"stable"@en . "Half Yard Coal (Cumbria)"@en . . . "Coal."@en . . "318.0"^^ . "319.0"^^ . "HFYD"@en . . . . . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Langsettian Substage (Carboniferous Period) (319-318 Ma BP)."@en . "Half Yard Coal (Cumbria)"@en . .