188 I. C. WHITE — THE MANNINGTOfl OIL FIELD. 



Monongalia by the development of a new anticline which elevates the oil 

 rock into the gas belt along its previous trend, and thus causes the oil 

 level to veer westward, at the same time reducing the rate of dip and 

 consequently broadening the oil belt in that region, as shown by the map. 



Source of the Hydrocarbons. — The oil is found in the Pocono sandstone 

 (Vespertine, X, etc. of Rogers) or lowest member of the Carboniferous 

 system, its geological equivalent being the Logan sandstone of Ohio, the 

 Shenango and Sharpsville sandstones of Pennsylvania, and the Marshall 

 group of Michigan. This geological horizon has furnished oil at several 

 localities in this country : the " Slippery rock " and '' Manifold " oil sands 

 of Pennsylvania, the " Mecca " sand of Ohio, and the main sand at Burn- 

 ing springs and Volcano, West Virginia, all belonging to the Pocono beds. 

 It was from this same horizon that natural gas was obtained in the 

 Kanawha valley fifty years ago, and there first utilized for manufacturing 

 purposes. The Warfield gas wells of Kentucky are in this sand, and it 

 also furnishes oil at many localities in that state, while the asphalt de- 

 posits (residua of evaporated petroleum) of Alabama occur in the same 

 series. Hence it will be perceived that this horizon is one which holds 

 hydrocarbons over a wide area, just like the older Catskill (Venango oil 

 sands: and upper Chemung beds (Bradford and Warren sands) below. 



This oil rock was several years ago dubbed the "Big Injun " sand by. 

 some facetious driller in Washington county, Pennsylvania, where it is 

 about 250 feet thick and very hard, thus rendering the progress of the 

 drill through it quite slow and suggesting the name which it has ever 

 since maintained in oil parlance, viz, the " Big Injun " sand. It is also 

 sometimes called the "Manifold" sand, from the farm in Washington 

 county on which was obtained the only paying well in that county at 

 this horizon, out of the hundreds and thousands that have been drilled 

 through it, though the name " Mount Morris " sand is more appropriate, 

 since it has proven more productive of oil in the Mount Morris-Manning- 

 ton field than anywhere else. 



The oil and gas are not disseminated uniformly through the sand rock 

 but occur in " pay streaks " at 60 to 135 feet below the top of the Pocono 

 sandstone, the richest and main horizon being found at 85 to 110 feet. 

 At about 20 feet in the sand there is a layer which frequently furnishes 

 a small flow of gas, but has never vet produced any oil. Then at (50 to 

 75 feet the " first pay " is usually obtained, and at Xo to 110 the " second 

 pay;" while a " third pay " may be found at 120 to 135 feet. These 

 " pay streaks " are merely coarser and more open layers of sand in which 

 the oil, gas, or water, as the case may be, finds a good receptacle. 



The texture of this sand is not coarse and pebbly like the ( 'atskill con- 

 glomerate of the Venango sand group, and hence its oil wells are never 

 so large as those from the latter beds, but they are on that account the 



