Hengistbury Head is at the most easterly end of Dorset and is a popular area for hikers. The cliffs are tall, but surrounded by water, with Christchurch Harbour just 400m round the corner to the east. These are Barton Age and are rich in fossil seeds. Therefore, this is an ideal location for the microfossil collector.
♦ It is highly recommended that you take a map. The location is at the very eastern end of Bournemouth and, until you get near, it is not signposted.
♦ It is best accessed by dropping down from the A35 once you get near Christchurch. From the roundabout, where the A35 meets the A3060, continue straight over the next two roundabouts, heading towards Christchurch.
♦ After crossing over a railway bridge, take the B3059 towards Southbourne. Go straight over the first roundabout, over a narrow bridge, and then straight over the next roundabout. The next right is the road that will lead to Hengistbury Head and is signposted as a car park.
♦ Continue all the way to the furthest car park, which is very large with plenty of spaces. Park here and walk across the grass fields to the shore. From here, walk east to the cliffs.♦ Ref: SZ 17429 90505
FIND FREQUENCY: ♦♦♦ – At the base of the cliff, a sand and clay bed of lignite (part of the Boscombe Sands) is packed with a large variety of seeds, with a good level of preservation. The bed is easy to find. It is 2m thick, but is not uniform throughout its thickness. The siltiest part of this bed is the most productive for seeds.
CHILDREN: ♦♦♦ – This location is suitable for older children. The beach is fairly safe, as long as you keep away from the cliff. The location is more popular with schools looking at the geology of the small ice age gravel cliffs at the start of the walk.
ACCESS: ♦♦♦ – The walk from the car park to the seed bed is not that far. However, if you are not used to Bournemouth, the start can be a little hard to find. Therefore, a good road map is useful.
TYPE: – Fossils are found by taking samples from the beds within the cliff for processing at home. The cliffs can be dangerous, so take extra care. As this site is an SSSI, only take samples that have collapsed from the cliff and not from the actual bedrock.
Hengistbury Head provides an excellent opportunity to collect seeds from Barton Age clays. It is the start of the fantastic Eocene coastline, which continues into Hampshire, including Barton-on-Sea and Milford-on-Sea. There are no macro fossils here, apart from the occasional mollusc mould. The fossils found here are microfossil seeds, within a bed of lignite clay.
When you first get to the shore at Hengistbury Head, you will notice the small, low cliffs are gravels. You need to continue to keep walking until the cliffs become taller. The lignite bed can clearly be seen at their base. There are two excellent beds for seeds, both within the final 2m of cliff. The first is a charcoal black lignite bed and the second, a silty clay bed with lignite. Both are full of fossil seeds, which can easily be processed at home. Therefore, it is recommended that you take some samples back, or sieve on site and then take the sediment back for viewing under a microscope or hand lens. There are many different varieties of seeds here.
Microfossils are mostly found in the lignite beds from the Boscombe Sands. This layer is often found at the base of the cliff, and consists of black carbon. The bed is full of seeds. Another bed, which is higher in the cliff, is a silty grey bed, sometimes exposed on the shore beneath the cliff, where the sea has washed fallen debris. This bed has a lot of plant material that also includes seeds.
The best sections are found where the sea has washed out the middle cliff sections and the basal beds are exposed. Bag up samples in heavy duty bags, but make sure you write on them what bed the samples are from and make a note of any important information.
The best way to process your samples is to wet-wash them, which will also clean the samples. It is not a bad idea to do a second wash to clean them further, as this makes looking at them under a microscope easier.
Samples should be sieved to 500 microns, 300 microns and then 250 microns. These will capture all the seeds covering various sizes. You will then need a microscope to view these. (UKGE Ltd sells a wide range of microscopes)
Microfossils from Hengistbury Head are well known for the huge range of fossil seeds that can be found there. The problem is that these seeds, unless preserved, can deteriorate very quickly. After a while of being exposed to air, the seeds will open up and ‘pop’, and once this happens they start to crumble. Therefore, you must preserve them or keep them in air tight containers.
Hengistbury Head is a promontory of low-dipping Eocene sands and clays, with a gravel capping. Hengistbury Head is of particular geological interest because of the abundance within the sandy clays of sideritic ironstone nodules. These are in in Middle Eocene, Lower Barton Formation strata of about 40 Mya, which were deposited at the junction of estuarine or deltaic conditions.
The cliffs here are over 35m tall, divided into four groups –
- River Gravels at the top then;
- Warren Hill Sand Member of the Barton Clay Formation The beds comprise some 10m of slightly laminated sands, the upper part being yellow with Solen and Panopea The lower part is grey with Pinna. The sands are Bartonian in age.
- Barton Clay Formation. The beds comprise some 3m of stiff brown and grey clays, with beds of fine sand. Below are fine grey-brown silty clays with abundant mollusc moulds in nodules and Nummulites rectus. Glauconitic fine grey-green clayey sand with some quartz grit and Nummulites prestwichianus follows and then coarse-grained sands and quartz grit at the base.
- The Barton Clay here does not look similar to the Barton Clay at Barton and Highcliffe and it does not contain obvious and well-preserved shelly fossils, like those at Barton. However, fossils are present. They are entirely from the middle part of the Lutetian Stage of the mid-Eocene
- Boscombe Sand Formation. It is in the final section where fossil seeds can be found The Boscombe Sands are divided into buff and chocolate coloured sands, with small pebbles, and lignitic sands and clays. It is this bed, which makes up the final 2m of cliff, that is most productive.
The beds at Hengistbury are relatively poor in fossils overall but the total faunal and floral lists are quite diverse.
Common sense should always be used at all locations and prior knowledge of tide times is essential. The sea can often reach the base of the cliff, which are sheer in places and frequently crumble.
A trowel is important for taking samples and we recommend sieves of no greater than 0.5mm for sieving on site. Sample bags are also essential.
Hengistbury Head is part of the Jurassic World Heritage Coastline. Please follow the Fossil Code of Conduct on the safety notes page below.