. . "Stratified bedrock. Occurs onshore. Deposited during the Ordovician Period (486.9-443.1 Ma BP)."@en . "Gilnahirk Formation [Obsolete: use GILN]"@en . "443.1"^^ . . . . . "Gilnahirk Group"@en . "Gilnahirk Group"@en . . . "stable"@en . . "GILN"@en . "486.9"^^ .