. . . "stable"@en . "FW"@en . "Taken at the sharp incoming of tuff or tuffaceous sandstone, or locally calcareous sandstone and shelly limestone of the overlying Asaphus Ash Formation."@en . "468.0"^^ . "Felin-Wen Formation"@en . . . "Mudstone with subsidiary calcareous sandstone and sandstone. Stratified bedrock. Occurs onshore. Deposited during the Llanvirn Series (Ordovician Period) (468-458.2 Ma BP)."@en . "458.2"^^ . "Murchisoni Beds"@en . "Silt-laminated mudstone with sparse, scatterd thin sandstone or calcareous sandstone beds."@en . "c.70m"@en . . "Taken at the sharp incoming of silt-laminated mudstone of the Felin-wen Formation above the hemipelagic laminated and burrowed mudstone of the Aber Mawr Shales Formation. Base not observed in the Newcastle Emlyn district."@en . "Felin-Wen Formation"@en . . .