"Coarse grained sandstones, thin siltstones and a locally developed limestone member at the base. Richly fossiliferous."@en . "Corwen Grit Member"@en . "stable"@en . "445.2"^^ . . "Corwen Grit [Obsolete: use CWG]"@en . . . "Glyn Formation"@en . "Limestone, sandstone and siltstone. Stratified bedrock. Occurs onshore. Deposited during the Hirnantian Age (Ordovician Period) (445.2-443.1 Ma BP)."@en . . "CWG"@en . "Base overlies calcareous sandstones of the Dolhir Formation."@en . . . . . "443.1"^^ . . "Top is succeeded by pale grey siltstones with some interbedded thin sandstones of the Fron Frys Formation."@en . . "70 metres. Lateral variations, 21 metres - 70 metres."@en . "Corwen Grit Member"@en .