. "Breccia, mudstone and sandstone with subsidiary pebbly (gravelly) sandstone. Bedrock. Occurs onshore. Formed during the Stephanian Stage (Carboniferous Period) - to - Cisuralian Epoch (Permian Period) (307.5-274.4 Ma BP)."@en . "274.4"^^ . "Clent Formation And Haffield Breccia Formation (Undifferentiated)"@en . "See the Lithology descriptions for the component formations."@en . "Clent Formation And Haffield Breccia Formation (Undifferentiated)"@en . "CLHB"@en . . "stable"@en . . . . "307.5"^^ . .