By PROFESSOR W. E. BENTON, A.R.S.M., F.G.S.
Minerals Worked.—The principal minerals worked within the limits of the South Staffordshire Coalfield are coal, ironstone, and fireclay from the Carboniferous formations, and limestone from the underlying Silurian rocks.
The Coal is bituminous, non-caking, and much of it contains a high percentage of water and oxygen. Some of the seams produce excellent house-coal, others manufacturing and steam coal.
The Ironstone is an argillaceous carbonate of iron, occurring as nodules in the roofs of the coal seams, or as thin beds within them.
The Fireclay, particularly in the neighbourhood of Stourbridge, has a high refractory power.
Quantity of Minerals Raised.—The annual produce of minerals during the last twenty years has remained without any considerable alteration. The Government Mineral Statistics for 1885 are not yet published, but in 1884 the quantities of minerals raised in South Staffordshire Coalfield were:—Coal, 9,688,047 tons; ironstone, 116,951 tons; fireclay, 205,320 tons; limestone (no statistics given). The respective values of these minerals at the mines were estimated at:—coal, £2,785,313; ironstone, £62,974; fireclay, £42,781.
The total number of persons employed at the mines during the same period was 23,782.
Destination of the Minerals.—The greater part of the coal is consumed in the district for house purposes, for steam raising, for the manufacture of bricks, pottery, glass, salt, &c. The remainder is carried out of the coalfield into the south and south-western districts of England by the London and North Western, Great Western, and Midland Railway Companies, for house and steam purposes. The gas coals and coke used in the Birmingham district are not the product of the South Staffordshire Coalmeasures, but are brought principally from North Staffordshire, Derbyshire, and Yorkshire.
The whole of the ironstone raised is smelted within the district, in addition to large quantities of iron ore (hydrated oxide) brought from the Northampton and North Staffordshire mines. The manufacture of pig iron has within the last decade decreased to such an extent that less than one-third of the existing furnaces of South Staffordshire are at present in blast.
The quantity of pig produced in the coalfield in 1884, was 356,873 tons; in the reduction of which 810,936 tons of coal (including coal converted into coke) were used, or about 45½ cwts. of coal to one ton of pig iron. The whole of the pig iron is retained in the district. The finished iron trade retains its importance, more than one-third of the existing puddling furnaces and rolling mills in Great Britain occur within the limits of the South Staffordshire Coalfield.