. "Barton Sand Formation"@en . "Barton Sand Formation"@en . . "37.7"^^ . . . "Sand. Stratified bedrock. Occurs onshore. Deposited during the Bartonian Age (Palaeogene Period) (41-37.7 Ma BP)."@en . . "41.0"^^ . "Barton Sand [Obsolete: use BAS]"@en . . . "stable"@en . "BAS"@en . . "Sand."@en .