174 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Pob. 10, 



Permian beds referable to the Salopian type to the north of this 

 part of England, except in the case of the little outlier at Rushton 

 Spencer, north of Leek, where they occupy a small area, and rest 

 directly on Lower Carboniferous beds of the Yoredale series. Their 

 occurrence at this spot was first pointed out by Mr. E. W. Binney*, 

 and more recently by Mr. A. H. Green in the memoirs of the Geolo- 

 gical Surveyf. Both of these geologists concur in considering the 

 beds to be of Permian age ; and their position with reference to the 

 Lower Carboniferous strata on which they rest is a point of interest 

 and importance as bearing on the question concerning the extent of 

 the denudation of the Carboniferous rocks before the Permian period 

 in this locality, coincident, as it is, with the axis of elevation, to 

 which I shall again refer, and which forms the special subject of our 

 inquiry. 



Mineral Characters of the Salopian Type of Permian Beds. — It 

 may, I think, be safely afiirmed that over the whole tract of country 

 above described the Permian beds belong to the Roth-todt-liegendes 

 or lower stage, and are all of one type — and this notwithstanding 

 local and exceptional interpositions of peculiar beds deriving their 

 origin from the agency of ice (as shown by Professor Eamsay in the 

 case of the trappoid breccias), or on account of marginal conditions, as 

 shown by Sir R.Murchison in the case of the Cardeston brecciated rock. 

 With these and similar exceptions, the whole series (attaining a 

 thickness of 1500 or 2000 feet in Warwickshire) consists of an 

 assemblage of brown, red, or purple sandstones, often calcareous, 

 alternating with red shales and marls, and characterized by much 

 irregularity in the stratification. Both the sandstones and the local 

 breccias and conglomerates are distinguishable from those of the 

 Bunter Sandstone with which they usually come in contact ; and the 

 frequent interposition of beds of red marl gives the group a fades 

 differing from that of any of the divisions of the Bunter Sand- 

 stone. 



Such is the character of these beds, whether we find them in 

 Denbighshire or Shropshire on the one side, or in Warwickshire on 

 the other. They form a group of strata of themselves, differing in 

 their mineral characters from the Permian rocks either of the North- 

 west or North-east of England. Their original marginal limits may 

 at intervals be traced both in Shropshire on the west, and in 

 Leicestershire and North Staffordshire on the east, notwithstanding 

 the obscurity occasioned by the overspreading of the Triassic forma- 

 tion. The beds at Rushton Spencer form, in my opinion, a mar- 

 ginal outlier, deposited in a hollow, along the line of the barrier 

 of Lower Carboniferous rocks, which originally divided the beds 

 belonging to the Salopian type from those of the Lancashire 

 type. 



* Memoirs of the Lit. and Phil. Society of Manchester, vol. xii. 



t '■ Geology of Stockport, Macclesfield, &c.," by E. Hull and A. H. Green. The 

 position of these beds is shown in a section by Mr. Green in our joint paper 

 " On the Millstone Grit of north Stafibrdshire &c.," Quart. Journ. Geol. Soc. 

 Tol. XX. p. 260, fig. 7. 



