. "449.75"^^ . . . . "Sheets of massive, unbedded, poorly sorted, generally lithic-rich welded lapilli-tuff of andesitic and rhyolitic composition; interbedded volcaniclastic sandstone, siltstone, pumice lapilli-tuff and accretionary lapilli-tuff. Contains the rhyolitic welded lapilli-tuff (Seascale Hall Member) and, in BH RCF1, a rhyolitic lava flow or lava-like tuff."@en . "Brown Bank Tuff Formation"@en . "458.2"^^ . "BBA"@en . . . "255.55m in Type Section (355.5m in core because of andesite sill); 188m in Sellafield BH No.2; 127m in Sellafield BH No. 4; 45m in Sellafield BH No.5."@en . "Brown Bank Ignimbrite Formation [Obsolete: use BBA]"@en . "stable"@en . "Lapilli-tuff and tuff with subsidiary foliated felsite and trace volcaniclastic-sandstone. Stratified bedrock. Occurs onshore. Deposited during the Caradoc Series (Ordovician Period) (458.2-449.75 Ma BP)."@en . "At the change from coarse, eutaxitic, fiamme-rich lapilli tuff at the top of the Bleawath Formation to generally lithic-rich sequence above. Various members of the Formation overlap on to the top of the Bleawath Formation."@en . "At the upward change from the generally lithic-rich sequence to homogeneous andesitic welded tuff of the Fleming Hall Formation."@en . . . . "Brown Bank Tuff Formation"@en . .