328 



PEOCEEDIN-GS OP THE GEOLOGICAL SOCLETY. [April 8, 



>^^ 



several disconnected patches of newer formations, which are found at 

 intervals resting on Lower Carboniferous rocks. I shall not, there- 

 fore, stop to discuss the age of the sand- 

 stones of Eoach Bridge, near Blackburn 

 (which, Mr. Binney, F.E.S., considers^ 

 probably belong to the Permian series*), 

 nor of the sandstones of Low Moor, 

 near Clitheroe (which will properly form 

 the subject of a future memoir of the 

 Geological Survey). I shall only assume 

 them to be either of Permian or Triassic 

 age, a fact which is beyond controversy, 

 for the purpose of offering another illus- 

 tration of the enormous denudations which 

 have taken place before the Triassic, and 

 probably before the Permian period, in the 

 Yale of Clitheroe, at the base of the Pendle 

 Pange of Hills t. 



Eef erring to my former paper J for the 

 thickness of the Carboniferous series at 

 this place, and premising that the red 

 sandstones of Low Moor rest on the con- 

 torted edges of the Carboniferous Lime- 

 stone beds, it is clear that the amount 

 of strata denuded at this place is that of 

 the Coal-measures, Millstone and Yoredale 

 series, and part of the limestone itself, as 

 follows : — 



Upper, Middle, and Lower Coal- ®^ * 



measures 8460 



Millstone -grit series 5500 



Yoredale series 5000 



Carboniferous limestone (in part) 250 



r§ 



19210 



or nearly 20,000 feet vertical of strata, an 

 amount of materials at the waste of which 

 one feels as much astonishment as at the 

 gathering together of it. And if (as is 

 most probable) this denudation took place 



^ " Further obserrations on the Permian and 

 Triassic strata," &c., Mem. Lit. and Phil. See. 

 Manchester, vol. iii. 3rd series. 



t I regret not being at liberty to give a fuller 

 account of the Low-Moor sandstones, which were 

 formerly regarded as Carboniferous, but have 

 '^ \^_ [p^" been determined by Mr. Tiddeman and myself to 



be of later age, A full account will be given in 

 a future memoir. 

 $ " On the thickness of the Carboniferous rocks of the PendleEange," swjp?'«,p,321. 



S'^ 



