Geology Site Account

Site name: Bradwell Chenier Ridges (Part of Dengie SSSI)

Grid reference: TM 035 081 (entry to the site)

Description of site:

Along this section of coast, between the salt marshes and the upper tidal flats there are large ridges composed entirely of shell debris known as chenier ridges. Up to 3 metres high and 25 metres long, they result from the erosion of the tidal flats by waves winnowing away at the finer sediment to expose the shells. The ridges have been observed to move landward at around 8 metres per year.

The shells are mostly of the common cockle Cerastoderma edule but in the youngest ridges are shells introduced into British waters since the seventeenth century and therefore giving an indication of the relative age of the ridge. Older shell ridges have been found inland in the reclaimed marsh behind the sea wall and these represent former shorelines.

The area is a nature reserve administered by the Essex Wildlife Trust and is accessible at all times. Parking is available at Eastlands Farm. Enter the reserve via the Saxon chapel of St. Peter-on-the-Wall, walk northwards along the sea wall to Sales Point then south along the beach. Please keep to the sea wall during the shorebirds breeding season between April and August inclusive.

St. Peters chapel from the air with the Bradwell chenier ridges beyond. Photo: © Essex County Council