Geology Site Account

Site name: The Cliff, Burnham-On-Crouch SSSI (also known as Butts Cliff), Althorne, near Burnham-on-Crouch

Grid reference: TQ 9214 9678

Brief description of site:

The Cliff or Butts Cliff is a low cliff of London Clay on the north shore of the River Crouch, between Althorne and Burnham-on-Crouch. It is an interesting site which has yielded a remarkable number of London Clay fossils since it was discovered in the early 1970s. These include fossil fish (mainly sharks teeth), crustaceans and bird bones. The fossils have been washed out of the clay by the tide and are found loose in the beach shingle. It is the type locality for several species.

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Details

Also known as Butts Cliff this is one of the most important London Clay sites in Britain. A cliff on the outer bend of the River Crouch near Burnham-on-Crouch is being eroded and London Clay fossils such as sharks' teeth can be found in the beach shingle below the cliff. Selenite (gypsum) crystals can also be found. There has been extensive collecting since the site was first discovered in the early 1970s and it has yielded a remarkable fossil fauna.

The most important fossils are the bones of birds. This includes type specimens of two small species, Coturnipes cooperi (a game bird) and Parvicuculus minor (a protocuculid). The site is of considerable value in expanding the limited knowledge of small Eocene birds species and avian evolution.

The site also yields similar fish species to those from Sheppey; however, unlike that site it is possible to bulk sample material at Burnham and thus obtain quantifiable faunas. The assemblage consists mainly of shark, particularly hexanchids, and this material is better preserved than at Sheppey (although lacking in nodules). It is the type locality for several fish species, for example the shark Weltonia burnhamensis and the ray Burnhamia daviesi.

Finding fossils at Althorne today requires good eyesight and a lot of patience. Searching is usually carried out by lying on the beach.

A fossilised tooth of the shark Otodus obliquus from Althorne. A relative of the Great White Shark this creature was one of many sharks that inhabited the London Clay Sea. This example was found on the beach at Althorne by Essex Rock and Mineral Society member John Tompsett in the 1970s when fossils at this site were much more numerous. Photo: G.Lucy