308 
soutliern half of tlie escarpment overlying the Coal- 
measures, there is, in place of the Quicksands, beds of Marl, 
or hardened mud, of varying colour and thickness, derived 
from the disintegration of the shale and finer sandstones of 
the Coal-measures. Where sandstones are prevalent, the 
Marl is usually found to be sandy and micaceous ; where 
shales, it is finer and more silky to the touch. 
The only part of the line of the escarpment where there 
appears to be the slightest trace of conformability is where 
the highest strata of the Upper Coal-measures (above the 
Red Rock of Rotherham) appear to be deposited evenly 
below the Limestone. But if it be remembered, that they 
form the uppermost beds in a large trough or basin-shaped 
area, and in consequence wiU be far more evenly or horizon- 
tally bedded than those composing the outer or deeper rings 
of the hollow, their seeming conformity will be recognised 
as onl}'- apparent, and that in reality they are quite as dis- 
tinctly separated as the older members of the series. 
Should there at any time be pits sunk in search of coal 
at sufiicient distances east of the Limestone Escarpment, it 
appears very probable that the lower beds of the Coal- 
measures will crop up in succession from below these 
highest measures, and will thus furnish another link in 
the chain of evidence proving that the whole of the Coal- 
measures, at any rate in Yorkshire, were formed and subse- 
quently denuded before the advent of the Permian Lime- 
stone formation. 
