102 
ECONOMIC GEOLOGY OF AMITY QUADRANGLE, PA. 
75 feet below the Sewickley, but this may be the rider coal which is 
common throughout much of the Monongahela Valley. The reported 
thickness here is 2 feet 6 inches, and in the air shaft near by there is 4 
feet of it. 
Washington coal. 
No. 11. No. 15. No. 16. 
(Seep. 114) (Seep. 114) (Seep. 114) 
No. 17. 
(See p. 114) 
Sewickley coal. Waynesburg "A" coal. Redstone coal. 
No. 18. No. 19. No. 20. No. 21. 
(See p. 103) (See p. 112) (See p. 112) (See p. 101) 
ansa" hi 
IFig. 6.-Sections oi the Washington, Sewickley, Waynesburg" A,' and 
-tone coals in the Amity quadrangle. Scale I inch 5 feet. 
QUALITY. 
One sample of the Redstone coal has been analyzed. It was taken 
from the bank above the Nottingham mine in the same way as the' 
samples of the Pittsburg coal (see p. 95), and was analyzed at the fuel- 
testing plant at St. Louis. The composition is as follows: 
Analysis of Redstone coal from country bank near Hackett. 
Sulphur 
Moisture . . 
1 . 46 
Volat ile nuil ter 
35. 56 
Fixed carbon. . 
53. 39 
Ash 
9. 59 
2.05 
100. 00 
This analysis indicates a coal of fairly good quality, ranking the 
Redstone in this region next in value to the Pittsburg. The quantity 
of fixed carbon is high, the percentage of ash only slightly exceeds that 
in the Pittsburg, and the amount of sulphur is not extreme. 
An analysis from I. Teeple's bank near Monongahela, east of the 
quadrangle, is given for comparison . 
a Second Geol. Survey Pennsylvania, Rept. K, 1876, p. 379. 
