Great Oolite Group

The Great Oolite Group is a Middle Jurassic stratigraphic unit that outcrops in southern England. It consists of a complex set of marine deposits primarily mudstone and bioclastic ooidal and fine grained limestone, deposited in nearshore to shelf settings.[1] It is exposed at the surface as a variably thick belt extending roughly NE-SW from the coast of Dorset up to the Humber. It is also present at depth in the Weald and Wessex Basins, as well as offshore. Several of the constituent formations, notably the Taynton Limestone Formation and the Forest Marble Formation are notable for their fossil content, including those of dinosaurs and pterosaurs and some of the earliest mammals.

Great Oolite Group
Stratigraphic range:
Type	Group
Sub-units	Cornbrash Formation, Chipping Norton Limestone, Sharp's Hill Formation, Taynton Limestone Formation, Forest Marble Formation, Hampen Formation, White Limestone Formation, Rutland Formation, Blisworth Limestone, Blisworth Clay Formation, Chalfield Oolite Formation, Corsham Limestone Formation, Athelstan Oolite Formation, Horsehay Sand Formation, Tresham Rock Formation
Underlies	Ancholme Group
Overlies	Inferior Oolite Group
Thickness	22–200 m (72–656 ft) (224 m (735 ft) offshore)
Lithology
Primary	Limestone, Mudstone
Other	Sandstone
Location
Region	Europe
Country	England
Extent	Dorset to Norfolk
Type section
Named for	Oolite