"426.7"^^ . "432.9"^^ . "stable"@en . . . "Stratified bedrock. Occurs onshore. Deposited during the Wenlock Epoch (Silurian Period) (432.9-426.7 Ma BP)."@en . "Brinkmarsh Beds"@en . . . . . . "Brinkmarsh Beds"@en . "BKM"@en .