100 



LOG OF WELL AT PETROLIA. 



The railway journey from Hagersville to Thedford 

 presents little of geological interest. The whole district 

 is so heavily covered with drift that rock exposures are 

 seen in but few places and only where streams have denuded 

 the mantle of drift. The Onondaga-Hamilton contact 

 is probably situated in the vicinity of London. East of 

 Sarnia and a short distance south of the railway between 

 London and Sarnia, is the centre of the oil district in 

 Ontario at the town of Petrolia. The surface rock is 

 Hamilton yielding the characteristic species of that forma- 

 tion in some abundance. A deep well drilled in the Petrolia 

 oil field gave the following log: — 



Hamilton. 



Blue shale 



Shale and limestone 



Onondaga 



Limestones (oil horizon) . . . 

 Monroe? 



Banded grey, brown and 



black dolomites 



Salina 



Salt... 



Dolomite 



Salt and dolomite 



Dolomite 



Salt 



Salt and dolomite 



Salt 



Grey dolomite 



Salt... 



Dolomite and salt 



Salt... 



Dolomite, limestone and 

 grey shales 



Salt 



Guelph and Niagara . . 



Dolomites 



Cataract (?) 



Red and dark shales 



Limestones 



Richmond (Queenston) 



Red shales 



Thickness. 



Depth. 



Ft. 



90 

 240 



190 



690 



65 

 20 



140 

 30 

 90 

 50 

 25 

 10 

 67 

 40 



138 



130 

 90 



275 



60 

 90 



275 



M. 



27-36 

 72-96 



37-76 



209-76 



19-76 

 6-o8 



42-56 

 9-12 



27-36 



15-20 

 7-6 



3-04 

 20-36 

 12 -16 



41-95 



39-52 

 27-36 



83-6 



18 -24 

 27-36 



83-6 



Ft. 



90 

 330 



520 



1,275 

 1,295 

 1,435 

 1,465 

 i,555 

 1,605 

 1,630 

 1,640 

 1,707 



i,747 

 1,885 



2,015 

 2,105 



2,380 



2,440 

 2,530 



2,805 



M. 



27-36 

 100-32 



158-08 



367-84 



387-60 

 393-68 

 436-24 

 445-36 

 472-72 

 487-92 

 495-52 

 498-56 

 518-92 

 53i-o8 

 573-04 



612-56 

 639-92 



723-52 



741-76 

 769-12 



852-72 



