. "422.7"^^ . . "Knucklas Castle Formation"@en . . "Knucklas Castle Formation"@en . "stable"@en . . "425.0"^^ . . . . "Knucklas Castle Beds [Obsolete: use KCA]"@en . "KCA"@en . . "Stratified bedrock. Occurs onshore. Deposited during the Ludfordian Age (Silurian Period) (425-422.7 Ma BP)."@en .