. . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Duckmantian Substage (Carboniferous Period) (318-314.75 Ma BP)."@en . "Hard Coal (South Lancashire)"@en . . . "Hard Mine Coal [Obsolete: use HARD]"@en . "HARD"@en . "stable"@en . "318.0"^^ . . "Hard Coal (South Lancashire)"@en . . . "Coal."@en . . "314.75"^^ . .