. "0.423"^^ . "Gerrards Cross Member [Obsolete: use GCGR]"@en . . . "1 - 10 m, average 4 m thick."@en . . . "0.86"^^ . "At surface."@en . "Gravel with subsidiary clay and sand. Stratified superficial deposits. Occurs onshore. Formed during the Cromerian Stage - to - Anglian Stage (Quaternary Period) (.86-.423 Ma BP)."@en . "Gerrards Cross Gravel Member"@en . . "Rests unconformably on bedrock geology."@en . "Gerrards Cross Gravel Member"@en . "Comprises 1 - 10 m of sand and gravel, locally with lenses of silt, clay or peat and organic material."@en . "GCGR"@en . "Gerrards Cross Gravel Formation [Obsolete: use GCGR]"@en . . "stable"@en . .