148 THE POPULAR SCIENCE MONTHLY. 



well-known fact that wells sunk into the black shale yield no consider- 

 able quantity of oil, unless from strata resting upon it. 



The foregoing statements, it will be seen, go to substantiate the 

 theory upheld by Newberry, in common with other geologists, that 

 ttie strata yielding much oil have only served to store the oil which 

 comes from other strata below. T. S. Hunt holds that the petroleum 

 of the limestone of Ontario, Canada, and other localities is largely the 

 result of decomposition of the organic matters in these same rocks, and 

 not of distillation from below. This view Newberry opposes on the 

 following grounds : The Corniferous limestone, from his very extended 

 observations, contains little hydrocarbons; oil and gas springs are 

 rare where it underlies the surface ; no considerable quantity of petro- 

 leum has been derived from wells in the Corniferous, Niagara, or any 

 other limestone ; even at Chicago there are no paying wells. Borings 

 have been unsuccessful in Ohio wherever the Corniferous is the surface 

 rock ; and, further, there is no Corniferous limestone where Hunt cites 

 it in Kentucky. There is positive proof that part of the oil comes 

 from a lower horizon, and probably the Canada oil comes from under- 

 lying Silurian Collingwood shale. On Oil Creek are the argillaceous 

 shales of the Waverley and Chemung strata, forming the sides and 

 bottom of the valley, and below are several beds of sandstone, with 

 the black shales of the Portage and Genesee still lower. In Ohio 

 these favorable conditions are wanting ; the sand-rocks of Oil Creek 

 thin out and give place to fine, impervious, argillaceous shales ; the 

 strata become more homogeneous and free from crevices, and hence 

 the oil cannot penetrate them so well. In Cuyahoga County, Ohio, 

 the wells reach down through carboniferous rocks to the Huron shale, 

 but there are no good wells, because the sandstone reservoirs are lack- 

 ing, and only close-grained shales are present. 



Hunt, on the other hand, holds that the petroleum of Southwest 

 Ontario, and probably in other localities, is to be sought in the olifer- 

 ous limestones of the Corniferous and Niagara formations, both of 

 which abound in indigenous petroleum [American Journal of Sci- 

 ence, III., ii., 369), which, in the case of the Ontario limestone, he 

 shows cannot have come from overlying strata. He also mentions a 

 well sunk at Terre Haute, Indiana, 1,900 feet deep, which yields two 

 barrels of oil daily ; and a second one, very near, which yields 25 

 barrels. This one is 1,625 feet deep, and passes through TOO feet of 

 coal-measures, TOO feet of carboniferous limestone, with underlying 

 sandstone and shales, 50 feet of Genesee slate (or its equivalent), and 

 at a depth of 25 feet below this the oil-vein was met with in Cornif- 

 erous limestone. A third well, a mile east, at a depth of 2,000 feet 

 showed no oil. 



The truth seems to be, that these limestones may contain a little 

 petroleum indigenous to them, but they have not furnished the grand 

 supplies of very productive regions. Before leaving this part of the 



