"stable"@en . "314.75"^^ . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Duckmantian Substage (Carboniferous Period) (318-314.75 Ma BP)."@en . "318.0"^^ . "DLO"@en . . . . . "Durham Low Main Coal (Northumberland And Durham)"@en . "Durham Low Main Coal (Northumberland And Durham)"@en . . "Coal."@en . . "Little Wonder Coal (Rothbury Area) [Obsolete: use DLO]"@en . . . .