. . . . "stable"@en . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Langsettian Substage (Carboniferous Period) (319-318 Ma BP)."@en . . "Bottom Busty Coal (Northumberland and Durham)"@en . . "BBU"@en . "Coal."@en . . "318.0"^^ . . "Bottom Busty Coal (Northumberland and Durham)"@en . "Widdrington Main Coal (Rothbury Area) [Obsolete: use BBU]"@en . "319.0"^^ . . .