coalfieldn.

1734 J. T. Desaguliers Course Exper. Philos. I. iv. 242 Such Mill-wrights, as have work'd at Coal-pits and Mines, know better, as they have been us'd to large Horse-walks in Coal Fields, &c.

1811 J. Farey Gen. View Agric. Derbyshire I. 162 Immense and important..Coal-measures, which commence in Derbyshire and Nottinghamshire, and proceed through Derbyshire into Yorkshire..may be called the great Derbyshire and Yorkshire Coal-Field.

1867 W. W. Smyth Treat. Coal & Coal-mining 62 On the south-east of Tamworth, the clearing away of the red marls reveals a coalfield.

1935 H. Heslop Last Cage Down i. v. 50 Wasn't there enough trouble in the coal-field, what with unemployment, means tests, and National Governments, without all this tomfoolery?

1985 P. Cooke in D. Gregory & J. Urry Social Relations & Spatial Structures x. 225 The geological conditions of the coalfield were such that up to a quarter of the average collier's earnings actually derived from deadwork.

2000 Eng. Nature Mag. Jan. 2/2 The Environment Agency is building higher flood defence banks..because of mining subsidence from the Selby coalfield.