. "Coal."@en . "314.75"^^ . . "Bottom Main Coal (Durham)"@en . . . . . "BMNC"@en . . "Bottom Main Coal (Durham)"@en . "stable"@en . "318.0"^^ . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Duckmantian Substage (Carboniferous Period) (318-314.75 Ma BP)."@en . .