"458.2"^^ . . . . . . "[Obsolete: use ARD]"@en . "Middle Ardwell Beds [Obsolete: use ARD]"@en . "Middle Ardwell Beds [Obsolete: use ARD]"@en . "Ardwell Farm Formation"@en . "ARBM"@en . "Obsolete name. Stratified bedrock. Occurs onshore. Deposited during the Caradoc Series (Ordovician Period) (458.2-449.75 Ma BP)."@en . "archaic"@en . . . . "449.75"^^ .