Barton on Sea is a suburb of New Milton, a coastal town on the south
coast of Hampshire, 6 miles east of Bournemouth. The town is home to
23,000 people, many of whom have a heightened awareness of the
coastline, if not for its fossils, then for the rate at which it
retreats due to erosion, threatening land and properties in the process.
Fortunately for the residents the areas considered most
valuable/vulnerable are now shielded by a series of sea defences,
including boulder barriers and planting of vegetation on the slumping
Left: View from Highcliffe across the slumping cliffs
beneath Barton on Sea. The coastal defences can be seen in the
foreground and again in the far distance.
gastropod fossil, found within the Barton Clay.
The fossils of the Barton Clay are nothing less than spectacular and
have interested visitors to the area for centuries. The highly fossiliferous
Barton Clay exposed in the cliff between Highcliffe and
Barton on Sea provides an opportunity to explore a
prehistoric marine environment dating from 40 million
years ago. Throughout the year the soft clays and sands are eroded by
extreme weather conditions and rough seas, exposing countless fossils in the process, in particular bivalve and
gastropod shells, and shark and ray teeth.
Access can be made at either end of the section, although
Highcliffe is recommended for its convenience - a
large car park and neighbouring restaurant provide parking
and refreshments all year round. From the car park a surfaced footpath
leads directly to the foot of the cliffs.
Left: Parking is available in the cliff-top car park at Highcliffe,
accessed along Waterford Road.
Right: A surfaced footpath provides access to the
beach and cliffs.
Looking across the Solent from Barton on Sea on a clear day
the distinctive outline of the chalk Needles and lighthouse can
be seen at the western tip of the Isle of Wight. Immediately left
(as it appears) of the Needles is
Bay, another classic fossil hunting location and a continuation
of the Barton Clay discussed below.
Left: An early morning
view across the Solent towards the Needles from the beach at Barton on
Right: A close-up of the Needles through the zoom
The geology of Barton on Sea
Figure 1: Geological
summary of the cliffs between Highcliffe and Barton on Sea.
The Barton Clay Formation exposed in the cliffs between Highcliffe
and Barton on Sea was deposited at the bottom of a warm (>22°C
/ 72°F) shallow marginal/shelf sea, relatively close to land, during the Bartonian stage of the Eocene epoch, approximately
40.4 - 38.9 million years ago (see
geologic timescale). At this time southern Britain lay 40°N of the
equator (11° south of its current latitude), equivalent to the
present-day latitude of Spain.
The Barton Clay measures approximately 30m thick and is one of three
formations belonging to the Barton Group exposed in the cliff. Overlying
the Barton Clay is the Chama Sand (5.5m) and Becton Sand (22m), together
the three formations
measure approximately 60m, although no more than 30m is exposed at any
given point. Neither of the latter formations are the subject of this
report, however it should be noted that the Chama Sand appears towards
the top of the cliff, close to where the above panoramic was taken, and
descends gradually as the beds dip eastward. The overlying Becton Sand
appears at the top of the cliff a short distance from the sea defences
to the east. The cliff-top is capped by up to 5m of Pleistocene gravels, deposited
around 800,000 years ago.
The Barton Clay Formation includes both sand and clay to varying
degrees in each of the ten beds which make up the formation,
shallow/near-shore and deeper/off-shore conditions respectively. The varying
composition reflects the changing sea levels and proximity to land
throughout this time. The presence of sand is indicative of a high energy environment,
in this instance the coastline, and accumulates to a greater extent
relatively close to its source. During periods of regression (falling
sea levels) the shallowing sea forced the coastline seaward and closer
to the Barton area, delivering
a greater volume of sand to the area. Clay on the other hand (formed of
silt/mud) is indicative of a deeper, low energy setting - the finer
particles are able to remain suspended within the water and travel a
greater distance from their source, before settling to the sea floor. During periods of transgression
(rising sea levels) the coastline was pushed inland, reducing the supply
of sand to the Barton area and favouring the accumulation of silt/mud.
The fossils of the Barton Clay reveal a diverse marine and
neighbouring terrestrial ecosystem, the latter of which is evidenced by
fossilised plant material - mostly drift wood. However it's the
fauna which attracts the most attention, in particular the shells of
gastropods, bivalves and scaphopods (see example fossils below). These
fossils provide evidence of a benthic mollusc fauna consisting of many hundred
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Where to look for fossils?
Fossils can be found along the entire stretch of coast between
Highcliffe and Barton on Sea, however the Barton Clay is best
represented towards the former, where a near complete sequence is
exposed in the slumping cliffs. Travelling east the gently dipping beds
become progressively obscured below beach level, simultaneously providing
access to the overlying formations.
At Highcliffe access to cliffs can be made with ease,
indeed fossils occur in high concentrations in the seaward end of the
slumped Barton Clay, so it's not necessary to travel far to find a diversity of fossils. Close inspection of
the Barton Clay reveals a mass of broken fossil material alongside
plenty of complete specimens too, especially gastropods. Throughout the
year the sea and rain erodes the soft clay, leaving the fossils
protruding from the surface and loose on the beach.
Left: Fossils can be found in abundance at the foot of the slumped cliff. Right: After stormy weather
and rough seas fossils can be found loose on the beach.
As with all coastal locations, a fossil hunting trip is best timed to coincide
with a falling or low-tide. For a relatively low one-off cost we
recommend the use of Neptune Tides software, which provides
future tidal information around the UK. To download a free trial
Alternatively a free short range forecast covering the next 7 days
is available on the BBC website
What fossils might you find?
Below are a small selection of fossils discovered within (or
the Barton Clay. Due to the slumping nature of the cliffs, much of
the apparently in situ material is no longer so, making the
task of identifying the bed name/letter a challenge. Consequently
for the purposes of this investigation, all fossils are simply
assigned to the Barton Clay Formation and are only indicated as in
situ where it was reasonably apparent.
Where possible the
genus of each specimen has been indicated, if a confident ID can't
be achieved a question mark has been added to indicate so. Among the
more frequent finds include bivalve, gastropod and scaphopod shells; less
include shark and ray teeth, fish bones, and pieces of turtle
carapace, although following periods of stormy weather the frequency of
finds can increase significantly.
Left: A juvenile Striatolamia(?) shark tooth
exposed on the weathered surface of a fallen slab of Barton Clay.
Note the high concentration of benthic shell debris.
Right: A small piece of fossilised drift wood found within the Barton Clay.
worm tubes. These worms extended a plume of feeding arms from the
shell opening, which was permanently fused to a solid surface.
Right: A Dentalium Scaphopod tusk-like
shell. These mobile molluscs lived partially buried in the sediment
(wide end down), feeding on benthic foraminiferas.
Left: A Volutospina gastropod, found
in situ within the Barton Clay. Right: A large shell fragment of a
Volutospina gastropod, found loose on the beach.
gastropod, found in situ within the Barton Clay. Right:
A Sycostoma gastropod, found in situ within the Barton
gastropod (8mm), found in situ within the Barton Clay. Right:
A Trachelochetus gastropod, found in situ within the Barton
Bathytoma gastropod, found in situ within the Barton Clay.
Right: A Volutocorbis gastropod, found in
situ within the Barton Clay.
gastropod, found in situ within the Barton Clay. Right:
A Nipteraxis gastropod, found in situ within the Barton
Left: An isolated
valve of a Nemocardium bivalve, found in situ within the
Right: An isolated valve of a Crassatella bivalve,
found in situ within the Barton Clay.
Left: A large shell
fragment of a Pycnodonte bivalve, found within
the Barton Clay. Right: A collection of bivalves
and gastropods within the Barton Clay.
Left: An isolated
lower valve of a Cubitostrea bivalve, found within the Barton Clay.
Right: An isolated upper valve of a Cubitostrea
found within the Barton Clay.
Tools & equipment
It's a good idea to spend some time considering the tools and
equipment you're likely to require while fossil hunting at
Barton on Sea. Preparation in advance will help ensure your visit is
productive and safe. Below are some of the items you should consider
carrying with you. You can purchase a selection of geological tools
and equipment online from
Steel point: In some instances
it's not necessary to use a hammer and chisel to remove the matrix
surrounding the fossil. Sometimes all that's required is some
careful precision work using a steel point. This is particularly
relevant with crumbly matrix, where chiselling may otherwise shatter
a fragile fossil.
Hand lens: A hand lens enables the fossil hunter to enjoy the finer
details of the specimens they find. It's often remarkable how well preserved
some of the most intricate structures can be. We recommend
a lens with x10 magnification that folds away into a metal casing to protect
it from damage.
Strong bag: When considering the type of bag to use it's worth setting aside
one that will only be used for fossil hunting, rocks are usually
dusty or muddy and will
make a mess of anything they come in contact with. The bag will also
need to carry a range of accessories which need to
be easily accessible. Among the features recommended include: brightly coloured,
a strong holder construction, back
support, strong straps, plenty of easily accessible pockets and a rain cover.
Walking boots: A good pair of walking boots will
protect you from ankle sprains, provide more grip on
slippery surfaces and keep you dry in wet conditions. During your
fossil hunt you're likely to encounter a variety of terrains so
footwear needs to be designed for a range of conditions.
For more information and examples of tools and equipment
recommended for fossil hunting
or shop online at
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Protecting your finds
It's important to spend some time considering the best way to
protect your finds onsite, in transit, on display and in storage.
Prior to your visit, consider the equipment and accessories you're
likely to need, as these will differ depending on the type of rock,
terrain and prevailing weather conditions.
wrapped in foam, ready for transport. Right:
A small compartment box containing cotton wool is ideal for
separating delicate specimens.
When you discover a fossil, examine the surrounding matrix (rock)
and consider how best to remove the specimen without breaking it;
patience and consideration are key. The aim of extraction is to
remove the specimen with some of the matrix attached, as this will
provide added protection during transit and future handling;
sometimes breaks are unavoidable, but with care you should be able
to extract most specimens intact. In the event of breakage,
carefully gather all the pieces together, as in most cases repairs
can be made at a later time.
For more information about collecting fossils please refer to the
following online guides:
Fossil Hunting and
Conserving Prehistoric Evidence.
Join us on a fossil hunt
Left: A birthday party with
a twist - fossil hunting at
Right: A family hold their prized ammonite at Beachy Head.
Discovering Fossils guided fossil hunts reveal evidence of life that
existed millions of years ago. Whether it's your first time fossil
hunting or you're looking to expand your subject knowledge, our fossil
hunts provide an enjoyable and educational experience for all. To find