Geology Site Account

Site name: Star Lane Pits

Grid reference: TQ 939 872

Brief description of site:

Disused brick pits of Star Lane Brickworks. A site of significant geological interest with unique exposures of loess.

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Summary of geological interest

Loess is a very fine silt which originated as a wind-blown dust carried great distances from cold, dry land close to an ice sheet to settle and be compacted to form a sedimentary rock. In Britain loess is only found here in south-east Essex and in Kent.

Loess was once extensively excavated for brick making at several sites in this area and the last surviving brickworks was at Star Lane, Great Wakering, which closed in 2005. At Star Lane the most recently quarried areas have been restored by infilling and returning the fields to agriculture but the early flooded pits still survive to the east of the former works. Here there are two low cliffs of orange loess.

These exposures provide evidence of an exceptionally cold period of the ice Age - thought to be the most recent glacial stage around 20,000 years ago - when there was very little vegetation and, at its maximum, the ice sheet extended as far south as Norfolk.

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Scientific interest and site importance

Loess is a light-coloured fine-grained accumulation of clay and silt particles that have been carried great distances by the wind from the cold, dry environments at the edge of the ice sheet. In glaciated areas abundant fine-grained material was available from exposures of glacial moraine, or till, and there was little vegetation to prevent the wind picking up this material (Sumbler 1996). Loess is common on the Continent but in Britain only in east Kent and here in South-east Essex are substantial thicknesses of this material preserved (Bridgland 1995). It was probably deposited during the most recent glaciation of Britain (at least 20,000 years ago) although it is very difficult to date and some may be older. Loess is also called brickearth, but this is an unhelpful term as it has been applied to any fine-grained sediment that has been used for making bricks.

The loess in this area, and particularly at Star Lane, is of scientific interest because it is primary loess, in other words it is a wind-blown (aeolian) deposit and has not been reworked. Its porous character, its ability to stand in vertical faces for long periods (as exemplified by the remaining exposures at Star Lane) and columnar jointing are all typical of a primary in situ deposit. This site is also the only place in Essex where sections in loess can still be seen and are publicly accessible.

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Other information

The site consists of flooded pits to the east of the former brickworks. One of these pits is now a private fishing lake but an adjoining pit is a lake and nature reserve that is currently publicly accessible via a footpath from Alexandra Road. On the eastern edge of this lake, adjacent to the path, are the two low cliffs of orange loess, which form a small, but very fine, exposure. The land is privately owned.

Exposure of orange-coloured loess adjacent to the lake on the site of Star Lane Brickworks, Great Wakering. Photo © G. Lucy