266 MR. E. W. BINNEY ON THE PERMIAN BEDS 



that I have greatly increased the thickness of the permian 

 beds, which in a former paper I only estimated at 330 feet.* 



The red marls and gypsum deposits are the highest mem- 

 bers of the permian group which I have as yet met with, 

 and although generally dipping in the same direction as the 

 overlying trias beds, are frequently uncomformable to them. 

 This will account for the permian deposits not being so often 

 exposed in natural sections. 



The thin ribbon beds of limestone, containing much clay 

 and iron, lying in the lower part of the red marls, as found 

 in South Lancashire in the neighbourhood of Manchester, 

 become thicker and more like the Yorkshire and Durham 

 limestones in grain, colour, and composition, as you proceed 

 towards the north at Stank and Barrow Mouth. 



The sandy conglomerate beds, containing rolled pebbles' of 

 Hug Bridge, Norbury, Cheetham weirhole, and other places 

 in South Lancashire, appear to gradually pass first into the 

 arenaceous conglomerate of Barrow Mouth, and then into 

 the calcareous conglomerates of Rougham Point, Kirkby 

 Stephen, Brough, and West House. When the deposit is 

 near a coal-field, it is generally arenaceous in character, and 

 when in a limestone district, calcareous; thus shewing that 

 most of the materials composing it were derived from or near 

 the neighbourhood in which it is now found, and not brought 

 from a distance. But certainly the cement in many places 

 has a great resemblance to volcanic ash.j 



The conglomerate is generally, but probably not always, 

 unconformable to the lower new red sandstone of Collyhurst, 

 Sutton, Belah, &c., having been often deposited in hollows 

 and on waterworn surfaces of that rock. 



* See Author's paper in vol. II. of the Quarterly Journal, previously quoted. 



t I am convinced that some of the mottled clays and shales of the upper coal 

 field, as well as many of the permian beds, have a great deal of volcanic ash in 

 their composition, 



