288 SKETCHES OF CREATION. 



tations. Some of these conditions it is impossible to ascer- 

 tain without considerable general geological knowledge, 

 and a minute acquaintance with the local geology of the 

 region under consideration. 



In determining upon the first condition, it is necessary 

 to know what are the characteristics of a formation con- 

 taining the materials for oil, and what particular forma- 

 tions in the chronological series have been proven to con- 

 tain such materials. Experience has shown that commi- 

 nuted vegetable matters disseminated through a matrix 

 of fine argillaceous materials, and forming a black, or car- 

 bonaceous, or bituminous shale, are the chief source of sup- 

 ply in all the productive regions of the United States and 

 Canada. The intimate mixture of vegetable and argilla- 

 ceous particles seems to facilitate the chemical rearrange- 

 ments involved in oil- genesis. Pure vegetable matters 

 form beds of coal, in which the organic material is approx- 

 imately fixed. The distinction between the " splintery" 

 and " fatty" coals corresponds with their difference in pu- 

 rity. Cannel coals are highly carbonaceous shales. Like 

 the " black shale" of the West, they afford copious supplies 

 of liquid hydrocarbons. 



The mother-rock of the oil in some of the most produc- 

 tive regions of the continent seems to be the "black shale" 

 of the West, which is the Genesee shale of the New York 

 geologists. This fact was first pointed out by my friend 

 Professor Newberry, now of Columbia College. I have 

 little doubt that this formation affords the oil obtained in 

 Northwestern Pennsylvania; parts of Enniskillen and Both- 

 well, in Ontario ; in Eastern and Central Eastern Ohio ; in 

 the Glasgow region of Southern Kentucky, and in North- 

 ern and Middle Tennessee. It is also probable that it sup- 

 plies the oil in most of the wells of Southwestern Pennsyl- 

 vania, West Virginia, Southeastern Ohio, and Northeastern 



