. "Fells Shale"@en . . "stable"@en . . . "FESH"@en . "346.7"^^ . . "c.2m"@en . . "330.3"^^ . "Fells Shale"@en . . "Sapropelite. Stratified bedrock. Occurs onshore. Deposited during the Visean Age (Carboniferous Period) (346.7-330.3 Ma BP)."@en . . "A formerly productive bed of oil-shale."@en .