590 CHARLES S:) (PROSSER 
In the above section there is a very marked difference in the 
percentage of calcium and magnesium carbonates in the sandstones 
which are referred to the Bedford and Berea formations. The 
following table gives the analysis by Professor D. J. Demorest, of 
Ohio State University, of samples from zones 2, 4, and 6 of the above 
section. 
Zone No. 2 Zone No. 4 
(1% to 2 ft. Sandstone,|(4 to 5 in. Sandstone, Zone No. 6 
4 to 5 it. below 2 to 6 in. below (Base of Berea) 
Zone 6) Zone 6) 
Per cent Per cent Per cent 
CaCO yee ee ees: | 18.75 6.50 0.25 
Mig € Ossie oo ae asec 7.60 2.00 ©.00 
Hes@ Wether aie er 4.00 2.90 I.00 
Quartz ache sees hve crates 52.80 59.10 76.00 
eldspariiins (air acrerriee is 4.40 9.30 8.00 
Clay oh ae are ose 8.40 20.60 14.50 
An examination of the above table at once shows the high 
percentage of calcium and magnesium carbonates in the sandstones 
of zones Nos. 2 and 4, which are included in the Bedford, and the 
very small amount, only { of 1 per cent, in the basal sandstone of 
the Berea. The sandstone layer almost at the very top of the 
Bedford, only from 2 to 6 in. below the base of the Berea or zone 
No. 6, contains 63 per cent of CaCO, and 2 per cent of MgCO,, or 
a total of 84 per cent of these carbonates as against the { of 1 per 
cent of CaCO, in the basal sandstone of the Berea. While in the 
thicker Bedford sandstone, zone No. 2, between 4 and 5 ft. below 
the base of the Berea the proportion is still more marked, since it 
contains 18.75 per cent of CaCO, and 7.60 per cent of MgCO,, or 
a total of 26.35 per cent of these carbonates. This shows that 
more than one-fourth of the entire composition of this sandstone is 
composed of the calcium and magnesium carbonates, which clearly 
explains why this stone becomes rotten on weathering and the basal 
Berea with only } of 1 per cent of CaCO, does not. Again, there is 
a marked increase in the amount of quartz in passing upward from 
the Bedford into the Berea, which is 52.80 per cent in zone No. 2, 
59.10 per cent in zone No. 4 almost at the top of the Bedford, and 
76 per cent in zone No. 6 at the base of the Berea. The percentage 
of quartz is almost 17 per cent greater in the basal sandstone of the 
