538 E. WILSON" ON THE PEEMIANS OE 



Carboniferous Limestone in that direction during its accumulation*; 

 but surely the pre-Permian elevation and denudation of the Pennine 

 axis is satisfactorily demonstrated by the above-mentioned overlap of 

 Coal-measures, dipping east at so high an angle, by Peruvians prac- 

 tically horizontal. The total absence of that very durable rock the 

 Magnesian Limestone at any distance from its escarpment (e. g. west 

 of the Erewash) indicates, to my mind, that we have there passed 

 beyond its original margin in that direction, a margin that would 

 probably have been found as on the south, had it not happened to 

 lie in the course of a powerful denudation. The great dissimilarity 

 in mineral character and sequence of the Permian deposits on the 

 west from those on the east of the Pennine axis points to the same 

 general conclusion. It is not without considerable diffidence and 

 reluctance that I venture to differ in any way from so high an autho- 

 rity as Professor Hull ; but, with all due deference, I must say that 

 I cannot help considering the evidence afforded by the Red-Rock and 

 Anticlinal faults near Stockport, and advanced by him in proof of the 

 pre-Permian age of the Pennine axis, to be at best equivocal. Eor, 

 as I apprehend the matter, we have there two contiguous and parallel 

 faults. One of these, the Red-Rock fault (A), Professor Hull sup- 

 poses has had two movements, the earlier of which was synchronous 

 with the only (local) movement of the other or Anticlinal fault (JB); 

 but if so the later throw of A was the greater throw of A ; and yet 

 that movement did not affect B in the slightest degree — though, being 

 presumably at that time dislocated, it might be expected that if they 

 ever acted in unison they would do so then. But as they did not 

 do so then, their parallelism does not prove that they did so before ; 

 and the old objection still remains that A faults Bunter &c. and B 

 passes under without affecting it. Hence there is no particular reason 

 for believing that the Anticlinal fault, or by consequence the Pennine 

 system to which it belongs, was post-Permian. That there was an 

 old east-and-west barrier, as enunciated by Jukes, and that this 

 barrier divided the Lancastrian and Salopian Permian hydrogra- 

 phical areas, as so ably argued by Hull (Q. J. G. S. 1869), I do not 

 doubt — as also that the easterly extension of that barrier may be 

 taken to explain the difference between the Permian deposits of Leices- 

 tershire and Notts, and the southerly degradation and attenuation 

 of the latter ; but, so far as I have been able to trace them, I do not 

 find that the Permians of the north-east of England show any ten- 

 dency to assume a Lancastrian facies going west. There is indeed 

 a change in their character most decided and general ; but that 

 change is a tendency to get thicker and (with local variations) 

 purer going north or north-east, indicating successive increasing 

 subsidences of the Permian north-east basin in such directions. As 



* The before-mentioned prevalence of Mountain-Limestone chert in the 

 brecciated Lower Bunter clearly shows that prior to the accumulation thereof 

 the Pennine axis in Derbyshire had not only been formed, but had undergone 

 an enormous amount of denudation. 



