126 Coa l-measures. 



Cheshire, and Lancashire. Three or four beds of igneous 

 rock, called loadstone, lie in the limestone. The Mill- 

 stone grit of these areas is much mingled with shale, and 

 between it and the Carboniferous Limestone there are 

 often thick beds of shale and sandstone, called the Upper 

 Limestone Shale, or Yoredale rocks. North of the 

 Kibble the Carboniferous Limestone itself is divided by 

 numerous interstratincations of sandstone and shale, 

 with occasional beds of thin coal, and this increasing in 

 the northern parts of Northumberland, the equivalents of 

 the southern mass of Carboniferous Limestone die away 

 into a few subordinate beds of limestone, and fairly pass 

 by degrees into a lower coal-field, with several poor 

 beds of coal. 



The Lancashire, Cheshire and North Staffordshire 

 coal-fields, exclusive of the Millstone grit, vary from 

 about 3,500 to 7,500 feet in thickness, counting from 

 the beds on which the unconformable Permian strata 

 happen to rest. They include about 30 coal-beds in 

 North Staffordshire, in Lancashire 14 good seams about 

 St. Helens, 15 at Wigan, 16 between Manchester and 

 Bolton, and 13 at Burnley. Many of these, which in 

 different districts go by different names, are equivalent 

 beds. Fish remains and many marine and estuarine 

 or fresh water shells occur among the interstratified 

 shales and sandstones. There are also many beds of 

 ironstone. The Nottingham, Derbyshire, and Yorkshire 

 coal-fields united give about 1 5 beds of workable coal. 

 All these are ironstone areas, and North Staffordshire 

 is the great pottery district of England. The finer 

 clay is imported, only the coarser qualities for tiles, &c., 

 being native. 



The Newcastle coal-field is about 1,600 feet thick, 

 and contains about 16 beds of coal throughout the 



