From Longman Dictionary of Contemporary Englishcoalfieldcoal‧field /ˈkəʊlfiːld $ ˈkoʊl-/ noun [countable] TPGan area where there is coal under the ground
Examples from the Corpus
coalfield• Final editing of a technical report on the Telford 1:25 000 sheet, which includes the Coalbrookdale coalfield, is in progress.• Coal-fired plants are mainly located inland, and very close to existing coalfields.• Other coalfields have changed in similar ways.• During their period production trebled in the coalfield.• A detailed revision of the coalfield areas commenced in 1902.• The work on the coalfields was intensified and a widespread search for minerals which were normally imported, was carried out.• The mass of new information which started to accumulate with the pre-war coalfield revision was greatly augmented during the wartime period.• He was active in the Yorkshire coalfield while I was active in the Nottinghamshire coalfield. 