Fossil Hunting at Osmington Mills on the Jurassic Coast of Dorset.

Fossil Coast Drinks Co is pleased to introduce Steve Snowball as a guest blogger who will be sharing his knowledge, experience and expertise in a series of blogs about fossil hunting on the Jurassic Coast of Dorset. Steve is an accomplished 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.

The rugged coastline of Osmington Mills in Dorset

If you happen to be in the vicinity of Weymouth, or Ringstead Bay, it might be your opportunity to visit the type section of the Osmington Oolite Formation, displayed in the cliff near Osmington Mills.

The hard limestones of the Osmington Oolite is packed with fossils but they are difficult to extract as the rock is extremely hard and the site is a SSSI (Site of Special Scientific Interest), so no digging or hammering into the bedrock’s allowed. That said, beneath the cliff, the rocks and boulders from innumerable falls can provide an excellent hunting ground and a couple of hours of searching in the debris might be rewarded with some fossils in more manageable size rocks, to take home.

From Ringstead Bay, (the car park is at DT2 8NG with a daily rate charge of £6 in 2023) walk west towards the headland at the far end of the bay. This is Bran Point. Around the Point, the fallen and wave-carried rocks are mostly from the various beds that comprise the Osmington Oolite Formation, although being on the beach, it’s often hard to identify from which bed they are derived.

The Osmington Oolite Formation is part of a larger group of rocks known as the Corallian Group. These are Upper Jurassic rocks of Oxfordian Age (163.5 to 157.3 million years ago) and form a very complex succession of limestones, marls, sandstones, silts and mudstones.

Bran Point between Ringstead and Osmington Mills

Fossils are often packed into the rocks and boulders around Bran Point but are invariably in rocks that are way to heavy to lift! However, loose fossils are often found here and although mostly of bivalves or gastropods, large ammonites or sections from large ammonites are found here and can be prepped using an air pen, or you might engage the services of somebody who preps fossils if you are lucky to find a good specimen.

Myophorella clavellata the Jurassic clam

You can see the rocks here are littered with fossils of the bivalve, Myophorella clavellata (Right), a Jurassic clam! These are from the Trigonia Beds of the Corallian Group.

The reef here, which can clearly be seen just off-shore at low tide is known as Bran Ledge and the foreshore is littered with these fossils clams, which can be found as wave-worn specimens in amongst the rocks or as better quality specimens, if you’re lucky as shown (below).

Examples of Myophorella clavellata or Jurassic Clam fossils

Take time to look carefully at Bran Point, as ammonites and sections of these creatures are found here, in the beach shingle and rocks especially after cliff falls. The nice ammonite (below) was found by Wayne Sayers.

As you proceed around Bran Point, the cliffs of Osmington Mills come into view. The rocks and boulders increase here and the going can get tough, particularly when there is sea weed covering the rocks, so take care!

If you have children in tow, you might wish to reconsider this stretch of coast and just take in the view!

The winter storms and heavy rainfall of 2023/2024 have caused immense damage to the Jurassic Coast, resulting in unprecedented cliff falls, slippages of large tracts of land into the sea, the disappearance of coastal paths and many access points to the beach. Please be aware of these conditions, as the section from Osmington Mills to Black Head, further west, was particularly hard hit.

Bathrotomaria gastropod fossils

Always let somebody know that you are visiting coastal sites and the time you might be expected back. Check tide times carefully. Wear sensible boots or shoes too. The seaweed covered rocks can be hard to navigate and to walk upon, so care is required.

Bathrotomaria gastropods (Left), a common find at Osmington. There is no hammering in the bedrock allowed at SSSI sites but you are allowed to extract fossils from fallen blocks.

At Osmington Mills, the rocks are very hard but the careful use of a geological hammer or lump hammer and a chisel can reduce the matrix surrounding the fossil to a manageable size and ready to be transported home. Don’t be tempted to do precise preparation of the specimen in the field. At home, you can take your time.

Example of Osmington Mills fossils in matrix

Huge ‘doggers’ or nodules (Below) which protrude from the cliff face and which can be seen further west towards the beach access point at Osmington Mills. These are formed from a very interesting cross-bedded, sandstone of marine origin.

Examples of the doggers’ or nodules of Osmington Mills

Further information on the geology of the section can be found on Ian West’s website at Wessex Coast Geology And after an exhausting day on the beach, why not visit The Smuggler’s Inn at Osmington Mills. Excellent food and beers but booking is advised in the peak season.

About Guest Blogger - Steve Snowball

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.