Marloes Sands is a geologically wondrous location, encompassing
towering cliffs, a beautiful expanse of sand and clean sea water
throughout the year. Although finding fossils can prove more difficult
than at other locations, the geological features alone will impress most
visitors. Unless you're actively studying the subject, or an experienced
palaeontologist, this locality is not recommended for collecting
The surrounding area is managed by the National Trust, who
provide information about the geology and wildlife from a small office
within the cliff-top car park; the staff are always happy to direct
visitors to the beach. A small parking charge is payable at the National
Trust office upon arrival.
Trust car park and information office. Right:
Public footpath leading to the beach - 700m.
Access to the beach is made along a gravel surfaced footpath,
located 100m back along the road, north of the car park. The walk
takes about 10 minutes and leads to the foreshore. Once you reach
the beach a small wooden bridge crosses a small stream, beyond which
a short walk leads to the vantage point that the following two
photos were taken from.
Left: View over the
southern end of the bay. Right: View over the
northern end of the bay.
The geology of Marloes Sands
Marloes Sands comprises four main geological groups - Skomer
Volcanic, Coralliferous, Gray Sandstone and Old Red Sandstone (fig.1
below). From the beach access point, heading south (left when
facing out to sea), visitors will pass through each group in turn,
until you reach the end of the bay (Old Red Sandstone).
Figure 1: Detailed
stratigraphy of Marloes Sands - adapted from Walmsley and Bassett,
Fossils are less common in all but the Coralliferous Group (see
stratigraphy above), which reveals a wealth of marine organisms from
the Silurian period (circa 428 million years ago). The photo below
Left: shows and accumulation of loose rocks from the Coralliferous
Group, from which the specimens featured on this page were largely
strata belonging to the Coralliferous Group. Right:
Skomer Volcanic Group rocks containing lagoonal ripple marks.
Visitors can also find evidence of ripples within the older Skomer
Volcanic Group, which are thought to have been formed in a shallow
lagoon, 439 million years ago; the photos below show some of the
large symmetrical examples found at the cliff base.
Left: Roy props up
a large section of rock featuring prehistoric ripple marks. Right:
Some of the ripple marks are evident of large slabs.
At the southern end of the bay you reach the 'Old Red Sandstone'
which was formed from sediments weathered out of a mountain chain,
extending from what is now Scandinavia through Scotland to the
Catskill Mountains of America. Although fossils weren't discovered
here during our recent visit the Old Red Sandstone holds the
evidence of an extraordinary period of the planet's history, when
the vertebrates developed, flourished in the seas and rivers, and
emerged on to the land, where the first vascular plants took root
and the first arthropods crawled, breathed air and took wing.
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Where to look for fossils?
Fossils are not abundant at Marloes Sands and visitors will need to
search hard to find productive spots. The best places to search are the
scree accumulations at the base of the cliff, although these themselves
are limited to just a small number. In September 2007 there were two
relatively productive areas, both situated towards the southern end of
the bay; however, despite the illusion of rapid erosion this particular
cliff collapse originally occurred over twenty years earlier.
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?
Once a productive spot is found it's possible to collect a range of
marine based fossils, in particular Trilobites and Cephalopods, although
these are among the less common specimens. The most common fossils are
corals, brachiopods and bivalves, many of which have been crushed
Left: A small
trilobite tail. Right: A close-up on the
Left: Two Loxonema gastropods in amongst a number of brachiopod
impressions. Right: Isolated fragment of
Left: An impression
of a Rhynchonellid brachiopod shell. Right:
A Lingula brachiopod.
Left: A small
section of a cephalopod clearly showing the horizontal segmentation
of the body. Right: A second cephalopod.
Left: A small inner
side of a Leptostrophia brachiopod shell Right:
A small coral.
Corals are also common within selected horizons, some of which
feature delicate feather-like structures, as shown below. The
presence of corals within this relatively brief window of time,
reveals a period of shallow marine conditions, as the corals
themselves required plenty of sunlight to survive.
Left: A narrow,
feather-like coral. Right: A close-up of the
Other interesting finds include isolated pebbles within the
shales, known commonly as erratics; the photos below show two
examples. Note, the example of the left shelters two small
brachiopods along its lower edge, these were either washed into
position after death, or more likely attached themselves to the
pebble prior to burial. Erratics with smoothed edges (as shown)
indicate they've been exposed to extensive rolling within a
river/stream or on a beach foreshore, prior to deposition - this
evidence reveals these shallow waters were also close to land.
Left: An isolated
beach pebble and who brachiopods. Right: A second
beach pebble containing multiple cracks caused by exposure to
pressure through time.
Tools & equipment
Left: A strong bag
and walking boots are recommended. Right:
A hammer & chisel are useful for splitting prospective rocks.
It's a good idea to spend some time considering the tools and
equipment you're likely to require while fossil hunting at
Marloes Sands. 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
A strong hammer will be required to split prospective rocks. The
hammer should be as heavy as can be easily managed without causing
strain to the user. For individuals with less physical strength and
children (in particular) we recommend a head weight no more than
Chisel: A chisel is required in conjunction with a
hammer for removing fossils from the rocks. In most instances a
large chisel should be used for completing the bulk of the work,
while a smaller, more precise chisel should be used for finer work.
A chisel founded from cold steel is recommended as this metal is
especially engineered for hard materials.
Safety glasses: While
hammering rocks there's a risk of injury from rock splinters
unless the necessary eye protection is worn. Safety glasses ensure any splinters are deflected away from the eyes. Eye
protection should also be worn by spectators as splinters can
travel several metres from their origin.
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