. . . . "Ironstone."@en . "Curdly Ironstone"@en . . "CUR"@en . "Ironstone. Stratified bedrock. Occurs onshore. Deposited during the Arnsbergian Substage (Carboniferous Period) (327-323.75 Ma BP)."@en . . . "stable"@en . "323.75"^^ . "Curdly Ironstone"@en . . "327.0"^^ .