Geology Site Account

Site name: Purfleet Road, Aveley SSSI

Grid reference: TQ 555 798

Summary of geological interest

Site of Special Scientific Interest designated for the importance of its geology.

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Site description

During excavation for the A13 trunk road to the south of Aveley in 1997 rescue excavations under Essex County Councils Field Archaeology Unit discovered a sequence of Ice Age sediments that were equivalent to those that contained the fossil elephants at Sandy Lane Pit directly to the north. Excavations for the cutting beneath the Purfleet Road bridge provided a section through the Mucking Formation which is the downstream equivalent of the Taplow terrace of the Thames. The sections revealed a cold-climate gravel at the base overlain by fossiliferous sands and clays (known as the Aveley Silts and Sands). The upper part of the interglacial sequence was represented by two layers of clay rich in vertebrates, molluscs, insects, plant remains and pollen indicating that the climate was at least as warm as the present day. The whole sequence is capped by sand and gravel indicating a return of very cold conditions.

The fossils support the conclusion that inter-glacial represented here is the same as that represented at Sandy Lane Pit, i.e. the penultimate interglacial (Marine Isotope Stage 7) and therefore about 200,000 years old (in recognition of this site this interglacial stage is often called the Aveley Interglacial). Bones of a range of mammals were found such as brown bear, wolf, giant deer, mammoth, straight-tusked elephant, rhinoceros, horse, bison and a very large lion. Of particular interest was the first discovery in Britain of the bones of a jungle cat, a marsh-dwelling animal that today lives in China, Central Asia and Egypt. The find received national press coverage, the Daily Telegraph covering the story with the front page headline Mother of the modern moggie found in Essex.

At least two distinct temperate phases appear to be present, an early one dominated by woodland species and a later one reflecting the development of open grassland with the appearance of mammoth, horse and rhinoceros.

Although grassed over, the road cutting has been designated a Site of Special Scientific Interest (SSSI) for the importance of the geology. The cutting can be seen from the Purfleet Road bridge.

North side of the cutting for the new A13, immediately east (Grays side) of the bridge where Purfleet Road crosses the new road. Photo © Peter Allen