"Bedrock. Occurs onshore. Formed during the Brigantian Substage - to - Pendleian Substage (Carboniferous Period) (330.9-327 Ma BP)."@en . . . "Carraun Shale Formation And Dergvone Shale Formation (Undifferentiated)"@en . . "Carraun Shale Formation And Dergvone Shale Formation (Undifferentiated)"@en . . "CADV"@en . "See the Lithology descriptions for the component formations."@en . "stable"@en . . "327.0"^^ . "330.9"^^ . .