Harwich
Region: Essex
Nearest Town: Harwich
Geological Age: Ypresian • Eocene • Palaeogene • Cenozoic
Site Type: Foreshore
About the Site
Harwich Foreshore is an important Early Eocene fossil and geological locality on the north-east Essex coast.
The site extends along the eastern side of the Harwich promontory, where a distinctive hard rock layer known as the Harwich Stone Band is exposed across the upper foreshore. This is one of the best places in Britain to see evidence of the major volcanic activity taking place around the North Atlantic during the Early Eocene.
The surrounding sediments can also produce fossils, particularly fruits, seeds, fossil wood and shark teeth. Harwich has a remarkably long history of fossil collecting, with discoveries from the area being recorded for more than three centuries.
Most fossils encountered today are small and are found amongst beach shingle or other loose material. The site is therefore better suited to careful surface searching than excavation.
Geology & Stratigraphy
The main geological exposure at Harwich belongs to the Harwich Formation, part of the Thames Group and of Early Eocene, Ypresian age.
More precisely, the exposed sediments belong to the Wrabness Member of the Harwich Formation. The Wrabness Member consists mainly of clayey silts and silty clays containing numerous layers of volcanic ash.
The most distinctive of these layers is the Harwich Stone Band.
This forms a hard tabular bed approximately 20–25 centimetres thick and contains a central volcanic ash layer. BGS identifies the Harwich foreshore between Beacon Cliff and Harwich Green as the formal reference section for this band.
The volcanic material was produced during the intense volcanic activity associated with the opening of the North Atlantic in the Early Eocene. Ash fell into the sea and became incorporated into the marine sediments accumulating on the seabed.
More than 30 volcanic ash horizons are known within the wider Wrabness Member succession, making these deposits particularly valuable for correlating rocks across eastern England and the North Sea region.
Older literature often describes these rocks as the Harwich Member of the London Clay or as London Clay Division A1. Modern BGS lithostratigraphy instead places them within the separate Harwich Formation, below the London Clay Formation.
The Harwich Stone Band is unusually resistant compared with the surrounding softer sediments and forms a natural rocky platform on parts of the foreshore.
Palaeoenvironment & Palaeoecology
The Harwich Formation was deposited in a shallow marine shelf environment during the Early Eocene.
Fine mud and silt accumulated on the seabed while marine organisms lived in the surrounding water and sediment. BGS interprets the muddy eastern facies of the Harwich Formation as representing an inner- to mid-shelf marine setting.
At intervals, volcanic ash fell into this sea. Some ash settled directly onto the seabed, while other material was disturbed and redistributed by marine currents before burial.
The fossil assemblage also contains substantial evidence of nearby land. Fruits, seeds and pieces of wood were transported into the sea before becoming buried in the marine sediment.
Harwich is particularly important for its fossil plant material because it provides evidence of the warm vegetation growing around the London Basin during the earliest part of Thames Group deposition.
Fossil Preservation & Taphonomy
Fossil preservation at Harwich takes several forms.
Small fruits and seeds can occur within concretions or as pyritised specimens, while pieces of fossil wood may also be preserved by mineralisation.
Fish and shark teeth can weather completely free of the sediment and become concentrated amongst modern beach shingle.
Fossils have also been recorded from the softer sediments immediately above and below the Harwich Stone Band. These include fish teeth, plant material and microscopic marine fossils.
Modern waves and tides continually move loose material across the foreshore. Some fossils found on the beach may therefore have travelled after being released from the bedrock.
Harwich Harbour has also undergone a long history of dredging and coastal engineering. Loose fossil material on the modern beach should consequently not automatically be assumed to have come from the precise geological layer directly beneath the place where it was found.
Material observed securely within an undisturbed exposure provides much stronger geological context.
Collecting Guidance
Visit around low tide, when more of the foreshore and Harwich Stone Band are visible.
Search loose shingle and washed material around the margins of the exposed rock platform.
Small hard fossils can become concentrated where tidal movement has removed finer mud and sand.
Beach conditions can change considerably between visits. At times potentially productive areas may be covered by sand or silt.
A falling tide followed through to low water generally provides the most useful collecting window.
Useful equipment includes:
- sturdy waterproof footwear with good grip
- gloves
- knee pads
- a hand lens
- small specimen boxes or bags
- labels or a notebook
- a phone for checking tide information
A geological hammer is not recommended for this locality.
Much of the geological interest lies in the exposed Harwich Stone Band itself, which should remain undamaged.
What to Look For
Search carefully amongst small shingle and naturally washed material.
Shark teeth are one of the characteristic loose finds. Look for smooth, polished enamel and a definite crown rather than simply pointed dark stones.
Fossil fruits and seeds can be very small. They may occur as dark, rounded or irregular mineralised objects showing recognisable biological structure.
Pieces of fossil wood may preserve grain or other plant structure and can sometimes be strongly pyritised.
Historically, pyritised wood from this coast was known locally as “platimore”.
The Harwich Stone Band itself is also worth examining without removing it. Look for its hard tabular form and contrast with the surrounding softer sediments.
Small marine fossils occur within the succession, although many are much less obvious than the larger fossils associated with some other London Basin localities.
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
On the eastern side of Harwich in north-east Essex, close to the entrance to the Stour and Orwell estuaries.
The principal geological section extends along the foreshore between approximately Beacon Cliff and Harwich Green. BGS gives this stretch as the reference exposure for the Harwich Stone Band.
Directions
Travel to Harwich and head towards the seafront.
The locality can be approached from the promenade around Harwich Green and the Low Lighthouse, or from the seafront farther south.
From the promenade, descend onto the beach using an established access point.
The Harwich Stone Band appears as a hard, comparatively flat rocky layer crossing parts of the foreshore.
There is no need to walk onto harbour structures, breakwaters or other restricted areas to reach the fossil locality.
Parking
Public parking is available close to the Harwich seafront.
Wellington Road, Harwich, CO12 3DL provides convenient parking close to Harwich Beach. Tendring District Council identifies this as the nearest public car park to the beach.
Parking is also available at The Quay, Harwich, CO12 3HH, although this is a smaller pay-and-display car park.
Check current charges and restrictions when visiting.
Terrain
Harwich is considerably easier to access than many London Clay coastal localities.
The promenade provides a firm route above the beach, while the collecting area contains:
- shingle
- sand
- muddy foreshore
- hard rock platforms
- shallow pools
- seaweed
- coastal structures
The exposed Harwich Stone Band can be uneven and becomes slippery when wet or covered with algae.
The beach is also used by boats and other maritime activities, particularly around the old town waterfront.Access, Permissions & Responsible Collecting
The seafront and beach at Harwich are publicly accessible.
Use established promenade and beach access points to reach the foreshore.
Collecting should concentrate on small fossils already lying loose amongst the beach material.
The Harwich Stone Band is the principal protected geological feature of the SSSI and should be left intact. Do not hammer, break or remove pieces of the exposed band.
Likewise, avoid digging into the surrounding geological exposure simply to obtain fossils.
Careful surface searching provides the most appropriate collecting method and preserves the site's important geology for future visitors and research.
Safety & Legal Information
Safety Information
The principal hazards are tides, slippery rock, sharp beach debris and maritime activity.
The hard Harwich Stone Band can become extremely slippery when covered by seawater or algae.
Wear footwear with good grip and take care when crossing exposed rocky surfaces.
Metal, glass and other debris can occur on a working estuarine shoreline, so gloves are useful when searching through shingle.
Check tide times before entering the lower foreshore.
Harwich lies beside one of Britain’s busiest harbour approaches. Stay away from harbour structures, working areas and the water itself, and supervise children closely.
SSSI / Legal Restrictions
Harwich Foreshore is a geological Site of Special Scientific Interest and is also recognised through the Geological Conservation Review.
Its principal geological importance is the exceptional exposure of the Harwich Stone Band, together with its Early Eocene fossil flora and long history of geological study.
The Stone Band should therefore be treated as a geological feature to observe and preserve rather than as material to collect.
Keep fossil collecting to naturally released loose specimens on the beach.
Do not hammer, cut into or remove sections of the Harwich Stone Band or carry out substantial excavation of the surrounding sediments.
Any organised excavation or scientific sampling capable of damaging the protected geological interest would require the relevant permissions and consents.