. "Sandstone. Stratified bedrock. Occurs onshore. Deposited during the Langsettian Substage (Carboniferous Period) (319-318 Ma BP)."@en . "stable"@en . . . . "319.0"^^ . "Sandstone."@en . . . "318.0"^^ . "Harrock Hill Grit"@en . . . "Harrock Hill Grit"@en . "HHG"@en .