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GEOLOGY COAL MEASURES The Leicester Coalfield occupies that part of the county west of the Charnwood Hills. It extends also into South Derbyshire, but the two are so intimately connected together that it will be necessary in describing this coalfield to include the whole area. The formation is composed of a series of sandstones and shales with many seams of coal and ironstone. The coal seams vary in thickness from a maximum of 1 5 ft., but the majority of workable seams are from 7 ft. to 8 ft. or less. The strata are bent into a flat arch having its axis running in a north- westerly and south-easterly direction parallel with that of Charnwood Forest, so that the seams on the east dip to the east, while those on the west dip in the main to the west, although there are several minor disturbances which alter this general arrangement. The effect of this is that the coalfield is separated into three areas, the western or Moira Coalfield, the eastern or Whitwick Coalfield, and the central region of lower unproductive measures. The coal seams on either side of the anticline have not as yet been correlated with one another ; there is considerable difference in the nature of the measures on the two sides of the coalfield, and until further advance has been made in the palaeontology of these rocks it is not possible to compare the seams with any certainty. The following is a list of the principal seams on the two sides of the coalfield : MOIRA OR WESTERN COALFIELD WHITWICK OR EASTERN COALFIELD Average Average Name of Coal Seam Thickness Name of Coal Seam Thickness ft. in. ft. in. Ell 3 Stone Smut Rider .... 3 8 Dickey Gobler 36 ( 3 o Jack Dennis, Block or Wat- Stone Smut to son 40 (60 Little or Five Feet ....50 Swannington 40 Main 140 Soft or Three Quarters ..20 Toad or Little Woodfield ..40 Slate Coal Rider . . . . i o Slate 38 Slate 50 Woodfield 60 Yard 40 Stockings 70 Rattlejack 30 Eureka 4 6 Stinking or Sulphurous ..30 Stanhope 46 Main 60 Kilburn 46 Smoilc 36 Upper Lount 3 Middle Lount 56 Nether Lount 60 Roaster Associated with some of these seams are beds of fireclay which are of much importance, especially about Moira and Swadlincote, where they are employed for the manufacture of firebricks, saggers, &c. The clays in the upper part of the measures are also extensively used for sanitary pipes, &c. In the south-eastern part of the coalfield the seams are worked beneath a thick covering of Keuper Marl and Sandstone, the Coal Measures them- selves, except at Heather, being entirely hidden by this formation. 7