22 ECONOMIC GEOLOGY OF AMITY QUADRANGLE, PA. 
Section of C one maugh formation in Matilda Davis No. 2 well, etc. — Continued. 
Feet. 
Slate 60 
Lime 5 
Sand 43 
Slate 12 
Lime 50 
Slate 7 
Lime 31 
Slate 35 
Lime 9 
597 
Coal, Upper Freeport. 
The complete record of this well is given graphically in PI. II. It 
is probable that this is not strictly accurate, owing to the difference' 
between the drillers' and geologists' interpretation of certain beds. 
Such possible discrepancies should be kept in mind in studying any. 
record. It is especially probable in this particular case that some of 
the limestone noted is in reality hard sandstone, because in regions 
where the Conemaugh formation outcrops it contains only a small 
proportion of limestone. 
On account of the variability of the strata and frequent inaccura- 
cies in drillers' interpretations two sections are given below. 
The section of the J. L. Thompson No. 5 well (48) is better than the 
average. 
Section of Conemaugh formation in the J. L. Thompson No. 5 well, borough of Deemston. 
Feet. 
Coal, Pittsburg. 
Slate 15 
Lime 25 
Slate 60 
Red rock 10 
Slate 40 
Lime 30 
Slate 20 
Sand, Murphy 45 
Red rock 60 
Lime 30 
Red rock 20 
Sand, white 40 
Slate, black 40 
Slate 50 
Sand, Dunkard a .50 
549 
Coal, Upper Freeport. 
a The word ' ' sand " in all discussions of the solid rock of this area is used in the sense for which it was 
coined by the well drillers, meaning any sandy stratum. 
