"Approx. 1800 metres."@en . . "Fishguard Volcanic Group"@en . . . . . "Drawn at base of rhyolitic and dacitic lavas of the Porth Maen Melyn Volcanic Formation where it rests conformably on dark mudstones of the Aber Mawr Shale Formation."@en . "stable"@en . "468.0"^^ . . "Volcaniclastic rocks (both pyroclastic and reworked volcanic rocks) and trace basalt, dacite, lava, rhyolite, tuff and volcaniclastic-breccia. Stratified bedrock. Occurs onshore. Deposited during the Abereiddian Stage (Ordovician Period) (468-461.25 Ma BP)."@en . "Fishguard Volcanic Complex [Obsolete: use FIV]"@en . . "Fishguard Volcanic Series [Obsolete: use FIV]"@en . . . . "Fishguard Volcanic Group"@en . "Rhyolitic and dacitic lavas, basaltic pillow lavas. Spilitic breccias, acid tuffs and intercalated volcaniclastic sediments. (Correlative of Fishguard Volcanic Group-Llanrian Volcanic Group."@en . "FIV"@en . . "461.25"^^ . "Drawn at conformable upward passage from rhyolitic lavas of the Goodwick Volcanic Formation to dark grey mudstones of the Caerhys Shale."@en . . .