Geology Site Account

Historical site only

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Site description

London Clay has been worked at South Ockendon since at least 1930 to supply the cement works in Grays. Clay was mixed with water and turned into a slurry so that it could be piped to the works. Since cement manufacture ceased in Thurrock the clay has been pumped under the Thames to the cement works in North Kent. Fine expanses of London Clay could be seen, although the method of working “ by planing the face at a slope of about 25 degrees €“ was not conducive to fossil collecting.

The clay exposed was the lower part of the London Clay formation, similar to Walton-on-the Naze and Birchanger, near Stansted. Although fossils have never been common in the clay here, a number of interesting finds have been made over the years, particularly in the 1970s. Fossils such as molluscs, bird bones, fish remains, echinoid spines and turtle bone fragments have all been found. Shark and ray teeth have also occurred including the tooth of a new species of stingray Dasyatis wochadunensis, named after Wochaduna, the early English name for (South) Ockendon. The London Clay here has also yielded nine species of plant, found by sieving woody pockets in the clay for fossilised seeds and fruits.

The pits are private property and there is no public access. Grangewaters Outdoor Education Centre, to the south, is based on several lakes which are former clay pits.

London Clay being excavated at South Ockendon in the 1980s. Photo © G.Lucy