92 
ECONOMIC GEOLOGY OF AMITY QUADRANGLE, PA. 
coal. The names applied to various portions of the Pittsburg coal 
are shown graphically in fig. 5. 
In most regions the brick coal and bottom coal are distinct, sepa- 
rated by a thin binder, but in this quadrangle they can generally not 
be distinguished. In only one or two instances are other binders 
noted below the bearing-in coal, but in several cases nonpersistent 
binders have been noted above it. 
The greatest thickness of coal known in the quadrangle- is that 
recorded in the Moses Smith drill hole near Bissell, West Bethlehem 
Township, as shown in the following 
section (PL V, No. 1): 
Roof division 
Main clay 
Lower division . 
= 
/ Breast coal, 
Bearing-in coal, 2" to r 
Section of Pittsburg coal near Bissell. 
Ft. in. Ft. i 
Slate, black. 
Coal 1 4 
Slate, black 
Coal 4 
Fire clay 
Slate, black 1 
Coal 6 
Slate . . 1 
Coal, breast and bottom . 5 10 
Slate, bottom. 
Bottom eoaV 
Total coal 8 
30 " Sections 2 to 9, inclusive, PL V, 
show the characteristics of the coal 
in various parts of Chartiers Valley. 
The lower division in this vallev is 
Fig. 5.— Generalized section of Pittsburg coal from 4 feet 2 inches to 5 feet 10 
bed, with names of the various benches. ^ches ^^ ^ main day from 2 
to 22 inches. The upper division runs from 2 inches to 2 J feet and 
varies from clean coal to very bony. The bearing-in bands occur a 
little below the middle of the lower division. Local thin partings 
occur in all the mines, and therefore when a published section of 
the coal shows a parting other than those noted above it must be 
regarded as exceptional and not representing general conditions. The 
measurements of the known sections in Chartiers Valley are as follows : 
Coal section at the Manifold mine (PL V, No. 2). 
Coal . . . 
Shale.. . 
Coal . . . 
Fireclay 
Coal . . . 
Binder. 
Ft. 
in 
2 
6 
1 
2 
10 
1 
3 
