58 Natural Brines of Oil Fields [256 



This is a shallow geosyncline in which the surface rocks are 

 chiefly of Pennsylvania!! age except where in the center of the 

 basin there are from 800 to 1300 feet of Permian strata over- 

 lying the Pennsylvanian. In this area the Mississippian and 

 Devonian rocks underly the surface at from 1600 to 2000 

 feet and 2200 to 3000 feet, respectively. Around the rim of 

 the basin these strata outcrop. On the east they reach the 

 surface along the Alleghany front and on the west in central 

 Ohio. The distance across the center of the basin from 

 outcrop to outcrop of the Devonian strata is about 180 

 miles. The difference in elevation between the highest and 

 lowest point which the same strata attain is about 8000 feet. 

 Thus it is apparent that the geosyncline is to be considered 

 as a very shallow basin. Across the basin and paralleling the 

 Appalachian mountain folds, the strata are folded into a 

 series of minor anticlines and synclines. Towards the east- 

 ern outcrop these flexures become more and more pronounced. 

 In this area the dip along the flank of the folds is about 

 200 feet to the mile, while in the central part of the basin it 

 seldom exceeds 75 feet to the mile. Westward the folds die 

 out almost entirely and the strata rise to the surface in central 

 Ohio at the rate of about 30 feet to the mile. The strata 

 under consideration therefore are comparatively little folded 

 and consequently little metamorphosed. Faulting is also 

 absent except for a minor fault of a few miles in extent in 

 central West Virginia. Southward across Kentucky and 

 Tennessee the basin narrows and the strata are folded and 

 faulted to a greater degree. On this account and also because 

 of the lack of data on the deep underground waters of the 

 area that part of the basin is not included in this discussion. 

 The northern end of the basin is also not considered here be- 

 cause in that area meteoric water has entered, through old 

 abandoned oil wells, the deeper sands and destroyed more or 

 less the original water content of these strata. 



Stratigraphy of the Area. The drill has penetrated strata 

 from the Permian to the Lower Devonian in the search of 

 oil in the central part of the basin. The Permian and Penn- 



