. "Coal."@en . . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Asturian Substage (Carboniferous Period) (310-307.5 Ma BP)."@en . . "Fiery Coal (In Swansea Member, South Wales)"@en . . "FRYC"@en . "Lower Swansea Six Feet Coal (South Wales)"@en . . "310.0"^^ . "307.5"^^ . . . "stable"@en . "Fiery Coal (In Swansea Member, South Wales)"@en . . .