"170.9"^^ . . . "174.7"^^ . "stable"@en . . . . "HDS"@en . "Harford Sands"@en . "Sand and sandstone."@en . "Harford Sands"@en . "Sand and sandstone. Bedrock. Occurs onshore. Formed during the Aalenian Age (Jurassic Period) (174.7-170.9 Ma BP)."@en . .