. "Allt-Y-Clych Conglomerate Formation"@en . . . "ACC"@en . "Allt-Y-Clych Conglomerate Member (Form Facies) [Obsolete: use ACC]"@en . "stable"@en . . "Conglomerate, mudstone and sandstone. Stratified bedrock. Occurs onshore. Deposited during the Rhuddanian Age (Silurian Period) (443.1-440.5 Ma BP)."@en . . "12 - 80 metres."@en . "Allt-Y-Clych Conglomerate Formation"@en . . "Sharp and erosional. Taken at base of first bed of pebbly mudstone or conglomerate above the Tycwtta Mudstones or Yr Allt Formation."@en . . . "440.5"^^ . "Gradational but taken at base of first thick mudstone unit of overlying Pistyll Gwyn Mudstones."@en . "443.1"^^ . "Conglomerates, pebbly mudstones and sandstones. A few thin mudstone beds."@en .