MISSISSIPPIAN SERIES. 29 
Section of Pocono formation in the Luse well near Beallsville. 
Feet,. 
Sand, Big Injun 290 
Slate - - 20 
Slate shells - 45 
Sand - - - - 113 
Slate shells - 36 
Lime 65 
Slate 6 
Lime. 21 
Slate 5 
Slate shells 14 
Hard lime 20 
Red rock (Bedford?) 20 
Lime , 5 
Slate 17 
Lime 13 
Sand, Gantz 30 
Slate 21 
Sand, Fifty-foot 24 
Slate shells — 5 
Sand 35 
Slate and shells . 35 
860 
This formation contains five principal sandstone horizons — the 
Big Injun, Squaw, Thirty-foot, Gantz, and Fifty-foot sands. The 
most important of these geologically is the Big Injun, Mountain, or 
Manifold sand, as it is variously called. In portions of Pennsylvania 
where it outcrops it now goes by the name Burgoon sandstone. In 
Washington County this sandstone averages 250 feet thick and is very 
persistent. Its top is always in contact with the Greenbrier limestone 
and is therefore perfectly definite and very convenient as a datum for 
well drillers. The Gantz and Fifty-foot sands form a very prominent 
oil horizon, made famous by many old wells in the Washington field. 
These sands are recognizable in most of the wells. Toward the west, 
northwest, and southwest they run together and are known as the 
Hundred-foot sand. The various sands recognized by the drillers are 
described in detail under the heading "Oil and gas" (pp. 47-59). 
Red shale (Bedford'!)' — In the Burgettstown quadrangle a bed of 
red shale occurs at many places between the Thirty-foot and Gantz 
sands and may be a part of the Bedford group of Ohio. On account 
of the scarcity of complete records in the Amity quadrangle it is 
known here in only five wells, but when properly recorded it ought to 
be a fair datum horizon. In the J. M. Miller well (306), in West Pike 
Run Township, it is 5 feet thick; in the Luse well (15), at Beallsville, 
20 feet; in the J. L. Thompson Nos. 3 and 4 wells (46, 47), in the 
borough of Deemston, 10 feet. In the Gantz well, at Washington, it 
is recorded as 8 feet of " reddish sand." In parts of western Pennsyl- 
