"Chudleigh Group"@en . "In the Chudleigh area the lower boundary is taken at the incoming of black sooty and siliceous mudstones of the Chudleigh Group (Winstow Chert Formation) above the purple, green and grey mudstones of the underlying Tamar Group (Whiteway Mudstone Formation). The contact is generally sharp. In the Plymouth area it is taken at the incoming of dark grey cherts and siliceous mudstones of the Chudleigh Group (Winstow Chert Formation) above the mid grey silty mudstones of the Tamar Group (Saltash Formation)."@en . . "359.3"^^ . . . "Thin bedded cherts and siliceous mudstones, black mudstones and limestones passing up into thick-bedded to massive sandstones with subordinate conglomerate and mudstone."@en . "319.0"^^ . "The upper boundary is taken at an angular unconformity where fine-grained glauconitic sandstone of the Upper Greensand Formation rests upon thick-bedded to massive, locally pebbly to conglomeratic sandstone of the Ugbrooke Sandstone Formation."@en . . "Chudleigh Group"@en . "Sandstone with subsidiary chert, conglomerate and mudstone. Stratified bedrock. Occurs onshore. Deposited during the Tournaisian Age - to - Namurian Stage (Carboniferous Period) (359.3-319 Ma BP)."@en . . . . "stable"@en . "CHUD"@en . . "Not known but probanly about 550m+"@en . "Culm [Obsolete: use CHUD, CU]"@en . .