. "Foel Formation"@en . "Heterolith of dark-grey, peloidal limestones, shelly, oncolitic and locally oolitic limestones, porecllanous limestones, and fossil plant-bearing calcareous siltstones and calcareous sandstones. Limestones locally dolomitised. The oldest exposed parts of the Clwyd Limestone Group, the Foel Formation records peritidal deposition during the onset of the Dinantian transgression of North Wales."@en . . . "Lower Brown Limestone [Obsolete: use FOF, LEEL, LNML]"@en . "stable"@en . . "Conformable contact with thicker-bedded limestones of the Llanarmon Limestone Formation."@en . "FOF"@en . "Locally conformably overlies reddened \"Basement Beds\" (Ffernant Formation or Penbedw Formation); but elsewhere rests unconformably on Silurian rocks of the Clwydian Range (Nantglyn Flags Formation and Elwy Formation."@en . . . "Limestone, sandstone and siltstone with subsidiary dolomitic limestone. Stratified bedrock. Occurs onshore. Deposited during the Chadian Substage (Carboniferous Period) (346.7-344.5 Ma BP)."@en . . "To 88m"@en . . "346.7"^^ . "344.5"^^ . "Foel Formation"@en . .