Oxford Clay

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Oxford Clay
Stratigraphic range: Callovian-Oxfordian
OxfordClay Weymouth.JPG
Type Geological formation
Unit of Ancholme Group
Sub-units Peterborough Member, Stewartby Member, Weymouth Member
Underlies West Walton Formation
Overlies Kellaways Formation
Lithology
Primary Claystone
Other Mudstone
Location
Region Oxford, Peterborough, Dorset, Yorkshire
Country  UK
Type section
Named for Oxford

The Oxford Clay is a Jurassic marine sedimentary rock formation underlying much of southeast England, from as far west as Dorset and as far north as Yorkshire. The Oxford Clay Formation dates to the Jurassic, specifically, the Callovian and Oxfordian ages,[1] and comprises two main facies. The lower facies comprises the Peterborough Member, a fossiliferous organic-rich mudstone. This facies and its rocks are commonly known as lower Oxford Clay. The upper facies comprises the middle Oxford Clay, the Stewartby Member, and the upper Oxford Clay, the Weymouth Member. The upper facies is a fossil poor assemblage of calcareous mudstones.

Oxford Clay appears at the surface around Oxford, Peterborough and Weymouth and is exposed in many quarries around these areas. The top of the Lower Oxford Clay shows a lithological change, where fissile shale changes to grey mudstone. The Middle and Upper Oxford Clays differ slightly, as they are separated by an argillaceous limestone in the South Midlands.

The Callovo-Oxfordian Clay also occurs in the Paris Basin (France) and it is a potential host formation to dispose high-level radioactive waste in France.

Palaeontology[edit]

The Oxford Clay is well known for its rich fossil record of fish and invertebrates.[2] Many of the fossils are well preserved, occasionally some are found exceptionally well preserved. Animals which lived in the Oxford Clay Sea include plesiosaurs, marine crocodiles, ichthyosaurs, cephalopods (such as belemnites), bivalves (such as Gryphaea), and a variety of gastropods. Dinosaur eggs are stratigraphically present in the Lower Oxford Clay. Geographically, they are located in Cambridgeshire, England.[3]

Ornithischians[edit]

Indeterminate euronithopod remains stratigraphically present in the Lower Oxford Clay and geographically located in Cambridgeshire, England.[3]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Ornithischians of the Oxford Clay
Genus Species Location Stratigraphic position Material Notes Images

Callovosaurus

C. leedsi[3]

  • Cambridgeshire[3]

Lower[3]

"Femur."[4]

Lexovisaurus[5]

L. durobivensis[6]

Lower[6]

Indeterminate[8]

  • Bedfordshire[9]

Loricatosaurus[3]

L. priscus[3]

  • Cambridgeshire[3]

Lower[3]

Sarcolestes[3]

S. leedsi[3]

  • Cambridgeshire[3]

Lower[3]

"Partial mandible."[10]

Saurischians[edit]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Saurischians of the Oxford Clay
Genus Species Location Stratigraphic position Material Notes Images

Cetiosauriscus[3]

C. stewarti[3]

  • Cambridgeshire[3]

Lower[3]

"Rear half of a skeleton."[11]

Eustreptospondylus[12]

E. oxoniensis[12]

Middle[12]

Disarticulated skull and skeleton, with some referred limb elements.[13]

Sauropoda

Indeterminate[14]

The caudal vertebrae from Cambridgeshire were mistakenly considered part of the syntypic series of "Ornithopsis" leedsi by Upchurch and Martin (2003).[15]

Theropoda

Indeterminate[12]

Middle[12]

Metriacanthosaurus[16]

Plesiosaurs[edit]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Genus Species Location Member Abundance Notes Images

Cryptocleidus

C. eurymerus

A cryptoclidid

C. richardsoni

A cryptoclidid

Liopleurodon

L. ferox

A thalassophonean pliosaurid

L. pachydeirus

A thalassophonean pliosaurid

Marmornectes

M. candrewi

A pliosaurid

Muraenosaurus

M. leedsi

A cryptoclidid

Pachycostasaurus

P. dawnii

A pliosaurid

Peloneustes

P. philarchus

A thalassophonean pliosaurid

Picrocleidus

P. beloclis

A cryptoclidid

"Pliosaurus"

"P." andrewsi

A thalassophonean pliosaurid; represents a new genus distinct from Pliosaurus

Simolestes

S. vorax

A thalassophonean pliosaurid

Tricleidus

T. seeleyi

A cryptoclidid

Thalattosuchians[edit]

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Genus Species Location Member Abundance Notes Images

Gracilineustes

G. leedsi

A metriorhynchine metriorhynchid

Lemmysuchus

L. obtusidens

A teleosaurid belonging to Machimosaurini

Metriorhynchus

M. superciliosus

A metriorhynchine metriorhynchid

Steneosaurus

S. durobrivensis

A teleosaurid

S. edwardsi

A teleosaurid

S. leedsi

A teleosaurid

Suchodus

S. brachyrhynchus

A geosaurine metriorhynchid

S. durobrivensis

A geosaurine metriorhynchid

Tyrannoneustes[17]

T. lythrodectikos

A geosaurine metriorhynchid

Economic use[edit]

Oxford Clay has a porous consistency and is soft and is often used in the making of roads. It is also the source of the Fletton stock brick of which much of London is built. For brick making, the Oxford Clay has the advantage of containing carbon which provides part of the fuel required in firing it so reducing the requirement for an external fuel source.

See also[edit]

References[edit]

  1. ^ "Oxford Clay Formation". The BGS Lexicon of Named Rock Units. British Geological Survey. Retrieved 21 August 2017. 
  2. ^ Martill, D.M.; Hudson J.D. (1991). Fossils of the Oxford Clay. Palaeontological Association. 
  3. ^ a b c d e f g h i j k l m n o p q r s "10.9 Cambridgeshire, England; 1. Lower Oxford Clay," in Weishampel, et al. (2004). Page 540.
  4. ^ "Table 18.1," in Weishampel, et al. (2004). Page 396.
  5. ^ Weishampel, et al. (2004). Pages 539-540.
  6. ^ a b "10.7 Dorset, England; 3. Lower Oxford Clay" and "cambridgeshire">"10.9 Cambridgeshire, England; 1. Lower Oxford Clay," in Weishampel, et al. (2004). Pages 539-540.
  7. ^ "10.7 Dorset, England; 3. Lower Oxford Clay," in Weishampel, et al. (2004). Page 539.
  8. ^ Listed as "?Lexovisaurus sp." in "10.10 Bedfordshire, England; 1. Oxford Clay," in Weishampel, et al. (2004). Page 540.
  9. ^ "10.10 Bedfordshire, England; 1. Oxford Clay," in Weishampel, et al. (2004). Page 540.
  10. ^ "Table 17.1," in Weishampel, et al. (2004). Page 367.
  11. ^ "Table 13.1," in Weishampel, et al. (2004). Page 265.
  12. ^ a b c d e f g "10.14 Oxfordshire, England; 8. Middle Oxford Clay," in Weishampel, et al. (2004). Page 540.
  13. ^ "Table 4.1," in Weishampel, et al. (2004). Page 72.
  14. ^ a b "10.14 Wiltshire, England; 4. Oxford Clay," in Weishampel, et al. (2004). Page 540.
  15. ^ 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.
  16. ^ http://www.prehistoric-wildlife.com/species/m/metriacanthosaurus.html
  17. ^ Mark T. Young; Marco Brandalise de Andrade; Stephen L. Brusatte; Manabu Sakamoto; Jeff Liston (2013). "The oldest known metriorhynchid super-predator: a new genus and species from the Middle Jurassic of England, with implications for serration and mandibular evolution in predacious clades". Journal of Systematic Palaeontology. 11 (4): 475–513. doi:10.1080/14772019.2012.704948. 

Bibliography[edit]

  • Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.

Further reading[edit]

  • Andrews, C. W. 1910. "A Descriptive Catalogue of the Marine Reptiles of the Oxford Clay, Part I". British Museum (Natural History), London, England: 205 pp.
  • Andrews, CW. 1913. A descriptive catalogue of the Marine Reptiles of the Oxford Clay, Part II. British Museum (Natural History). pp. 205pp.
  • M. J. Benton and P. S. Spencer. 1995. Fossil Reptiles of Great Britain. Chapman & Hall, London 1-386
  • J. B. Delair. 1973. The dinosaurs of Wiltshire. The Wiltshire Archaeological and Natural History Magazine 68:1-7
  • P. M. Galton. 1980. European Jurassic ornithopod dinosaurs of the families Hypsilophodontidae and Camptosauridae. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 160(1):73-95
  • D. M. Martill. 1988. A review of the terrestrial vertebrate of fossils of the Oxford Clay (Callovian-Oxfordian) of England. Mercian Geologist 11(3):171-190