"314.75"^^ . "stable"@en . . "310.0"^^ . . . "Bottom Usworth Coal (Northumberland And Durham)"@en . . "BUSC"@en . . "Coal."@en . . "Bottom Usworth Coal (Northumberland And Durham)"@en . . . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Bolsovian Substage (Carboniferous Period) (314.75-310 Ma BP)."@en .