This is another Jurassic location where ammonites can be found. The ammonites from Osmington Mills can be quite worn and hard work is required to get them out of the rocks. However, sometimes if you are lucky, you can find one lying on the foreshore.
♦ Osmington Mills can be accessed by parking at the bottom of the road there, which is off the A353.
♦ Once on the beach, walk east towards Ringstead. Both Black Head and Bran Point will be seen along this stretch of coastline.
♦ Alternatively, you can park at Ringstead and walk west.
♦ Ref: 50.63391°N, 2.37571°W
FIND FREQUENCY: ♦♦♦ – Fossils at Osmington Mills can often be found, but you will have to work to find them. A heavy lump hammer may come in handy. Occasionally, you can find ammonites washed out along the foreshore.
CHILDREN: ♦♦ – Osmington Mills is very rocky and therefore we do not recommend it for children.
ACCESS: ♦♦♦ – It is a fairly easy location to access, although it can be hard going over the rocky foreshore.
TYPE: – Most fossils are found in the large boulders along the foreshore, but fossils can also be found washed out on the foreshore or within the cliff face.
This site is part of the Jurassic World Heritage Coastline, is a SSSI and private land. No hammering on the cliff is allowed and digging is strictly forbidden. Damage has already been caused to the heritage site by people using power tools. This is strictly against SSSI rules and any attempt to ignore them may result in prosecution.
The best fossils are found in the boulders along the foreshore. These can be split using a large hammer and a chisel. The material is quite hard, so you will have to work for your finds. Occasionally, fresh cliff falls yield ammonites, which are easily extracted from the blocks. At low tide, check the foreshore exposures, as these can also contain good fossils, which the sea has washed out of the rocks for you.
An exceptional section of Corallian here contains many fossils, mostly trace fossils, including Spongeliomorpha. Concretion blocks, which are derived from the Upper Greensand and Gault Clay, contain oysters, serpulids, echinoids, the ammonite Hoplites, and other derived fossils. These can mainly be found along the beach below Black Head.
Walking east, once the Preston Grit is reached near to small waterfall, you can find bivalves (Pleuromya, Gryphaea and Myophorella hudlestoni). Occasionally, the trace fossil Diplocraterion parallelum can be seen. The Middle White Oolite is crowded with the trace fossil Arenicolites variabilis, which leads onto the Trigonia Beds. Many fallen blocks contain the bivalve, Myophorella clavellata.
The cliffs at Osmington Mills are well known for their excellent sections of Corallian Beds and Kimmeridge Clay. Landslips of the Cretaceous Cenomanian Basement Bed are also often seen. West of Osmington Mills, the upper part of the Corallian and the lower Kimmeridge Clay are more frequent and, at Black head, a full sequence of Kimmeridge Clay from the basal beds to levels above the White Stone Band can be observed. East of the slipway at the car park at Osmington Mills, the lower cliffs are formed from Northe Grit.
At the lowest point of cliffs, there is a waterfall over the Preston Grit. Walking east, the Qualicosta Bed forms a ledge west of Bran Point. From here, a fault brings the Middle White Oolite Bed against the Pisolite. Continuing east, the Trigonia Beds can be seen in the cliffs, which dip to beach level.
Common sense when collecting at all locations should always be used and prior knowledge of tide times is essential. Care should be especially taken at Osmington Mills of tide times, as the sea can cut you off. Access down to the beach at Osmington Mills can also be dangerous after heavy rain, as mud slippages can make the path very slippery.
The material at Osmington is very hard and therefore heavy-duty hammers and chisels should be taken. Ideally, safety goggles should be worn when hitting rock and suitable walking shoes should be worn.
This site is an SSSI and forms part of the UNESCO World Heritage Jurassic Coast. This means you can visit the site, but hammering the bedrock is not permitted. For full information about the reasons for the status of the site and restrictions please download the PDF from Natural England – SSSI Information – South Dorset