1869.] HULL GEOLOGY OF CHESHIRE. 175 



I now pas3 on to trace the characters and distribution of the 

 Permian rocks of the latter type. 



Permian Beds of the Lancashire Type. 



Distribution. — A fine exhibition of these beds may be observed 

 along the banks of the Mersey, above Stockport, where they are 

 interposed between the conglomerates of the Bunter Sandstone and 

 the coal-measures of Cheshire. Passing towards the north and west, 

 we find them opened out on a large scale at Collyhurst, near Man- 

 chester, where they were first identified as of Permian age by Mr. 

 Binney*, as being clearly overlain by a series of marls with lime- 

 stones containing fossils of Permian genera. Prom Manchester, they 

 have been traced by the same geologist, along the southern margin 

 of the Lancashire coal-field to Whiston, near St. Helens; and 

 throughout they occupy a position of discordance, both as regards 

 the Trias above and the coal-measures beneath. At Stockport the 

 formation attains a thickness which I have estimated at 1500 feet. 

 Whether or not it is so great, it is undoubtedly considerable ; and had 

 it not been for the superposition of the fossiliferous marls and lime- 

 stones, which have been clearly determined to overlie this rock, by 

 borings at Heaton Mersey, the whole (as far as lithological character 

 is concerned) might have been regarded as of the Bunter Sandstone 

 age. 



Mineral Characters and Composition. — Instead of a series of inter- 

 stratified sandstones, marls, breccias and conglomerates, such as that 

 which forms the Lower Permian rocks of the Salopian type, we have 

 in Cheshire and Lancashire a mass of homogeneous sandstone, 

 resembling in every respect (except in position) the lowest divi- 

 sion of the Bunter Sandstone of Shropshire and west Cheshire. 

 This rock is generally so soft as to be used for foundry pur- 

 poses, and consists of bright red and variegated sandstone, with- 

 out pebbles, fine-grained, and traversed by planes of current- 

 lamination. 



"When I first saw this rock in the quarry at Collyhurst, and judging 

 only by mineral character, I thought I recognized in it the " Lower 

 Mottled Sandstone " of the Bunter, with which I had been so 

 familiar in Shropshire and west Cheshire ; but the position of the 

 fossiliferous marls which here overlie this sandstone, and which 

 contain remains of the genera Turho, Rissoa, Natica, Gervillia, 

 AxinuSy MyoGoncha, and Tragos, determines beyond doubt the 

 Permian age of the sandstone rock, as shown by Mr. Binney. It 

 clearly forms a lower stage of the Permian formation in this part of 

 England. 



The contrast between these beds and their representatives in 

 Shropshire and the midland counties is, in fact, as great as between 

 the Bunter Sandstone and Permian beds of those counties. 



The Upper Permian series of South Lancashire requires but short 

 * " On the Geology of Manchester," Trans. Geol. Soc. Manchester, vol. i. 



