GENERAL GEOLOGY OF CLAYSVILLE QUADRANGLE. 
59 
slope of the Finney syncline between the 580-foot and 680-foot con¬ 
tours. I hroughout this area the Gordon sand has an average thick¬ 
ness of not more than 15 feet, being rarely 30 feet, and having a pay 
streak usually less than 10 feet thick. Nevertheless, it has been one of 
the most prolific sands in the region, a large number of the wells 
having had an initial flow of 100 to 500 barrels per day. Many 
of these were drilled ten to twenty years ago, but are yet being 
pumped. To the north and west from Taylorstown station the oil is 
derived entirely from this sand. It should be noted that the produc¬ 
tive belt is widest where the rocks have the least dip. In the vicinity 
of Taylorstown the top of the Claysville anticline is flat, the crest line 
being very indistinct, and, as shown on PI. XIII, it lies at least a mile 
farther to the west than the corresponding feature shown on the map 
of the surface structure (PI. X, pocket). In the productive region 
along the eastern side of this anticline measurements were made 
directly to the sand in a large percentage of the wells, and the struc¬ 
ture is mapped with great accuracy. The occurrence of several dry 
holes (Nos. 82, 83, and 720) and a gas well (No. 719) northeast of 
Taylorstown is inexplicable, so far as structure goes, all of them 
being clearly within the productive area as indicated by the structural 
map (PI. XIII). The nonproductiveness of this spot may be due to 
the imperviousness of the sandstone over a small area, though the 
fact that well No. 719 is a small gas well would be somewhat against 
this view. No mention is made of the condition of the sands in the 
records of these wells. The records of wells Nos. 719 and 720 were 
used in making the structural map. Eastward from this point the 
width of the belt gradually narrows as the dip increases, and at the 
same time the productive area of the Fourth and Fifth sands overlaps 
more and more that of the Gordon sand group until in the vicinity of 
West Washington and a mile or so farther west most of the wells 
nave obtained at least a showing of oil in all the sands below and 
including the Gantz, many of them having been pumped from three 
sands. 
At the east end of the basin at Finney the Fourth and Fifth sands 
produce oil in about the same territory as the Gordon sand group, 
with the exception that the pool in the Gordon sand seems to extend 
farther to the south along the top and eastern slope of the Washing¬ 
ton anticline. Most of the gas in the northern portion of this dome 
comes from the Fifth sand, the records showing but one well (No. 
347) that obtained gas in the Gordon sand. On the northern side of 
the small basin west of Woodell the southernmost line of wells is in 
the Fifth sand. These all show salt water in the lower portion of 
the sand, with oil directlv above. On the southern side of this basin 
after diligent inquiry, only the wells shown on the map could be 
found, and hence it is taken for granted that the evidence furnished 
