The Ravenscar Group is a

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

lithostratigraphic Lithostratigraphy is a sub-discipline of stratigraphy, the geology, geological science associated with the study of stratum, strata or rock layers. Major focuses include geochronology, comparative geology, and petrology. In general, strata are ...

group A group is a number of persons or things that are located, gathered, or classed together. Groups of people * Cultural group, a group whose members share the same cultural identity * Ethnic group, a group whose members share the same ethnic iden ...

(a sequence of

rock strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...

) which occurs within the

Cleveland Basin The Cleveland Basin is a sedimentary basin in Yorkshire, England. Formed initially by rifting during the Mississippian period of the Early Carboniferous. It is West–East trending and lies between the intrabasinal highs of the Askrigg Block and t ...

North Yorkshire North Yorkshire is the largest ceremonial counties of England, ceremonial county (lieutenancy area) in England, covering an area of . Around 40% of the county is covered by National parks of the United Kingdom, national parks, including most of ...

and extends to both the Hambleton and

Howardian Hills The Howardian Hills are an Area of Outstanding Natural Beauty located between the Yorkshire Wolds, the North York Moors National Park, and the Vale of York. They take their name from the Howard family who still own local lands. Topography Th ...

. The name is derived from Ravenscar on the

coast where rocks of this age occur. It was earlier known as the 'Middle Jurassic Series'.British Geological Survey 1:50,000 scale geological map sheet (England and Wales series) no 34 ''Guisborough'' It is the stratigraphic equivalent to the

Inferior Oolite Group The Inferior Oolite is a sequence of Jurassic age sedimentary rocks in Europe. It was deposited during the Middle Jurassic.Weishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weishampel, David B.; Dodson, Pet ...

and most of the

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 shel ...

, being overlain by the

Cornbrash Formation The Cornbrash Formation is a Middle Jurassic geological formation in England. It ranges in age from Bathonian to Callovian, the uppermost part of the Middle Jurassic. Dinosaur remains are among the fossils that have been recovered from the forma ...

of the latter unit.

References

Geological groups of the United Kingdom Geologic formations of England Aalenian Stage Bajocian Stage Bathonian Stage Geology of North Yorkshire {{UK-geologic-formation-stub