Kimmeridge Clay

Kimmeridge Clay
Stratigraphic range: Kimmeridgian–Berriasian PreꞒ Ꞓ O S D C P T J K Pg N
Grey cliffs of Upper Kimmeridge Clay above the beach at Egmont Bight
Type	Geological formation
Unit of	Ancholme Group (onshore), Humber Group (offshore)
Sub-units	Birch Sandstone Member Burns Sandstone Member Claymore Sandstone Member Dirk Sandstone Member Magnus Sandstone Member Ptarmigan Sandstone Member Ribble Sandstone Member
Underlies	Portland Sand Formation, Speeton Clay Formation, Spilsby Sandstone
Overlies	Ampthill Clay, Corallian Group
Lithology
Primary	Mudstone
Other	Siltstone, Sandstone, Conglomerate
Location
Region	England (surface) North Sea (subsurface)
Country	United Kingdom
Type section
Named for	Kimmeridge Bay
Location	Type section - North Sea well 47/15- 1 at 885-919 m depth Type area - coastal outcrops from Black Head, Weymouth to Chapman's Pool

The Kimmeridge Clay is a sedimentary deposit of fossiliferous marine clay which is of Late Jurassic to lowermost Cretaceous age and occurs in southern and eastern England and in the North Sea.^[1] This rock formation is the major source rock for North Sea oil. The fossil fauna of the Kimmeridge Clay includes turtles, crocodiles, sauropods, plesiosaurs, pliosaurs and ichthyosaurs, as well as a number of invertebrate species.