West, Ian M. 2017. Geology of Hengistbury Head: Geology of the Wessex Coast of southern England. Internet site: www.southampton.ac.uk/~imw/hengist.htm. New Version: 6th January 2017.

This is an old version. Please go to the better

Hengistbury Head Revised Version, updated in 2017.

Hengistbury Head, near Bournemouth - Geology Field Guide, old version

Ian West,
Romsey, Hampshire
and Visiting Scientist at:
Faculty of Natural and Environmental Sciences,
Southampton University,

Webpage hosted by courtesy of iSolutions, Southampton University,
Aerial photographs by courtesy of The Channel Coastal Observatory .

See also associated webpages
Hengistbury Head - Geological Bibliography
Barton-on-Sea and Highcliffe - Geological Field Guide
Coast Erosion and Sea Defences at Barton-on-Sea and Highcliffe
Barton and Highcliffe - Erosion History
Highcliffe, Barton and Hordle - Bibliography
Bournemouth Cliffs
Southbourne and Southbourne Coast Erosion (within the Bournemouth Cliffs webpage)

Click here for the full LIST OF WEBPAGES

For references to publications on Hengistbury Head go to: Hengistbury Head - Bibliography

A general overview from the southwest of Hengistbury Head, Bournemouth, Dorset, seen from a helicopter, 6th July 2013

Introduction to Hengistbury Head, Bournemouth, Dorset, a former ironstone mining locality, and now known to be fairly close to an offshore oilfield, helicopter view, 6th July 2013

Hengistbury Head, Bournemouth, Dorset, seen from the southern end of the Double Dykes, 16th February 2012

A general view of Hengistbury Head, Bournemouth, Dorset, 16th February 2012

Hengistbury Head,view along beach towards Isle of Wight, 2002

Geology and Oceanography Students from Southampton University walk over ironstone nodules at Hengistbury Head, Bournemouth, Dorset

Hengistbury Head, Bournemouth, Dorset in a gale, with university students on a field trip

Hengistbury Head, old quarry on the top

Hengistbury Head - cliff top view ENE

..| Related Webpages and Field Guides

|Home Page and List of Webpages |Contact Ian West
|Field Guides Introduction |Hengistbury Head - Bibliography |Bournemouth |Brownsea Island, in Poole Harbour |Sandbanks Sand Spit |Hordle Cliff |Barton and Highcliffe - General |Highcliffe, Barton and Hordle - Coast Erosion |Highcliffe, Barton and Hordle - Bibliography |New Forest Geology |Solent Estuaries Click here for the full LIST OF WEBPAGES --------------

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1.4. INTRODUCTION - Age of the "Hengistbury Beds" [not done]
1.5. INTRODUCTION - Middle Eocene Climatic Optimum (MECO)

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2.1. INTRODUCTION - Topographic Maps
2.2. INTRODUCTION - Geological Maps
2.3. INTRODUCTION - General Palaeogeographic Maps and Palaeogeography

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3.1 STRATIGRAPHY AND SEDIMENTOLOGY - Lower Barton Clay - General
3.2 STRATIGRAPHY AND SEDIMENTOLOGY - Lower Barton Clay - Basal Pebble Bed
3.3 STRATIGRAPHY AND SEDIMENTOLOGY - Lower Barton Clay - Prestwichianus Bed
3.4 STRATIGRAPHY AND SEDIMENTOLOGY - Lower Barton Clay - Hengistbury Head Succession
3.5 STRATIGRAPHY AND SEDIMENTOLOGY - Lower Barton Clay - Seismites
3.6 STRATIGRAPHY AND SEDIMENTOLOGY - Lower Barton Clay - Clay Mineralogy
3.7 STRATIGRAPHY AND SEDIMENTOLOGY - Lower Barton Clay - Geochemistry

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7.1 FOSSILS - Introduction
7.2 FOSSILS - Marine Shells
7.3 FOSSILS - Plant Fossils

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7.1 PLEISTOCENE STRATA - Flint Gravels
7.2 Pleistocene Strata - Brickearth

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9.1 LOCATION - -
9.2 LOCATION - -,
9.3 LOCATION - -
9.4 LOCATION - -
9.5 LOCATION - -

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Hengistbury Head is the best part of the Bournemouth coast for geology and geomorphology. It is an attractive area of country parkland and archaeological site between the sea and the town of Christchurch. It provides impressive views across Christchurch Bay eastward to the Isle of Wight, and southwest to the Isle of Purbeck. Hengistbury Head has been greatly modified by quarrying for sideritic ironstone in the 19th century and also extensively by coast erosion. It retains one obvious quarry in the centre of the hill, but the remains of quarrying and quarry tips round the north and west side are now largely overgrown. The path up to the top of Hengistbury Head is over a broad quarry terrace, and the Lilly Pond on the north side is a small flooded quarry. The prominant headland is now only about half the size that it was in the 18th century (see maps which follow). After the quarrying the headland became a private estate. However, it was later opened up to the public and in due course became one of the public parks of Bournemouth. Attached to Hengistbury Head is a sandspit, Mudeford Spit, which unfortunately is no longer natural but largely covered in beach huts. It is still a pleasant place though.

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. The nodule are not now seen on the beach in their former abundance; in fact only a small number are accessible. The reason for this is that the process of beach replenishment takes place regularly at Bournemouth and has done so for many years. The Bournemouth does not entirely stay in place but moves by longshore drift (under the influence of southwesterly winds) in an eastward direction. There is a long groyne that was built many years ago at the end of Hengistbury Head. This holds back most of the sand which is accumulating over the original beach and covering the ironstone nodules. In the 1950s the situation was different and the accumulation near the long groyne was of certain items coming from the raw sewage waste which was discharged just off the Bournemouth beach (beaches east of Bournemouth Pier Outfall were usually affected by sewage waste then and it was a minor nuisance when swimming). So it is a cleaner place now, but with much poorer ironstone rock exposure for the geologist. The nodules, though, can still be seen in the cliff.

The Eocene strata of Hengistbury Head are mainly clays and sands belonging to the basal part of the Barton Formation (details will be given further on). These marine sediments of about 40 million years ago were deposited at the junction of estuarine or deltaic conditions to the west and a shallow marine gulf to the east. The climate was warmer than would be expected for a place at about 40 degree north because of the MECO, the Middle Eocene Climatic Optimum. There has been much leaching of carbonate so that shelly fossils like those at Barton-on-Sea are not found at Hengistbury Head, only hollow moulds. Pleistocene gravels occur in the uppermost part of the cliffs above the Eocene strata.

The visitor has plenty to see. There is an Information Centre near the Double Dykes (historic embankments) and it is easy to walk along the beach or over the top of the hill. It is good that Hengistbury Head is protected. The present writer has known the place very well for a long time, because his geological studies were at Southbourne in about 1950 with a direct view of Hengistbury Head.

With regard to car parking, there is a large car park, shown on an image above, with fairly moderate charges, and with a height barrier so that it is not in general use for coaches. Parking on nearby roads is possible, but difficult in the height of the summer season. There is a good interpretation centre - the Hengistbury Head Outdoor Education and Field Studies Centre. There is also a cafe, toilets and a small road train which provides transport to Mudeford Spit.

Further down, we will discuss the geological details, with the aid of photographs, maps and diagrams.


(Supplementary Note re History - Plans for a Hengistbury Head Mansion
Hengistbury Head (otherwise known as: Hednesbury, Christchurch Head, Warren Head, Warren Hill or Warren Hill Common) has at times in the past been a private estate, and not always an area for public access. At one stage it belonged to Sir George Meyrick; his Keeper, George Brewer, is shown on patrol with a dog at the Double Dykes in the British Medical Association (1934) publication on Bournemouth. Later Hengistbury Head was sold to Mr Selfridge. The following are some notes from Young (1989):
"Gordon Selfridge, the founder of the London Store, had become the owner of a considerable area of the land from near Belle Vue Road across to Double Dykes, all of Hengistbury Head and much of Stanpit Marsh. He had intended to have a grandiose mansion built on Hengistbury Head, but eventually abandoned the idea, and instead all his property in this area was put up for sale on 6th August 1930. Hengistbury Head and Double Dykes, an area of 357 acres, was bought by Bournemouth Corporation, thus securing the preservation of an area of immense archaeological and ecological value." )

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1.2 - INTRODUCTION - SAFETY - [done]

Safety for Geology at Hengistbury Head and Adjacent Area

For information on safety at Hengistbury Head please abide by any warning or safety notices in the area and instructions from the Field Centre or from coast wardens. The foot of the cliff is best avoided but if it is approached then safety helmets should be worn. Although there are few hard rocks present apart from the ironstone the falling of debris from the clays or pebbles from the gravels could be a risk. There was an accident to a party of girl guides by a mudslide during heavy rain in 1976 ( (Turner in: Bray and Hooke, 1998b, p. 240) Watch out for any place where there are signs of loose debris on the cliffs or where debris has fallen recently. Obviously, when walking on Warren Hill, the cliff edge should be avoided, particularly since it may consist of crumbling sand and gravel. Avoid climbing the cliffs and the rocks of groynes, and also take care not to enter treacherous mud in Christchurch Harbour. Adders used to live on the heaths, but may not be particularly common. In general, Hengistbury Head is not a particularly dangerous place, but accidents could happen in unusual circumstances. Hazards relating to swimming, boating or fishing exist in places, particularly near the Run, but such activities are not subjects of this guide. Note that geological work here should be very discreet, and hammering should be avoided.

As in the case of other localities individual geological visitors and field leaders should make their own risk assessments and no liability is accepted.

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Introduction to the Specific Area of Hengistbury Head


A simplified geological and general topographic map of Hengistbury Head, Bournemouth, Dorset, introductory

Hengistbury Head is a headland and hill of about 36m height situated between Christchurch Harbour and Poole Bay. It is less than one square kilometre in area, but full of interest, geological, archaeological, botanical etc. and is a particularly valuable piece of unspoilt countryside to the east of the Bournemouth conurbation. For general topography the Ordnance Survey, Outdoor Leisure Map 22, The New Forest, 1:25,000 shows Hengistbury Head and adjacent area in general context. The locality is also within the are of the Ordnance Survey Landranger 1:50,000 Sheet 195. The map reference of the highest point, the summit of Warren Hill is SZ 170907. The Ordnance Survey maps mentioned here are too small scale for detailed studies within the Hengistbury Head area and for that purpose a 1:10,000 or larger scale map is needed (enquire from the Ordnance Survey or an Ordnance Survey map supplier).


Hengistbury Head in 1890s

This map is based, with some modifications, on Ordnance and geological surveys of the 1890s, the latter by Clement Reid. It is part of the early version of the one-inch-to-one-mile Geological Survey Sheet 329 for Bournemouth. Compare it to a modern large-scale Ordnance Survey map and to the new edition of the Geological Survey Map, 1:50,000 Series, Solid and Drift, which is recommended and can be purchased from the British Geological Survey. The new map has geology from a survey of 1984-1986 by Bristow, Freshney and Williams, and topography from an Ordnance Survey sheet of 1986.


The main geological map which includes Hengistbury Head is the British Geological Survey Sheet 329, Solid and Drift - Bournemouth, 1:50,000 series, 1991 edition. There is also an older edition of 1895, reprinted in 1947 (this shows Hengistbury Head in very simple terms, but with the Run extended to Highcliffe and it is therefore of historic interest; it does not different between "Plateau Gravel Terraces". The 1992 edition shows more detail, but it is not easily seen in this relatively small area. After all, Hengistbury Head is only about one and a half kilometres long and a small feature on a map of scale 1:50,000. A simplified, larger-scale map is shown above. It does not necessarily accord with the BGS map in every detail, and the serious researcher must consult the Geological Survey sheet. Larger scale maps may be available, but not in print for the public, at the British Geological Survey.


Aerial Photographs


Some aerial photographs are now show to help understand the topography and geology of Hengistbury Head.


An old aerial photograph of Mudeford Spit, Hengistbury Head, Bournemouth, Dorset, probably from about 1960

Old aerial photo of Hengistbury Head, showing Mudeford Spit

A general overview of geomorphological features and some potential, future flood problems of Hengistbury Head, Christchurch Harbour and Mudeford Spit, Dorset, as shown on a satellite photograph, with additional notes


The top two photographs above are old aerial photographs of the Hengistbury Head area. The upper one is of Mudeford Spit in the 1950s or 60s. Notice that the large car parks have not then been established at Mudeford, and that Christchurch airfield (where the present author flew gliders) was still in existence. The second and lower old photograph shows more of Hengistbury Head at a slightly later date; more details regarding this are discussed separately below.

The lowest image above is a modern satellite photograph from the 1990s, of Hengistbury Head and Christchurch Harbour. It shows the recent sea defences, mostly of rock armour, that have been placed on Mudeford Spit (compare with older aerial photographs). Note the extensive housing development in the Mudeford area. Most of this is above the present flood risk level, but there are some low parts shown to be at risk by the Environment Agency Flood Map website . At distant intervals of time, perhaps about once every 250 years (but very irregular), major hurricanes can hit the area. With rising sea-level and coastal erosion, such hurricanes in the future might cause washover into Christchurch Harbour. If that happens on a major scale then harbour flood levels might result in a break out of the main outflow of Christchurch Harbour back its probably original position near Hengistbury Head and not at the northern end of Mudeford Spit. No implication is made that this is an immediate risk, it is merely a consideration of just what could happen in the future at, of course, an unknown date. The sea is transgressing and will continue to transgress.


The middle aerial photograph, above, is old, undated, but probably from the 1960s or early 1970s. Notice particularly that the waste tips and the low angle, clay fan north of the ironstone quarry were almost unvegetated at this time. In the 1950s these slopes were very bare but fun for riding a bicycle up and down (I was a schoolboy then). The quarry in the 1950s was relatively dry and drained out through a ravine to the north. I searched the ironstone nodules in it for fossils. Fortunately, after protests from Southbourne residents, it had been decided not to proceed with the plan to fill the quarry with waste, and later it was dammed so as to make it into a pond. Coast erosion on the south side was becoming a problem and threatening the path which crosses west to east south of the quarry. Notice also in the photograph the narrowness of the beach at the southeastern end of the headland. This has long been subject to wave erosion and ironstone nodules have accumulated at its foot. An image is provided below of the scene in about 1825. This cliff looked much the same in the 1950s and 1960s but in fact had retreated to a significant extent from the 19th century. The effect of the long groyne and the limited sand dune development to the northwest of it is worth studying in the photograph. Some vegetated alluvial fans are visible on the cliffs. An path extended along the foot of the cliffs through the area of small sand dunes. Walkers are now diverted southward to the beach and the sand dunes are fenced off. See also the tidal-delta where sand is washed into Christchurch Harbour by the flood tide. The boat channel avoids this submerged but shallow delta, passing it by southwards diversion. [done to here, 12th January 2017]

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Poole and Christchurch Bays, Shoreline Management Plan - SMP - Key Publications

See these important documents on the plans for the coastal management or shoreline management of the area. Summarised contents of a version are given below and look for the section of interest. However, this SMP is not the final version, and there will be an update. If you do not find it directly from the links here, search by Google etc for the latest version, using the keywords - "Poole Christchurch SMP".

Poole and Christchurch Bays Coastal Management Group. 2010. (SMP - Shoreline Management Plan)
Poole and Christchurch Bays Coastal Management Plan (or SMP - Shoreline Management Plan). Draft SMP2. Draft version of the SMP, later to be replaced by final version (see this when it is available. SMP2 is due to be published in April 2010.). Available online as PDFs at Poole and Christchurch Bays Coastal Management Plan.

Contents: Draft SMP2
Section 1, Introduction
Section 2, Environmental Assessment
Section 3, Basis for Development of the Plan
Section 4, Appraisal of Options and Rationale for Preferred Plan:
Section 4.1, Introduction.
Section 4.2, Policy Development Zone 1 Central and Eastern Sections of Christchurch Bay (Hurst Spit to Friars Cliff).
Section 4.3, Policy Development Zone 2 Christchurch Harbour and Central Poole Bay (Friars Cliff to Flag Head Chine).
Section 4.4, Policy Development Zone 3 Poole Harbour and Associated Coastline (Flag Head Chine to Handfast Point, including Poole Harbour).
Section 4.5, Policy Development Zone 4 Swanage (Handfast Point to Durlston Head).
Section 5, Summary of Preferred Plan and Implications
Section 6, Policy Summary, including Policy Summary Map.
Appendices (all documents open in a new window)
Appendix A, SMP Development.
Appendix B, Stakeholder Engagement.
Appendix C, Baseline Process Understanding, including Coastal Process Report and Flood and Erosion Mapping. Accessible from a separate page including No Active Intervention (NAI) and With Present Management (WPM) assessments, and summaries of the data used in assessments.
Appendix D, Natural and Built Environment Baseline (Thematic Review).
Appendix E, Issues and Objective Evaluation.
Appendix F, Strategic Environmental Assessment.
Appendix G, Scenario Testing.
Appendix H, Economic Appraisal.
Appendix I, Estuary Assessment.
Appendix J, Habitat Regulation Assessment - Appropriate Assessment.
Appendix K, The Metadatabase, GIS and Bibliographic Database is provided to the operating authorities on CD. It will be included in the final SMP.
Appendix L, Water Framework Directive (WFD)
Appendix M, Review of Coastal Processes and Associated Risks at Hengistbury Head.


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Archaeology of Hengistbury Head

Archaeological map of Hengistbury

Because Hengistbury Head is notable for metal-working in iron age times, the archaeology and geology have a direct relationship. Iron was manufactured from the local siderite and and other minerals were imported to the area for silver extraction. Gold and bronze was worked here and Kimmeridge oil shale was turned on lathes to make armlets. This map by John Lavender summarises the discoveries. It also attempts to estimate the position of the coastline 2000 years ago. It is a very good map but probably far from the true situation in this respect. Sea-level in Southampton Water has risen at a rate of about 1 to 2mm per annum during the Holocene (Hodson and West, 1972) (and is rising even more rapidly now - with regard to coast erosion prospects see the paper of Few, Brown and Tompkins (2004)). The Christchurch Harbour side of the headland would have been very different with lower sea-level and this part of the harbour might have been narrower. The alluvium and salt-marshes, however, would have been less developed at that time. On the seaward side the coast may have been much somewhat further south than shown. There could even have been lower ground (with a lower gravel terrace) between Warren Hill and the sea, although this is just speculation. Were the Double Dykes just a barrier across the neck of the peninsula, or were there embankments on the south side of the hill? All this is unknown. What is very likely, however, is that important archaeological remains lie buried under the alluvium and the salt marsh north of the headland.

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A chart showing lithostratigraphic schemes for the Palaeogene strata of the Bournemouth and Poole area, including Brownsea Island and Barton-on-Sea


The sequence of Eocene strata at Hengistbury Head, Dorset, with comparison and correlation to the Boscombe Sands and Barton Clay section at Friars Cliff and Highcliffe


The stratigraphy of the Lower Barton Formation at Hengistbury Head, Bournemouth, Dorset, shown diagrammatically and based on Bristow et al. after Hooker, with some notes from Curry


The diagram above had been modified after Bristow, Freshney and Penn (1991). Note that the ironstone bands are renumbered. Only three bands of ironstone nodules are easily seen at the high part of the cliff. The lower two are more persistant and conspicuous.


A view of the nearly vertical cliff of Hengistbury Head, Bournemouth, Dorset, near the highest point, so as to show the Eocene succession from the Boscombe Sand though the so-called Hengistbury Beds up to the Warren Hill Sand and Pleistocene gravel, photo 27th June 2010 - unlabelled


A view of the nearly vertical cliff of Hengistbury Head, Bournemouth, Dorset, near the highest point, so as to show the Eocene succession from the Boscombe Sand though the so-called Hengistbury Beds up to the Warren Hill Sand and Pleistocene gravel, photo 27th June 2010 - labelled


The vertical succession in the central part of the cliffs of Hengistbury Head, Bournemouth, Dorset, photographed in June 2010


Use the photographs above, which shows the highest part of the cliff of Hengistbury Head, to recognise the stratigraphical subdivisions and the positions of the ironstone nodules.

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Introductory Overviews of the Cliffs and Strata

The cliffs of Eocene strata at Hengistbury Head, Bournemouth, Dorset, from the middle part of the hill towards the western end


At Hengistbury Head looking down the cliff of mainly Hengistbury Beds to a very broad beach with sand and shingle derived from the renourishment at Bournemouth, Dorset, September 2013


The cliffs of Eocene strata at Hengistbury Head, Bournemouth, Dorset, from the middle part of the hill towards the east

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Boscombe Sands (Bracklesham Group, Middle Eocene, Palaeogene)

Black, carbonaceous Boscombe Sand, Bracklesham Group, Middle Eocene, at Hengistbury Head, Bournemouth, Dorset, November 2008

The lowest stratal unit seen at Hengistbury Head is the Boscombe Sand of Bracklesham age. This is 20 to 27 m. in thickness and underlies much of the Bournemouth area (Bristow, Freshney and Penn, 1991). The deposit is exposed in the cliffs at Boscombe but these sections are now much damaged by the Bournemouth urbanisation. Sea defences, promenade, drainage, vegetation and restrictions on access have spoilt the exposures. At Hengistbury Head, however, the sands are still very well seen, at least in part, at the base of the cliff.

The formation consist of mainly fine to medium grained sand, consisting dominantly of quartz grains, but an unusual feature is that flint grains are common at some levels (Bristow, Freshney and Penn, 1991). This may be related to the extent of flint battering that occurred on the ancient "Chesil Beach" of the eastern Bournemouth area (see above - the battered and rounded pebbles). The mean grain size varies 1 phi and 3.5 phi, with a average of 2.2 phi. Sorting is well sorted to poorly sorted with a skewness of between +0.7 and -0.5 and an average skewness of +0.1 (See Bristow, Freshney and Penn, 1991 for more data on sand statistics).

Bedding architecture is of two main types. Planar laminated beds with a few planar cross-bedded units containing flint pebble and cobble beds in the lower part, are associated with marine sands. Bi-directional cross-bedded strata in the upper part are estuarine sand. Thus it seems in general to be a regressive sequence.

At Hengistbury Head in particular the uppermost part of the Boscombe Sands are dark grey, almost black, in colour. These contain upward-coarsening, carbonaceous, silty bioturbated sands, and remobilised muddy sands or slurry beds, containing clasts of carbonaceous sand (Bristow, Freshney and Penn, 1991). The carbonaceous sands have been referred to by Plint , as bituminous, but it seems more likely that they merely contain plant debris. See Plint (1983) for discussion of these sands. The sands have probably been subject to liquifaction by seismic shocks (not surprising because this was the time the "Alpine" tectonics started in the Dorset area). At Friars Cliff there are conspicuous dewatering structures.

Chandler (1963) obtained more than 50 species of plants from the Boscombe Sands. There are a few brackish and marine bivalves present, but it is not easy to find molluscan fossils in these strata. Dinoflagellate cysts indicate the intricata Assemblage Zone ( Costa et al. 1976).

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Pebble Beds at the Top of the Boscombe Sands

(For comparison see also:
Barton Clay at Barton and Highcliffe. Look at the base of the Barton Clay at Friars Cliff and compare to the base at Hengistbury Head.)


Two pebble beds near the junction of the Boscombe Sand Formation and the Lower Barton Clay (Lower Hengistbury Beds), Hengistbury Head, Bournemouth, Dorset, New Years Day, 2002


The pebble beds at the top of the Boscombe sand and the base of the Lower Barton Clay Formation, Hengistbury Head, Bournemouth, Dorset, 2010, with some jarosite


The bed of large ovoid, flint pebbles at the top of the Boscombe Sands, Hengistbury Head, Bournemouth, Dorset, seen fairly close, with jarosite, in 2010


Selected pebbles, with percussion marks, from the top Boscombe Sands Pebble Bed, Eocene, Hengistbury Head, Bournemouth, Dorset, 16th February 2012


Percussion marks in a selected pebble from the pebble bed at the top of the Boscombe Sands, Hengistbury Head, Bournemouth, Dorset, 16th February 2012


Percussion marks from Eocene beach impacts, pebble bed at the top of the Boscombe Sands, Hengistbury Head, Bournemouth, Dorset, 16th February 2012


At the top of the Boscombe Sands at Hengistbury Head there are two pebble beds. The pebbles are of characteristic "Chesil Beach" type. They are very rounded and they all have percussion marks resulting from pebble-to-pebble impacts on a well-sorted pebble beach. Such percussion marks or impact marks are actually small conchoidal fractures and are formed when a pebble has literally been thrown up on a clean pebble beach (without sand) by the action of large storm waves.

Confirming the former existence of a major storm beach, like the Chesil Beach, is the presence of a Maastrichtian flint pebble in the Boscombe Sands at Boscombe (Curry). The Maastrichtian is not not present on the land area of southern England, and the pebble could only have come from the English Channel area to the south. Also compatible with the occurrence of a "Chesil Beach" is the fact that there is much minute flint debris in the Boscombe Sands (Edwards et al.). The pebbles have been shaped by the impacts and the minute conchoidal fractures. The flint debris has been deposited in the sands.

The existence of such a storm beach is not surprising, but the evidence of substantial wave height is odd. The Chesil Beach in Dorset has a very great fetch, and the nearest land opposite to the beach at Chiswell is Venezuela. Thus very large storm waves occur from time to time. The Eocene "Chesil Beach" of Poole Bay seems to have been facing the southeast (because there is evidence of land to the west). It is surprising that the wave fetch was sufficient. Perhaps the Middle Eocene weather, know to have been very hot (Middle Eocene thermal maximum) was also prone to great storms or hurricanes in this region (about 40 degrees north).

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Lower Barton Clay Formation - "Hengistbury Beds" - Introduction

The cliff at Hengistbury Head, Bournemouth, Dorset, central part, showing Eocene strata

Slumped sandstone in the Barton Clay or Upper Hengistbury Beds, Hengistbury Head, Bournemouth, Dorset, 16th February 2012

Succession at Hengistbury Head

Barto Clay or Hengistbury Beds at Hengistbury Head

The Barton Clay succession above the Boscombe Sands has been discussed in the past under the term "Hengistbury Beds". These are greyish green to greyish-brown, sandy clays with much fine sand and some glauconite. Siderite nodules occur in the upper part, the Upper Hengistbury Beds, but not in the lower and more glauconitic part, the Lower Hengistbury Beds. They commence with a bed of large, rounded flint pebbles with obvious percussion marks, that have originated on a beach. These flint pebbles attain up to 15cm diameter. Quartz grit is abundant in the clays immediately above the pebble bed (Curry (1976). The bed with the large pebbles is, according to Plint (1983) a locally notable transgression horizon - T5 - which he considered to be the result of a eustatic rise in sea-level within the Bartonian Stage (although at the top of the Bracklesham Formation, or Group).

The Lower Hengistbury Beds are generally more coarse-grained, in addition to being more glauconitic. The small discoidal foraminifer Nummulites prestwhichianus (Jones) occurs at 5m above the base at Hengistbury Head, according to (Curry (1976), but it may not be at all easy to find.

The Upper Hengistbury Beds have three or four levels of ironstone nodules and also irregular beds or "balls" or fine sand. Like the Lower Hengistbury Beds, these strata appear at first sight to be unfossiliferous. Fossils, do occur in the ironstone nodules, (see below) but are found only rarely.

In the clays there is no calcium carbonate preserved. Occasional sharks teeth have been attacked by sulphuric acid solutions from oxidation of pyrite, and the teeth are prone to have whitish encrustations. Shell moulds occur, according to Curry, particularly at a level 13m above the pebble bed (T5).

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Fossil Content of the Strata at Hengistbury Head

Turritella gastropod shell moulds in Hengistbury Ironstone, Hengistbury Head, Bournemouth, Dorset

There are abundant fossils present at Hengistbury Head, but they are not conspicuous and therefore not often found by the briefly-visiting geologist. Dedicated fossil collectors and palaeontologists can find the fossils. Sharks' teeth are the most commonly found in the Lower Barton Clay here (I have probably found 10 or 12 of these, although I am not a serious fossil collector. They are often found in damaged condition, having been affected by the acids from the oxidation of pyrite.They may be as common at Hengistbury Head as they are in the Barton Clay at Barton and Highcliffe. These can be found on the weathered surface of the so-called "Hengistbury Beds" or Lower Barton Clay simply by regularly searching for several days. More information on fish teeth is given below. There are numerous other fossil bivalves and gastropods present but they are not easily seen. Many of these are listed below.

Erosion of the cliffs now is very limited because of a wide beach, so the chances of finding fossils are actually very small. The place was in the past subjected to more rapid erosion. I am afraid that the general visitor on a short trip to Hengistbury will usually find no fossils.

The ironstone nodules contain fossil shell moulds and sharks teeth only rarely. At the present only few ironstone nodules are present on the shore, whereas up to about the 1960s they were still abundant. This increases the difficulty in finding fossils within them. Moulds of gastropods are present. They include small examples of Turritella, as shown above, and the bivalve Cardita. Other species of molluscs that may be present in the nodules. Sharks teeth and have been found occasionally in the ironstone, but they are rare. Many fossils occur in the clays but they are not conspicuous.

Hengistbury Head is quite an important fossil locality and hundreds of specimens have been found over one and half centuries. This is a place, though, only really of interest to the specialist because the fossils are very difficult to find and they cannot be extracted as shells, only as moulds on a friable slab of clay. It is not like Barton or Highcliffe where there are obvious white fossil shells of aragonite or calcite. It is better for the general fossil collector to go to the cliffs between Barton and Highcliffe.

There are various reasons for the relative difficulty in finding the thes fossil contents of Hengistbury Head. Firstly fossils are just not widely distributed in the strata. If this was the case then they would be seen in more of the siderite (ironstone) nodules, although it must be accepted that there can be loss during diagenesis. Fossils do occur in the nodules (and I have a collection from them) but they are exceptionally rare. Most nodules show none. Unfortunately now, very few nodules are visible now because the beach has built up with sand and shingle, and because of sea defences. Only a few are visible in the old quarry. Hengistbury Head now does not look the same as in the past and the exposures are not as good.

In the clays the shells are preserved as moulds, not as shells of aragonite or calcite, as at Barton-on-Sea. The calcium carbonate has been dissolved away, although it is not quite as to just when this happened. Furthermore at the present (2013) the Head is not undergoing its usual erosion (because of a wide beach) and it is not as rapidly retreating a coast as at Barton-on-Sea.


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Hengistbury Head - Early Fossil Records

There are older reports of fossil content in the Eocene strata of Hengistbury Head, discussed briefly by White (1917). Sir Joseph Prestwich (1848) looked for fossil at Hengistbury Head. He stated that he found a few Bracklesham and Barton Clay species above the "lower part of the clay" at Hengistbury.

A note on sheet 16 of the original Geological Survey map records, without giving their precise positions:
Cardium semigranulatum,
Cytherea obliqua,
Pinna affinis,
Thracia sp.,
"Lamna elegans" [shark's tooth], [quite likely to be Stratiolamia macrota - see below]
Otodus appendiculatus [shark' tooth]
leaves of dicotylodonous plants [plants are listed further below].

There was some successful later work. Dr. Cowper Reed, a notable geologist, was assistant to the Woodwardian professor of geology at Cambridge University in 1892, and was the curator of the Woodwardian (later the Sedgwick) Museum at Cambridge. He came to Hengistbury Head to search for fossils in about 1913. He went to Holloway's disused quarry in the centre of Hengistbury Head which at that time would have been a good exposure (it was still good by the 1950s). Reed (1913) found a number of fossils between the highest and the second-highest band of siderite concretions (approximately 2 to 4 metres below the base of the Warren Hill Sands). These were probably just moulds. Actual shell material does not survive the very acid conditions resulting from the oxidation of pyrite at Hengistbury Head. Even sharks teeth are attacked to some extent by the acid.

Some selected fossil bivalves from the Barton Clay Formation, two species of which occur at Hengistbury Head, in addition to occurrence at Barton and Highcliffe

Six of these fossil, the good specimens, found by Dr. Cowper Reed were identified by him as:

Nuculana (Leda) minima,
Protocardium turgidum,
Corbula pisum, [this is a very common small bivalve of the Eocene, only 3 or 4mm in size, i.e. pea-sized, and fairly robust. It ranges from Bracklesham Group, through the Barton Clay and up into the Headon Hill Member.]
Crassatella sulcata
(Solander), [a very common Barton Clay bivalve, and quite distinct from Crassatella sowerbyi which occurs in only the Bracklesham Group - see image above]
Panope (Glycimeris) intermedia
Calyptrea aperta
Solander" [this has a range from Woolwich Beds to Headon Hill Formation ].

Cowper Reed then listed another 14 species, less well-preserved, with more or less uncertainty. These are the species listed as with uncertain identifications:

Anomia lineata?
Arca duplicata?
Pectunculus (Axinaea) dissimilis?
Cardium cf. formosum?
Cyrena cf. crassa?
Meretrix (Cytherea) cf. incurvata?
Callista (Cytherea) sp.
Cardita sulcata (Solander)? [This is species has a range of the Barton Formation]
Cardita sp. (small)
Corbula ficus?
Corbula cuspidata?
Tellina sp.
Turritella sp. (the gastropod, see also photograph above, which probably shows the common, Bracklesham to Barton, Turritella (Haustator) imbricateria Lamarck)
Callianassa sp. (a shrimp)

About 8 or 9 feet [about 3 metres} below the second ironstone band down Dr. Reed obtained " Mytilus affinis and Tornatella nysti" from dark chocolate clay with grains of glauconite. At the base of the cliff at the north-eastern corner of the headland he found, surprisingly, an example of Schizaster d'urbani [an irregular echinoid and not a common fossil].

The fossils in the Lower Barton Clay of Hengistbury Head occur in patches, and Osborne White (1917) when writing the old Geological Survey memoir on Bournemouth said that could only discover rare and faint impressions of shells at the horizons indicated. Internal casts of a small Corbula (Corbula pisum?)were said to be common [Corbula pisum has a wide range from the Bracklesham Group to the Headon Hill Formation], and with remains of other bivalves, in a band 2 feet above the lowest level of ironstone nodules in about the middle of the southeastern cliff of Hengistbury Head. Note that in 1917, although the question of a possible Barton age of the strata had arisen the clays with ironstone at Hengistbury Head were then placed in the Bracklesham Beds.

Hengistbury Head was visited by the first Australian Commonwealth Palaeontologist, Frederick Chapman, in about 1913. He discovered foraminifera there. See his paper in the Geological Magazine - Chapman (1917).

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Hengistbury Head - Fossil Plants

See particularly Chandler on Hengistbury fossil plants.
Chandler (1960).

This listing below is from the Palaeobiology Database online, with some additional notes of mine. Palaeobiology Database - Hengistbury Head.
The following plants from Hengistbury Head are listed


Pinopsida - Pinales - Araucariaceae

Araucarites sp. leaf, Presl 1833 [related to the Monkey Puzzle Tree and Norfolk Island Pine]

Pinopsida - Pinales - Pinaceae [the pine trees]

Pinus dixoni (Seed/fruit) [Note that succinite - amber, which comes from Pine trees occurs is present in the Bournemouth cliffs.]
Pinus sp. Leaf Linnaeus 1753. [ Ord (1914) records having twice found the remains of pine cones at Hengistbury Head. Incidently, pine trees were millions of years ago native to the Bournemouth district, although the pines there now were brought in artificially in Victorian times!]

Magnoliopsida - Theales - Pentaphylacaceae
Cleyera ? variabilis (Seed/fruit)


Daphne sp. (Seed/fruit)
Epacridicarpum mudense (Seed/fruit)
Mastixicarpum crassum (Seed/fruit)
Symplocos sp. (Seed/fruit)
Rhamnospermum bilobatum (Seed/fruit)

Magnoliopsida - Rhamnales - Vitaceae

Vitis sp. seed/fruit Linnaeus

Perissodactyla - Lophiodontidae

Lophiodon cf. lautricense Hooker 1977, (1 specimen; fragment of mandibular symphysis with five roots)


Sequoia couttsiae Heer. Wood. [Big tree, Redwood Tree etc - i.e. an Eocene tree related to modern descendents - the Californian Sequoias. It once formed great forests in Europe. Locally it covered Dartmoor.][See Chandler, M.E.J. 1922. Sequoia Couttsiae, at Hordle, Hants: A study of the characters which serve to distinguish Sequoia from Arthotaxis. Annals of Botany, os-36, (3), pp. 385-390. This is a record from the Headon Hill Formation. It is very abundant in the Hordle Leaf Bed. Available online as a PDF file, for a fee.]

Limnocarpus headonensis. Seed/fruit
Stratiotes hantonensis Seed of a water plant. [Stratiotes is a perenial aquatic plant, floating in summer and submerged in winter. The leaves are similar to pineapple leaves.]
Scirpus lakensis. Seed/fruit [sedge or bulrush]
Caricoidea obscura. Seed/fruit
Caricoidea sp. Seed/fruit
Palmophyllum sp. leaf [palmelloid green alga]

Nipadites burtini. seed/fruit [the Vietnam Swamp Palm, a notable fossil from Honeycombe Chine, Boscombe, Bournemouth. It is well-known from the Lower and Middle Eocene, including the London Clay of the Isle of Sheppey]

Hantsia pulchra. Sseed/fruit
Brasenia ovula. Seed/fruit
Palaeobursera sp. Seed/fruit
Carpolithus cornutus. Seed/fruit
Carpolithus sp. Seed/fruit. Linnaeus, 1768


Some further brief information on plant remains at Hengistbury Head has been given by Ord (1914). He commented on fossil remains within the siderite nodules, which at that date, were visible in much greater numbers than they are at present. He said that "The ironstone concretionss contain sharks' teeth and vertebrae, both Otodus and Lamna being represented. Compressed tree-stems frequently traverse them; these are of considerable size, occasionally 5 feet in length. The bark is sometimes preserved having a black shiny appearance like coal, and the wood is usually riddled with teredo-borings [Teredina]. Fragments of lignite and vegetable debris are common and I have twice found remains of pine cones."

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Hengistbury Head - Later Fossil Discoveries

Curry (1977) in an important paper on the age of the Hengistbury Beds, reported finding new fossils. At about 13 metres above the pebble bed (probably this is a reference to the basal pebble bed, occurring just above the Boscombe Sands in a diagram above), Curry made a collection of clay moulds. He did not give the full list but reported those which had not been found by Cowper Reed or by Hooker, were therefore additional. The list of these newer discoveries follows:

Nucula cf. ampla
Mactra 2 spp.
Phorus cf. agglutinans
Euthriofusus regularis
Surculites errans
Sconsia ambigua
Athleta cf.nodusus
Akera striatella
Turris spp.

Breakdown of the clay in water yielded to Curry several species of smaller molluscs. Those discovered include

Lutetia pisiformis (Charlesworth)
Marginella pusilla Edwards
Conomitra parva (J. de C. Sowerby)
Roxania coronata (Lamarck)
Volvulella lanceolata (J. de C. Sowerby)
Crenilabium crenatum (J. de C. Sowerby)
Pteropod (free-swimming gastropod) - Skaptotion bartonense Curry

There were also pyritic internal moulds of the foraminifer Globulina.

Four of the mollusc species are especially significant for dating according to the late Dennis Curry(incidently also the former owner of Curry's stores). Venericardia sulcata (Solander), Crassatella sulcata (Solander), Sconsia ambigua and Akeria striatella are well-known from the Barton Beds but not from the Bracklesham Beds. In contrast a single mould of an umbo of Venericor planicosta was found by St. John Burton "a third way up Hengistbury Head". V. planicosta occurs throughout the Bracklesham but has never been found in the Barton Clay elsewhere. It could have been reworked, of course, particularly since there is evidence of reworking in the Boscombe Sand at Hengistbury Head (Bristow, Freshney and Penn, 1991) and there is obvious slumping in the "Upper Hengistbury Beds". It is likely that the "Hengistbury Beds" really are Lower Barton Clay Formation, but perhaps with very minor reworked Bracklesham fossils. Bristow, Freshney and Penn, 1991 discussed the matter in general and accepted the Hengistbury Beds as equivalent of part of the Lower Barton Clay taking the pebble bed at the base (after Plint 1983) as the lower boundary. This seems to be an acceptable solution.


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Fish Teeth - the Sharks' Teeth of Hengistbury Head


Stratiolamia macrota a common fossil shark's tooth of the Eocene Barton Clay at Barton-on-Sea, Highcliffe and Hengistbury Head, Hampshire and Dorset, southern England


Finding sharks' teeth washed out of the Barton Clay between Highcliffe and Barton-on-Sea, Hampshire, 24 November 2007

Tooth of the Eagle Ray - Myliobatis, washed out of the Barton Clay and found on the beach between Highcliffe and Barton-on-Sea, Hampshire


Fossil shark's teeth are common in the Barton Clay of the cliffs of Hengistbury Head, as they are in the Barton Clay of Barton and Highcliffe, further east along the coast. Mostly the teeth probably belong the species Striatolamia macrota Agassiz. This common fossil is well-known to collectors from the Barton Clay of here and at Barton and Highcliffe as "Odontaspis macrota" (a synonym). It is the most frequently found of the Palaeogene odontaspids, but, of course, not all sharks' teeth found at Hengistbury Head are necessarily of this species. The Eocene Odontaspids were probably, as at the present day, large-bodied sharks with conical snouts. The teeth were not identified in detail in the past and in the old literature they may sometimes have been referred to "Lamna elegans" which was a rather general name for fossil Eocene sharks' teeth. For more information, although largely regarding the Bracklesham Group, see the work of: Kemp (1977) and Kemp, Kemp and Ward (1990) for identifying Eocene vertebrates, particularly sharks' teeth.

About 10 metres above the pebble bed (i.e. just below band 3 ironstone nodules in the diagram above) a seam with fish teeth was found by Dennis Curry. The teeth were identified by Mr. F.C. Stinton (Fred Stinton the Eocene otolith specialist of Bournemouth). The seam yielded at least 15 species, including:

Eugalus minor (Ag.),
Physodon secundus (Winkler),
Scyliorhinus minutissimus (Winkler) [cf. Scyliorhinus canicula, the common Catshark of the coastal waters of Europe - a nocturnal fish of the continental shelves],

and also representatives of the following genera:

Odontaspis [i.e. Stratiolamia, discussed above],
Myliobatis [the combe-like teeth of this Eagle Ray, Myliobatis are very common in the Barton Clay at Barton-on-Sea, probably as numerous as the teeth of Odontaspis],
Sphyraena and

"Mr. F. C. Stinton, who kindly made the identifications, states that the assemblage can be matched in the Lower Barton Beds but that it includes no species which are exclusive either to the Bracklesham Beds or to the Barton beds. Chandler (1960) studied a series of plant remains from the Hengistbury Beds [see listing above], but these also (p. 197) yielded no definate evidence as to the age of the Hengistbury Beds" [extract from p. 402 of Curry (1977).]

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Lower Barton Clay - "Lower Hengistbury Beds" - Glauconie ['Glauconite']


[Go down to thin-section petrography]


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The lowermost part of the Lower Barton Clay, the "Lower Hengistbury Beds" (an old and informal name for the lowest part of the Barton Clay Formation here) consist of sandy clays and argillaceous (clayey) sands that contain much 'glauconite' or glauconie. Strictly speaking, 'glauconite' should be differentiated into one of three different types, dependent on clay mineral composition. The green mineral shown here has not been examined by X-ray diffraction for clay mineral composition. Professor Bale (in his great work on Barton Clay geochemistry in 1984) found that the glauconies of the Barton Clay Formation are predominantly glauconitic-mica and can be regarded as equivalent of the highly-evolved glauconies of Odin and Matter (1981). Unfortunately he did not investigate the Hengistbury Head, basal part of the Barton Clay Formation [probably still at that time, regarded as Bracklesham, below the Barton], unless it is proven to be different, expect it to be glauconitic-mica (and thus not expandible).


Glauconie or (or 'glauconite' in every day language) normally occurs in any abundance only in strata which has originated at type of relatively high, sea temperatures. The Cretaceous 'greensands' are examples of this, because the Cretaceous greenhouse type climate had unusually high temperatures. The glauconie or 'glauconite' shown here originated during part of the Eocene Optimum - a phase of temperatures several degrees above normal for the palaeolatitude (about 40 degrees north). The glauconitic sands and sandy clays of the Bracklesham and Barton Groups usually contain abundant marine molluscs. The deposits at Hengistbury Head, well above sea-level, have been decalcified so that white aragonitic and calcitic shells have been lost. However, moulds of shells are not common. They have been found by the expert on Eocene molluscs the late Professor Denis Curry (see Curry (1977)).

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Ironstone Nodules - Introduction

[version check - partial revision - 31st Dec. 2016]

Eocene ironstone nodules at Hengistbury Head, Bournemouth, Dorset, 2006

Ironstone or siderite nodules fall from the cliffs of the Upper Hengistbury Beds, Eocene, Hengistbury Head, Bournemouth, Dorset, view from helicopter, 6th July 2013

Ironstone nodules in situ and fallen at the eastern end of Hengistbury Head, Bournemouth, Dorset, 2007

Ironstone on the beach

Ironstone at southeastern end of Hengistbury cliffs in 1825

Ironstone at southeastern end of Hengistbury cliffs in January 2002

Ironstone nodules occur at several levels in the Lower Barton Clay ("Upper Hengistbury Beds") of Hengistbury Head. Fallen nodules were once common along all the coast of Hengistbury Head and some examples are shown in the left-hand photograph. Many have now been covered by beach material, because erosion is not as active as it once was, and there seems to be, for various reasons, much accumulation of beach sand. The Hengistbury Beds dip gently towards the east, that they are easily accessible at the eastern end of the head (see right-hand photograph). The southeastern coast of the head was subject to intense erosion, and originally it had little beach material other than the ironstone nodule. The central picture of 1825, "The Cliff at Christchurch Head" is from British Medical Association (1934) with notes by Druitt (1934). The later removal of ironstone from here and other parts of the headland was blamed for serious erosion problems (to be discussed separately below).

The ironstone nodules are brown (on the exterior) rather irregular concretions of siderite (FeCO 3 - ferrous carbonate), with a content of some sand and clay. They contain pebbles in some cases, and, as discussed below, fossil shell moulds and sharks teeth only rarely. A lump of the ironstone, thrown in with coke in old-fashioned boiler fire will produce an irregular lump of iron (as I tried out when I was a boy).

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Ironstone Nodules - Compaction State

As noted above (fossil section - plants), Ord (1914) comented on the compaction of tree remains in the siderite nodules. The tree stems are compressed. In contrast, shell moulds of Turritella, as shown above, do not show any severe compression. Small compression of fossils has been mentioned by other authors. Therefore the siderite nodules developed under some metres or possible tens of metres of burial, but probably not more than 100 metres. They probably originated under early burial in a similar manner to calcitic septarian nodules, which usually shown only limited, if any, compaction of shells.

Although there is no doubt that they are of quite early origin, they, after further though, have probably not originated in the Sulphate Reduction Zone (the top zone of burial diagenesis theory, the phase when sulphide minerals such as pyrite were formed). They are much more likely to have been formed in the Fermention Zone. This is the methane-rich zone that occurs after the sulphate reduction has taken place, and it is a zone in which diagenetic carbonate can be precipitated (e.g. the Kimmeridge Clay ankerites have almost certainly formed in this zone).

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Mining of the Ironstone Nodules - History and the Quarry


A helicopter view of central Hengistbury Head, Bournemouth, Dorset, with the old ironstone quarry converted to a pond, 6th July 2013


The old ironstone quarry in the centre of Hengistbury Head, Bournemouth, Dorset, now flooded and forming an acidic pond


The southern part of the quarry pond in the centre of Hengistbury Head, Bournemouth, Dorset, seen with colourful vegetation in September 2013


Nodules of ironstone or siderite placed at the dam of the quarry pond, Hengistbury Head, Bournemouth, Dorset, September 2013


A 1939 topographic map of the central quarry and adjacent area of Hengistbury Head, Bournemouth, Dorset, with some additional notes


The old clay tips of the ironstone quarry in the centre of Hengistbury Head, Bournemouth, Dorset, looking southeast, at the southeastern end - tips now vegetated, 2013


In about the middle of the 19th century, the Hengistbury Ironstone nodules were being investigated for use as a source of iron and then quarried quite extensively. The following notes come from the comments of Alfred Tylor, Esq. F.G.S. in 1850:

"Having lately had an opportunity of paying a visit to Hengistbury Head, I was much interested in finding that these blocks have been found to contain so large a percentage of iron as to be available for economic purposes. As productive iron ores have not previously been known to occur in the English tertiaries, I have thought the fact of sufficient interest to be laid before the Geological Society.

Mr. Holloway, of Christchurch, who has undertaken these works informs me that the occurrence of large masses containing iron in these cliffs appears to have been discovered in the reign of Charles II., during a survey of the adjoining harbour of Christchurch. The king was recommended to establish iron-works here for the purpose of founding cannon; the ore was to be obtained from the shore, and the charcoal from the neighbouring New Forest; this scheme, however, was not carried out. Within the last three years Mr. Holloway sent specimens to South Wales for examination. The first impression of the of the ironmasters was unfavourable; for although, from the oxidation of the iron, the Septaria presented externally a highly ferruginous crust, yet when the mass was broken, the grey and earthy fracture more resembled ordinary compact limestone; and further the constant occurrence of fragments of carbonized wood presented an appearance to which they were not accustomed. Mr. Holloway, however, informed me that these blocks were found to contain about thirty per cent. of iron, and that moreover, vegetable matter was present in sufficient quantity to facilitate the reduction of the ore. Many hundreds of tons of Septaria have been shipped to the iron works in South Wales; and the works have already attained sufficient importance to induce the proprietor to lay down more than a mile of tram-way, leading along the base of the cliffs to the ancient but almost deserted haven of Christchurch..."

Mr Holloway's investigations led to the formation in the middle of the 19th century of the Hengistbury Mining Company. The ironstone was broken up placed and in barges and towed by steamer to Southampton. From here it was taken by colliers on their return voyage to Wales (Druitt, 1934). The exporting of ironstone was balanced by the importing of coal, the original business of John Edward Holloway, and it effectively dealt with the problem of balasting the barges in addition to making money. The removal of ironstone continued from the 1840s for a further 23 years. In 1847 Holloway applied to Sir George Gervis, the Lord of the Manor, for a lease to remove the doggers. The lease was granted the following year and the accessible stone began to be removed, being transferred from the beach to the loading place, probably near the lime kiln, by cart (Powell, 1995).

In 1849 the Hengistbury Head Mining Company was registered in the names of Samuel Homfray and Mary Ann Davies of South Wales. Within two or three years a tramway was built to transport the stone to the landing. Powell comments that by 1852 most of the loose material and that which could be won from the reef at low water had been removed. Mining then commenced into the base of the cliffs. This began to affect the erosion of the Head and the form of the Run and associated sand spit (this will be discussed in more detail separately). The southern sand bank extended northwards, overlapping the northern and diverting the rivers around the eastern side of Mudeford Spit. Within six years Hengistbury Head had so reduced in size that the Old Harry Rocks, off the Isle of Purbeck, were now visible from previously sheltered anchorages in Christchurch Bay. This concerned the Admiralty. There was also much local protest about the removal of what was considered as a valuable protection from coast erosion, especially by James Druitt, 1816-1904, Town Clark of Christchurch. Contemporaries took to calling the low-lying, Valley Gravel cliff between Warren Hill and Southbourne along by White Pit etc, "Druitt's Deluge". After much dispute, eventually the removal of ironstone from below high water line was stopped in 1856. There was also an unsuccessful prosecution for "malicious trespass" and taking away ironstone.

Rather than the coast the plateau of the Head now began to be quarried away. See (Powell, 1995) for details. The shape of Hengistbury Head was modified appreciably and many familiar features now are the result of this. The sandy western scarp at the hill top is one. The "Batters", ridges which fringe the hill on the north side are of quarry spoil. More was tipped over the west end of the Head and the old tips are now being eroded by the sea (notice the sloping debris in them). The work was done by carts and tramways, with horses being watered at the Lily Pond which was made for this purpose. At a later stage in the industry blasting was used, resulting in some horrific accidents. Holloway's Dock was built and the ironstone came down an inclined plane direct to the quayside (Powell, 1995). Work finally stopped in 1870.

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Thin-section Petrography

Introduction: Only a few slides (thin-sections) of Hengistbury Ironstone have been examined and only a few are shown here. The history of the some of the thin-sections is not known. They have been in a collection for many years. Most contain some glauconie (i.e. "glauconite" in common language, but not differentiated into its specific types). In other slides the green mineral is scattered and seen as isolated grains just here and there. The "glauconite" is a particular characteristic of Hengistbury Ironstone, but it could occur in any ironstone within the marine Barton Clay Formation. It would not be expected in the non-marine Headon Hill Formation above, but I cannot be sure because no detailed investigation of these higher siderites has been made.

A complication is that ironstone nodules in different beds at Hengistbury Head may be different, and it is not known from which beds the particular slides were made. There are at least three levels of siderite nodules and the mineralogy (and presence or absence of glauconie) of these beds has not been studied in detail.

1. Another thin section of Hengistbury Head siderite with much fine quartz sand, by Ian West, slide IMW S12, wide slide



Hengistbury ironstone, or siderite, seen in thin-section, introductory photomicrograph by Ian West



A sample of Hengistbury Head ironstone, or siderite, seen in thin-section, medium magnification, with much, well-sorted quartz sand, but no obvious glauconite, introductory photomicrograph by Ian West



An unusual specimen of Hengistbury ironstone with very large glauconie or glauconite grains, theoretically incompatible, with the fine quartz silt, in sideritic ironstone of Hengistbury Head, Bournemouth, Dorset, thin-section preparation and photomicrography by Peter J. Bath


5. A thin-section view of large and irregular glauconie or glauconite grains, not only theoretically incompatible in energy terms with the fine quartz silt, but partly of large, anomalous morphology in ironstone of Hengistbury Head, Bournemouth, Dorset, thin-section preparation and photomicrography by Peter J. Bath. Corrected version of image, 31 Dec. 2016, imw


6. Glauconie or glauconite in fallen debris from the green basal part of the Lower Barton Clay, the

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Notes on the Thin-section Petrography


It might be useful if the main petrographic features of the Hengistbury Head Ironstone or siderite nodules could be summarised. That would mean that archaeologists or other looking for ironstone transported to kilns or elsewhere might have some guidance as to whether the material was from Hengistbury Head or elsewhere. Here are some of the main points regarding the Hengistbury Head Ironstone. Note, however, that different beds are likely to be very different in proportions of components such as sand and clay and "glauconite". Furthermore the petrographic observations are only based on about seven thin sections, so this is rather limited as seen from a statistical viewpoint. The thin sections, though, have not been made at the same date or by the same people. They come from collections of Ian West and Peter Bath. A more thorough study of new material would be very useful. There follow the limited conclusions based on these slides.

1. Siderite: The siderite (ferrous carbonate) is in very small crystals. Much of it is seen to consist largely of equigranular, equant, microsparite siderite crystals, each of about 15 to 18 microns., fairly uniform in size. They may be similar to those figured by Curry, Hodson and West (1968) from Bracklesham strata of the Fawley Power Site in Southampton Water (fig. 5 on p. 193, and drawn by Ian West). A new detailed study is needed. The siderite may almost colourless in the central part of unweathered ironstone nodules but very brown and oxidised on the periphery.

2. Fine Sand: Much fine sand occurs in the siderite nodules. It is well-sorted, fine-grained quartz sand of about 70 microns diameter, i.e. just above silt size. In some cases this may form perhaps 30 percent or so of the thin-section material. There are patches within the nodules that are almost free of quartz sand. Some of the fine sand is in a patchy distribution as a result of bioturbation. The sand grains are generally matrix-supported and their even distribution in the siderite suggests that they have been moved from a grain-supported fabric to a matrix-supported fabric by the growth and displacement of the siderite. In general an abundance of fine quartz sand is a distinctive feature of much of the Hengistbury Head ironstone. This would have not been good with regard to reducing the siderite nodules to iron. There would have been much unwanted silica. Dr. Frank Greens tells me that in the old type of kilns this silica would melt to form molten glass floating above the iron. In general, the Hengistbury siderite seems to be relatively impure with a high silica content.

3. "Glauconite": A distinguishing feature of Hengistbury Head ironstone, is that it almost all seems to contain the green, iron silicate - glauconie (commonly referred to as "glauconite", but detailed studies recognise that there is more than one variety of this mineral. The particular type of the Hengistbury Head glauconie has not been established, as far as the present author is aware. In many cases the glauconite grains are of approximately the same particle size as the quartz and consist of the usual microcrystalline glauconite. However, as shown in some photomicrographs above, some "glauconite" is present that much coarser than the fine quartz sand. In the thin-sections examined it is not oxidised and thoroughly green rather than brown. A particularly interesting feature is the development of fibro-radiating siderite crystals around the glauconite grains. This does not occur around the quartz grains. There is some partial replacement of glauconite by siderite and, as a result, the glauconite is not as rounded as is normally the case and has rather irregular boundaries.

5. Muscovite: A small proportion of muscovite is present and around this, too, fibro-radiating siderite has been seen.

6. Plant Material - Lignite. There is some plant material in the siderite and again fibro-radiating siderite has been seen on a small specimen of a carbonised twig fragment.

7. Pyrite. (iron sulphide). Some patches of fairly fine-grained pyrite are present and there are some small dark folia, rusting a little, and these may be small flat pieces of plant debris with pyrite. This is, as is well-known, a very early product of reducing conditions in the reduced sediment shortly after deposition. It has probably formed below the level at which the early sandy clay can be disturbed (and therefore oxidised) by wave action. It may have formed from a few centimentres down to about a metre, immediately after sedimentation. It is normal in the Eocene marine sediments of the area, and occurs in unusually large quantities in the underlying Eocene strata of Bournemouth and Poole Harbour (see asociated webpages on Brownsea Island, Sandbanks and Bournemouth). It it the reason for the "Mynes" of Parkstone and Browsea Island and was once of considerable economic importance as a source of Alum (at Alum Chine and Alum Bay in the Isle of Wight). It is not important at Hengistbury Head, and is as is usual in marine sediments, just a minor, dispersed constituent. The crystals of this apparently black, opaque mineral are very small and are common features not of any special significance.

However, having the mentioned the familiar circumstances of pyrite in the Bournemouth region, it should be noted that its occurrence in siderited nodules does tell a diagenetic story. Obviously pyrite, the sulphide and siderite, the carbonate, cannot form at the same time.

ADD DIAGRAM [in preparation] 6. Nodule expansion (Todd, 1913) is, of course, normal in septarian nodules, and some of the ironstone shows septarian features. However most of the nodules are not conspicuously as septarian, as are the calcitic nodules, higher in the Barton Clay Formation at Highcliffe and Barton-on-Sea.

-------------- [old sections follows - new text is above [below to re-organsised and moved up]

Some parts of the nodules are almost free of quartz sand and consist of fairly uniform, slightly brownish, microsparite siderite. In the more common sandy parts there are occasional small burrows occupied by sand-free siderite. The overall colours of the thin-sections vary according to the extent of oxidation of the siderite. Most are brownish-grey but the exterior oxidised parts of the nodules are very brown, both in the hand-specimen and in thin-section. Amongst heavy minerals pleochroic tourmaline grains have been seen in thin-section. A sphere of chalcedony, a little larger than the quartz grains was seen in one slide.

The thin-sections do not show any abundance of fossils, but may contain evidence of bioturbation. They appear almost unfossiliferous, unlike for example, the calcitic septaria of the Middle Barton Beds. A few rare examples of poorly preserved miolinid foraminifera have been seen in thin-section.

In making comparisons it should be borne in mind that there may be some nodules at Hengistbury Head that differ in their petrography to some extent. Siderite from other horizons in the region, such as for example in the Headon Hill Formation of the Solent Group, has not been studied for comparison. This is likely to have a fossil content though that would be easily recognised as different. In general, using the descriptive details given above, it is quite likely that Hengistbury siderite could be recognised easily in a thin-section of an isolated or transported specimen (eg. archaeological material).


An ironstone specimen from Sowley Pond, an old iron-working site in the southern part of the New Forest is very similar. It differs significantly only in being highly oxidised and brown, with the glauconite destroyed. There is little doubt that it is piece of Hengistbury ironstone transported here for iron production.

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Warren Hill Sand (Eocene)

Exposure of the Warren Hill Sand, Eocene, northwest of the Coastguard Hut, Warren Hill, Hengistbury Head, Bournemouth, Dorset, November 2008

Above the glauconitic clays of the Hengistbury Beds in the cliff section at Warren Hill, Hengistbury Head, there are 10 metres of very fine grained, buff and yellow, unfossiliferous, cross-bedded sands. They are overlain by the Pleistocene river gravel (Bristow, Freshney and Penn, 1991). The sands were first noted by Sir Charles Lyell (1827). In 1879 Gardner referred them to the Highcliff Sands, because they were thought to be the equivalent of the Sands at Friar Cliff, Highcliffe, which underlie the Barton Clay. The dip of the strata at Hengistbury Head is such that they appear to correspond in structural terms with that unit. However, much more recently, Curry (1977) correlated the Hengistbury Beds with the Barton Clay, as mentioned above. If that correlation is correct (and the faunal evidence is quite good) then these sands correspond to the uppermost part of the Lower Barton Clay and to almost all of the Middle Barton Clay (the well-known, fossiliferous Barton Clay). These sands were then renamed the Warren Hill Sand by Freshney et al. (1984, p.46).

Now a fault has been recognised as running through Christchurch Harbour (Bristow, Freshney and Penn, 1991), and some penecontemporaneous movement (possible in Bartonian times) might have caused changes in lithology on either side of it. However, it remains, to say the least, rather surprising that the fossiliferous, gastropod-bearing Barton Clay of Barton and Highcliffe is apparently replaced here by a yellow sand with burrowing bivalves such as Pinna, Solen and Panopea Curry (1977). If these are lateral equivalents then the sand is the shallower facies from the near the lower intertidal zone.

Looking down on flying Sand Martins, Riparia riparia, which live in holes in the Warren Hill Sands, Hengistbury Head, Bournemouth, Dorset, 27th June 2010

The Warren Hill Sands at the upper part of the cliff near the Coastguard lookout contain holes made by Sand Martins, Riparia riparia. The photograph shows these flying around near their burrows in the hot weather of June, 2010. They were seen from above, but the cliff edge is not safe enough or stable enough to be approached in this area.

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Pleistocene Gravels

Low-level Pleistocene gravel between Southbourne and Hengistbury Head, Bournemouth, Dorset

Between Southbourne and Hengistbury Head is a low-level gravel terrace. The base of this is a little above high-water level, in other words the top of the beach. Mostly tbe base cannot be seen because of beach sand but occaionally there is some limited exposure of Boscombe Sands. At the top of the gravel is brown brickearth, a type silt. Over this is some Holocene, i.e. modern blown sand and soil.

This particular terrace is the Pennington gravel terrace according to Allen and Gibbard (1993) . This is not absolutely certain, however, and therefore one should be cautious about equating it with the pre-Ipswichian, i.e. late Wolstonian gravel at Pennington, near Lymington. It is obviously quite near the Ipswichian Interglacial level, but it has to be noted that gravels occur both above and below Ipswichian Interglacial deposits at Pennington and at Lepe Beach. See also Bridgland for discussion of these Wessex Basin gravels.

As shown in the photograph above there are interesting cryoturbation effects [effect of freezing and thawing in the active zone of a periglacial environment] at the top. These are well-developed in other gravels as at Lepe Beach.

There are two higher gravel terraces on Hengistbury. The highest is under the coastguard building. There is a slope down to east to a slightly lower gravel which seems to be the Bransgore Gravel of Allen and Gibbard (1993) . This fringes the valley of the River Avon and to a lesser extent the valley of the Stour.

(further discussion will be added later)

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Late Pleistocene History - Palaeovalleys

The Pleistocene palaeovalleys made by rivers flowing across Poole Bay and Christchurch Bay, English Channel, modified after Velegrakis et al. 1999


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Coast of Solent Meads - Low Gravel Terrace

Newspaper report -fears of Hengistbury Head, Bournemouth, becoming an island

Low gravel cliff west of the Double Dykes, Hengistbury Head, Bournemouth, Dorset, February 2007

Low ground at the Double Dykes, Hengistbury Head, Bournemouth, Dorset, with gravel-filled gabions as protection against storms, view eastward

Gabions used for protection of the southern end of the Double Dykes, Hengistbury Head, Bournemouth, Dorset, view towards Bournemouth and the west

Low gabion sea defences just east of the Double Dykes, Hengistbury Head, Bournemouth, Dorset

The low gravel terrace coast near the southern end of the Double Dykes ,Hengistbury Head, Bournemouth, Dorset - notice the gabion sea defences, the rock armour groynes and the offshore bar, aerial photo 2005 courtesy of the Channel Coastal Observatory

The stretch of low gravel cliffs, only a few metres high between Southbourne and Hengistbury Head is of interest with regard to coastal erosion or sea flooding. It is the first low stretch of any length east of Sandbanks and therefore of interest with regard to global warming and rising sea-level. This Hengistbury Head to Southbourne stretch is more exposed to severe action by southwesterly waves than is relatively sheltered Sandbanks. However, this coast is fairly robust, consisting of firm Pleistocene flint gravel over Eocene sand and clay bedrock. It has retreated regularly but not dramatically and over the years there has been loss of the southern end of the Double Dykes. The hinterland consists of former agricultural fields now used for recreation and as nature reserves. Buildings are predominantly on slightly higher ground or away from the coast, and this is mostly an open area of public park.

Archaeological monuments here are important, though, and any major coast erosion would be serious because of proximity to Christchurch Harbour to the north. There is no marked embayment at present at this area of low ground so there is no reason to be concerned that any drastic erosion is taking place now. With the problem of rising sea-levels, and the prospect of the eventual return of the very rare, long return period hurricane, the distant future deserves some less optimistic consideration.

There has long been fear of the sea breaking through the low ground of Solent Meads between Hengistbury Head and the high ground of Southbourne. It was discussed in a local newspaper article, above, in 1977. According to a television report it came up for discussion again in 2007 in a meeting between local residents and the council authorities. It will no doubt be discussed again and again, but there is now a new aspect to it, that of global warming and sea-level rise.

Thus it is not surprising that when Few, Brown and Tomkins (2004) referred to this low area at Hengistbury Head they briefly mentioned:
"the possibility of a catastrophic breach .. across the low-lying portion of Hengistbury Head...".

However, it is not a very likely event in the short term and the coast is not deeply indented here. There is no obvious evidence of break-though beginning at the moment. The chance much increases over a long interval of time, particularly if there is a rise in sea-level and the occurrence of many severe storms.

Although an erosional breach north to Christchurch Harbour is unlikely in the short term, washover by storms causing flooding over the area could occur. In places, particularly just east of the Double Dykes the top surface is only about 1.5 metres above high-tide level. Much of the ground is probably at about 2 to 2.5 metres. This is within the range of storm surge added to high tide.

A severe hurricane could cause both high waves and a large surge of sea-level (like that which occurred in 1824). A great English Channel sea flood could easily overtop the low cliff and sea defences here so that seawater could wash northward towards Christchurch Harbour. The type of extreme hurricane that could cause such damage would probably be one centred just south of the coast; such intense storms in the appropriate place are obviously very rare. The 1824 event caused most flooding and fatalities in the Portland and Weymouth area. The return period for such a major Katrina-type hurricane is probably of the order of 250 years and perhaps even more. Obviously it is not known when such an event will occur. It is possible that a lesser storm might overwash the very low cliff and produce a northward flood effect.

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Low Coast at Hengistbury and Future Rise in Sea-Level

Future sea level rise estimates for the Wessex coast

The table here is from IPCC. It provides an indication of possible rates of sea level rise over the next hundred years. Something like half a metre of relative sea level rise seems probable in this region, but the real figure could be higher. There is some local downwarping resulting from isostatic rebound (melting of the ice in the north, with uplift in northern UK, and downwarping in the south). This increases the relative rate of sea level rise in the local area.

Such a rise in relative sea-level here would reduce the minimum cliff height to little more than a metre in places (and little more than half a metre at the gabions). In these circumstances the risk of overwashing of the cliff and the flooding of the meadows by seawater becomes very high.

The effect of relative sea level rise in the Hengistbury area is almost certain to increase the rate of erosion. The extent of erosion may depend on the survival or not of the Bournemouth sea defences over the next hundred years (a previous seawall and promenade at Southbourne has been destroyed). There is quite a good supply of sand to west of Double Dykes at present, but it diminishes there. The natural sediment supply in the Hengistbury Head area is partly from the local cliffs there and partly from the cliffs of Bournemouth. Sand and gravel travel from west to east by longshore drift in natural circumstances. The supply from the west could be re-established if the Bournemouth cliffs of sand, clay and gravel were being eroded again. This would reduce the erosion rate at Hengistbury Head but it would be unlikely to be welcomed at central Bournemouth. It is not known, of course, whether the Bournemouth sea walls would hold or whether they would be damaged and rebuilt or just abandoned. There are too many unknowns to predict what would happen at Hengistbury Head with sea-level rise and erosion. Probably the protection of built up coastline in the region, and especially low-lying, built-up coastline (Weymouth, Sandbanks, Selsey Bill etc), would be the priority. Cost factors might not necessarily allow everything appropriate to be done.

New sea defences in the stretch between Southbourne and Hengistbury Head have been requested by local residents, according to a media report. However, it should be noted that additional sea defences are not necessarily an answer to the potential problem of erosion and overwashing between Hengistbury Head and Southbourne. Hard sea defences can increase erosion on the eastern downdrift side as is seen at Naish Farm, Highcliffe and Becton Bunny, Barton. Hard sea defences in this stretch near the Double Dykes could increase coast erosion at Hengistbury Head, eventually affecting the coast of Christchurch Bay (Hurst Spit has had to be rebuilt artificially because of shortage of beach material due to the Milford-on-Sea sea defences). If a sea wall is raised high above the ground behind and then seawater overtops flooding can be more serious because the water cannot escape back to the sea quickly (this it the type of situation that occurs behind the high Chesil Beach at Chiswell, Portland). The matter is far from simple!

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Erosion at Hengistbury Head

Hengistbury Head, Bournemouth, Dorset shown from the west in an old and modern photograph illustrating the extent of coast erosion

An old photograph of Hengistbury Head, Bournemouth, Dorset, pre-1947 but date unknown

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Beach Processes and the Long Groyne


Looking down to the pebble accumulation at the eastern part of the beach at Hengistbury Head, Bournemouth, Dorset, 5th September 2013


Beach sand accumulation at the Long Groyne, Hengistbury Head, Bournemouth, Dorset, 2010


1939-1940 map of eastern Hengistbury

Groyne at southeastern end of Hengistbury - old photo

Groyne at southeastern end of Hengistbury - January 2002

For a general discussion of sea defences, coastal management and the problems of the area in the future with rising sea level see the important review paper of Few, Brown and Tompkins (2004); Scaling Adaption: Climate Change Response and Coastal Management in the UK. This is available online. It has been produced by the Tyndall Centre for Climate Change Research. There is much on the future of Christchurch Bay, Christchurch Harbour, Mudeford Spit and Hengistbury Head etc.

Hengistbury Head is fortunate in that the Long Groynes at the end of the Head is a holding point for beach sand drifting from west to east, the normal long shore drift direction here. Periodically the holiday resort of Bournemouth has dredged sand added to its beach as a replenishment or renourishment process. Some of this beach sand stays in the Bournemouth area for some time. However, with the prevailing longshore drift from about Bournemouth Pier in an eastward direction, much of this sand progressively makes its way towards Southbourne and then Hengistbury Head. The beach at these place is noticeably wider than in the past, and they are inevitably the longer term beneficiaries of the Bournemouth replenishment. Of course the matter is not simple and some sand remains for some time in the Bournemouth area and probably some even moves westward to Sandbanks. However the benefit at Hengistbury Head is obvious and there has much build-up just to the west of the Long Groyne. New sand dunes are developing.

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Hengistbury Site of Special Scientific Interest (Christchurch Harbour SSSI)

English Nature have provided an SSSI (Site of Special Scientific Interest) citation for Hengistbury Head, as part of the Christchurch Harbour area. This has been summarised by Bray and Hooke (1998b), from which the following section is an extract.

" Description and Reasons for Notification of Site.

Then site comprises the drowned estuary of the Rivers Stour and Avon and the peninsula of Hengistbury Head. The varied habitats include saltmarsh, wet meadows, drier grassland, heath, sand dune, woodland and scrub, and the site is of great ornithological interest. Hengistbury is a stratigraphically important bridging exposure linking the Tertiary formations outcropping around Poole and Christchurch Bays. It will also provide an important comparative locality in the eventual correlation of the Eocene sediments of St. Catherines Hill. The Boscombe Sands, exposed at the base of the cliff are important not only in the environmental and geographical reconstruction of very late Auversian (Upper Bracklesham) time, but also contain a unique type of bituminous sand. The upper part of the cliff exposes an unusual 'marginal' variety of the Barton Beds.

In addition, the site is designated for its flora and fauna, outlined in the SSSI citation and notification.

Principles of Conservation

The principle of conservation for the site is to maintain representative sections through the strata currently exposed in the cliff face for further research. There should be regular monitoring of the site to ensure that its present condition is maintained. In particular the section should be observed for unauthorized coastal protection measures, the establishment of vegetation or slumped material at the cliff base over large sections of the site and vegetation obscuring sections of the upper cliff. Access to the site should be maintained.

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INDUSTRY continued:


Possible future production from the Beacon Oilfield south of Hengistbury Head?


Oil and gas prospects, and fracking possibilities, of Poole and Christchurch Bay and surrounds, Bournemouth, Dorset area, south of England - map


The offshore Beacon Oilfield, near  Hengistbury Head, Poole Bay, Bournemouth, Dorset and problems of producing the oil


Because it was once a major location ironstone quarry, much of Hengistbury Head is a former industrial area, a type of "Brownfield Site". Its main use now is, of course, largely for conservation and recreational purposes. However, although the quarrying has long since ceased, the place has entirely not lost its economic potential.

A potentially important oilfield, a structure of the Sherwood Sandstone lies to the south of Hengistbury Head (and Southbourne). This is the Beacon Field. It is effectively a separate but similar field to the Sherwood Reservoir that has worked for many years from Wytch Farm south of Poole Harbour. The Beacon Field is within a special licence block of Penenco UK who own the Wytch Farm Oilfield (held by BP until 2011). Perenco have recently received planning permission for work at Wytch Farm until the year 2037. The main oilfields of Wytch Farm may have been almost emptied by then. Produduction from the main Sherwood Reservoir has already fallen from a peak of about 100 thousand barrels a day down to 17 thousand barrels a day.

It is unlikely that Hengistbury Head could be used as an onshore well-site for extended reach drilling to the nearby, potential, new offshore oilfield in the English Channel. Hengistbury Head is too special a special place of natural, historical and archaeological interest in addition to being an important reacreational park of Bournemouth. It would seem unlikely that this would really happen.

Extended Reach Drilling (ERD or horizontal drilling) has been used for upto about 10.5 km in Poole Bay. Elsewhere in the world now there are plans for horizontal drilling upto 15 km. The map above shows that a 15 km horizontal borehole from the Wytch Farm ERD site M on Goathorn Peninsula could probably access the structure, a potential oilfield. This would avoid the complications of trying to find a drilling site closer to the structure.

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Mudeford Spit (Mudeford Sandbank)- General

The northern end of Mudeford Spit, with the Black House, as seen with a zoom lens from the top of Warren Hill, Hengistbury Head, Bournemouth, Dorset, June 2010

Old aerial photo of Hengistbury Head, showing Mudeford Spit

Mudeford Spit and Mudeford Quay as seen in an arial photograph from about 1960

A view of Mudeford Spit from Hengistbury Head, Bournemouth, Dorset, at low tide in September 2005

Lines of wooden huts, some on stilts, on a very low barrier beach, Mudeford Spit, Hengistbury Head, Bournemouth, Dorset

Mudeford Spit, Hengistbury Head, Bournemouth, Dorset, an aerial view of the Hengistbury end

Composite aerial photograph of the end of Mudeford Spit, and of Mudeford Quay and the Run, Hengistbury Head, Bournemouth, Dorset, courtesy of Channel Coastal Observatory, 2001

Black House at the northern end of Mudeford Spit, a sand spit projecting northward from Hengistbury Head, Bournemouth, Dorset; seen from across the Run

Mudeford Spit is the sand spit extending northward from Hengistbury Head and partially blocking the entrance to Christchurch Harbour. The waters from the rivers Avon and Stour and tidal water from Christchurch Harbour flow out via the Run, which the narrow channel at the end of the sand spit.

The spit largely consists of sand, especially on the seaward (southeast) side with some gravel on the shore on the Christchurch Harbour side. It has some sand dunes which are better developed towards the distal end. These were originally higher and been trampled and damaged. Some Marram Grass grows on these. Much of the spit is covered with beach huts. These are usually raised on timber posts or platforms to reduce problems of flooding. Sheltered from the southwesterly winds and waves by Hengistbury Head, they seem to withstand the usual storms quite easily. Fortunately, they have not yet had to encounter the 1 in 250 year type of storm. In 1824 the sea rose several metres in a storm surge associated with a hurricane and parts of Christchurch were flooded. The spit, relatively free from buildings at that date, survived this, although possibly with a much widened Run (more information is given below in the section on historic records). At the northern end of the spit is the Black House, a conspicuous old brick building covered in tar.

Access to Mudeford Spit is easy, even in winter, with frequent motor ferry from Mudeford Quay and road trains from the car park at the western end of Hengistbury Head. It is much more heavily used by visitors now, even in winter, than when I knew it 50 years ago. At that time there was no road train and the ferry was a small, open, wooden boat that could not always cross the Run easily in a strong ebb current. It was a rather more remote place at that time.


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Mudeford Spit - Erosion and Sea Defences

The relatively natural sandy end of Mudeford Spit, Hengistbury Head, Bournemouth, Dorset

A sea wall preventing loss of sand and gravel near the Black House, Mudeford Spit, Hengistbury Head, Bournemouth, Dorset

A scour area near the Black House, Mudeford Spit, Hengistbury Head, Bournemouth, Dorset

Mudeford Spit is sheltered by Hengistbury Head and does not face major storm waves of long fetch arriving from the southwest. Waves coming from the southeast are to some extent limited in size because of a small fetch; there is protection by the Isle of Wight. Its protection depends on the headland and its sand supply has always come round the head. However, it is now sediment starved because of the Long Groyne at Hengistbury Head and a more recent range of rock armour groynes. It will, of course, continue to lose sand and there is no natural resupply now.

Obviously this is a spit which without further intervention should decline and reduce to a small sea-washed sandbar in a few decades. However, there is a 50 year plan for its survival. Few, Brown and Tomkins (2004) in an astute viewpoint and well-referenced paper have summarised the situation:

"The Poole and Christchurch Bays Shoreline Management Plan,... recommends a continuation of 'hold the line' defences for Mudeford Sandbank, a low-lying spit across the entrance of Christchurch Harbour (Halcrow Group, 1999). The presence of the spit reduces wave attack in the harbour and attenuates tidal range by narrowing the harbour entrance (Christchurch Borough Council, 1997). Christchurch Borough Council decided to upgrade the defences, opting for a set of new rock groynes and a rolling programme of beach nourishment. The scheme is intended to cope with changing conditions over its design life of 50 years....

Christchurch Harbour might seem well defended at its mouth, but agency and local level officials expressed concern about the potentially severe impacts of combined river/tidal flood events on Christchurch town, the prospect of sea level rise disrupting urban drainage systems, and the possibility of a catastrophic breach to the south across the low-lying portion of Hengistbury Head. Mudeford Sandbank itself has been vulnerable to past breaching during high seas, which caused extensive flooding around the harbour (Christchurch Borough Council, 1997). Engineers interviewed predicted that natural or artificial sedimentation processes will enable the sandbank to maintain its height vis-a-vis a rising sea level, but pointed out that this assumption depends heavily on the assumption that present beach recharge will continue along the beaches further to the west."

This is probably a good general assessment of the situation. As you may have noticed, there is, however, some concern about the eventual recurrence of an 1824 (Hurricane Katrina - type) "Great Gale" which may affect much of the low ground just above sea-level in the region. Consider also that there is a need of financial support for the continuation of any future sea defence work. That funding could be affected by a major recession or a different fashion or political viewpoint. A possible problem is that there might be need at some future date to divert funding to the vulnerable and low parts of the east coast of England which may be more seriously affected by rising sea-level.

Of course, in geological terms of millions of years a sand spit is a temporary feature that is extremely mobile. It will move back inland as the coast recedes and vary in length, width and details from time to time. Like Christchurch Bay in general Mudeford Spit will race inland at the high velocity of about one kilometre every two thousand years or so (or even more with global warming!). This rate of retreat is quite abnormal in geological terms but has happened at intervals during the last few million years because of glacio-eustasy (melting of ice and warming and expanding of seas).

However, note that this an average rate of average rate under consideration. For very short intervals of time such as one or two hundred years or maybe a thousand years nothing much may happen. Unfortunately, this can suggest to some people that present coast is a permanent feature. Indeed, at the time of writing (2007) Mudeford Spit appears very stable and there is almost no sign of drastic change. It is well protected by rock armour and has adequate sand and shingle. It is very suitable for public enjoyment.

However, it is not permanently stable. A 1 in 50 year storm event will happen sooner or later but it might not produce very serious damage. The 1 in 200 or 250 year event also certainly will. One day, the next "Great Gale" (as of November 1824) will arrive and it will change Mudeford Spit (and other coastal areas) quite drastically by high storm-surge flooding, probably all within 12 hours. Later the spit may stabilise again, but if it does it will be further inland. It will look much the same but it will not be in exactly the same place. The hurricane event may not happen this year, it may not happen in your lifetime, but one day or night the great storm will come. It is obviously sensible to expect it and plan for it.

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Mudeford Quay (Haven Houses)

An aerial view of the Run, the outflow channel of Christchurch Harbour, and of Mudeford Quay, Dorset

Mudeford Quay with a sturdy sea wall against the Run and swans and crab-fishing, Mudeford, Christchurch Dorset, England

High tide at the car park, near the Haven House, Mudeford, Hampshire

Waves break on the submerged sand bar that is a continuation of Mudeford Spit, near Hengistbury Head, Bournemouth, Dorset

The north side of Mudeford Quay or Haven Houses, with Christchurch Harbour near flood level

On the north side of the entrance to Christchurch Harbour, the Run, there is a shorter sand and gravel spit, Mudeford Quay, now mostly, but not entirely, covered with concrete and tarmac. Here is the Haven House Inn, a car park, a cafe, a fish shop and a few other buildings. It is a centre for sailing activities.

This smaller peninsula is an interesting place because much of it is only a short distance above high tide level. The original sand and gravel spit would have been a consequence of currents, wave action and long-shore drift and its top would have been at the upper limit of normal wave action (unless having an addition of blown sand). The sea-wall, concrete and tarmac has "petrified" this spit, at some time in the past, perhaps in the 1940s. It receives no natural addition of sand or gravel, and remains as a marker of safe ground in relation to a past sea-level. It is thus good for the observation of the general sea level rise in the region and any further increased rate resulting from global warming.

The general rate of sea-level rise during the last few thousand years has been between 1 and 2 mm per annum. This is shown by dated estuarine deposits at Fawley at the southern end of Southampton Water (Hodson and West, 1972). Later studies have shown that it has been rising at the increased rate of about 3 to 4 mm per annum since the 1940s. It will flood, of course, at high tide within about 100 years. However, this is not the current risk; more serious is a return of the 1824-type hurricane which caused a storm surge in the central to western English Channel. Such a hurricane (like Hurricane Katrina) can raise sea-level by 2 or 3 metres above high tide level, but fortunately this is so rare that it has not happened since 1824 (for more on the effects of this storm, which flooded Christchurch see Chesil Beach and English Channel Storms Webpage). The average return period is not known, but such a storm is something like a 1 in 250 year or 300 year event, and, of course, it will happen again sooner or later.

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The Run

The Run at Mudeford, as seen in 2005 from near Gundimore, Dorset

Ferry crossing the Run between Mudeford Spit and Mudeford Quay, near Hengistbury Head, Bournemouth, Dorset

Outflow of muddy, brown river water through the Run and into the sea at Mudeford, Christchurch, Dorset, 26 July 2007

Swans sheltering from a summer gale on the southeastern bank of the Run, at Mudeford Spit near Hengistbury Head, Bournemouth, Dorset, July 2007

The Burton diagrammatic map of Mudeford Spit and the Run, showing the location of the lagoon in 1931, near Hengistbury Head, Bournemouth, Dorset

Steamer Point, near Mudeford,  Dorset - information regarding the steamer

The Run is the outflow channel from Christchurch Harbour, carrying the waters of the Avon and Stour and tidal water. It seems to have remained fairly stable in terms of position in recent years flowing out to sea over a submerged sand bar near the well-know, former residence of poets - Gundimore. In the past, though, Mudeford Spit (that is the Hengistbury side) has extended much further towards the northeast, having gone beyond Steamer Lodge to Cliff End. It has almost approached Highcliffe Castle. From time to time the extension has been breached, somewhere near the present termination. The remains of the channel have become a temporary lagoon. A good record of events, from the study of old maps and other records, has been given by the late Mr St.John Burton (1931) of Barton. Some aspects of his records are summarised here, but it is recommended that you read his paper in full, because there are many interesting points regarding the history of Mudeford Spit, the Run and Mudeford Quay.

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The Run - History - Changes in Position

The Run is interesting because although it is usually northeast of the Black House and the present position of Mudeford Spit, it changes from time to time. For some years it may extend much further to the northeast, approaching Highcliffe. Then it can break and return to a situation like that at present (2007). Here are some records of its history.

Early Records

1366 - Erosion at Highcliffe

To judge from the following historical record in Samuel (undated), there seems to have been great land loss in the 14th century.

At Highcliffe, adjacent to the Chewton Bunny, Christchurch priory provided 40 acres compensation for land loss to local villeins. The loss must have been at least 40 acres within an easily memorable time. An acre is about 4000 square metres. If a strip 2 acres wide and 20 acres long was lost then the erosion would have been about 126 metres landward. If the strip was one acre wide and 40 acres long then the erosion would have been about 63 metres. These would be minimum figures. If the time was say 10 years then the erosion rate would have been at least 6 metres per annum, which is about 6 times the figure for the maximum erosion rate in Christchurch Bay in recent times. It could have been more than this.

A summary of the information is quoted below. The full document is a manuscript in the British Library - T16, part II, Folio 38a. It is in Latin, but a historian might be able to obtain from it a clearer picture of the ravages of the sea at that time.

[Because of major loss of land around Highcliffe by coastal erosion of Barton Clay -] "Christchurch Priory has granted its villeins of South Chewton forty acres in lots to the west of Chewton Mill in the thirty-first year of King Edward's reign (1366), in return for which the men have paid two marks as entry fee and are renting each acre at two-pence payable annually at the Feast of St. Giles: therefore they are not to be charged because of these acres, but neither are they to be excused from services which they did before this present concession; they may never claim compensation from the Priory for any of their land waste by the sea, nor relief from gifts previously owing by custom to the Priory: and if it is necessary to move their homes owing to marine devastation the men agree to rebuild at their own expense on the forty acres.

Sea level rise at about this time had major effects elsewhere. The Norfolk Broads were peat (turbary) diggings abandonned by the end of the 14th century because of increased flooding resulting from a rise in sea-level (Lambert, J. et al. 1960)

--- Short (Breakthrough) State ---.

1654 Old maps of this date were seen by Burton (1931). The end of Mudeford Spit was opposite the ferry at Mudeford Quay.

1703 - Daniel Defoe's Storm

On 26 November 1703 there was a famous storm that destroyed most of the windmills in England. This was a serious event, like the 1824 hurricane. It is considered to have changed the mouth of the Beaulieu Estuary in the relatively sheltered waters of the Solent by forming a new spit. According to Legg (1999) this had been recorded in parish registers as: "The great storm, both at sea and land, the greatest man knew in England was on the 26th day of November in the year 1703". For more on this see the Chesil Beach Storm and Hurricane webpage. See also Defoe in the Chesil Beach Bibliography.

If it affected a spit in Solent it would be surprising if it had no effects at Hengistbury and Mudeford Spit, but no details are known.


Maps by Bowen. End of spit in similar situation to that in 1645.


Part of Isaac Taylor's 1759 map of Christchurch Bay, Hampshire


The Admiralty Chart of Lt. Murdock Mackenzie, two inches to one mile, 1785, was discussed by Burton (1931). The end of Mudeford Spit was within a hundred metres SE of the Haven Houses, Mudeford Quay. The width of Run was 90 yards at high tide. There was a considerable expanse of sand on both sides of the entrance, and stretching seaward for as much as 260 yards at the widest point. The opening at low water has a width of 300 yards. The sand on the north side extends only half-way to Steamer Lodge, but on the south it extends not only as far as Hengistbury Head but actually round its southeast corner. Perhaps there was active sand supply at the time from the eroding, Bournemouth sand cliffs.

1784 - Battle of Mudeford

Two smuggling luggers, loaded with tea and brandy, were approaching Christchurch Harbour at Mudeford. The sloop-of-war HMS Orestes arrived off Beerpan Rocks, Hengistbury Head at 6am. About 300 people were involved bringing the goods ashore at Mudeford and transporting them away on waggons drawn by 300 horses. There was a fierce battle from 6 in the morning until 9 in the evening. Many shots were fired from small arms and cannon. The smugglers scraped out a breastwork in the sand-dunes for defence (Morley, 1994). It is quite likely that much sand was available there at that time because extensive shoals of sand are shown near Steamer Point on the map of Isaac Taylor (1759) and much sand is recorded, as mentioned above, on the Admiralty Chart for 1785.


- 1 inch Ordnance Survey Map. No lengthening of Mudeford Spit beyond Mudeford (i.e. entrance still near Gundimore).

1824 - "The Great Gale" - A Severe Hurricane

English Channel Hurricane of November 1824 - Map showing the effects on Devon, Dorset and Hampshire

A major hurricane, known as "The Great Gale", with disastrous effects, including fatalities, in the Portland, Weymouth area. Sea-level rose in the Dorset region in a storm surge of 2 or 3 metres and parts of Christchurch (Bridge Street etc) were flooded. It is not clear, though, whether the Christchurch flooding was sea-flooding or river-flooding or some combination of both. Burton (1931) noted some washover gravel deposits at the back of Mudeford Spit but these are not dated, and may or may not be the results of this storm. Since Hurst Spit was driven back about 40 yards it is unlikely that Mudeford Spit was completely unaffected (although it has protection from the southwest waves by the Head). It does not, however, seem to have been broken through near Hengistbury Head, and major washover effects are not obvious (see the following comments regarding the Run).

1825-1826 - Greenwood's Map. A wide opening to the Run is shown on a map of Greenwood according to (Burton, 1931). I have not seen this map and do not know how reliable it is. It is interesting that the entrance to the Fleet Lagoon, near Weymouth, at Smallmouth became four times its normal width after the 1824 hurricane because of the subsequent outflow of the storm surge and the overtopping waters which had been pushed into the lagoon. Could something similar have happened with regard to Christchurch Harbour and Mudeford Spit; in other words was the run temporarily widened by the hurricane flood water outflow?

(Supplementary notes on the exceptionally rare conditions of hurricane flood outflow:-
The Fleet Lagoon received a huge quantity of water during the 1824 hurricane because of the overtopping of the Chesil Beach by very large waves coming from the southwest, in addition to a storm surge of 3 metres or more. The Fleet flooded deeply with a maximum of up to 9 metres at East Fleet Church. This stock of water moved down to the outflow channel - Smallmouth, the local equivalent of the Run, and flowed out in a torrent, widening the mouth, destroying the ferry house and drowning the ferryman. See Chesil Beach Storm webpage for details.
Christchurch Harbour may not have received this large amount of water, although no data is available. Mudeford Spit is much lower than the 14m high Chesil Beach but it is also much more protected, particularly from southwest storm waves. However, unlike the Fleet Lagoon, Christchurch Harbour is fed by two rivers, the Avon and Stour both of which are prone to flooding and these rivers may flood from rain during a hurricane. It would of course be expected that the sea flooded over Mudeford Spit, because of course it did that at the larger spit of Weymouth. Input of seawater elsewhere is less likely. Normally seawater cannot get over the low cliffs between Southbourne and Hengistbury Head and there are sand dunes on the cliff top which suggest that it not happened in very recent times. In the exceptional conditions in November 1824 a storm surge coincided in part with a high spring tide and with severe wave action. Sea level was effectively raised up to several metres above normal levels, although we not know just how much at Hengistbury, and this was probably less than at Lyme Regis for which there is data. If much seawater really was able overtop the low cliffs then it could have run down the supposed river channel and thus could have fed to Christchurch Harbour and added to the flood water from other sources. This is a "worst case scenario" though and it may not have happened, as yet. Local historians may discover old records regarding Christchurch which provide useful information. Look for data on the night of 22-23 November, 1824)

1829 - The steamer was wrecked and pushed into the cliff at Steamer Lodge (see photograph of notice above) apparently in about 1829. Is it possible that the wreck happened earlier and in connection with the 1824 hurricane? That had a storm surge of 2 or 3 metres or more and this would have easily enabled a steamer to be beached up at the cliff (in this same storm a ship was washed onto farmland at Parkstone, near Poole Harbour). However, there may have been other storms in the early 19 th century that had a storm surge.
It is worth observing that if a steamer can be driven into the cliffs at Mudeford, then at times, albeit rare, Mudeford Spit must be flooded over with seawater as has happened to the larger Melcombe Regis sand spit (Weymouth sea front).

1847 - Admiralty Chart of Captain Sheringham. The Run now extends at low tide to halfway between Haven Houses and Gundimore. Very shallow bar, only 1 foot of water at low tide. The general pattern was as previously. However, there was new accumulation of sand and shingle south of the Haven Houses.

1849-1852 - Removal of loose ironstone, a natural rock armour, from the shore at Hengistbury Head (Powell, 1995).

--- Extension State ---.

1870 - Ordnance Survey Map, Sheet 87, Hampshire.
Mudeford Spit has now extended nearly to Cliff End. This may or may not have been the first extension of the Spit following the removal of ironstone at Hengistbury Head.

1880 - Mudeford Spit extended to about halfway between Steamer Lodge and Highcliffe Castle, as shown on the map below.
A party from the Geologists' Association viewed the extended Run on 29 March, 1880 (Gardner, 1880):
"The Members then drove to Mudeford, and thence found their way along the base of the cliffs to Highcliff. The new channel recently created by the Stour and Avon for a mile along the base of these cliffs caused much surprise when the rapidity with which it had been formed became known."

Old geological map of Hengistbury Head and Mudeford Spit, near Bournemouth, Dorset, revised to 1891

Round about 1880 the problems of the Run extending to Highcliffe concerned Louisa, Marchioness of Waterford who owned the Highcliffe Estate is given by Dale (1914):

Louisa, Marchioness of Waterford, living at Highcliffe Castle, attempted to reduce the perennial problem of the Highcliffe Estate - the erosion of the cliff by the sea (Dale, 1914). A major factor was the Run, the river outflow from Christchurch Harbour. This was running close to the cliffs increased the rate of erosion. Lady Waterford thus ordered the placing near the Castle of blocks of limestone, and even "granite-porphyry", with the addition of slabs of the "Shell Bed" or "Stone Bed" from the base of the Becton Sand (Barton Sands) (Burton, 1931). The blocks were there in 1880. The objective was to turn the extended course of the Run outward rather than directly restraining the action of the sea (West, 1885). The groyne was eventually destoyed and by 1931 only a few of the stones were visible at low tide (Burton, 1931).

--- Breakthrough State ---.

- Mudeford Spit broke through near Gundimore

1893 - MS Geological Survey Map, Sheet 87, 1893 - Mudeford Spit extended to opposite Steamer Lodge

1895 or 1896? - Mudeford Spit probably broke through near Gundimore (Burton, 1931)

1898 - Geological Survey Sheet 87 of 1898 - Opening of the Run is opposite Gundimore (no change)

--- Extension State ---.

The Run extended past Cliff End

--- Breakthrough State ---.

1911 - November
Breakthrough of the Run southeast of Gundimore (White, 1917)

Two and half years after the opening in 1911, the end of the spit was a quarter of a mile further east (Ord, 1914).

After 1913
The rate of extension if uninterrupted would have taken the end of the spit almost to Highcliffe Castle by the 1930s. However there may have been another break, although Burton is not specific about this.

1929 - Winter
Some erosion took place on the main part of Mudeford Spit. The sand dunes here were originally 16 feet (4.9m) to 20 feet (6m) high but had already been reduced by trampling by summer visitors. In 1929 prolonged and severe gales swept the coast and erosion of dunes took place on the harbour side. Many dunes were cut in half, leaving vegetation hanging from them (Burton, 1931).

--- Extension State ---.

1930 early January
A southeasterly gale took place. This did not affect the position of the end of the Run, which was probably then in extended situation. Erosion, however, took place of a 200 yard long and 10 yard wide line of sand dunes at Cliff End. The height of the shore at the base of the cliff was lowered by 6 feet. The roots of the Marram Grass were washed out and spread along the margin of the lagoon. Sand was driven into the lagoon Burton (1931).

1930, September 18th -

A old map of Mudeford Spit and the Run, Hengistbury Head, Bournemouth, Dorset, from the 1930s with some additional notes from 1957

The lagoon near Steamer Point, between Mudeford and Highcliffe, Hampshire, probably in about 1939, and having originated as a relic of a former channel of the Run

The end of Mudeford Spit had reached a point at high-water mark almost due south of Steamer Lodge (Burton, 1931). A lagoon, still present there at that time , is a relic of a former channel of the Run (see map above).

1930 September 19th
There was a southeasterly gale accompanied by a very high tide. The wind, however, veered southwest after several hours. The only effect was a shortening of the spit at low tide by about 100 yard. The Run turned in towards the low (20 feet) cliff near Steamer Lodge, and Burton (1931) thought that the coming winter it would invade the lagoon still present at the base of the cliff, unless a breach takes place at Mudeford.


Salmon Fishing in the Run from Mudeford Spit, perhaps at a time when the spit was in extended state

Burton (1931) commented that (on page 161): "The recent chart shows the sandspit extending to about halfway between Steamer Lodge and Highcliffe Castle and the entrance below this and immediately south of it. The length of the spit is that attained in 1880."

--- Breakthrough State ---.

1940s to 2006

A breakthrough near Gundimore must have occurred after the publication of Burton's (1931) paper and before 1939, but I do not know exactly when this happened.

Here is an account of the breakthrough by Herbert (1947):

"The famous salmon fishing at Mudeford was sadly handicapped some years ago through the sea breaking down the sand barrier. This destroyed part of " The Run," where the fishing took place. It is a pleasant pastime, and an interesting one, to watch the fishermen at their work. They seem to take things very philosophically, these Mudeford fisherfolk - whether the catch is good or bad it appears to be all the same to them, although of course it makes a very material difference.
The coast here keeps on changing. I shall never forget motoring down one Sunday morning some years ago. The car park attendant, who so well knows my love of Mudeford, met me with these words: " The sea has broken through at the other end!" I hurried round the bend, and what a change I saw! The sea had indeed broken through the barrier, and had joined "The Run." Mudeford hardly seemed the same place. Considerable damage had been done to the sea wall, and many of the huts endangered. Unfortunately, owing to the war, all the huts have now gone, but I understand the council are taking steps to rebuild.
A friend of mine was speaking later to one of the fishermen about the storm and the consequent result on the salmon fishing, but he merely shook his head sadly and said, " Ah! it's the sea," as if he fully recognised its mastery."

1989 - December - Storm Surge Flooded Mudeford Quay

On the 16th - 18th December, 1989, a depression caused strong winds gusting over 80mph. Waves over 20 feet in heigh were reported in the English Channel and there were huge tides, presumably as a result of a storm surge. Davison et al(1993) wrote:
"fter seemingly endless blue skies, hot summer sunshine and a benign autumn, severe gales struck in mid-December, 1989. Winds blew with ferocious force from far out in the Atlantic and a combination of this long fetch from the south west, where waves were reported 20 feet in height, strong winds gusting over 80 mph and huge tides, led to massive flooding along the Hampshire coast and on the Isle of Wight. The depression responsible was code named Low "A". The far west in Christchurch Bay took a heavier pounding than on the night of the Great Storm of 1987. The Borough Flood Protection Officer, Frank Tyhurst, was amazed to find the tide two feet above an average spring tide, the highest level in recorded history, an entirely unexpected occurrence. Water flooded into Bridge Street and Wick Lane and the entire Mudeford Quay was inundated. A 90-year-old lady slept soundly, totally oblivious of the waters swirling round her bedroom. She was rescued but lost her false teeth.

The Future

Obviously consideration of the future of Mudeford Spit is mostly a speculative discussion point, but it is also a matter of real interest. Most spits in the region are undergoing erosion, as discussed in the next section, particularly in they are situated such that sea defences have cut off the sediment supply source. Only one, however, Hurst Spit, has been almost destroyed.

The construction of the Long Groyne and a promenade and other sea defences at Hengistbury Head have greatly limited supply of sand from the west. With the supply cut off it is very unlikely that Mudeford Spit will extend once more towards Cliff End. There is already now a sand-starvation problem, which has already necessitated some replenishment by dredged sand. Global warming and increased rate of rising sea-level will not help. The question is not whether it will extend again, but whether it can survive without a serious breach further to the south and nearer Hengistbury Head. Sea defences to the south and east mean that there is risk that Mudeford Spit will eventually follow the artificially-reconstructed Hurst Spit in becoming a type of engineered harbour wall.

Of course, no-one can be sure exactly what will happen, and there may be surprises in store. When the next major hurricane of 1824-type (a Katrina style hurricane with 2 to 3 metre storm surge) strikes the coast here it is, of course, bound to be damaging and it might cause flooding up to Christchurch, as seems to have happened in the past. It is not known just how much it would damage the spit or whether it may just break some sea defences further west and release a sand supply from Hengistbury Head to the spit again. Thus it is not known whether the final effects of the next one in 300 year hurricane would be a destructive or constructive process regarding the sediments of Mudeford Spit, but a destructive result is more likely. For further discussion on the sea defence scheme for Mudeford Spit see Few et al. (2004).

A plot of indicators of former sea levels so as to show the sea-level rise over the last 9000 years in southeast England, modified after Devoy (1982)

To obtain some idea of the future prospects it might be useful to make comparison with other spits.

Similar Sand Spits

Erosion of a marram grass dune ridge at Dawlish Warren, Devon

Mudeford Spit has many similarities to Dawlish Warren, a sand spit on the southwest side of the Exe Estuary. Although Dawlish Warren is larger and wider, it has similarly been naturally supplied by sand from the west. In Victorian times Brunel built the coastal railway to Dawlish which isolated the cliffs of sand from the beach. This railway and associated sea defences have now cut off the sand supply from the west (cf. effects of Bournemouth promenade and the Long Groyne at Hengistbury Head). Of course, there may have undoubtedly been other complicating factors, but since then the coastal protection to the west has been major erosion at Dawlish Warren. A large part of the spit which had beach chalets in the 1930s has disappeared, and what remains is now a nature reserve. The narrower spit that has been left is still undergoing erosion on the seaward side, so that sand dunes are cut by small sea cliffs, as shown in the photograph above.

Mudeford Spit has some similarities to the east-facing sandspits at the entrance to Poole Harbour - Sandbanks and the South Haven Peninsula (although this is much larger). These Poole Harbour entrance spits have also received their sand from the Bournemouth Cliffs. The supply is now cut off by sea-walls and sea defences. However, there has been some offshore reserve in Hook Sand. Both Sandbanks and the South Haven Peninsula are undergoing some erosion although neither are seriously threatened as entities by this.

The Melcombe Regis or Weymouth Sand Spit, which is now the holiday resort of Weymouth has been extensively built over. It has not been breached or seriously eroded in recent times, but has been almost completely flooded over in the 1824 event. The solid Georgian Houses have survived this.

Mudeford Spit might be compared to some extent to the spit at the other end of Christchurch Bay, that is Hurst Spit. This, however, is much larger and it is a gravel spit rather than a sand and gravel spit. These are both the consequences ot it being much more exposed to southwesterly storm wind and waves. The castle and adjacent area has survived because it the accretion area (the southeastern "natural tip heap")of the spit. The main beach between Milford-on-Sea and the castle, however, has suffered from the cut-off of shingle supply because of the unfortunate existence of sea-defences to the west. The result is that it has been flattened in storms and almost destroyed. However, the local authorities saved it by being rebuilding artificially from gravel dredged from the Shingles Bank. This has been done so effectively and neatly that it is not at all obvious to the casual observer that the bank has been destroyed and reconstructed. However, most of it is still gravel and to some extent vulnerable to extreme storms. It is now holding for the present, but has not yet been subjected to a real hurricane. For more on this see the Hurst Spit webpage.

The best surviving spit in the region is Calshot Spit of mainly shingle at the entrance to Southampton Water. Henry VIII's castle survives on the end and the spit has an ancient history. The reasons for this are (1) it is in a relatively protected area, the Solent, and (2) it has not been seriously affected by any major construction of sea defences to the west. There are still small gravel cliffs at the western end of the Spit keeping it supplied.

The Chesil Beach is not a good comparison because it is much larger, it is of gravel, it is part of a tombolo rather than a spit and it faces the southwesterly storm waves. However, the Chesil Storm webpage might be of interest because it contains a record of major storm events in the region, and detail regarding the disastrous 1824 hurricane.

Readers with further interest in comparisons should read about the East Coast spits such as Spurn Head and Orford Ness. See also Mosby (1939) on breach of a sand spit at Horsey on the east Norfolk coast.

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Sunset seen from the top of Hengistbury Head, Bournemouth, Dorset, February 2012

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I am particularly grateful to the Director and staff of the The Channel Coastal Observatory for permission to use their excellent, vertical, aerial photographs. I much appreciate the help of Dr. Travis Mason. I am much obliged to Dr. Frank Green for discussion on siderite at kilns of Pitts Deep and for the opportunity to examine samples and slides. Peter J. Bath has been particularly helpful with regard to thin-sectioning and photomicrography and his contributions are much appreciated.

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Go eastward along the coast to Highcliffe and Barton

Go westward along the coast to Bournemouth Cliffs

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Hengistbury - Bibliography and References .

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Copyright © 2016 Ian West, Catherine West, Tonya Loades and Joanna Bentley. All rights reserved. This is a purely academic website and images and text may not be copied for publication or for use on other webpages or for any commercial activity. A reasonable number of images and some text may be used for non-commercial academic purposes, including field trip handouts, lectures, student projects, dissertations etc, providing source is acknowledged.

Disclaimer: Geological fieldwork involves some level of risk, which can be reduced by knowledge, experience and appropriate safety precautions. Persons undertaking field work should assess the risk, as far as possible, in accordance with weather, conditions on the day and the type of persons involved. In providing field guides on the Internet no person is advised here to undertake geological field work in any way that might involve them in unreasonable risk from cliffs, ledges, rocks, sea or other causes. Not all places need be visited and the descriptions and photographs here can be used as an alternative to visiting. Individuals and leaders should take appropriate safety precautions, and in bad conditions be prepared to cancell part or all of the field trip if necessary. Permission should be sought for entry into private land and no damage should take place. Attention should be paid to weather warnings, local warnings and danger signs. No liability for death, injury, damage to, or loss of property in connection with a field trip is accepted by providing these websites of geological information. Discussion of geological and geomorphological features, coast erosion, coastal retreat, storm surges etc are given here for academic and educational purposes only. They are not intended for assessment of risk to property or to life. No liability is accepted if this website is used beyond its academic purposes in attempting to determine measures of risk to life or property.

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Dr Ian West, author of these webpages

Webpage - written and produced by:

Ian West, M.Sc. Ph.D. F.G.S.


at his private address, Romsey, Hampshire, kindly supported by Southampton University,and web-hosted by courtesy of iSolutions of Southampton University. The website does not necessarily represent the views of Southampton University. The website is written privately from home in Romsey, unfunded and with no staff other than the author, but generously and freely published by Southampton University. Field trips shown in photographs do not necessarily have any connection with Southampton University and may have been private or have been run by various organisations.