"Stratified bedrock. Occurs onshore. Deposited during the Gorstian Age (Silurian Period) (426.7-425 Ma BP)."@en . . . "CCBL"@en . . "425.0"^^ . . "stable"@en . . "Lower Cwm Clyd Beds"@en . . "426.7"^^ . "Lower Cwm Clyd Beds"@en . .