Seasalter
Region: Kent
Nearest Town: Whitstable
Geological Age: Ypresian • Eocene • Palaeogene • Cenozoic
Site Type: Foreshore
About the Site
Seasalter is a London Clay fossil locality on the north Kent coast, immediately west of Whitstable.
The LBPS locality represents the fossil-bearing foreshore at Seasalter, particularly the eastern Seasalter frontage where broad areas of London Clay can become exposed around low tide.
Unlike the large cliffs of the Isle of Sheppey, most collecting here takes place on a very flat foreshore. London Clay can be exposed over a surprisingly large area when conditions are favourable, but mud, sand and shingle may cover much of it at other times.
Seasalter is particularly known for fossils preserved within phosphatic nodules. Crabs, lobsters and fish remains can occur within these nodules, while smaller shark and fish teeth may be found loose amongst the shingle.
Some excellent specimens have been found at Seasalter, but identifying productive nodules takes practice and many contain no fossil at all.
Geology & Stratigraphy
The fossil-bearing bedrock belongs to the London Clay Formation, part of the Thames Group and of Ypresian age.
BGS records London Clay along the coast from Seasalter towards Whitstable, where it forms low coastal exposures and underlies parts of the foreshore.
The London Clay consists mainly of marine silty clay and clayey silt, with levels containing concretions, phosphatic material, pyrite and occasional sandy or silty partings.
Detailed fossil and collecting records place the Seasalter fauna approximately around the traditional London Clay Divisions A3 and B1. These subdivisions are commonly encountered in older literature and remain useful when comparing historical fossil records.
In the modern BGS lithostratigraphic scheme, Division A3 corresponds to the Ockendon Member, while Division B forms part of the Aveley Member.
Seasalter therefore lies around an interesting part of the London Clay succession close to the transition between these two modern members. Because the precise position of this boundary across the active foreshore is not firmly established, the locality is best described more generally as exposing the London Clay Formation.
Palaeoenvironment & Palaeoecology
The London Clay at Seasalter was deposited in a warm marine shelf environment during the Early Eocene.
Fine mud and silt accumulated on the seabed while sharks, bony fish, crustaceans, molluscs and other marine organisms occupied the surrounding waters.
The transition represented by the traditional A3–B1 interval formed part of the repeated changes in water depth and sediment supply recorded through the London Clay succession.
Material from nearby land also entered the marine environment. Fossil wood, fruits and seeds are therefore found alongside marine animals, having been transported offshore before burial.
The modern Swale and Whitstable coastline developed much later. Today’s tides simply expose and redistribute fossils from this ancient marine deposit.
Fossil Preservation & Taphonomy
Seasalter is particularly known for phosphatic nodules containing three-dimensional fossils.
These nodules can preserve crabs, lobsters and fish remains. Fossil-bearing examples are often light cream, grey or brown, but colour alone is not a reliable guide.
Parts of a fossil may sometimes be visible at the surface of a nodule. Dark markings, however, can also result from staining or mineralisation and should not automatically be interpreted as fossil shell.
Fish and shark teeth can weather completely free of the London Clay and become concentrated amongst shingle and other resistant material.
Pyritised fruits, seeds and fossil wood can also occur.
The flat foreshore is continually reworked by modern tides. Fossils and nodules may therefore be moved considerable distances after leaving the London Clay.
A loose fossil should not be assigned to a precise stratigraphic bed simply because of the point on the beach where it was found.
Collecting Guidance
Visit around low tide, when the widest area of fossil-bearing foreshore is exposed.
The flat beach means the water retreats a long distance and can reveal extensive patches of London Clay.
Search where tidal movement has washed softer clay away and left nodules, pyrite, shingle and other hard objects exposed on the surface.
Conditions can vary markedly between visits. Mud and modern sediment may cover productive areas, while periods of stronger tidal scouring can reveal fresh patches.
There is little benefit in arriving at high tide because most of the useful collecting surface will still be underwater.
Useful equipment includes:
- waterproof boots with good grip
- gloves
- a hand lens
- small specimen bags or boxes
- labels or a notebook
- a phone for checking tide and weather information
A geological hammer is generally unnecessary.
What to Look For
The characteristic Seasalter find is a phosphatic nodule containing fossil material.
Look for small cream, pale grey or brown nodules amongst the washed foreshore material.
Crustacean remains may appear as recognisable pieces of carapace, claws or segmented shell emerging from the surface.
Do not assume that every black or dark mark is a fossil. Mineral staining can create convincing-looking patterns on otherwise unfossiliferous nodules.
Fish remains can also occur within phosphatic nodules, sometimes preserving portions of the skull three-dimensionally.
Small shark and fish teeth may occur loose amongst the shingle. Look for definite enamel surfaces and organised tooth shape.
Pyritised fossil fruits and seeds may appear as dark or metallic objects with regular biological form.
Pieces of fossil wood may preserve grain or other recognisable structure.
Use Fossils at this Site for individual species identification.
Fossils at this Site
Explore fossils recorded from this site, see how to recognise them and, where enough LBPS records exist, what collectors are actually finding.
What collectors are finding
Typical examples from this site
Different anatomical parts or preservation styles can look very different. Choose an example to view it larger.
About this information
Fossil occurrences come from reviewed LBPS records. Encounter frequency and abundance use eligible collecting sessions where all finds were recorded. Preservation rarity uses the condition recorded at the time of collecting. Identification photographs may come from dedicated Fossil Examples or linked public LBPS Specimens; neither influences rarity or frequency calculations.
Visitor & Access Information
General Location
Seasalter, immediately west of Whitstable in Kent.
The LBPS locality covers the fossil-bearing Seasalter foreshore rather than the entire coastline westwards through the Swale marshes.
The neighbouring Tankerton locality lies on the opposite side of Whitstable and should remain separate.
Directions
Travel to Seasalter, west of Whitstable.
Public access is available from the roads and coastal routes running along the Seasalter frontage.
The most productive ground is exposed seaward of the normal shingle beach around low tide.
Look for the broad flat areas of London Clay and associated shingle rather than expecting a conventional cliff exposure.
Parking
Canterbury City Council operates a public car park on Faversham Road, Seasalter.
The current traffic order identifies the Faversham Road car park between the sea wall and Faversham Road and permits parking for up to 12 hours.
On-street parking may also be available nearer parts of the foreshore, subject to current restrictions.
Always check signs on arrival.
Terrain
The upper beach consists mainly of shingle.
Beyond it, the low-tide foreshore can include:
- exposed London Clay
- soft mud
- wet sand
- shallow pools
- patches of shingle
- seaweed
- old bait-digging holes
The site is exceptionally flat and the sea retreats a considerable distance at low tide.
Mud can become deep close to the upper beach in some areas, while holes dug for bait may be hidden by water or loose sediment.Access, Permissions & Responsible Collecting
Use established public beach access and coastal paths.
The King Charles III England Coast Path runs along the Seasalter coast and continues westwards towards the Swale estuary.
Collecting should concentrate on naturally released fossils and nodules lying loose on the foreshore.
There is no need for large-scale excavation of the London Clay platform.
Take only a reasonable amount of material and avoid disturbing wildlife, saltmarsh or other sensitive coastal habitats.
The surrounding coast is internationally important for birds, particularly during the winter months. Canterbury City Council asks visitors to keep a safe distance from birds and leave wildlife and plants undisturbed.
Safety & Legal Information
Safety Information
The principal hazards are soft mud, concealed holes and the tide.
Parts of the foreshore can contain deep sticky mud. Do not continue across ground that becomes progressively softer simply to reach more distant exposure.
Bait digging has historically left holes in the foreshore, some of which may become partly filled with loose sediment and difficult to see.
Wear sturdy footwear and pay attention to the ground immediately ahead.
Check tide times before visiting and keep track of the incoming water.
The coast is exposed to wind and weather, and the broad low-tide foreshore can leave collectors some distance from shelter.
SSSI / Legal Restrictions
Seasalter lies at the eastern end of the environmentally important Swale estuary complex.
The western Seasalter coast and neighbouring marshes include or adjoin The Swale SSSI, SPA and Ramsar site, while the Swale Estuary Marine Conservation Zone extends eastwards towards Whitstable.
These designations principally protect internationally important coastal habitats, birds and marine ecosystems rather than identifying Seasalter as a geological fossil SSSI.
Keep fossil collecting low impact and concentrate on naturally released loose material.
Do not damage saltmarsh, disturb feeding or roosting birds or remove substantial quantities of sediment.
Follow any local or seasonal restrictions in force at the time of your visit.