. . "161.5"^^ . "Ampthill Clay Formation and Kimmeridge Clay Formation (Undifferentiated)"@en . "149.2"^^ . "Kimmeridge Clay Formation and Ampthill Clay Formation (Undifferentiated) [Duplicate: use AMKC]"@en . "Ampthill Clay Formation and Kimmeridge Clay Formation (Undifferentiated)"@en . . "Mudstone with subsidiary calcareous mudstone, calcilutite, limestone, sand, sapropelite, silt and siltstone and trace ironstone and sandstone. Bedrock. Occurs onshore. Formed during the Oxfordian Age - to - Kimmeridgian Age (Jurassic Period) (161.5-149.2 Ma BP)."@en . . . "AMKC"@en . . . "stable"@en .