30 J. J. STEVENSON — LOWER CARBONIFEROUS, APPALACHIAN BASIN 



The Pocono n^mhr West Virginui. — The oil-well records preserved in 

 Doctor White's report on the geology of West Virginia. exhi])it the 

 varic^tions of the Pocono under cover in that state. 



The northern tier of counties consists of iNIonongalia and INIarion at 

 the east, Wetzel and Tj'ler at the west along the Ohio river. In north- 

 ern Monongalia near the border of Greene count}^ Penns3'lvania, the 

 section is in contrast with records from the latter county, for a well 

 shows 



Feet 



Sandstone 150 



Shale and sandstone 1 60 



Sandstone 100 



a total of 410 feet, the middle containing 125 feet of shale. In a neigh- 

 boring well the upper sandstone is 173 feet, with another sandstone of 

 55 feet at 55 feet below it. The records in Mai'ion count}" are mostly 

 incomplete, usually giving only the upper plate, which varies from 142 

 to 168 feet, but in one well the driller reports 50 feet of limestone below 

 this plate, while at 40 feet lower there begins a mass of shale and sand- 

 stone 195 feet thick. In w^estern Marion the thickness of the sand is 

 given as 140 feet, but just over the line in Wetzel it is reported to be 

 250 feet, while elsewhere in that county it varies from 127 to 192 feet. 

 The complete record of one well shows, however, that these variations 

 ma}^ be due in some degree to the caprice of the driller, who may end 

 the record for the "Big Injun" at the base of the upper plate or ma}" 

 continue it until the first thick bed of shale has been reached ; for in 

 that well the driller reports two beds of sandstone, 151 and 150 feet, 

 separated b}^ 4 feet of shale. There is, however, a distinct individuality 

 about the upper plate, that known in West Virginia oil districts as the 

 " Big Injun." In complete records of wells in IMarion, Monongalia, 

 Wetzel, and counties of the northern " panhandle '' of the state, a shale 

 of varying thickness separates this upper plate from one below, known 

 in some localities as the " SquaAV sand." In Monongalia the upjier plate 

 is from 150 to 173 feet, the shales from 55 to 57 feet, and the lower plate 

 from 35 to 100 feet. In Marion the upper plate is 130 to 140 feet ; one 

 record gives 30 feet for the shale, and there is no record for the " Squaw." 

 Northward from Wetzel, in the northern " panhandle," which is west 

 from Greene, Washington, Allegheny, and Beaver counties of Penns}"!- 

 vania, one finds the two sandstones differentiated in most of the records. 

 At !Moundsville, in Marshall count}', the Big Injun is 1G5 feet, resting 

 on 50 feet of shale ; at Wheeling, in Ohio county, 139 feet, with 45 feet of 

 black shale between it and the Squaw, 25 feet thick; at Wellsburg, 

 Brooke county, one finds Big Injun 140 feet; Shales. 50 feet ; Squaw, 50 



