Oxford Clay

Oxford Clay is a Jurassic marine sedimentary rock underlying much of South East England, from as far west as Dorset and as far north as Yorkshire. The Oxford Clay is argillaceous (consists of clay) and is of Callovian to lower Oxfordian age.

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 presently studied by Andra as a potential host formation to dispose high-level radioactive waste in France.

Additional recommended knowledge

Essential Laboratory Skills Guide

What is the Sensitivity of my Balance?

Daily Sensitivity Test

Palaeontology

The Oxford Clay is well know for its rich fossil record of fish and invertebrates.^[1] Many of the fossils are well preserved, occasionally some are found exceptionally well preserved. Animals which lived in the Oxford Clay Sea include: Ichthyosaurs, Cephalopods (such as Belemnites), Bivalves (such as Gryphaea), and a variety of Gastropods.

Uses

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

• Clay
• London Clay
• Weald Clay
• Cheltenham Clay
• List of fossil sites (with link directory)

References

1. ^ Martill, D.M.; Hudson J.D. (1991). Fossils of the Oxford Clay. Palaeontological Association.