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extending southwards to Clayton-in-the-Clay, the ground 
rises to a slightly higher elevation than the district west- 
ward ; this is due to the presence of a thick-bedded, softish, 
light brown or buff Sandstone. A short distance northwards, 
at Hunsworth and Brierley, a second Sandstone occurs ; 
these have been described in a paper read to this Society by 
Professor Green as the Houghton Common and Brierley 
Eocks respectively. The uppermost bed, the Houghton 
Common Rock, is extensively quarried on Ackworth Moor 
Top, extends to East Hardwick, and probably passes 
under the escarpment of the Permian Limestone. On the 
higher ground, near Pontefract, two Sandstones may be seen 
separated by Shales. The upper one is the most important, 
and is extensively quarried. It is a yellowish colour, soft, 
and thick-bedded. The bold projection on which Pontefract 
Castle is built is composed of the same rock ; is very 
probably the equivalent of the one on Houghton Common. 
A little eastward it disappears beneath the Permian Lime- 
stone Escarpment, being still of the same yellow colour 
as elsewhere. There is still another important Rock which 
bears a close relation to the Permian Limestone. It may be 
»seen at Harthill, and extends in a north-westerly semi-cir- 
cular form by South Anston, Aston, Whistow, and Rotherham. 
It is known as the Red Rock of Rotherham. It is a thick 
massive Grit of a red, purple, or salmon colour. It was 
considered and described by Professor Sedgwick as the New 
Red Sandstone, the equivalent of Rotbliegende. Since 
Sedgwick's time it has been a source of continual difficulty. 
Messrs. Thorpe and Farey regarded it as a regularly inter- 
bedded Sandstone of the Coal-measures, of local extent. 
Recent investigations of the Geological Survey point to its 
deposition some time after the measures on which it rests, 
to which it does not appear to be quite conformable, had 
become consolidated and smoothed down after being 
