52 ECONOMIC GEOLOGY OF AMITY QUADRANGLE, PA. 
sand in several wells in West Bethlehem Township and the borough 
of Deemston. 
This sand was named Big Injun by some driller in this county on 
account of its unusual thickness and hardness. 
Squaw sand. — In the northern and eastern portions of the quad- 
rangle a sand commonly occurs 20 to 50 feet below the bottom of the 
Big Injun. This is known to drillers as the Squaw sand. In many 
places it is over 100 feel thick, and in the J. L. Thompson wells it 
reaches L30 feet, but it is irregular and often missing. In the Rogers! 
ville quadrangle it has not been recognized. 
Thirty-foot sand. This sand occurs below the Squaw and 450 to 
650 feet below the top of the Big Injun sand. The name Thirty-foot 
means nothing as regards its thickness, for it varies from a knife edge 
up to 170 feet. The sand is not uniformly present and occurs rather 
irregularly; but i^ believed to correspond approximately in its upper 
and lower limits to the Berea sand of the Burgettstown and Beaver- 
regions, to the Butler gas sand of northern Pennsylvania, and to the 
Berea grit of Ohio. 
The interval from the Pittsburg coal to the top of this sand varies 
from 1,560 to 1,865 feet. In South Strabane Township the known 
limits are between 1 ,560 and 1 ,630 feel ; in the southwest corner of the 
quadrangle 1 ,750 and 1 ,770 feel . In the immediate vicinity of Zollars- 
ville the sand is not recorded, but near Deemston the limiting figures 
are 1,810 and 1,865 feet. Se\er;il wells in this vicinity exhibit a 
much smaller interval only 1,720 to 1,740 feci -this being due to a 
local thickening of the sand. Southwest of Beallsville the interval is 
usually 1,800 to 1,855 feet, but it varies irregularly, and some meas- 
urements arc reported which, are considerably less. In the Somerset 
field l,805fee1 is recorded, and near Finley ville about 1,850 feet. The 
Thirty-foot sand, so far as known, is not productive anywhere in the 
quadrangle. 
The Thirty-foot sand of Washington is not the same as the Thirty- 
foot of Armstrong County, but probably corresponds closely with 
what is there known as tin 1 Gads, Butler, or Murrysville sand. 
Gantz sand. — Next below the Thirty-foot sand is the Gantz, which 
was named from the farm near Washington on which oil was first pro- 
duced from this sand. This was the first producing oil well in the 
county. 
The Gantz sand ranges from 60 to 160 feet below the top of the 
Thirty-foot sand and is a short distance above the Fifty-foot sand. 
It varies in thickness from 10 to 60 feet. In some wells the Gantz 
thickens up enough to unite with the Fifty-foot, and in such cases the 
combined sand is known as the Hundred-foot and is the equivalent 
of the Hundred-foot sand of Beaver, Butler, and Armstrong counties. 
It is supposed also to be the same as the First sand of Oil Creek. 
