1 84 CARBONIFEROUS. 



Bolton, Rochdale, Oldham, Ashton-under-Lyne, and Staleybridge. 

 The Coal-measures admit of the following divisions : ^ — 



Upper (Ardwick) Series. — Shales, sandstones, and limestone with Spirorbis, 

 Fish-remains, etc. Thin coal-seams. 1680 to 2000 feet. 

 A bed of black-band ironstone with Anthracosia also occurs in this series. 

 The limestone, known as the Ardwick Limestone, from Ardwick near 

 Manchester, is an important horizon in the higher part of this series. 

 It contains Spirorbis, Anthracomya, etc. 



Middle Series. — Sandstones, shales, clays, and thick coal-seams, from the 

 Worsley Four-foot Coal to the flags below the Arley Mine, 3000 to 

 4000 feet. This division includes the celebrated Cannel Coal of 

 Wigan, which there attains its greatest development (three feet). 

 Many Fish-remains have been found in it. A)ithracosia and Anthra- 

 cotJiya have also been found in the series. 



Lower or Canister Series. — Flags, shales, and thin coals, with Canister floors 

 and roofs of shales, 1400 to 2000 feet. Near Billinge and Upholland 

 these beds have yielded Goniatites Listet'i, Avicidopecten papyraceus and 

 Spirorbis. 



The terms Arley Mine, Mountain Mine, Balcarres Mines, etc., are applied to 

 seams of coal. The seams worked vary from two to nine feet in thickness. The 

 Wigan Cannel Coal takes a fine polisli, and has been manufactured into various 

 useful and ornamental objects. Peacock Coal has been met with at Rochdale. 

 The term "Bullion " is used for nodules of argillaceous limestone. 



The Blenfire Rock, a massive red sandstone exposed in Oldham Edge, and the 

 Chamber Rock, a flaggy sandstone quarried at Rocher, belong to the Middle 

 Coal-measures. The Riddle Scout Rock (flagstone), the Upholland flags, the Old 

 Lawrence Rock (flagstone) of Huyton, the tilestones of Dineley Knowl, and the 

 Woodhead Hill Rock (hard flaggy sandstone), are locally known in the Lower 

 Coal-measures. Some of the beds have been used for the manufacture of grind- 

 stones and scythe-stones. 



Among other rocks of economic importance are the Burnley and Rochdale 

 flagstones, and rocks quarried at Orrel and Billinge Hill, near Wigan, Rainhill, 

 Bolton, and St. Helens. 



The Burnley Coal-field is a detached basin on the north : ^ the 

 Cheshire Coal-field is an ofif-shoot to the south. The Cheshire 

 Coal-field comprises a small area lying to the south of the Mersey, 

 above Stockport, and extending to the east of that town by Poynton 

 to IMacclesfield ; and also a narrow strip of Coal-measures exposed 

 along the eastern shore of the estuary of the Dee, known as the 

 Park Gate Coal-field. Near Macclesfield the Kerridge Rock com- 

 prises a thick mass of sandstones in the Lower Coal measures. 



5. SOUTH YORKSHIRE, DERBYSHIRE, AND NOTTINGHAMSHIRE 

 COAL-FIELD. 



This is the largest Coal-field in England, and extends from 

 Leeds and Bradford, by Halifax, Wakefield, Dewsbury, and 



^ See works on the Geology of Prescot, Oldham, Wigan, and Bolton-le-Moors 

 (Geol. Survey), by E. Hull ; and on the Geology of Stockport, etc., by E. Hull 

 and A. H. Green ; also papers by E. W. Binney, Trans. Manchester Geol. Soc. 

 vol. i. etc. ; and C. E. De Ranee, P. Geol. Assoc, v. 389. 



2 See Geology of the Burnley Coal-field (Geol. Survey), by E. Hull, J. R. 

 Dakyns, R. H. Tiddeman, J. C. Ward, W. Gunn, and C. E. De Ranee ; Geology 

 of Stockport, etc., by E. Hull and A. H. Green ; and E. Hull, Q. J. xxxiii. 

 627 ; Coal-fields of Great Britain, ed. 4, p. 232. 



