Geology Site Account

Temporary exposure of fossiliferous deposits during road excavations. Further excavations in the vicinity could yield further fossils.

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Site description

The spectacular finds in Ilford came to an end with the closure of the brick pits, the classic locality of Uphall Pit being worked out and levelled by 1874, although the Cauliflower Pit continued to produce specimens at least until 1898. In the second half of the 20th century, however, the post-war redevelopment of Ilford town centre led to many more discoveries, which has enabled geologists to examine new sections in the classic Ilford brickearth and interpret them in the light of current knowledge of the evolution of the Thames valley. The general term brickearth is used here to describe the fossiliferous silt, sand, clay and organic deposits that occur beneath the Ilford area and have yielded fossil mammals since the early 19th century. The age of these deposits is still controversial and the deposits of two interglacial stages are thought to be present.

One of the first of these excavations was a 1,000 feet long trench for a six foot sewer pipe in the late 1950s which ran from Green Lane (TQ 447 865) to Ilford High Road (TQ 446 868), in the vicinity of Connaught Road. The sections revealed here were compared with the descriptions of the classic sections made in the 19th century Ilford brick pits. The next significant excavation was in 1959 (reported in the Philosophical Transactions of the Royal Society in 1964) when a series of boreholes north-west of Seven Kings station for a new school (TQ 452 871) revealed an organic horizon beneath the brickearth with abundant freshwater molluscs and plant remains including fruits, seeds and pollen, all of which enabled geologists to reconstruct the climate of the interglacial stage represented here.

In the 1950s and 1960s there were numerous excavations in the town centre that produced bones of mammoths and other mammals which indicates how astonishingly rich and widespread the fossiliferous deposits beneath Ilford are. Most of the excavations were for the foundations of buildings such as the police station, C&As store (now Woolworths), the extension to the telephone exchange and the new Harrison Gibson store following the fire in 1959, but, as is the nature of temporary excavations, the finds and sections were rarely adequately documented. The Harrison Gibson site was of particular interest because the excavation was for an underground car park and therefore was of some depth. The brickearth has also been repeatedly encountered in shallow excavations at Ilford Cemetery (TQ 449 867). The locations of many finds are contained in the records of the former Passmore Edwards Museum in Stratford, as a result of specimens being donated over the years.

However, the most interesting and informative recent excavation was in March 1984 for the Ilford Southern Relief Road (Winston Way) when bones of mammoth, giant ox and rhinoceros were discovered during construction of the Richmond Road pedestrian subway (TQ 442 865) and excavated by archaeologists and geologists from the Natural History Museum in London and the former Passmore Edwards Museum in Stratford. A striking feature of this site were narrow vertical dykes, regularly spaced every 1.2 metres (4 feet) and infilled with sand. Such features have been recorded in the Ilford brick pits by Victorian collectors and interpreted a suncracks. They are now understood to be typical of the polygonal pattern of cracks that form in permafrost “ evidence of an exceptionally cold climate during a subsequent glacial stage.

An excellent exhibition of fossil mammals from Ilford was mounted at Redbridge Local History Museum in Ilford Central Library from December 1986 to February 1987 which included many spectacular fossils borrowed from the Natural History Museum in London. A booklet The Return of the Mammoth was produced to accompany the exhibition. The museum today has some fossils from Ilford on permanent display.

Vertebra of a woolly rhinoceros in the excavation for a pedestrian subway at Richmond Road, Ilford in 1984. Photo: Passmore Edwards Museum