Purbeck Group

Purbeck Group
Stratigraphic range: Tithonian–Berriasian
Strata of the Purbeck Group in Durlston Bay, Dorset
TypeGroup
Sub-unitsLulworth Formation, Durlston Formation and Haddenham Formation
UnderliesWealden Group
OverliesPortland Group
Thickness45 to 120 m in South Dorset, 77 to 186 m in the Weald
Lithology
PrimaryMudstone, Limestone
Otherevaporites, chert
Location
RegionEurope
Country UK
ExtentSouthern England
Type section
Named forIsle of Purbeck
LocationDurlston Bay cliffs

Exposures of the Purbeck Group in Dorset shown in dark blue

The Purbeck Group is an Upper Jurassic to Lower Cretaceous lithostratigraphic group (a sequence of rock strata) in south-east England. The name is derived from the district known as the Isle of Purbeck in Dorset where the strata are exposed in the cliffs west of Swanage.

The Purbeck Group is famous for its fossils of reptiles and early mammals. This sequence of rocks has gone by various names in the past including amongst others the Purbeck Beds, Purbeck Formation, Purbeck Limestone Formation and Purbeck Stone.[1]

Rocks of this age have in the past been called the Purbeckian stage by European geologists. The Purbeckian corresponds with the Tithonian to Berriasian stages of the internationally used geologic timescale.

  1. ^ Hopson, P.M.; Wilkinson, I.P.; Woods, M.A. (2008). "A stratigraphical framework for the Lower Cretaceous of England" (PDF). British Geological Survey Research Report. RR/08/03: 1–77.