PERMIAN STRATA OF EAST CHESHIRE. 227 



it was 200 yards thick. In the Ockley-Brook_, as well as 

 the Norbury section, there appeared to be no evidence of 

 a fault, but only the covering up of the inferior by the 

 superior strata. 



When we take the strike of the Coal-measures seen near 

 Norbury Mill and follow it northwards through Tork- 

 ington, Offerton, and Brinnington to Beat-Bank Bridge, 

 the strata exposed in Ockley Brook may be a little to the 

 east of the line, but in my opinion not so much as to 

 allow the Coal-measures to come in again on the dip and 

 so make the Ockley-Brook Permian strata an isolated 

 patch. The uppermost bed of red clays is only seen for a 

 few yards before it disappears under the drift. So far as 

 my knowledge extends, no actual borings have been made 

 on the dip to ascertain the nature of the strata ; but, from 

 the reddish colour of the drift northwards, it appears pro- 

 bable that Trias beds succeed the Permian clays. 



The Permian sandstone of Ockley Brook, of five yards 

 thickness, was not seen at all in the Norbury section; 

 but if it be the same sandstone as that found at Fogbrook 

 and Stockport, estimated by Mr. Hull to be 500 yards 

 thick, it has diminished greatly in the distance of two 

 miles. 



As a great portion of the future supply of coal must, 

 most probably, be looked for under the Permian and Tri- 

 assic formations in Great Britain, it is very essential that 

 all the circumstances under which the Carboniferous strata 

 disappear beneath those deposits should be carefully ascer- 

 tained and correctly described. When Permian or Triassic 

 beds are found on the rise of the strata they indicate a 

 fault where the Coal-measures have been thrown down; 

 but when they are met with on the dip of the strata they 

 may indicate a down-throw fault similar to the one last 

 mentioned, or else an overlap of the Permian or Triassic 

 strata simply resting unconformably on the Carboniferous 



Q 2 



