Butts Cliff (Burnham-on-Crouch) Fossil Hunting

Butts Cliff on the River Crouch is known for small early Eocene shark and fish remains weathered from the London Clay. Crabs and exceptional bird fossils add to its scientific importance. Search permitted loose material carefully, keeping well clear of soft estuary mud and unstable banks and using the signed riverside route.

FIND FREQUENCY: ♦♦♦♦ – Small teeth and nodules occur in loose material, but conditions and beach cover vary.
CHILDREN: ♦♦♦ – The long walk, mud and sharp debris make this unsuitable for young children.
ACCESS: ♦♦♦ – Use the signed route; no convenient roadside parking is confirmed.
TYPE: Low river cliff and tidal foreshore with London Clay fossils.

DIRECTIONS

♦ Head towards the marina and ferry at the southwest side of Burnham-on-Crouch. The original guide recommended the car park in this area for the longer walk to Butts Cliff. Use signed public parking, checking the displayed conditions, and walk west along the riverside path around the marina towards Creeksea.
♦ The original guide also recorded two roadside spaces at Creeksea, between the single and double yellow lines, usable only between November and March. Check the signs before parking; these few seasonal spaces should not be relied on for a visit.
♦ At Creeksea, follow the signed Ferry Road detour inland from the old slipway, then rejoin the riverbank footpath towards Butts Cliff. The official Burnham-to-Althorne route climbs over the cliff. Stay on that route rather than trying to pass the cliff at the waterline, and plan the return around the tide.
♦ Locality reference: 51.63369°N, 0.78178°E
♦ What3Words collecting area: ///neckline.shuts.tiger

FOSSIL HUNTING

Butts Cliff is especially important for small vertebrate fossils washed from the London Clay into beach shingle. Sharks’ teeth dominate the published fish assemblage; documented examples include Otodus obliquus, Isurolamna affinis, Weltonia burnhamensis and species of Hexanchus. Most specimens are small, so patient examination with a hand lens is more useful than breaking large stones.

Crab remains also occur in phosphatic nodules. Large septarian cementstones are a different feature and are commonly poor in recognisable fossils. Loose specimens can have travelled along the beach, so their find position alone does not identify their original bed. Bird bones are exceptional finds of scientific value: preserve their context and seek expert advice rather than attempting rapid preparation.

A chronological record of fossil discoveries, geological research and conservation milestones at Butts Cliff (Burnham-on-Crouch).

1974 – The fossiliferous river section documented
R. I. Kirby published a field-meeting account of Burnham-on-Crouch, recording the fossil-bearing exposure that subsequently became an important London Clay research locality.

1977 – Two fossil bird species named
C. J. O. Harrison and C. A. Walker described Coturnipes cooperi and Parvicuculus minor from small leg bones collected here. Their type specimens made the locality significant in studies of early Eocene birds.

1986 – Geological Survey correlation published
The Southend and Foulness memoir placed The Cliff in palaeontological Unit P13, roughly 26 m below the historical Claygate Beds base, and highlighted its unusual pteropod record.

2006 – A new crab from Butts Cliff described
Sharnia burnhamensis was named from a fragmentary carapace collected by R. Johnson. The specimen is the species’ holotype.

2024 – Earlier bird interpretation reassessed
A modern review retained uncertainty over the affinities of Coturnipes cooperi. Its fragmentary type had been compared with messelornithid birds, so the old description as a definite quail-like gamebird should not be treated as settled.

GEOLOGY

The low river cliff cuts early Eocene London Clay Formation, part of the Thames Group. These marine clay-rich sediments are assigned to Division D, an informal subdivision rather than a separate formation or member. Published accounts describe only a small window into the much thicker formation.

Erosion supplies nodules, teeth and other durable remains to the shore. Slumping displaces the clay and complicates the local sequence, while tides redistribute the loose material. The detailed section distinguishes the two published fossil-bearing nodule occurrences without treating them as a precisely measured, uninterrupted bed log.

Detailed geology and stratigraphy of Butts Cliff (Burnham-on-Crouch).

THAMES GROUP

London Clay Formation

Age, rank and local extent
The bedrock is Ypresian London Clay Formation within the Thames Group. The classic published section is about 2–3 m high; this is the exposed cliff, not the full formation thickness. No named formal member is established for this exposure.

Division D and the P13 correlation
The Geological Survey correlates the cliff with palaeontological Unit P13 and estimates it at about 26 m below the historical base of the Claygate Beds. The fish conservation account places it high in Division D, while the bird account describes a middle-D position. Division D is therefore the secure common correlation. P13 is a biostratigraphical subdivision, not a separate lithological bed to stack above or below D. Claygate strata are a correlation datum, not part of this exposed section.

Cliff phosphatic-nodule occurrence
Small phosphatic nodules, reported at 1–5 cm, contain chiefly Glyphithyreus wetherelli. Rotational slipping obscures their precise position.

Foreshore phosphatic-nodule occurrence
A separate foreshore occurrence has 4–8 cm nodules dominated by Zanthopsis leachii. Both occurrences are associated with, usually beneath, septarian bands. These nodule sizes are not bed thicknesses.

Loose material and preservation
The tide mixes specimens from the exposures. The particular nodule horizon of the loose Sharnia burnhamensis type specimen could not be established. Never assign unstratified finds by colour.

Marine setting and finer correlation
The formation accumulated as marine mud. The pteropod Camptoceratops prisca was specifically recorded from this locality and helped relate it to the regional upper London Clay succession. Published borehole descriptions of lithological Unit LF give regional context but are not a measured Butts Cliff bed log.

References
BGS Lexicon: London Clay Formation
Lake and colleagues (1986), Southend and Foulness
Dineley and Metcalf (1999), Burnham-on-Crouch fossil fishes
Collins and Saward (2006), Essex London Clay crabs
Benton, Cook and Hooker (2005), fossil bird sites

SAFETY

This is a tidal river shore with soft mud, slippery clay and unstable low cliffs. Check the tide and weather before setting out, keep a safe landward return route and leave well before water reaches it. Do not climb or stand beneath slumped faces. Never walk onto mudflats or use the foreshore as a shortcut around the cliff; apparent surface firmness does not prove the mud will support you.

Watch for broken glass and sharp debris before kneeling or handling beach material. Do not move rubbish or work around damaged structures to reach a fossil.

EQUIPMENT

Take a hand lens, a charged phone, tide information, footwear with good grip, labelled bags and small rigid boxes. A kneeling pad can make close inspection more comfortable on firm ground. A hammer is unnecessary for searching loose material and should not be used as a substitute for careful identification.

CLEANING AND TREATING

Keep small finds in separate labelled, padded boxes and retain any broken pieces together. Photograph fragile nodules before preparation. Remove loose surface sediment with a soft brush; avoid soaking crumbly clay or pyritised material. Do not force a nodule apart merely to see whether it contains a fossil, and avoid acids, bleach and varnish. Let stable mineralised specimens dry gradually at room temperature. Keep waterlogged wood and fragile wet bone protected from drying until a conservator has advised on treatment. If pyrite develops pale powder, cracking or a sulphurous smell, isolate the specimen and obtain conservation advice. Leave potentially important fish, bird or unusual crustacean remains unprepared for specialist assessment.

IDENTIFY YOUR FINDS

FURTHER READING

The geology of Essex — regional background
Crystals and minerals of the London Clay
Burnham-on-Crouch: fossil fish conservation account
British Tertiary fossil bird sites
New crabs from the London Clay of Essex
Geology of Southend and Foulness
Official Burnham-to-Althorne walking route

ACCESS RIGHTS

Butts Cliff is protected as The Cliff, Burnham-on-Crouch SSSI, with important fossil birds and fish, within the wider protected Crouch estuary. Use the signed public route and check current access directions and local notices. Coast Path access does not itself confer permission to collect fossils or excavate. Obtain any necessary landowner permission before collecting; do not dig into banks, seawalls or bedrock, and avoid disturbing birds, saltmarsh and other habitats. Restrict any permitted collecting to modest quantities of already loose material.

It is important to follow our ‘Code of Conduct’ when collecting fossils or visiting any site. Please also read our ‘Terms and Conditions‘

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