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 roughtly 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: Bajocian-Callovian
Sub-unitsCornbrash 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
UnderliesAncholme Group
OverliesInferior Oolite Group
Thickness22–200 m (72–656 ft)
(224 m (735 ft) offshore)
PrimaryLimestone, Mudstone
Country England
ExtentDorset to Norfolk
Type section
Named forOolite


See alsoEdit


  1. ^ "Great Oolite Group". The BGS Lexicon of Named Rock Units. British Geological Survey. Retrieved 31 May 2014.


  • Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.