GENERAL GEOLOGY OF BITRGETTSTOWN QUADRANGLE. 41 
The most important structural feature of the quadrangle is the 
Burgettstown syncline. This trough enters the quadrangle at the 
south edge, east of West Middletown, and extends in a direction 
about due north nearly to the north edge of the quadrangle. Here 
the trend changes to. northeast. This syncline has been broken by 
the east-west folding into three important structural basins in this 
quadrangle. The northernmost is at Five Points, where the cross¬ 
ing of a shallow syncline in an east-west direction forms a basin of 
considerable extent. The next basin to the south is at the bottom 
of the most pronounced east-west break and in the line of the Bur¬ 
gettstown syncline. This basin is named from Cross Creek village, 
although the center of the basin is over a mile to the east of the 
village. Near the south edge of the quadrangle is the third basin, 
which extends into the Claysville quadrangle. The center of the 
basin is a little to the east of West Middletown, on the south fork 
of Cross Creek. It is called the West Middletown basin. 
Two important domes rise on the east side of the Burgettstown 
syncline. One of them, called the Candor dome, is located north of 
the village of Candor. The rocks rise steeply through a distance of 
over 100 feet from the east, south, and west toward the center of 
the dome, but to the northwest the descent is gentle, the total amount 
being about 30 feet. The Westland dome, at Westland, in the south¬ 
east corner of the quadrangle, is a small but pronounced feature 
from which the rocks descend in all directions. 
On the west side of the quadrangle from Eldersville southward the 
rocks remain comparatively high as far as Cross Creek. This pro¬ 
duces an anticlinal nose, on the end of which is a very low dome, 
called the Gillespie dome. 
GEOLOGIC FEATURES BELOW THE SURFACE. 
CONVERGENCE SHEET. 
As has been previously stated, the convergence sheet is the drawing 
on which the final map of the sand depends, for with its completion 
the map making becomes a mechanical operation, in which judgment 
forms only a small part. The convergence sheet should be carefully 
studied and thoroughly understood before any actual drilling opera¬ 
tions which are suggested by the representations of the map are 
undertaken. 
The convergence sheet of the Burgettstown quadrangle is made 
from the records of 60 oil wells whose positions are fairly well distrib¬ 
uted over the quadrangle. Most of the records accepted are direct 
steel-tape measurements to the Hundred-foot sand, but where the 
Hundred-foot is absent or where the gas and oil comes from lower 
