"To 10m"@en . "Dee Valley Formation"@en . . "0.116"^^ . "0.0"^^ . . . "Clay, sand, silt and silty sand with subsidiary gravel, peat and sandy gravel. Stratified superficial deposits. Occurs onshore. Formed during the Devensian Stage - to - Holocene Epoch (Quaternary Period) (.116-0 Ma BP)."@en . "Tywi Formation [Obsolete: use DEEVA]"@en . . . . "stable"@en . "Dee Valley Formation"@en . "Probably unconformable, irregular and in places strongly incised into lithologically variable sediments of the Caledonia or Albion Glacigenic groups or into bedrock."@en . "Ground surface or unconformable below artificial deposits."@en . "DEEVA"@en . "Alluvium of silt, sand and clay with some peat, grading to gravel towards the base. River Terraces are composed of silty sand or sandy gravel with rare clay."@en . .