Ravenscar Group

The Ravenscar Group is a Jurassic lithostratigraphic group (a sequence of rock strata) which occurs within the Cleveland Basin of North Yorkshire and extends to both the Hambleton and Howardian Hills. The name is derived from Ravenscar on the North Yorkshire coast where rocks of this age occur. It was earlier known as the 'Middle Jurassic Series'.[1][2] It is the stratigraphic equivalent to the Inferior Oolite Group and most of the Great Oolite Group, being overlain by the Cornbrash Formation of the latter unit.

Ravenscar Group Stratigraphic range: Middle Jurassic Aalenian to Bathonian PreꞒ Ꞓ O S D C P T J K Pg N
Sandstones and mudstones of the Saltwick Formation exposed on the cliffs near Herbert Hole, south of Ravenscar, North Yorkshire
Type	Group
Sub-units	Saltwick Formation, Eller Beck Formation, Cloughton Formation, Scarborough Formation and Scalby Formation
Underlies	Cornbrash Formation
Overlies	Dogger Formation
Thickness	114m to c240m
Lithology
Primary	sandstone
Other	mudstone, limestone, ironstone, coal
Location
Country	England
Extent	Cleveland Basin, North Yorkshire
Type section
Named for	Ravenscar

References

1. http://www.bgs.ac.uk/Lexicon/lexicon.cfm?pub=RAG
2. British Geological Survey 1;50,000 scale geological map sheet (England and Wales series) no 34 Guisborough