{{Short description|Geological formation in England}} {{Use dmy dates|date=April 2022}} {{Infobox rockunit | name = Kellaways Formation | image = | caption = | type = Formation | age = Callovian | period = Callovian | prilithology = mudstone, siltstone, sandstone | otherlithology = | namedfor = | namedby = | region = England (onshore); St George's Channel (offshore)<ref name="Earthwise_Wales_Jurassic">{{cite web |url=https://earthwise.bgs.ac.uk/index.php/Jurassic_of_Wales |title=Jurassic of Wales |publisher=British Geological Survey |work=Earthwise |date=2016 |access-date=2 May 2026}}</ref> | country = United Kingdom | coordinates = | unitof =Ancholme Group | subunits = | underlies = Oxford Clay | overlies = Cornbrash Formation | thickness =0-50 m | extent = | area = | map = | map_caption = }}
The '''Kellaways Formation''' is a geological formation of the Callovian Stage from the Jurassic. It is found in the British Isles, immediately above the Great Oolite Group: below the Oxford Clay Formation and above the Cornbrash. It consists of two layers, the Kellaways Sand, a light green-grey clayish silt and sand with layers of sand concretions, overlying the Kellaways Clay, a dark grey plastic fissile clay.<ref name="BGS">{{cite web | url=http://www.bgs.ac.uk/Lexicon/lexicon.cfm?pub=KLB | title=Kellaways Formation | publisher=British Geological Survey | work=Lexicon of named rock units | accessdate=26 May 2015}}</ref>
They were laid down during the Callovian, offshore from the London-Brabant Island, between 165 and 160 million years ago, in the latitude of the modern Mediterranean Sea, when the structure of Britain was still taking shape. At this stage, the coal swamps of the north-western shore of the island had subsided below the sea so that the Kellaways clay was formed in fairly deep water and the Kellaways sand was blown and washed from what had become the hot desert land.
The holotype of the indeterminate eusauropod ''"Ornithopsis" leedsii'' has been recovered from this formation.<ref>Noé LF, Liston JJ, Chapman SD. 2010. ‘Old bones, dry subject’: the dinosaurs and pterosaur collected by Alfred Nicholson Leeds of Peterborough, England. Geological Society, London, Special Publications 343: 49–77.</ref>
==See also== *Guliemina
==References== {{Reflist}}
Category:Geologic formations of the United Kingdom Category:Callovian Stage Category:Jurassic System of Europe Category:Mudstone formations of the United Kingdom Category:Siltstone formations Category:Sandstone formations
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