Geology Site Account

The sunken ground of Grays Town Park is a good example of a disused brick pit. The Grays brickearth was famous for the remarkable abundance of Ice Age fossil mammals which can now be seen in the Natural History Museum collections.

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The Grays brickearth

The town of Grays developed around the brick-making industry which was once of great economic importance to the area. The undulating ground in various parts of Grays is the only evidence today of this industry. The sunken ground of Grays Town Park, a disused brick pit purchased by Grays Town Council in 1898, is a good example of this.

In 1804 there is a record of 500 men being employed in Grays making bricks to be shipped down the Thames for the construction of Martello towers. Seventy three of these giant towers were then being built on the south coast to resist the threat of Napoleonic invasion, each one needing half a million bricks.

The Grays brickearth was first brought to the attention of the scientific world in a paper in the 1830s (Morris 1836). The term brickearth is used here to describe the various layers of sand, silt and clay blown by the wind or deposited by the Thames during the Ice Age. It yielded a large number of spectacular fossil mammals to the workers in the Grays brick pits, which, in early Victorian times, made the town of Grays internationally famous among collectors of fossils. Fortunately one of the brick-makers was the Grays Chalk Quarries Company whose owner, Richard Meeson (1814-1871), was a fellow of the Geological Society and responsible for many of the fossils being recovered. He is commemorated by the road name of Meesons Lane in Grays.

The Grays brickearth was worked by hand and so there was the opportunity for fossils to be collected complete and undamaged. However, this often did not happen as is vividly illustrated by the following extract from A History of British Fossil Mammals and Birds by leading Victorian palaeontologist and zoologist Richard Owen (Owen 1846 pages 249-253):

"About three years ago, the workmen in a brick-ground near the village of Grays in Essex, disinterred a quantity of bones of an enormous mammoth, which they broke up as they were discovered, and sold the fragments for three-halfpence a pound to a dealer in old bones. This traffic went on weekly for more than half a year, and accidentally came to the knowledge of Mr. R. Ball, F.G.S., a sedulous collector of fossil remains, who recovered from the workmen some magnificent bones of the fore foot, with portions of the scapula and ribs. I had the account from Mr. Ball, to whom I am indebted for casts of the bones which he was so fortunate as to rescue from the destruction that awaited them.

Most of the fossils collected from the brick pits are now preserved in the Natural history Museum in London, including the bones referred to by Owen (which turned out to be from a straight-tusked elephant). In addition to mammoth and straight-tusked elephant there are bones of lion, wolf, brown bear, hyena, rhinoceros, monkey, bison, beaver and wild boar. The fossils are thought to be from the Purfleet interglacial (Marine Isotope Stage 9) and therefore about 300,000 years old.

The spread of brickearth was almost 5.5 kilometres (4 miles) long and extended from West Thurrock to Little Thurrock but it has been almost entirely quarried away. The largest brick-pit was probably the Orsett Road Pit, the northern edge of which can be seen as a steep bank from the allotments in Whitehall Lane (TQ 623 782) west to Grays Town Park. Part of this bank is the site of the Orsett Road Section (TQ 620 782) which was a geological SSSI until it was denotified as part of the Geological Conservation Review in the late 1980s. This section contained a highly fossiliferous bed of sand yielding abundant remains of molluscs and small vertebrates (Hinton and Kennard 1898). A map of the brick pits in Grays can be found in Tylor (1869 plate VII). Other important sites in the Grays brickearth were Globe Pit SSSI and the former Tunnel Cement Works Quarry, West Thurrock (see separate site entries).

Cutmarks on bones from the brickearth pro-vides evidence that humans were living in the area at the same time as these animals. No flint tools are represented in these collections probably because the pit diggers and fossil collectors did not notice them. However, gravel associated with the brickearth in Globe Pit has produced Clactonian flint chopping tools.

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Photo: A section through the Grays brickearth in a pit south of Orsett Road. The photograph was taken in 1901, probably during the Geologists Association field visit to Grays on 18th April of that year (Hinton 1901). By the time this photograph was taken the Grays brick industry was a thing of the past and this cliff, known as the Orsett Road Section, was one of the very last exposures of the famous Grays brickearth. Photo © British Geological Survey (P239410).