"GKC"@en . "Gortnaskea Coal (Dungannon)"@en . . . . . . "Gortnaskea Coal (Dungannon)"@en . "318.0"^^ . . . "stable"@en . . "Coal. Stratified bedrock. Occurs onshore. Deposited during the Duckmantian Substage (Carboniferous Period) (318-314.75 Ma BP)."@en . "Coal."@en . "314.75"^^ .