. . . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Langsettian Substage (Carboniferous Period) (319-318 Ma BP)."@en . . . . "stable"@en . "318.0"^^ . "Higher Bent Mine Coal [Obsolete: use HBTC]"@en . . "Higher Bent Coal (South Lancashire)"@en . "Coal."@en . . . "HBTC"@en . "319.0"^^ . "Higher Bent Coal (South Lancashire)"@en .