PETROLEUM AND NATURAL GAS. 
49 
Drillers' terms for oil and gas rocks, etc., and their geologic correlations. 
[+ indicates above Pittsburg coal; — indicates below Pittsburg coal.] 
Formation. 
[ononga-iela 
Drillers' name. 
Bluff sand 
Waynes burg or 
Pinhook coal. 
Mapletown coal 
[Pittsburg coal 
Murphy 
Geologists' name. 
I Little Dunkard 
sand. 
iBig Dunkard sand, 
fConnellsville coal . . . 
IGas sand , 
Waynesburg sand- 
stone. 
Waynesburg coal. . . 
Sewickley coal 
Pittsburg coal 
Morgantown sand- 
stone 
Saltsburg sandstone. 
Salt sand . 
Red rock . 
Big lime. 
Big Injun or Mani- 
fold sand 
Squaw sand 
Thirty-foot sand 
Gantz sand 
Fifty-foot sand 
Nineveh Thirty- 
foot sand. 
Gordon Stray sand 
Mahoning sandstone 
Upper Freeport coal. 
Kittanning or Clar- 
ion sandstone. 
Pottsville sandstone 
(Home wood + 
Connoquenessing) . 
Mauch Chunk red 
shale. 
Greenbrier limestone. 
Burgoon sandstone.. 
Gordon sand 
Fourth sand 
Fifth sand 
Bayard or Sixth 
sand. 
Elizabeth sand 
Approxi- 
mate 
maxi- 
mum 
thick- 
ness in 
this area 
Feet. 
60 
6 
10 
100 
100 
6 
70 
180 
100 
60 
300 
130 
170 
60 
100 
30 
30 
50 
50 
50 
50 
20 
30 
Average 
interval 
to top of 
bed from 
Pitts- 
burg 
coal 
Feet. 
+ 390 
+ 330 
-f 110 

- 200 
- 370 
- 500 
- 600 
- 800 
- 900 
-1,150 
-1,200 
-1,530 
-1,750 
-1,900 
-1,950 
-2,050 
-2, 100 
-2,130 
2,200 
2,300 
2,400 
2,500 
2,700 
2,750 
Correlation with 
sands in neighbor- 
ing fields. 
Hurry-up sand. 
Mountain sand. 
Berea or Butler 
County gas sand. 
First sandlHundred- 
> foot 
sand. 
Second sand. 
Gray or bowlder 
sand. 
Third sand. 
McDonald sand. 
Warren First sand. 
Warren Second sand. 
Murphy sand. — The uppermost sand commonly reported by drillers 
is known in the southeastern part of the quadrangle as the Murphy 
sand. It occurs in the Conemaugh formation at an interval of 170 to 
220 feet below the Pittsburg coal and varies in thickness from 25 to 120 
feet. This sand probably corresponds with the Morgantown sand- 
stone, which outcrops at about the same horizon in certain parts of 
southwestern Pennsylvania and northern West Virginia. It is not 
productive of gas or oil. 
Dunkard sand. — This is the name given to a sand or group of sands 
Bull. 300—07 4 
