Fossil Coast Drinks Co is pleased to introduce Steve Snowball as a guest blogger who will be sharing his knowledge, experience and expertise about fossil hunting at Tidmoor Point and Tidmoor Cove on the Jurassic Coast of Dorset. Steve is an accomplished author of "A Guide to Fossil Collecting in England & Wales" and co-author of four other highly acclaimed guides to fossil collecting on the Dorset coast.
Tidmoor Point and Cove are situated on the Fleet Lagoon, near Weymouth, an area of outstanding calm and beauty, which is protected for both its geology and bird life. Collecting here requires an understanding and an observation of the SSSI legislation, which forbids any digging into the clay bedrock and banks. This is also a protected area for ground nesting and many rare birds. Please respect this location.
The Oxford Clay Formation crops out here and from which a large variety of fossils are found along the foreshore.
The site is very muddy and collectors need to be prepared to get equally as muddy, as this is a hands and knees operation!
Small pyritised ammonites, belemnites, crinoids and lobster fragments are common finds, although vertebrate remains of fish, marine reptile bone, echinoids and crocodile teeth are also frequently found here.
Access requires a walk of around 15 minutes from the nearest road and car parking, so be prepared to take adequate provisions. There is not a McDonalds, ice cream kiosk, or Costa Coffee in sight!
Take the Chickerell Link Road (B3157) from Dorchester and drive to the junction with the Chickerell Road. Turn left at the traffic lights onto Chickerell Road, passing the Chickerell Army Training Camp on your right. At a distance of about 1/2 mile you'll see a lay-by. It's virtually opposite Tidmoor Holiday Cottages (a holiday let).
Park up here, or if you overshoot or there is no space, turn left into Putton Lane at DT4 9TP and park here instead. Cross over the Chickerell Road on foot and walk down the side of Tidmoor Cottages onto the concrete path that runs all the way down past the Army Firing Ranges to The Fleet.
Having walked almost the entire length of the concrete pathway, if the red flag is flying near the entrance to the Army grounds, or your hear gunfire, there is no access to the beach, as the Army is practicing! It is therefore highly prudent to check Army Firing Times beforehand, which are published online (click here).
At the bottom of the lane, bear slightly right and go through a gate, continuing to follow the narrow path, Crossing over the wooden planking which allows access over streams, you’ll reach a final metal gate to your right.
It can be extremely muddy at this point, so wear wellies and take care! Bear right, through what is marked as 'No Entry’. (Again, if the red flag is flying, you'll find this gate locked and you'll have to detour at this point to your left to Tidmoor Cove. Tidmoor Point will be inaccessible).
Bear right through the gate and keep bearing right, walking more or less parallel to the coast, until you finally reach Tidmoor Point. Don't be too eager to get onto the beach.
Wait until you see a concrete slipway, leading to a broken jetty (Photo Left) and descend to the beach here.
Tidmoor Point is in the Lamberti Biozone of the Oxford Clay and is characterised by the ammonite Quenstedtoceras lamberti. The ammonite fauna found here is totally different to those found at Tidmoor Cove, which is in the Mariae Biozone.
The images below from upper left to right show the ammonite Quenstedtoceras lamberti and belemnite, Hibolites hastata. Below left are fragments of lobsters (often found in phosphatic nodules) and below right are star-shaped ossicles of a crinoid (sea lily), Isocrinus fisheri. The ossicles formed the stem of the crinoid.
A typical collection of fossils which can be collected at Tidmoor Point. The large shells of the oyster, Gryphaea dilatata, an assortment of pyritised ammonites, belemnites and bivalves.
As with any fossil found in sea water, ensure they are thoroughly desalinated. Put your finds into an old pair of tights and drop it into the toilet cistern for a week or two. A constant change of fresh water will take out all of the sea salt. Then dry with a paper towel and place in an airtight container, with silica gel sachets.
Ammonites from this location are subject to pyrite disease, or pyrite rot. This is the result of the fossil being exposed to air and moisture and this will eventually destroy the specimen, unless preventative measures are taken.
There are many ‘old wives tales’ about how to treat pyrite disease but the only measure that works for the amateur collector is the use of Pyrite Stop. Coating them in varnish, Savlon, or even encasing them in resin does not work. If your pyritised ammonites begin to smell, it’s the ferrous sulphide gas that’s the cause and a sure sign that your specimen(s) have pyrite disease.
Discard any affected fossils and treat the others or else the disease can spread to your entire collection, destroying fossils, labels and even wooden cabinets! Pyrite Stop is available from ZOIC Palaeotech and it’s well worth the investment to keep your collection safe.
Tidmoor Cove, shown above on an exceptionally low tide, is accessible by returning to the metal gate and then turning right onto the coastal path. It’s signposted to Ferrybridge and you’ll see Littlesea Caravan site in the distance.
Whatever you do, do not attempt to cross from Tidmoor Point beach to Tidmoor Cove across the swampy section between them, even at low tide.
This is extremely dangerous section and thick mud will suck you in up to your waist, or worse! Just traverse the stream, via the wooden bridge and drop down onto Tidmoor Cove (sometimes referred to as Lynch Cove) and start to look for fossils.
This is the Mariae Biozone of the Oxford Clay Formation and the ammonite Quenstedtoceras mariae (shown above) is prevalent.
Identification of fossils from both Tidmoor Point and Tidmoor Cove can be found in the book, ’A Field Guide to the Jurassic Fossils of the Fleet Lagoon, Dorset’, published in 2023 by Siri Scientific Press and available from Amazon.
About Guest Blogger - Steve Snowball
Steve Snowball spent a total of 35 years working in education; initially as a teacher, then as a headteacher and finally as an education advisor in West Sussex. He retired to live on the Jurassic Coast of West Dorset, where he was able to pursue his keen interest in collecting fossils and spending time walking his dogs, enjoying landscape photography, oil painting and gardening. Steve is the author of ‘A Guide to Fossil Collecting in England & Wales’ and co-author of a series of four other highly-acclaimed guides to fossil collecting on the Dorset coast, all published by Siri Scientific Press.