Nibley Knoll () is a

geological Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland is a conservation designation denoting a protected area in the United Kingdom and Isle o ...

Gloucestershire Gloucestershire ( abbreviated Glos) is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn and the entire Forest of Dean. The county town is the city of Gl ...

, notified in 1974.Natural England SSSI information on the citation
/ref> The site is listed in the ‘Stroud District’ Local Plan, adopted November 2005, Appendix 6 (online for download) as an SSSI and a

Regionally Important Geological Site Regionally important geological and geomorphological sites (RIGS) (also known as regionally important geological sites or, especially in Wales, regionally important geodiversity sites) are locally designated sites of local, national and regional imp ...

(RIGS). Stroud District Local Plan, adopted November 2005, Appendix 6 ‘Sites of Nature Conservation Interest’

Location and geology

The site is in the

Cotswold The Cotswolds (, ) is a region in central-southwest England, along a range of rolling hills that rise from the meadows of the upper Thames to an escarpment above the Severn Valley and Evesham Vale. The area is defined by the bedrock of Jura ...

Area of Outstanding Natural Beauty An Area of Outstanding Natural Beauty (AONB; , AHNE) is an area of countryside in England, Wales, and Northern Ireland, that has been designated for conservation due to its significant landscape value. Areas are designated in recognition of ...

and is a significant geological location which shows a thick section of Lower and Middle

Jurassic The Jurassic ( ) is a geologic period and 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 Jurassic constitutes the middle period of ...

rocks. These span the junction between the Aalenian and Bajocian Stages. The lowest stratum which may be seen is the Cotswold Sand Formation of the Upper Lias. This is exposed in the sunken lane cuttings. The section above, which is the ''Cephalopod bed'' (top of the Aalenian Stage), is similar to the exposures on

Wotton Hill Wotton Hill () is a hill on the edge of the Cotswold Hills in Gloucestershire, England, north of Wotton-under-Edge. The Cotswold Way passes over the hill. The escarpment forms a biological and geological Site of Special Scientific Interest i ...

. The Lower

Inferior Oolite 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 ...

Freestones, are topped by 'hardground', which is a thin layer of tough limestone which is encrusted with fossil mollusc shells. One of the best fossiliferous sections is the Upper ''Trigonia'' Grit, which lies above the Freestone. There is an absence of Middle Inferior Oolite as a result of the effect of an important phase of uplift (warping) of the crust during the Lower Bajocian time interval. This demonstrates an important phase in earth movement in the region.

References

SSSI Source

Natural England SSSI information on the citation

Natural England SSSI information on the Nibley Knoll unit

External links

Natural England
(SSSI information) Image:Sheep on Nibley Knoll - geograph.org.uk - 1654030.jpg, On top of Nibley Knoll Image:Beeches, Westridge Wood - geograph.org.uk - 1653954.jpg, Nibley Knoll grassland and wood Image:Sheep above Millmans Farm - geograph.org.uk - 1654221.jpg, View from Nibley Knoll Sites of Special Scientific Interest in Gloucestershire Sites of Special Scientific Interest notified in 1974 Cotswolds {{England-SSSI-stub