"Charlestown Green Limestone"@en . "330.3"^^ . "330.9"^^ . "stable"@en . . . "Stratified bedrock. Occurs onshore. Deposited during the Brigantian Substage (Carboniferous Period) (330.9-330.3 Ma BP)."@en . "Charlestown Green Limestone"@en . . . . "CNGR"@en . . . .