

 part of the province but little is known, as west of London, where it con- 

 sists of 500 feet of red shale, it has not been reached in the borings thus 

 far put down. 



Hudson River. — The Hudson River, which is next met with, plays a 

 very unimportant part in the geology of gas and oil in Ontario, and con- 

 sists, in that part of the province under consideration, of a series of shales 

 and limestones immediately underlying the red and green shales of the 

 Medina. Unfortunately the great area of its supposed exposure north of 

 Toronto is overlaid with drift, but where the exposures are to be seen 

 they consist, as in the township of Toronto, Peel county, " of a scries of 

 bluish-gray argillaceous shales enclosing bands of calcareous sandstone 

 sometimes approaching to a limestone and of variable thickness.' 1 * 

 These sandstone bands are slaty in places, though at times having a solid 

 thickness of a foot. The formation has been reached in a considerable 

 number of wells — among others, those at Saint Catharines, Thorold, 

 number 14 of the Provincial company, in Bertie, all in the Niagara 

 peninsula; Swansea and Mimico, near Toronto; Toronto, Hamilton, 

 Brantford and London, where it was penetrated for 150 feet and found to 

 consist of limestone and shale. In the wells at Swansea and Mimico 

 there were found 440 and 493 feet respectively of bluish-gray shale. 

 This does not of necessity represent the total thickness of the formation 

 at these points, as boring began upon it immediately beneath the surface 

 deposits, in the Thorold well, where the formation was met with at 

 depth, it was found to consist of 700 feet of blue shale, and at Saint 

 Catharines it had a similar character and thickness. It is quite probable 

 that in the various borings limestone was found, though on account of 

 its shaly character it was termed shale by the drillers. 



Utica. — The Utica formation, upon which the Hudson river rests, is 

 found, wherever met with in drillings, to consist of a series of dark-brown 

 bituminous shales, becoming in places bluish toward their base, and 

 having a thickness of from 200 to 400 feet. Of its exact thickness in any 

 well it is very difficult to speak, on account of the similarity between its 

 upper members and the lower strata of the Hudson river. 



Trenton and Black River. — Beneath the Utica shales there is met with 

 a thick series of bluish limestones, which constitute the Trenton forma- 

 tion, including also the Black River. This series, which is regarded as 

 the Mecca of all Ohio drillers, has proved itself, in Ontario, to be com- 



*Geology of Canada, 1863, p. 212 



