2l6 NEW RED SANDSTONE. 



near St. Helen's, Astley, and Manchester, in South Lancashire, and 

 in the north-west of England.^ 



The beds of the Salopian type attain a thickness of about 1500 

 feet, and include : — 



Red and purple sandstones and marls, breccia, calcareous conglomerate, 

 and earthy limestones. 



The separation of the iron-stained Coal-measures below, and 

 of Triassic rocks above, from the Permian rocks in this area, has 

 not yet been satisfactorily determined.' 



The beds of the Lancashire type include : — 



Red marls with numerous bands of fossiliferous limestone, worked for lime, 

 130 feet. (These beds are considered to be the representatives of the 

 Magnesian Limestone of Yorkshire and Durham.) 



Bright red and variegated sandstone (Collyhurst Sandstone), from 300 to 

 1500 feet. 



The evidence furnished by these types led Prof. Hull to conclude 

 that a ridge of Lower Carboniferous rocks crosses the plain of 

 Cheshire beneath the Trias, and forms a boundary between the 

 Permian rocks. Mr. A. Strahan has expressed the opinion that no 

 Permian rocks are present under the Trias of South Lancashire, 

 west of Warrington.^ The Garstang sandstones, south of Lancaster, 

 are probably Upper Permian.* 



Permian beds are developed at Shrewsbury, near Shiffnal, 

 Kenilworth, at Coventry, Wolverhampton, west of Birmingham, 

 and around the Dudley Coal-field. The Alberbury breccia of 

 Alberbury by the Severn, west of Shrewsbury, is of Permian age. 



The occurrence of silicified stems of trees in the red sandstones 

 at Allesley, north-west of Coventry, has been noted by Dr. Buck- 

 land. These fossil remains have also been met with in the Drift 

 gravel of Warwickshire.^ 



Near Stafford the red sandstone has been worked for building- 

 purposes. In South Staffordshire the thickness of the Permian 

 beds is estimated at from 1000 to 3000 feet; and in North 

 Staffordshire from 500 to 700 feet. Here the beds rest uncon- 

 formably on the Coal-measures and older rocks ; and they are 

 exposed at Newcastle-under-Lyne. 



In Cheshire the Permian beds attain a thickness of from 600 to 

 800 feet.* In the Vale of Clwyd traces of Permian beds have been 

 indicated as resting on the Carboniferous Limestone, and being 

 overlaid unconformably by Bunter beds. Here, however, Prof. 



^ Q.J. XXV. 171 ; Triassic and Permian Rocks of the Midland Counties (Geol. 

 Survey), p. 1 1. 



* See A. Strahan, Geology of Cheshire, Iron and Steel Inst. 1S85. 

 3 G. Mag. 1 88 1, p. 436. 



* G. Mag. 1882, p. 563. 



* Murchison and Strickland, Proc. G. S. ii. 439 ; T, G. S. (2), v. 347 ; see 

 also Howell, Geol. Warwickshire Coal-field, p. 32. 



« E. W. Binney, Q. J. ii. 12. 



