RED SANDSTONE OP CUMBERLAND. 



177 



With the coal strata^ and is a part of that formation.* If such a red 

 sandstone, distinct from the new red sandstone, exist any where in Eng- 

 land, it is near Oldham and Rochdale in Lancashire. The sandstone 

 of Lancashire is coloured in Mr. Greenough's Geological Map of Eng- 

 land, as the new red sandstone, and in Mr. Smith's Geological Map, 

 as the old red sandstone ; but I am inclined to believe, that the true 

 position (gisement) of this sandstone in many parts of Lancashire, 

 is not yet ascertained : its reladons with the coal strata are different 

 from those of the new red sandstone in other parts of England. — I 

 propose to revert to this subject in a subsequent chapter. 



Professor Sedgwick, in a paper recently read at the Geological 

 Society of London, but not yet published, has described the red 

 sandstone formation on the north-western side of England, which had 

 not before been sufficiently examined. The formation agrees with 

 that on the eastern side of England in its leading features. First, 

 there rest unconformably over coal measures of Whitehaven, 



1. Coarse sandstone of great thickness, or the lower red sandstone. 



2. Magnesian conglomerate beds of considerable thickness. 



3. Magnesian limestone. 



4. Lower red marl and gypsum. 

 6. Red and variegated sandstone. 



The sandstone No. 2. and also other beds of red sandstone, some- 

 times approach to a position nearly conformable to that of the coal 

 measures. Too much importance appears to me to be attached io 

 this circumstance ; for whenever the coal strata take nearly an hori- 

 zontal position, the upper unconformable strata will take the same po' 

 sition, and may therefore be conformable in such situations, and un- 

 conformable in others where the subjacent strata are more inclined* 



* Le Gres, masse principale de terrain houiller, prende souvent une grand ex- 

 tension, en abandonnant an moins en majeure partie la houille avec I'argile schis- 

 teuse qui I'envellope. — Daubuisson, Traiti de Gdognosie, tome 2. 



M. H. Bonnard, in his Appergu Gdognostique des Terrains, p. 144., describes 

 the red sandstone as the upper part of the coal formation. 



A. Humboldt, in his Essai G6ognostique sur le Gisement des Roches, p. 

 mentions a red sandstone passing into porphyry, as the upper part of the coal for- 

 mation in Germany. 



Messrs. Daubuisson, and Bonnard, appears to have mistaken the lowest part of 

 the red marl and sandstone, for a portion of the regular coal strata. M. Hum- 

 boldt, makes a distinction between the unconformable red sandstone and the por- 

 phyritic red sandstone, which he cites as a part of the regular coal formation. 



2S 



