Introduction

Folkestone is one of the better places on the south coast for fossils. The range, quality and volume of fossils make this an excellent destination. Access to the beach is convenient, with plenty of parking and facilities, including toilets. If the weather has been wet, be sure to bring wellies or walking boots, as the clay is both wet and muddy.

The geology of Folkestone

The earliest rocks at Folkestone consist of Lower Greensand exposed to the north of the town and run through a sequence of Lower Greensand, Gault Clay (phasing into Upper Greensand) and Chalk, the whole sequence dating from approximately 120 to 80 million years old. The chalk increases in thickness to the north culminating with the famous white cliffs of Dover before dipping off to the north approaching Deal. It is the Gault Clay that is of particular interest; it is a dark blue-grey colour and has been extensively studied. The clay consists of mudstones with layers of phosphate nodules that delineate the margins of some of the clay beds, the whole Gault sequence achieves a thickness of 40m in places. The clay has been sub-divided into thirteen individual beds, each containing diagnostic fossil species and dates from the Middle to the Late Albian of the Cretaceous period, approximately 108-97.5mya. The clay from the Middle Albian is known as the Lower Gault and the beds from the Late Albian are known as the Upper Gault. The Upper Gault is more calcareous than the Lower Gault mudstones and is somewhat lighter in colour. Although both the greensands and chalk all contain fossils including ammonites, the preservation is by far the best in the clay.

Where to look for fossils?

Fossils can be found all year round, but the best finds are made following periods of wet weather when the clay is soft; however, during the summer months visitors can still find a large number of fossils within the boulders and rock pools.

Searching for fossils among the boulders and rock pools.

Searching for fossils on the foreshore requires a hands on approach! The fossils here have been washed out from the cliff and are often buried by shingle and soft clay. A small trowel is a great tool for uncovering the fossils, while some people prefer to dig with their hands! Either way, a large number of fossil fragments and complete specimens can be found this way.

What fossils might you find?

The Gault contains the fossils of many forms of marine creature: ammonites, belemnites, nautili, bivalves, crinoids, gastropods, fish remains and scaphopods are quite common. Ichthyosaur vertebrae have also been found over the years. In some of the clay bed sequences the fossils are preserved in phosphate; they tend to be dark, frequently broken and are often in concreted masses. The best preserved fossils are those that are pyritised, the preservation of these pyritised animal remains in the some of the Lower Gault beds is exceptional, shells tend to be preserved in their original proportions and are generally not crushed. Sometimes a beautiful coating of iridescent mother-of-pearl is to be found though this is usually partial or flaked off entirely.

Two excellent ammonite specimens from the foreshore (Left - Anahoplites planus) (Right - Euhoplites aspasia).

Our recent visit to Folkestone also yielded a much less common find - the remains of Protosphyraena ferox - one of the last of a group of swift, predatory ray-finned fishes without bony vertebrae. Scientists have never found a complete skeleton of this fish, only the head, pectoral girdle and tail are known (see below tooth).

(Left) Protosphyraena tooth. (Right) Artist impression of Protosphyraena - Fig 1, and actual skull example - Fig 2

Protosphyraena is believed to have grown up to twice the size of an average man. They were armed with a long, strong weapon at the extremity of the upper jaw, something like that of a sword-fish, but round and pointed and composed of strong fibres. The jaws are provided with three kinds of teeth: on the outer edge is a row of large, flat, cutting teeth, resembling those of a shark; inside, and placed irregularly, are small, blunt teeth; while in the back portion of the palate is the third set- small, sharp and needle-like in shape, forming a pavement.

Two small ammonites found near the base of the cliff.

(Left) Tiny ammonite found in a rock pool - Hysteroceras. (Right) well preserved pyrite ammonite - Hoplites dentatus.

(Left) A small belemnite - Neohibolites. (Right) A small shark tooth.

(Left) - A hetromorph ammonite - Hamites. (Right) A small bivalve.

(Left) Fish jaw including several teeth. (Right) A small fish vertebrae.

(Left) Robert's ammonite - Hoplites spathi. (Right) Close-up of Hoplites spathi crystals.

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.

(Left) Fossil wrapped in newspaper, 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...continued.

Join us on an organised fossil hunt

(Left) Participants listen to an event leader explaining the prehistoric evidence at Charmouth. (Right) Families handle some real fossils at the event base.

Discovering Fossils and JuniorGeo have joined forces to provide a series of exciting prehistoric experiences for families and individuals of all ages and levels of knowledge. Our events include an introduction to the local geology and fossils, followed by a group fossil hunt where everyone has an opportunity to find and collect a variety of fossils. To find out which events are taking place near you click here.

Visit our exciting online shop...

Click above to see a selection of our great value products and gifts available online from the Discovering Fossils shop - in partnership with JuniorGeo.

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