West, Ian M. 2014. Studland and the South Haven Peninsula; Geology of the Wessex Coast of southern England. Internet site: www.southampton.ac.uk/~imw/Studland.htm. Version: 6th July 2014.
Studland and South Haven Peninsula Field Guide

Ian West,

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

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

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Other Webpages on Studland and Adjacent Area:

|Studland - South Haven Peninsula (the main page on Studland - this webpage!) |Studland Peninsula - Poole Harbour Side |Studland - Tertiary Cliffs |Harry Rocks, Ballard Point |Swanage Bay |Studland and Harry Rocks; Bibliography |Sandbanks Peninsula |Brownsea Island Geology |Swanage Bay |Petroleum Geology of the South of England (re Wytch Farm Oilfield)

|National Trust - Studland|

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An oblique aerial view of the South Haven Peninsula, Studland, Dorset, by Alan Holiday, June 2011

The entrance to Poole Harbour at Sandbanks and Studland, Dorset, with Brownsea Island, aerial view by Alan Holiday, June 2011

A ride turns onto the beach at Shell Bay, near Studland, Dorset

Knoll Beach on a summer's day, Studland, Dorset, view northward

Shell Bay

Studland Bay

Little Sea, South Haven Peninusula in winter, 2000.


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Safety and Risk Assessment

Persons undertaking field work here should do so in accordance with the rules of the National Trust who own the area. In summer there may be need for protection against sunburn. If there is prospect of wet or cold weather then visitors or members of field parties should have available or wear good warm, wet-weather clothing and sturdy footware. It is useful to take a mobile phone in case of emergencies, especially if they are walking alone in the relatively deserted dune and heathland. Persons should not continue with field work if they are feeling cold, wet or unwell. They should certainly not persist if they are chilled or there is any risk of hypothermia. They should inform the leader or secretary of the group if they are leaving a field party or if they are feeling unwell. Take care with any risk from strong wave conditions. Be careful with slippery rocks at the Training Bank or elsewhere. In warm weather there may be occasional adders (poisonous snakes) in the heathland but they are rarely seen. They are not normally aggressive and with slither away but they should not be interferred with and no effort made to pick them up. The poison may not necessarily be very severe to healthy people but if bitten the person should go to a hospital for an antidote. Avoid going into the sea in Shell Bay because there can be a strong tidal current. Be careful not to wander on the busy road to the ferry when preoccupied with geological or geomorphological matters or in discussion. Note that in the Second World War the South Haven Peninsula was used for military training. The area has been cleared of missiles and mines etc, but renewed erosion could possible reveal some dangerous weapon that was missed. In that case do not touch it but report it to the authorities.

Redend Point cannot be rounded with dry feet except at low tide. Wading is not recommended but if it is done it should be undertaken with care because of an irregular sea-bed with rocks, some of which may be slippery. Watch out for falling debris at Redend Point, although it is only at certain places that there is any risk from this.

Some significant risk is involved if there is any attempt to proceed around the foot of the Chalk cliffs towards Harry Rocks. There is potential hazard from falling debris although in good weather this may be rare. There is a practical problem with slippery rocks and seaweed. Tide conditions must be checked carefully because there is a real possibility of being trapped by the tide. There is no way up the cliff beyond South Beach. A safety helmet, mobile phone and knowledge of the tide conditions are prerequisites. This shoreline scramble is not recommended for parties, although groups may wish to see the first cliff exposure of the Chalk.

If persons continue on the cliff top to Harry Rock and Ballard Point it should be noted that the chalk cliff edges are very abrupt and may be overhanging. They are very dangerous (at least one person has fallen and been killed) and it is important not to approach these for photography or as viewpoints and visitors should stay on the paths away from the edges. There is no fencing. This is not a good place for children unless they are strictly controlled and kept well back.

Further comments are given below in Notes for Field Leaders.

Visitors, and particularly students considering projects here, should be aware that a certain part of the South Haven Peninsula is used by naturists (nudists). The area is in the centre of Studland Bay and the immediate part of the dunes landward and is marked by signs. A newspaper article of July 2005 provides more information. Apparently the naturists are innocuous people, but it is stated that some troublesome characters also go there. However, there are undercover police patrols and in 2004 it seems that 16 people were arrested.

In practice, though, geologists, environmentalists, naturalists and walkers can enjoy their studies of beach and dunes and know nothing at all about any of this. There is unlikely to be any difficulties at the main tourist centres like Knoll Beach, Middle Beach, South Beach or most of Shell Bay. Simply avoid the northern part of Studland Bay in hot summer weather. At other times of year most of the peninsula is very quiet, remote and most of it free of any persons at all. Students undertaking projects involving northern Studland Bay might choose to work from September onwards, or in Spring, and should be in pairs. They should in any case, consult the National Trust, who own the area.

For further information please see the Safety on field trips webpage. Individual geological, geographical and environmental visitors, field leaders and project students should make their own risk assessments and no liability is accepted.

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1.2 INTRODUCTION: National Trust Property

National Trust facilities at Knoll Beach, Studland, Dorset

National Trust Pamphlet on  Studland, Dorset, first page

National Trust Pamphlet on  Studland, Dorset, second page

National Trust Pamphlet on  Studland, Dorset - the map enlarged

By kind permission of the National Trust, two pages of the main National Trust pamphlet on Studland are reproduced above (with an additional image showing the map enlarged). The National Trust owns and administers the Studland or South Haven Peninsula. They have a number of educational information sheets on various aspects of the natural history of the area. Information is available from their information centre and shop at Knoll Beach, Studland (see below). The address of the Studland office of the National Trust is:

The National Trust,
Purbeck Estate Office,
Studland, Dorset,
BH19 3AX
Telephone: 01929 - 450259

See also the main website of the National Trust.

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1.3 INTRODUCTION: General Features of Studland

We will now consider some general aspects of the location.

Isle of Purbeck Location Map

Old geological map of the Studland and western Poole Bay area

The Norman church of St. Nicholas at Studland, Dorset

The Bankes Arms pub at Studland, Dorset, conveniently near the South Beach and the path to Harry Rocks, is good for lunch and a drink

The grounds of the Bankes Arms  Studland, Dorset, with a rook and a jackdaw

Studland is a small attractive village situated on the east coast of the Isle of Purbeck, north of Swanage and the Chalk downs, the Purbeck Hills. A major Chalk promontory with Harry Rocks extends eastwards, just to the south of the village and as continuation of the Purbeck Hills. Close to the village are cliff exposures of Eocene strata, including the Reading Formation, the London Clay and the "Bagshot Beds" (or now Poole Formation of the Bracklesham Group). The latter include coloured sands at Redcliff Point, resembling those at Alum Bay, Isle of Wight, although on a smaller scale. To the north is the scenically attractive, South Haven Peninsula of sand dunes, lakes and heathland, much of which has built up in an area of shallow sea since the 17th Century.

The area is within easy reach of other famous localities such as Lulworth Cove and Kimmeridge Bay . Swanage is very close, with Durlston Bay to the south.

Sandbanks ferry from the ramp on the Shell Bay side Sandbanks ferry from Shell Bay, Jan 2003

Ferry arrives at South Haven Point, next to Shell Bay, Studland, Dorset

National Trust facilities at Knoll Beach in winter

The South Haven Peninsula can be approached by road either by going round Poole Harbour and travelling from Wareham to Corfe Castle and on to Studland by a minor road, or alternatively by the chain ferry from the |Sandbanks Peninsula. In winter, providing the ferry is operating it is quite quick to arrive by this means, but in summer there may sometimes be long queues of cars and then the Wareham route may be quicker.

When landing from the ferry on the south side there are toll booths at which to pay. Then on the left is a car park that is convenient for Shell Bay and there are toilets there. There is a fish restaurant on the right-hand side. The long, straight Ferry Road takes you on the south.

If you continue up this road, passing the Little Sea on the left you begin to approach Studland Village. Just before doing so, and before the Knoll House Hotel on a hill, turn left for Knoll Beach. Here there are large car parks and full facilities. There is a substantial car park at Middle Beach close to the village, a small one for south beach adjacent to the pub, and another car park at Shell Bay close to the ferry ramp. The main National Trust facilities are at Knoll Beach, shown here almost deserted on a cold winter afternoon, but very busy on a warm summer day. The peninsula is owned by the National Trust who can provide information and advice on student field work. Much of the North Haven Peninsula is a nature reserve and areas such as the Little Sea are not easily approached. There are walks, nature trails and bird hides though. The beach is of easy access on foot but a long stretch of it away from the car parks is used by naturists. Ordinary walkers are not excluded though. In winter there is some horse-riding on the beach. In summer there are various water sports in the pleasant shallow water of Studland Bay, which is characterised by a very gently shelving, soft sandy sea floor. Shell Bay has stong tidal currents, being at the narrow entrance to Poole Harbour.

The main geological interest is the historical build-up of the sand peninsula and dunes, as discussed below. The area is popular for various environmental studies, partly because it is undeveloped natural land and partly because there is an interesting progressive development of vegetation over the dunes. With sea, salt-marshes and a lake with reeds it is an important place for bird life.

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1.4 INTRODUCTION: Geological Maps

It is important to note that for an area such as Studland there have nomenclatural changes from the old series of BGS geological maps to new Bournemouth and the new Swanage maps. Re regard to the Chalk note that the Portsdown Chalk Formation is in the zone of Belemnitella mucronata. The older literature uses the zonal name, as the Formation name is relalively new. This should not cause much problem at Studland, and in webpages dealing largely with the Chalk, a conversion table is provided.

The Palaeogene or Tertiary strata are not quite so easy to deal with. The greatest change has been the replacement of the old "Bagshot Beds" with the name Poole Formation and an important subdivision of this into members. New maps in this webpage, use of course, the new scheme, but some parts of older maps are also reproduced (and may sometimes be more readily available because of copyright matters). There should be no problem in using an old matter in introductory terms, if the reader has some familiarity with both old and new nomenclatures. The experienced geologist will know whether an old or new scheme is being used.

[This website will be progressively updated to use the new scheme, but old terminology may persist in parts until time permits correction.]


A simplified geological map of the South Haven Peninsula and Studland, Dorset, based on modern geological maps, but completely redrawn, 2014


This simplified geological map above has been completely redrawn, with appreciable modifications. It is based partly on the data shown in the Bournemouth Sheet (No. 329) of 1991, and partly on the data shown in the Swanage Sheet (No. 342 east and 343) but does not show the Ordnance Survey data which is present on those maps. All boundaries have been shown with solid lines, unlike the BGS map, so distinction is not made between proven and postulated geological boundaries. The map is very simple in structural terms with some faults in the southernmost part and some minor synclines and a corresponding anticline. Away from the southern boundary area (i.e. at and near the Chalk) the structure is simple with overall a very low dip towards the north. Note that the map shows not just formations but also members. Some of these are very thin, just a few metres and they are variable in thickness. This particularly applies to the Poole Formation. This Eocene unit is a product of sedimentation in the hot Poole Delta. Channels within this delta were irregular and moved in position from time to time. There were lakes, and probably crevasse-splays in places. Abandoned channels in the local Eocene sediments were often filled with plant-rich clay plugs. Inevitably in such an environment, extremely reducing conditions were locally developed. Pyrite was worked economically in the past from the Poole Formation on Brownsea Island. There has been extensive oxidation of pyrite in the Parkstone Clay Member. This has resulted in brown, ferruginous cementation of the Parkstone Sand Member. The most obvious and well-known example of this is the Agglestone Rock and the nearby Puckstone. Similarly the Broadstone Sand Member shows iron-cementation at Redend Point. Here, too, there are pyritic pipes, now oxidised (above sea-level) to limonite, and coloured sands, with the colouring the result of the state and type of iron oxidation.

A special feature of the area, and shown on the map above, is the absence of the Reading Formation, with London Clay (very sandy) faulted against Portsdown Chalk.

The sand dunes and sand beach deposits of the South Haven Peninsula are discussed in the webpage: Studland - South Haven Peninsula etc.

Incidently, note that the BGS maps show "Head" associated with and mainly to the west of the dune ridges. Most Head is of Pleistocene origin, but there is a question about these particular deposits because of their close association with Holocene sand.

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1.4 INTRODUCTION: Older Geological Maps

Shown for interest, are some older geological maps of the area. Note, that, as mentioned above, these use an terminology at least in part. The older interpretations may to some extent differ from new ones. The new maps have been made with much more information available, including new boreholes and seismic data. Generally they are better, but on rare occasions, an older interpretation may seem to have more merit. This is mostly just a discussion point for the specialist. In some cases the old maps show features of historic significance.

Location and geology map, 1907

Location and geology map, 1890

Geological Map of the Swanage and Studland Area

An old geological map, above, is from Woodward (1907). Other maps are from an old hand-painted geological map of the area from Braye (1890).These provide an introduction to the geology and general topography of the area. Although the details of the town and roads have changed the geology shown here is basically correct. It is useful to obtain the current geological map of the British Geological Survey (formerly the Institute of Geological Sciences), Geological Map - Swanage, Sheet 343 and part of 342. Solid and Drift Edition. 1:50,000. There is an accompanying explanatory memoir by Arkell (1947). The present map - sheet 343 and 342 is broadly similar to the maps here but the details of the faults are corrected. The main feature is that the Cretaceous Chalk forms an east-west trending ridge, the Purbeck Hills. The most suitable topographic map for the area is the Ordnance Survey, Outdoor Leisure Sheet 15, Purbeck and South Dorset. Scale 1:25,000.

Melville and Freshney (1982) have provided a good brief introduction to the area, that is less detailed and technical than Arkell's memoir, but which is very useful. The field guide by House (1993) is highly recommended.

Map - Geology of the Isle of Purbeck Another old map is modified from Damon (1884). Modern changes in the geological mapping of the area have only been of detail. Some place names have changed since Victorian times. Also provided below is the full map of the geology of the eastern part of Dorset.

Map by Damon - Geology of central and eastern Dorset

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1.5 INTRODUCTION: South Haven Peninsula, Studland - Initial Description

A map by Steers (1946) after Diver (1933) of the South Haven Peninsula

Old chart of banks, bars and channels off the South Haven Peninsula, Studland, Dorset

South Haven Peninsula from the air

View of the South Haven Peninsula from the hills west of Studland

Dunes looking northward from near Knoll Beach, Studland

The South Haven Peninsula, Studland is the most notable place on the Dorset coast for studying blown and beach sand. In the left-hand map the main topographical features are shown, based on Canning and Maxted (1979) with additions and modifications. Canning and Maxted (1979) have used historic data, discussed below, and later information from aerial photographs, Ordnance Survey Maps and surveys carried out by the Nature Conservancy Council (now English Nature) to review later changes in this area. The top central map shows the shallow-water sandbanks and bars offshore and the Swash Channel and the Training Bank. The top right-hand map is based on an old edition of the geological survey map with some additions. The lower photographs set the scene from a distance and show the beach at Studland Bay and the dunes immediately landward.

Unlike the other major coasts where there is much sand it is relatively undeveloped. Weymouth, Swanage and Bournemouth owe their growth and prosperity as seaside towns to their superb sands. At Swanage the Wealden Group and at Studland and Bournemouth the Poole Formation (Bagshot Beds) provide ample sources of supply. The accumulation of sand, however, is controlled more by relationship to waves and longshore drift than to sources of supply. Worbarrow Bay, for example, has the same rocks as Swanage, but it faces west and has only shingle and a little coarse sand at the extremities (Arkell, 1947). Weymouth on the other hand, faces east like Swanage and Studland, and the beach is banked on Oxford Clay with no adequate source of sand in the neighbourhood. The next accumulation of sand westwards is on the Lias Clay at Lyme Regis, which similarly faces east. The main part of the Bournemouth coast is sheltered from south-westerly waves by the Purbeck peninsula, but eastwards, towards Hengistbury Head, where this shelter decreases, the beaches have large quantities of pebbles. In the Isle of Wight the sands of Sandown and Shanklin face east and there is no equivalent beach in the same geological formations on the west coast. The tendency for sand to accumulate on east-facing or lee shores and shingle on windward coasts is merely an extension of a tendency that can be observed in individual bays (Arkell, 1947). The South Haven Peninsula is remarkable, however, in containing a large quantity of sand and having built up over the last 400 years or so.

Eroded dunes, Shell Bay

Marsh behind dunes

Training bank

Studland beach in the evening, naturists' section

With this broad perspective in mind, we can now look more specifically at the Studland area. The South Haven Peninsula is formed by a strip of sand is 3.6 km long and widening from zero at Redend Point to 0.6 km in width. The main blown sand area consists of three broad parallel ridges, separated from each other and from the Tertiary land at the back by strips of marsh with scattered pools, of which the innermost widens southward into a freshwater lake about 1.5 km in length, called the Little Sea. The west shore of the Little Sea is the original coastline and is marked by a small rise on to higher land (6 m to 9 m); this is the Plateau Heath in the detailed map shown here. This was formerly a low sea-cliff of which the southward extension can be readily be followed, between the sea and the Knoll House Hotel, to Studland (Arkell, 1947). The old cliff is aligned with the present seaward shore at Sandbanks on the opposite side of Poole Harbour mouth, with which it forms an unbroken curve to Hengistbury Head. The blown sand of South Haven Peninsula breaks the curve and juts out into what must have once been part of the Bay. It is a very recent accretion. On the map are also shown newer ridges forming adjacent to the present coast.

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1.6 INTRODUCTION: Poole Harbour and the South Haven Peninsula

Poole Harbour map of Green, 1040

Some brief consideration of Poole Harbour should aid the understanding of the South Haven Peninsula at its mouth (Green, 1940). Poole Harbour has generally been considered to be part of the drowned valley of the ancient Frome - Solent River which extended eastward along the synclinal axis of the Hampshire Basin to curve southward round the eastern part of the Isle of Wight. The river system may at one time been so continuous in this manner, but recent offshore geophysical work has shown that the extended Frome river system at a fairly stage in the Pleistocene breached the Chalk ridge south of Poole Bay (Velegrakis). The old valley system has not only been detected by geophysical studies but a borehole at Sandbanks in 2002 penetrated the sediments of the old channel. There has been a major rise in sea-level of the Flandrian Transgression which has taken place from about 10,000 years ago after the melting of the ice of the last (Devensian) glaciation of the Pleistocene. This has flooded the old Pleistocene river valleys and formed Poole Harbour. Sea-level is still rising so the harbour should extend in size in the future. Sediment, however, is trapped on the mudflats and saltmarshes of the margins, however, and in the last two or three thousand years there has been some reduction in size of the harbour. Wareham, for example, to the west was once a significant port of Poole Harbour but here it is now silted up to a narrow river.

Green (1940)commented that, as we have noted, the mouth of Poole Harbour has become partially barred by the dune formations of South Haven Peninsula and Sandbanks (although almost all now built over), leaving one one of the most unusual inlets of the sea to be found anywhere along the British coast. He thought it difficult to imagine that such an anomalous inlet could have survived with what appears for the most part to be a fairly stable coastline, if it were not for the fact that the tidal range is so small, and consequently, in spite of the narrow entrance, currents of more than 2 or 2 knots are rarely to be detected within the harbour. Such alterations as can be seen taking place on the shoreline within the harbour are due only to the effects of wave action, limited as that is by the restricted fetch.

Green (1940) commented that at that date as regards depths, it was possible via Main Channel to reach Poole Quay from the Bar with an absolute minimum depth of just over two fathoms (six feet or 1.8m) below Port Low Water Datum (P.L.W.D.). Since the tide falls near to Low Water level for only a very limited period each day, it was generally reckoned suitable for vessels of 16 feet (4.9 m) to use the port. One limiting depth actually occurs right outside the harbour at the Bar, so a vessel which could safely cross the bar could rely on reaching the Quay. Proceeding via Middle Channel instead of Main Channel, the fairway, though wider, involves a stretch just north of Soldier Ground, where there was a limiting depth of about 8 feet (2.4m) below P.L.W.D. (Green, 1940).

The tidal regime at Poole is of unusual interest, althought the total rise and fall of the tide there is not great. The double high water, which is such a well-known feature at Southampton, is much more marked at Poole, and in fact at neap tides each month it is possible to detect "triple high water". At neap tides, however, the total range is little more than two feet ( 0.6m), whereas after new and full moon it rises to somewhat over six feet (1.8m). It will not be exactly the same at the South Haven Peninsula but this gives some idea of the rather limited tidal range. A consequence of this is that although there is much shallow water there is not an extensive area of exposed sand-flats or mud-flats off the peninsula at low tide (such as you find in the Bristol Channel region with its high tidal ranges).

An interesting generalisation regarding sediment movement in Poole Harbour was put forward by (Green, 1940) based on studies of tidal movement. The argument which he made is as follows. The ebb tide is stronger than the flood tide in the lower part of the harbour (i.e. near to the South and North Haven Peninsulas). On the other hand the flood, at least at the bottom, is stronger than the ebb in the upper reaches of the harbour. Thus, at both ends of the harbour there is evidence of a tendency to sweep material out of it, either up into the river mouth or out to the sea. He wondered whether this feature is responsible for the fact that the Poole Harbour has remained so long as a rather anomalous feature of the English coast. As far as this concerns us with regard to the South Haven Peninsula, we note then that the stronger ebb tide should be sweeping sediment out of the harbour past Shell Bay.

The conditions at the harbour entrance are probably abnormal. Green (1940) found that here where a large body of water sweeps through the same definate channel at both ebb and flood, there is a hard bottom, presumably scoured, from which it was impossible to collect any loose material of any kind.

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Wave Action

The South Haven Peninsula is in the western part of Poole Bay partially protected by the chalk promontory of Handfast Point and Harry Rocks. It is not directly affected by the prevailing south-westerly winds and storms, so that wave action is generally less severe than at the eastern end of the Bay at Hengistbury Head. This relatively sheltered area can receive significant wave action from the east, but the greatest fetch is from the southeast. Storms from this direction are likely to have most effect.

The following table of predicted extreme wave heights is based on the Hook Island Report ( BP Exploration, 1991) and applies to Hook Sands. The directions are in degrees from north and the wave heights are in metres. The figures are theoretical and apply to relatively deeper water because in the shallow water the waves will break and may not much exceed 3m. The table shows the approximate average interval of time in years at which major storm waves might be expected. Note that the largest waves are expected when the wind is in the sector 120 to 150 degrees (i.e. from the southeast) and should reach about 5m once in 10 years and about 6m once in 50 years. Even once a year they should reach almost 4m.

Return Period
- Years
Significant Wave Height (m)
. 90-120 deg. 120-150 deg. 150-180 deg. 180-210 deg.
1 2.67 3.84 3.47 1.07
10 3.63 5.13 4.60 1.34
50 4.29 6.00 5.37 1.52
100 4.58 6.36 5.70 1.75

Notice that rather similar circumstances apply at Whitecliff Bay on the Isle of Wight, and particularly at Weymouth in Dorset where the coast similarly faces the southeast. The southern part of Weymouth resembles the Sandbanks (North Haven) Peninsula, being built on a sand-spit. Leland, writing in 1546 speaks of southeastern winds breaking through the nearby Chesil Beach (there being no protective harbour walls then, of course). Sandown Bay and Swanage Bay also face southeast. Some of these places might suffer some erosion and/or flooding by a 50 year or 100 year storm event from the southeast.


Footnote: Severe Storm of 1866.
There was a severe storm at Studland on the 11th February, 1866. The direction of the wind is not known but there is reference to ships being blown out to sea, so perhaps it was from the southwest or the west. "A fearful hurricane levelled 99 large elm trees... This memorable gale practically swept the whole district, for at sea it played great havoc, and in Studland Bay alone 14 or 15 vessels were either wrecked or blown out to sea and sunk. The number of lives lost was never correctly known... Few of the bodies of the drowned sailors were recovered. One only was found in Studland Bay, which the late Mr. Luckham buried in the churchyard, and he erected a headstone at his own expense. The headstone which has a large shell embedded in it, was formerly surmounted with a cross ..." (Hardy, 1910) .

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Offshore Sediments

Areas of sea-grass and maerl offshore from Studland

Most of the sediment offshore from Studland is fine to medium sand. There is a large quantity of this at Hook Sand. Here there is a wedge of sand 12m thick, much of it occupying the ancient outflow channel of Poole Harbour. In places the offshore sand exhibit ripple and megaripple bedflows (BP Exploration, 1991) . The dredged Swash Channel, with its high current velocities is different. The bed of the Swash Channel is armoured by a surface layer of coarse gravel, except in the vicinity of its seaward end.

There is a particularly interesting feature of the seafloor further south. Marine biology surveys for the Hook Island Environmental Study (BP Exploration, 1991) have established the presence of a Maerl community near Handfast Point. This is an assemblage of free living calcareous algae (red algae) Phymatolithon and Lithothamnion. Carbonate from these has accumulated on the sea floor. It is interesting that there should be Recent carbonate sediments fairly close to the South Haven Peninsula which is notable for being almost totally carbonate-free. The carbonate sediments though are actually closer to the headland of carbonate rock, the Chalk which can provide cleaner, clearer water. The algal clasts are transported southward by tidal currents beyond the town of Swanage and small accumulations can be found on the beach in Durlston Bay immediately north of Durlston Head. They are not usually seen on the beaches of the South Haven Peninsula though. Maerl is known elsewhere particularly off the north coast of Brittany, as at Paimpol, where it has been dredged for fertiliser. It is also present at Falmouth and has been used for fertiliser there too, and is common off the west coast of Ireland. Some Lithothamnion occurs in the carbonate (mainly shell) sediments of the beaches of north Cornwall and Devon. It is favoured by clear water with a low content of suspended clay and often associated with shell debris.

The sea-grass Zostera mainly grows in the southern part of Studland quite close to the cliffs of Chalk. You will notice accumulations of dead sea-grass washed up on the beaches here.

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South Haven Peninsula - History

The North Haven Peninsula, Sandbanks, and the South Haven Peninsula, Studland as shown on part of Ralph Treswell's map of the Isle of Purbeck,  1585-6

Treswell's 1585-1586 map of the South Haven Peninsula area, Studland, of Sandbanks and part of Brownsea Island, with some additional interpretation and notes

This map by Ralph Treswell in 1585-6 (also with a personal interpretation) shows the South Haven Peninula in quite different condition from that at present. At that time there was shingle spit opposite the North Haven Peninsula (Sandbanks). However a small sand spit was developing northward from what is now Knoll Beach. Thus there was some surplus sand available here even then but not in the quantity of later years. It is possible that this small amount of sand came from the erosion of South Beach, Redend Point and Middle Beach. Tertiary sandstones are present at all of these locations.

The classic work on the history of the South Haven Peninsula is that of Captain Cyril Diver (1933) who investigated the area by collecting and comparing the evidence of old maps. Parts of four of the old maps he used are shown in this image. Additional old maps are shown below.

Diver found that the three successive ridges of blown sand have been built up since as recently as the 16th Century. In the maps of Saxton (1575), Camden (1607) and Speed (1611) the peninsula is shown as nothing more than the narrow strip of land (Plateau Heath) corresponding with the Tertiary country west of the old sea cliff. Little Sea is first shown in a map published in 1721. It was then a tidal inlet with a wide opening eastward into the bay, partly enclosed by the earliest of the three dune ridges. By the end of the 18th Century the inlet had become a lagoon, and the Second Ridge had formed. A survey of 1849 (Sheringham's map) shows the beginnings of the First Ridge, but it was still invaded by the sea at highest spring tides, when the water also flowed behind it into Little Sea, along the course of the present outer trough of marshland (East Marsh). By 1886 Little Sea was virtually cut off from the sea (as is shown by Ordnance Survey 25 Inch Map according to Canning and Maxted). During the general growth of the sand area the outlines of Little Sea and the other pools passed through many vicissitudes, and part of the dunes built seawards near the south end of the area before the 18th Century was consumed again by the sea (Arkell, 1947).

The area of ridges is narrower to the south. Here Southern Heath is the equivalent of the Third Ridge and Inner Ridge corresponds to the Second Ridge to the north (Canning and Maxted, 1979). They considered that the southern First Ridge may not be of exactly the same age as the northern one.

South Haven Peninsula - McKenzie's and Sheringham's surveys More detail is visible in the charts of Lieutenant McKenzie of 1785 and of Captain Sheringham of 1849, redrawn by Captain C. Diver in 1933. These show how the Eastern Lake - New Cut slack area originated as a cut-off area of shoal sand. On the seaward side of this was a low barrier beach, driven landwards and forming eventually into a dune ridge. The maps clearly show that it formed as storm beach ridge not directly as a blown-sand dune ridge. Blown sand was latter added to the beach ridge. Stone island seems likely to be the relics of an old recurved shingle spit extending from south to north before the major sand development of the South Haven Peninsula took place. It is old, corresponding to a lower sea-level and is now gradually being submerged by rising sea-level.

Little Sea The later part of the 19th Century, and the early years of the 20th Century saw further accretion in the central part of Studland Bay with a maximum growth of some 75 m between 1886 and 1924. In the same period about 180 m were lost by erosion in Shell Bay. Between 1894 and 1900 Eastern Lake was formed and, just after 1900, the northern and southern dunes united to form a continuous ridge, then on the foreshore. Before this happened, water was able to drain through Central Gap in the First Ridge. By this time Little Sea was completely landlocked and it is now a freshwater lake, fed by short streams, with two outlets taking any surplus water to Shell Bay.

Changes still continue. Surveys show an advance of about 80 m. in the 30 years before 1924 (Arkell, 1947). Canning and Maxted (1979) have plotted the " Zero Ridge " and the indications of a " Zero Minus One Ridge ". Arkell had already referred to a new ridge (the Zero Ridge) as showing signs of forming when his book was published in 1947 (note that work for it, though, was mostly completed in the 1930s). He mentioned that the growth is counterbalanced by the sea attacking at more than double the rate on the north-east coast of Shell Bay.

Since 1933 there has been erosion of the dunes in Shell Bay and near the Knoll Beach Car Park. Surveys of the Nature Conservancy Council have shown that between 1936 and 1970 there has been erosion in Shell Bay of up to 23 m with some accretion of the foreshore in the centre of the Bay (Canning and Maxted, 1979). The Training Bank breakwater extension in 1924 might have had some effect. Similar erosion has taken place at the Knoll Beach car park and immediately to the south. Seaward extension of the dunes in central Studland Bay has continued. The foreshore has been extended seaward by up to 146 m between 1936 and 1970, in particular opposite the northern part of the Little Sea. As a result Zero Ridge is a development since Diver named the other ridges. It is now up to 40 m wide and 6 m in height. Behind is Zero Slack which separates it from First Ridge (Canning and Maxted, 1979). Scattered mounds of sand colonised by sea lyme grass are the evidence of the developing Zero Minus One Ridge and Canning and Maxted at that time saw possible signs of Zero Minus Two Ridge of the future.

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More on the South Haven Peninsula in the 19th Century

Studland in 19th C.

Victorian map of the Isle of Purbeck, showing the Little Sea and the piers for ships

Brannon's 1860 map of Poole Harbour, Sandbanks and Studland etc, Dorset, with his plans for development

The general map of the peninsula is reproduced here again for convenience. With it, on the right, and below, are Victorian maps of the area. The top right map is based on a map in Damon (1884). It shows the original peninsula of Tertiary strata (Bagshot Beds or Poole Formation) and reworked Pleistocene gravel, with sand dunes building up on the eastern side of it. The original peninsula was probably not unlike the next peninsula further west, Goathorn Peninsula at the present time. In the 19th Century there seem to have been the development of two separate areas of sand. One was a spit building out northward from Redend Point (inner ridge and first ridge?) and the other an accumulation of sand (the third ridge) alongside the narrow sinuous promontory extending northward to South Haven Point. These seem to developed separately, although probably both receiving sand from a large supply in shallow water offshore. Old charts refer to the tide flowing through at high water Legg (1987) . The joining of the two sand accumulations has resulted in the formation of the Little Sea, and the Eastern Lake represents part of the former channel between the two. Eastern Lake was formed between 1894 and 1900 and just after 1900 the northern and southern dunes united to form a continuous ridge Canning and Maxted (1979).

Note that Stone Isle or Stone Island is shown on this and other 19th Century Maps as a larger feature than it is now. Presumably rising sea level has reduced its area.

Amongst maps shown above is one of Brannon (1860). This map of Poole Harbour, Sandbanks, Studland etc. contains his plans for further development of the region. The Training Bank was proposed and built, but other proposed schemes have not necessarily taken place in accordance with the original plans.

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Sand Sources for the South Haven Peninsula - Bournemouth Cliffs

A major source of sand lies in the cliffs of Poole Bay. From Christchurch Harbour to Handfast Point the external coastline is approximately 24km. The bay includes the sands of the |North Haven (Sandbanks) and South Haven peninsulas but northwest of Poole Head is an extensive stretch of cliffs with Eocene strata. These include the Poole Formation of sands, clays and lignite, formerly know as the "Bagshot Beds". The Poole Formation forms the cliffs of Poole Bay, and before the sea-defences and promenades were constructed here there were impressive yellow sandy cliffs in the Bournemouth area. Some unvegetated relics are still visible in places. The sand in these cliffs is mostly mature quartz sand, deficient in carbonate. At the top of these cliffs is a thin bed Pleistocene, periglacial, river gravel of subangular flints.

The coastline of Poole Bay is sheltered in the southern part of Studland Bay, near Redend Point. Northeast and eastwards from here the coastline becomes progressively more exposed to wave action. The southwesterly storm waves can reach in almost undiminished form the central to the eastern part of the bay (to Hengistbury Head). The character of the beach material reflects the available cliff material and the level of exposure to waves. There is a gradual transition from fine sands to shingle eastward from Studland to Hengistbury Head but the change is not even. East of Poole Head the beaches have locally varying proportions of sand and gravel. All areas are subject to longshore drift and many groynes have been placed along the foot of cliffs in the Bournemouth area to retard depletion of the beaches by this action.

The construction of the promenade and sea-wall in the early part of the 20th century and its progressive extension cut off the sand supply. A loss by longshore drift and by seaward movement gradually depleted the sand beaches. Because the original beaches were large the effect of this loss of supply was delayed for many years but became serious by the 1970s. Because of the importance to the holiday resort the Council decided to replenish them by a renourishment scheme. A pilot scheme was undertaken during 1970 and the first major scheme implemented in 1974/75. A second major scheme was completed during 1988/89 when about a million cubic metres of material was dredged from the main shipping channel into Poole Harbour, the Swash Channel and most of this deposited on the Bournemouth Beaches (Lelliott, 1990) Thus part of a potential source of sand for the future natural supply of the South Haven Peninsula was removed. For more information on beach replenishment at Bournemouth and for further references see Cooper and Harlow (1998). Considerable research has been commissioned by the Bournemouth Borough Council to investigate the problem of loss of sand from the Bournemouth beaches. This has included mathematical modelling by Hydraulics Research (BP Exploration, 1991) . The work confirmed that the beaches are eroding due to lack of replenishment material from natural cliff erosion following cliff stabilisation. Sand on the beaches is moved by longsthore drift, generally eastward, from a point close to Durley Chine. A westward component exists between Durley Chine and Poole Harbour where westward longshore drift and migration of sand onto the Hook Sand takes place. Durley Chine is near the limit at which southwesterly waves can pass Handfast Point (Harry Rocks), and there is a transition zone there reflecting wave and current activity. Thus the supply of sand to Hook Sand is predominantly from the Poole Formation in the cliffs from Durley Chine to Poole Head. Hook Sand must be regarded as the intermediate supplier of sand to Studland.

Thus sands from the Poole Formation or "Bagshot Beds" of the Bournemouth cliffs are the main source and these are carbonate-free. They have arrived at Sandbanks and then Hook Sand and crossed to the South Haven Peninsula in the past. Just a small amount has entered the seaward part of Poole Harbour. There has been very little supply of carbonate from the sea in the form of mollusc shells. There are individual shells and just a very small amount of comminuted shell debris on the beaches, but this is in small proportion in comparison with that on many beaches as in southwest England, for example Saunton Sands and Braunton Burrows. The local name "Shell Bay" may give a false impression, at least at the present time. If you collect samples up the beach to the sand dunes and investigate them for carbonate, you will discover that all carbonate has gone by the time you reach the dunes.

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Sand Sources - Sand Reserves at Hook Sand

A substantial area and a substantial thickness of fine to medium sand exists at Hook Sand. This sand bank is situated over the old channel out of Poole Harbour. This old river channel ran underneath the end of the |Sandbanks Peninsula (as shown by borehole and seismic) and not on the present course of the entrance channel. The base of the sand body is at about 12m depth. Because of the proposal in 1991 to build Hook Island, an artificial island on Hook Sand, for oil production purposes a thorough report has been prepared on this shoal, referred to elsewhere in this webpage. It is the Hook Island - Poole Bay - Private Bill - Environmental Study (BP Exploration, 1991).

Hook Sand probably represents one of the large bulk volumes of sand available in any one area within Poole Bay. The dredging of the Swash Channel and use of the sand on Bournemouth beaches means that it has already been used in part (Turner, 1994) , and thus its economic value has to some extent already been recognised. Beach replenishment is a successful and popular 'soft' engineering shoreline management technique and as Cooper and Harlow (1998) have pointed out the technique is likely to proliferate in the future. Consequently, the demand for, and the cost of finite fill material is set to increase. Sooner or later the large resources of Hook Sand may be thought useful for replenishing beaches somewhere on the nearby coast. No plans are known for this, though. Any reduction in size, and therefore protective effect, of the offshore bank might, however, have adverse effects on both the North Haven (Sandbanks) and the South Haven Peninsula. It is unlikely that any drastic activities would take place without a full study of the possible consequences, though, and no doubt there would adequate opportunity for advance discussion. Of course, the actual loss of a potential future source of sand for the South Haven Peninsula may be less important than the effects of increased wave action that might result.

See Cooper and Harlow (1998) for a summary of the extensive data on the Bournemouth beaches of Poole Bay, discussion of the methods used and predictions for the future. Their final comment is that the next replenishment of the Bournemouth beaches is unlikely to concide with the dredging of Poole Harbour, so an alternative 'borrow' source must be found. Hook Sand is not discussed in this paper, though, and other sources might be available

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Transfer of Sand from Hook Sand to South Haven Peninsula

The possible process of transfer of sand from Hook Sand to Studland Bay now needs consideration. At the present time there is a well-defined net residual drift of water and suspended sand (necessarily fine) from Hook Sand southward across the seaward end of the Swash Channel during periods of wave activity (BP Exploration, 1991) . This would have occurred on a much larger scale in the past before the Swash Channel was deepened and straightened by dredging. When the water was shallow much sand could be moved on the seafloor by waves without having to be lifted far into suspension. This former transfer of sand in historic times from the North Haven Peninsula to the South Haven Peninsula is not well understood. Comparison might be made with Mudeford Spit near Hengistbury Head. At one time this extended eastward far beyond its present position. Later this extension to the spit was breached and the sand was added to the beach east of Mudeford Spit (near Steamer Point). Now some small dunes have developed in this area. Thus, the origin of the South Haven Peninsula lies in a great build-up of sand at the |North Haven Peninsula (Sandbanks). Much of this may have been offshore in shallow water. Originally the outflow channel of Poole Harbour (now the Swash Channel) would have been south of this huge shoal of sand. Did it break through on a more northern route causing the sand to become part of the southern area? To illustrate this one can consider what would happen if the Swash Channel was to break through north of Hook Sand, although this is not likely to happen. The sand supply of Hook Sand would then contribute to the South Haven Peninsula and new dune ridges would eventually result.

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Sand Sources - Other

There are some other possible sources of sand but they are relatively minor. Some material is brought down by the Frome and Piddle rivers and certain other streams, but this seems for the most part to consist not of sand but of very find sediment in suspension (Green, 1940). It is either carried on out to sea, or is deposited in the upper reaches of the harbour. A certain amount, however, is deposited on shoals within the main part of the harbour, particularly where tidal currents are weakest and where Spartina is growing. In the lower harbour this takes place at present especially in the quiet water south and east of Brownsea Island. Note that some fine sediment may also enter the harbour from the sea as a result of tidal currents. Important to the study of sand sources at the South Haven (and North Haven) Peninsulas is that no significant quantity of sand is supplied from the river systems. It is all sand from the coast.

In addition to the obvious source in the Bournemouth cliffs there is another possible source area where sand is definately available. This is from the Tertiary cliffs of Redend Point and South Beach, Studland . Some sand must be provided here because active coast erosion takes place, but the quantity is small. There is available sand in the Reading Formation and in the Redend Sandstone but the stretch of cliffs is limited and the cliffs are not high. If you examine the photographs in the Studland - Tertiary webpage you will not see much evidence of major drift of sand northward round Redend Point. A small amount may pass the headland but it is not likely to be of much consequence. In any case Middle Beach, immediately north of Redend Point is undergoing erosion at the present as shown by the sea-defences which have been placed there.

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Reduction in Sand Supply?

Areas of sea-grass and maerl offshore from Studland

Old chart of banks, bars and channels off the South Haven Peninsula, Studland, Dorset

Waves breaking on Hook Sand, Studland

Ferry in the Swash Channel, off Studland


Studland Bay - comparison of old and newer charts

The Training Bank, Studland Bay, at low tide

As noted elsewhere in this webpage, the construction of the promenade and sea-defences on the Bournemouth coast took started about 80 years ago with progressive development since. The western cliffs of Poole Bay were not defended until a later stage. All this has effectively cut off any new sand supply. However, significant residual sand from historical erosion of Bournemouth cliffs probably exists at Hook Sand and adjacent offshore shoals. This is now largely prevented from reaching the South Haven Peninsula. There is effectively a ditch and rampart barrier on its route. The Training Bank was constructed from limestone blocks (Portland and Purbeck stone) in 1924 to direct the ebb and flow of tidal currents so as to maintain a navigable approach to Poole Harbour (Bird, 1995) . Since then the Swash Channel has been dredged and is now a relatively straight and deep feature. With both these obstructions it is unlikely that any large quantity of sand can now reach the South Haven Peninsula, but the matter requires further investigation. Whether any sand can still enter the bay south of the Swash Channel and Training Bank is not known, but this is probably not a major route.

Another possible route for sand transport to the South Haven Peninsula should be considered. That is by longshore drift along the Sandbanks Penisula (North Haven Peninsula) southwestward and then a feed of sand into the main channel at the point and some transfer of this across to the south side. Even if this has happened in this past, it is unlikely to be significant now. The former sand dunes of the Sandbanks Peninsula are almost entirely built over and there are concrete sea-defences, not sand beaches at the ferry. Sand cannot travel round the southeastern point of the peninsula and supply the channel.

Thus, there is no obvious means of substantial supply of sand now. There will be continuing loss of sand, though, to the south and to the deeper water. The stronger ebb tide in the Swash Channel will transport sand in a seaward direction . Further to the south and southeast some sand may be drifted away by the strong tidal currents. Tidal currents though are carrying the quite large particles of red algae ( Lithothamnion etc) of the Maerl, much larger than sand grains, as far south as Durlston Bay. Thus, although this is not understood in quantitative terms, overall there seems to be some net loss of sand and no significant gain. The South Haven Peninsula will probably diminish by erosion in years to come and may already be doing so at Shell Bay, in particular. The process might be slow, but evidence of coastal erosion on the peninsula should be watched carefully.

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Sand Transport - Eolian (Wind) Action

Marram grass is bent by the wind, while sand is blown into small linear dunes, Shell Bay near Studland, Dorset, 18th March 2006

Sand blown inland at the Foredunes or Zero Ridge, Studland, Dorset, March 2006

Here sand in Shell Bay and Studland Bay is being moved by an unusual, near-freezing, easterly wind on the 18th March 2006. Conditions were dry and overcast. The wind was so strong on this day that somewhere to the south of the coast a yacht was swamped and, sadly, only one of the two crew survived the icy sea. The rescue helicopter later passed our party when they had reached Harry Rocks.

Dressed for sand and storm, November, 2003

Into the storm, on Studland Beach, November, 2003

Sand transport by wind from Studland Bay into Shell Bay

On another cold day, this time in November 2003, sand is transported by a gale-force wind from the south. This is at the northern end of Studland Bay, close to Pilot's Point and the Training Bank. It was raining, quite heavily at times, and yet in spite of the wetness of the beach sand it was mobile under the strong wind-force. The prevailing wind-direction is from the southwest and, in general, southerly rather than northerly winds are more common. Thus it seems that much sand is transported northward along Studland Bay, and this perhaps, partly accounts for the relatively greater coast erosion in the southern part of the bay. Here in the north, some of the sand can be seen entering the sea at Pilot's Point at the eastern end of Shell Bay. Sand is transported by saltation (bouncing grains) and that is why it remains close to the ground, usually within a metre or less. Thus, were it not for heavy clothing one should be able to feel the sand on one's legs but not on one's face. This is a readily noticed and uncomfortable effect in deserts. Here, on the South Haven Peninsula, there is no significant quantity of silt and thus the dust-storms of deserts are not produced. Consequently, there are no deposits of loess or blown dust on the peninsula.

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Sand Transport - Blowouts

Blowouts or blow-outs are places where the dune surface has been lowered by the blowing away of sand. This is associated with local destruction of any binding vegetation, such as Marram Grass.

Shell Bay, near Studland, Dorset; the southeastern part seen from a boat in the channel

Blow-out at Pilot's Point, South Haven Peninsula, Dorset

Shown above, from the channel and close-up, is a blowout at Pilot Point. Here the end of a major north-south dune ridge of Studland has been cut across at Shell Bay. Any marram grass which might have held the sand in place has been destroyed and erosion has opened up a concave depression of loose sand. This might have been initiated naturally by coast erosion or it might have been formed by trampling destroying the vegetation. There are obvious signs of many people having walked here. It is located at the eastern end of Shell Bay where visitors may ascend the dune ridge to return to the ferry area. Of course it might be the result of both coast erosion and trampling.

A large blow-out north of Knoll Beach, Studland, Dorset

This large blow-out north of Knoll Beach is gently concave. It is not directly connected to the present beach and not obviously related to natural erosion. Furthermore it does not seem to be in a place where there has much erosion by human activity. At the northern margin there has been erosion of the soil and sand beneath in miniature cliffs. I do not know the origin of this one; it could even have been formed by explosives since this area was used for military training during the Second World War. Further study is needed; perhaps you would like to find it and investigate it!

Research elsewhere into blow-outs have shown that they can channel the wind and it achieves higher velocities within them. A study has been made of coastal dunes and blow-outs in British Columbia, Canada, and this provides a useful model. The following extract is from Anderson and Walker (2006), a good paper which is available on the internet.

"As flow enters the blowout, it accelerates by as much as 1.8 times that of incident flow on the beach and is steered up to the wall of the blowout. Once flow enters the blowout, it becomes steadier and faster and promotes increasing saltation. This confirms similar observations by Hesp and Hyde (1996), Hesp and Pringle (2001) and suggests that blowouts act as transport “conduits” that channel flow and sediment from a variety of incident flow angles through the foredune into the foredune plain. In addition, flow speed in this region is inversely related to flow steadiness, which confirms Walker and Nickling's (2003) wind tunnel observations of accelerated flow toward the crest of an artificial dune. Furthermore, in the narrowest reach of the blowout where streamlines are most constricted, flow steadiness, speed, and surface deflation are greatest. These effects are reflected in the more poorly sorted, coarser (winnowed) sands in this region. Under drier conditions, enhanced sand transport toward the head of the blowout would occur, promoting continued erosion of the trough and increased sand delivery into the foredune plain."

The comments above refer to blow-outs in the foredunes of a vegetated and moist area in British Columbia. Think about the observations in relation to the South Haven Peninsula. Is sand delivered back landward of the foredunes through blow-outs?

Footnote: Incidently, with reference to the notice seen in a photograph above, there has been some dispute between naturists and the National Trust who own the area, at least according to a recent television programme on the Studland area. Their territory seems to have been reduced recently by half a mile from this previous southern end. They are not often seen by geologists and we did not encounter any this occasion.

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Coastal Erosion on the South Haven Peninsula

In separate sections of this web page some coastal erosion is noted. At South Beach there are cliffs which are undergoing limited erosion. A small stack of sandstone has collapsed a short distance to the south of Redend Point. At Middle Beach metal gabions have been used to prevent coast erosion. There is obvious erosion of small sand dunes between Middle Beach and Knoll Beach. Beyond that to the north erosion is less evident. Shell Bay, though, shows some erosional features and is more indented in recent years than in the past. The main Studland Bay beach north of the Knoll Beach facilities has generally been an area of accretion or progradation.

Copland and Overton (1976) have presented data from NERC that shows the changes in position of the dune edge from 1936 to 1970 for the South Haven Peninsula. This is not reproduced here and reference should be made to that publication for details. On average Shell Bay has retreated by 8.2m in 34 years (0.24m per annum). The Pipley Pools or Knoll Beach car park area has retreated by 11.2m in the same period (0.33m per annum). The stretch between the car park and Pilot's Point has shown striking progradation of 80.3 m during this time (2.36m per annum). There seems little doubt that the erosion is continuing at Shell Bay and from South Beach through to the Knoll Beach car park. An important question is whether the long stretch of beach between the car park and Pilot's Point is still prograding, whether it is now static or in retreat.

Erosion of old dunes at the south side of Knoll Beach

Limited erosion at the base of the Foredunes, Studland Bay, north of Knoll Beach, Feb 2003

A photograph above is of erosion south of Knoll Beach and is compatible with the measured data referred to above. The right-hand photograph of the foot of the dunes north of Knoll Beach shows that at least some erosion is occurring where it would not be expected. Of course, this may be local and due to a particular storm. It is merely a type of indication that might be looked for elsewhere on the beach. Precise measurement and aerial photographs will show whether the beach is prograding, static or retreating. From an educational point of view it is worth examining the foot of the dunes and considering whether any evidence for erosion or progradation exists. Notice, incidently, in the photograph that some small amount of sand can be seen to have been blown from the dunes (from the west) onto the top of the beach. We will leave the matter of erosion now as an open question requiring further observations and data.

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4.1 THE DUNES: Introduction - Sand Dunes in General

The Studland dunes are very small compared to dunes elsewhere and for the most part they are not very active, being largely fixed by Marram Grass and heather. Nevertheless they are interesting small coastal dunes and provide an acid sand environment that is important in terms of ecology and botany. We will make some comparisons with dunes elsewhere before discussing the details.

Desert dunes reach the sea at Umm Said, southeast Qatar

Windward to left horn side of a barchan, Umm Said, Qatar. Note the wind-rippled, convex surface.

Driving to the slipface of a barchan, Umm Said, Qatar

The slipface of a barchan, with lineation from avalaching sand, Umm Said, Qatar

The photographs above are shown to place the Studland dunes in perspective. These huge dunes at Umm Said in southeast Qatar are near the coast. They are not true coastal dunes derived from coastal sand but are desert sand dunes that have travelled south-south east in this very arid region. The prevailing wind direction (of the "Shamal") is from the north-northwest towards the south-southeast. Individual barchans (crescent-shaped dunes with horns downwind) are so large that at one place there is the very unusual feature of quite a large quarry for building sand that has been opened within a single dune. Please go to the Sabkha webpage for more photographs of desert barchans.

Question: Why are well-developed barchans not formed at Studland, yet are such conspicuous features of Qatar?

Grey coastal dunes on the west side of the Akrotiri Peninsula, Cyprus

For contrast, here are coastal dunes not desert dunes, but of a semi-arid area, the Akrotiri Peninsula, Cyprus. They are unusual for their grey colour. This is the result of the local beach sand containing mafic minerals such as pyroxenes derived from the breakdown of debris of gabbros and ultramafics. Such material is transported to the coast by seasonal rivers. The fairly dry climate limits chemical weathering and decomposition of the mafics.

For comparison with the South Haven Peninsula, Studland note:
1. There is no significant amount of Marram Grass in the Cyprus dunes. This is probably the result of the semi-arid climate.
2. As noted above, unstable minerals are present in the sand which give a grey colour. The Studland sand, by contrast, is extremely mature and almost all quartz. Mafics will be in exceptionally small quantities (the reason for this is the complex Trias-Eocene-Recent history of the sand, especially its passage through the hot, acidic Eocene delta!).
3. The area is too dry, at least in summer, for permanent freshwater lakes, like the Little Sea, to develop behind the dunes. Small pools do occur. They are probably of freshwater in winter (and may add to the local problem of mosquitoes) but dry out later in the year. There is much halite precipitation summer in the main Akrotiri salt lake, which is a little further to the northwest.

Oregon Dunes National Recreation Area, Oregon, USA

Oregon Dunes, view westward to the Pacific Ocean

Oregon Dunes, view seaward from a high dune; colonization by European Marram Grass

Oregon Dunes, large barren dune with development of trees on an older dune

For further comparison, here are some coastal dunes in the Oregon Dunes National Recreation Area. They are much larger than the dunes of Studland. This is probably because there is are very great quantities of sand on the beaches of the bays between the rocky headlands of Oregon. The Oregon coast has had a great supply of sand from the Pleistocene glaciation and strong winds can blow in straight from the Pacific Ocean. As at Studland, there is a lake, another "Little Sea". This has been formed by sand dune ridges blocking the outflow of a stream, and like the Little Sea of Studland the water in it is fresh. Notice how the dunes are encroaching on the natural Douglas Fir forest and beginning to kill some trees. The vegetation of the hinterland is quite different from Studland; well-developed coniferous forest are almost everywhere except where destroyed by man. The climate is very seasonal with much winter rain. Overall it is fairly moist and not semi-arid and there are no salt lakes. The heather of Studland does not seem to grow here (perhaps it is a little too dry in the summer).

Unfortunately European Marram Grass has been imported into the region in the past, and you can see some in the picture. It spoils dunes by covering them with vegetation and consequently efforts are made to remove it. In contrast, for various historic and traditional reasons, and because it can give some protection against erosion, is popular in Britain! (I do not like Marram Grass and prefer to see sand dunes, but that is a personal view, and you may not agree).

Student Essay or Dissertation Work - Geography or Environmental Science

1. Find websites on the Oregon Dunes, USA, including the ones given below and write an essay comparing and contrasting this coastal dune environment with the coastal dune environment of the South Haven Peninsula, Studland, Dorset, England.

2. Compare and contrast the management and protection of the two regions, both of which are important for the environment and for recreation.

Oregon Dunes National Recreation Area and -
Geology of the Oregon Dunes.

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4.2 THE DUNES: Soil and Vegetation - Introduction

Schematic cross section through Studland dunes and beach

Succession of vegetation developing on dunes at the South Haven Peninsula

Dunes looking northward from near Knoll Beach, Studland

A wide sandy beach of Studland Bay forms the eastern seaward side of the South Haven Peninsula. Onshore easterly winds, especially during storms can blow the sand inland. The source of the sand is probably from the Tertiary strata of Poole Bay, although the details of its origin are not well-understood. The sand is generally non-calcareous, except for a few shells on the beaches. When blown inland it accumulates around any form of obstruction such as plants or driftwood. The sand of the dunes has the very low calcium carbonate content of 0.015% according to Canning and Maxted (1979), in contrast for example with 6% at Southport in Lancashire. Some beaches and sand dunes of Devon and Cornwall have very high carbonate contents. Musical sands, which produce a squeaky sound have been reported on the South Haven peninsula.

There is an interesting transition in terms of sediment stability and vegetation from relatively new dunes adjacent to the beach of Studland Bay back to older dune ridges and finally the Little Sea. The diagrams and the photograph above, and those further down, give provide an introduction to the transition landward. A transect can be made which will show the succession, and Copland and Overton (1976) recommended that this could be done along what was the northern boundary fence, that is a line across the peninsula roughly east-west near the middle and a short distance north of the Little Sea. The National Trust should be consulted before such field work is carried out, though. Note that the sequence may not be entirely systematic. There are local variations caused by trampling and subsequent erosion, and in addition the presence of occasional calciole plants caused by wartime debris and limestone placed beneath the ferry road (Copland and Overton, 1976). Work on the open heathlands can show succession at a later stage of development. Areas of heath are frequently burned, either by accident or at certain times of the year as part of the management programme. Copland and Overton (1976) stated that a variety of ages of heaths is present and can be dated by reference to Gimmington (1972) , a book on the ecology of heathlands. Figures for biomass and productivity of Dorset heaths are available in this book and BES journals.

The marram grass and heather, discussed below, are the conspicuous plants of the sand ridges and nearby low ground and are easily recognised. They are not the first plants to colonize the sand though. According to Canning and Maxted (1979), the first are salt-tolerant grasses such as sea lyme grass, Elymus arenarius with characteristic broad, waxy blue-grey leaves, and sand couch grass, Agrophyllum junceiforme, which has thin leaves.

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THE DUNES: - The Foredunes or Zero Ridge

Ramification of paths in the Foredunes or Zero Ridge, Studland Bay, Dorset, aerial photograph,courtesy of the Channel Coastal Observatory

Foredunes or Zero Ridge looking northward from near Knoll Beach, Studland

Marram grass Shell Bay

Mobile sand in Foredunes, near the centre of Studland Bay, looking east

Marram grass and Training Bank

Studland Bay

Heath-covered dunes and the Foredunes of sand with Marram Grass

As shown in the photographs, there is a line of Foredunes next to the beach. Directly adjoining the beach at Studland Bay, are the Foredunes. These have been referred to as Zero Ridge by Canning and Maxted (1979) and Copland and Overton (1976) . These dunes are shown here in various photographs taken near to Studland Bay, and mostly in winter. They tend to consist of loose, mainly mobile sand, partly held in place by marram grass, Ammophila arenariaprobably the most important single dune forming grass. This grass is not very salt-tolerant and depends on a continual supply of fresh sand for its survival Canning and Maxted (1979) . It is not very common inland because the sand supply is not active there. Marram grass produces underground runners, rhizomes, from which new shoots spring and its quite capable of growing upwards through many metres of sand, with the lower roots eventually dying off. According to Canning and Maxted (1979) , the dunes are now likely to be considerably higher as than previously as more sand is trapped. The amount of humus in the dunes is low and this explains their light colour compared to the older darker dunes.

Incidently, notice in the photographs the effects of different light conditions. Some pictures were taken just before sunset and have a reddish tinge. Notice that in one of the images the Foredune ridge is much flattened by trampling. This area is close to the popular Knoll Beach, towards the southern end of the peninsula and near a large car park. The image with untrodden loose blown sand is in the less-used naturist area. This central to northern part of Studland Bay, marked by red posts and by signs, is more distant from the car parks.

With regard to the Foredunes there is an interesting comparable feature on the sandspit of Dawlish Warren on the west side of the Exe Estuary in Devon (near Exeter). A marram grass dune ridge is a prominant feature on the seaward side of that sandspit. This spit has not recently accreted though. Instead it is in a serious state of erosion and much of it has already been lost. The marram grass ridge is already cliffed, unlike that at Studland.

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Older Dunes - Soil and Vegetation

Vegetation at back of dunes

Heath-covered dunes and the Foredunes of sand with Marram Grass

On the South Haven Peninsula any small amounts of calcium carbonate is soon removed by leaching and the soils become acid. Raw humus accumulates. Acid-loving plants such as ling, a type of heather, can become established much more rapidly than in other regions of the British Isles. Heather-covered dunes become conspicuous a short distance inland from the beach. This change to heather can be seen in some of the photographs above. You can see the environment well from a "Heather Walk" which extends southward from Shell Bay adjacent to the New Cut (the outflow from the small Eastern Lake). The photograph attached here shows the view looking southeast from the dunes at the margin of Shell Bay across the swampy area near New Cut towards the First Ridge and the Zero Ridge of Studland Bay. In the distance is the Chalk headland with Harry Rocks.

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Oilfield Beneath the South Haven Peninsula

For some information on the Wytch Farm Oil Field pleas go to:

|Studland Peninsula - Poole Harbour Side


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For location on the Poole Harbour Side please go to:

Studland Peninsula - Poole Harbour Side

5.1.1 LOCATIONS: Shell Bay - Introduction

Aerial photograph giving an overview of the channel between Sandbanks and the South Haven (Studland) Peninsula, Dorset, courtesy of the Channel Coastal Observatory

Shell Bay in summer, South Haven Peninsula, Dorset

Shell Bay, near Studland, Dorset; the southeastern part seen from a boat in the channel

Entrance to Poole Harbour

Shell Bay

Shell Bay with a freezing wind in Jan 2003

Eastern outflow

Reed-swamp at Shell Bay in January, 2003

Shell Bay is a northwest facing beach at the entrance to Poole Harbour, shown in the left photograph. The beach, as seen here is fairly clean beach of medium quartz sand, with a few footprints and some seaweed accumulation. It does not seem now to have the abundant shell content for which it was once known and which seemed to me to be more obvious back in the 1950s. Shells now seem more common in Studland Bay, but, of course, there may be variation in shell abundance within each year.

One of the images shows the view to the southeast in the direction of the Training Bank and the junction of Shell Bay and Studland Bay. Dunes covered with marram grass can be seen in the distance. The photograph was taken with a low sun late on a clear November day and from close to South Haven Point. A short distance ahead of us is the outflow from the Central Cut, referred to below.

In another photographs a channel across Shell Bay beach is seen looking northwest from the Phragmites reeds which flourish in the wet marshy areas near the channels at the back of the beach. The reed-swamp is a former continuation the Little Sea and water flows northward through this to the outflow channel into Shell Bay.

Notice that two of the photographs show the entrance to Poole Harbour, and across this can be seen the Sandbanks Peninsula. To the right are the Eocene sand and clay cliffs of Bournemouth, which, in the past, have provided the source of sand for both the Sandbanks (North Haven) and the Studland (South Haven) Peninsulas. A promenade and sea defences has now cut off any significant further supply.

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5.1.2 LOCATIONS: Shell Bay - Changes

Shell Bay, the northeast facing end of the South Haven Peninsula was straight in the first half of the nineteenth century. In 1940 Green commented that it then showed a marked concavity due in part to the development of of blunt, spit-like formation at the east corner, and to a hollowing out of the coast between the latter and South Haven Point (is Shell Bay even more hollowed out now?). Green referred to some anecdotal evidence of an eddy operating in Shell Bay on the ebb tide. Commander Euman noted that: "An old tin bath was seen moving in the main stream out through the Havens. Instead of continuing its journey outwards it passed back into Shell Bay north of Pilots' Pier, and continued close to the shore back towards the ferry, where it again joined the main ebb stream running southwards.

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5.1.3 LOCATIONS: Shell Bay - Antidunes

Eastern outflow

Outflow channel, Shell Bay

Standing Waves in outflow

There are two outflow channels from lakes in the South Haven Peninsula that cross the sands of Shell Bay. Near to Ferry Road and South Haven Point is the western outflow channel, the larger one, which comes from the Central Cut, an artificial overflow drainage from the Little Sea (see map above). This channel through the beach is shown in the left photograph above. The other photographs show the development of sedimentary structures within the fast-flowing channel. These photographs were taken on 12th November, 2000 during the wettest winter on record up to that time. Notice that the heavy flow produces standing waves and that the water is discoloured brown by the peaty soil around the Little Sea and the peaty sediment within it. The exact position of the channel on the beach varies and former positions leave pools and disturb the regularity of Shell Bay.

Underneath the standing waves (stationary waves) of water are above wave-shaped structures of sand. These are known as "antidunes". The South Haven Peninsula has not just got dunes; it has antidunes! These are bed waves of sand, in phase with the stationary water waves, and of sinusoidal profile along the direction of the stream. Unlike other types of dunes they migrate upstream. Laminae dipping gently up current accumulate on the upstream side of the bed undulation. They can give rise to low angle cross-lamination dipping at low angles (less than 10 degrees) in an upstream direction. Antidunes require special conditions; the flow velocity should be more than about 100cm/sec and the flow depth usually not much more than half a metre. They are generally unlikely to occur in deep water in natural conditions because extremely high velocities are needed for this. They have, however, been reported at the base of some turbidite flow units.

A feature of the standing waves in the outflow of the Central Cut at the time of the heavy water flow shown was a periodicity in water flow. Every minute or so there was a surge of faster flowing water that caused an increase in amplitude of the standing waves and some breaking of the waves. The right hand photograph was taken at such a time. I do not know what was the cause of the periodic surges. They also caused periodic collapse of the channel bank at curves in the stream.

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5.2 LOCATIONS: North Haven Point and the Sandbanks Peninsula

Sandbanks ferry from Shell Bay, Jan 2003

Sandbanks ferry from the ramp on the Shell Bay side

Sandbanks Peninsula from the air Entrance to Poole Harbour

The entrance to Poole Harbour is very narrow and crossed by a chain ferry. The Sandbanks Peninsula, on the north side, is shown in some photographs here for contrast with the South Haven or Studland Peninsula. Please to to the Sandbanks section of the Bournemouth webpage for more information.

This northern promonotory at the entrance to Poole Harbour was once a wild place of sand dunes like the South Haven or Studland Peninsula. As a natural sand spit it has long ago been effectively destroyed by development and the dunes are almost entirely either covered with housing or turned into gardens. Fortunately, however, this rather built-up area has greatly benefited from the planting of pine trees and nice gardens. Although these are not indigenous here, the pine trees have much improved the appearance of the area, stabilised the loose sandy soil and acted as wind breaks. Without these it might have been a rather bleak and unattractive area of housing. With the trees, the yatching and some of the best beaches in the Bournemouth area Sandbanks has become a very valuable and desirable place that is pleasant to visit. It is fortunate, however, that major development has not happened on the Studland side of the harbour entrance. If a bridge had been built the consequences would have been disastrous to the natural environment.

Notice the general shape of the Sandbanks peninsula with its narrow neck at Poole Head. It is clearly a type of recurved spit with sand accumulation at the southwest end, but the detailed structure is no longer visible. This sand has presumably come from the sandy Bournemouth cliffs and the groynes should indicate drift from northeast to southwest. On the right of this old photograph they do not, however; the sand has locally moved northeast and accumulated on the southwest side of the groynes. This, though, may be just a local effect. Many sandspits are hazardous places for development. Sandbanks is safer than most because the prevailing winds and, usually the storm winds are from the southwest and this peninsula is protected by the Isle of Purbeck. Threats to the area in terms of coastal erosion are not serious at present but could arise in years to come from a combination of circumstances of limited sand supply, gradual sea-level rise (a few mm per annum since the 1940s) and a sequence of severe southeasterly storms. Such storms have broken Calshot Spit, and even the Chesil Beach is said to have been breached in historic times (Arkell, 1947). Generally, however, Sandbanks is a safer sandspit than most, and even if it was breached in the narrow part near Poole Head, it could probably be repaired without too much difficulty.

By preventing erosion of the sandy cliffs, the sea-defences of Bournemouth have largely cut off the sand supply to the area to the southwest, that is to Sandbanks. The Bournemouth promenade has been there for about 80 years or more and major problems have certainly not arisen quickly. There has been some artificial renourishment to Bournemouth beaches by using dredged offshore sand and this might have helped the supply problem in the short term. In the long term, though, the source of sand supply has gone (unless there is major storm destruction at Bournemouth and renewed cliff erosion) and the net effect will be slow loss of sand and therefore gradually increasing coastal erosion at the North Haven Peninsula. Because of the barrier of the deep Swash Channel and the Training Bank there is little likelyhood of sand returning to Sandbanks from the South Haven Peninsula. Of course, if necessary some sort of renourishment on a large scale could be used to replenish the sand resources of the peninsula (think about possible sources). Incidently, a television local news report in February, 2003 stated that sea-defence work is to commence at Sandbanks. The even more difficult matter of sand supply supply to the South Haven Peninsula will be discussed in a separate section.

Questions for the Reader:

1. Where is there another sandspit in Dorset, closely resembling Sandbanks geomorphologically, but is on a smaller scale? It is less developed but has a few houses and a car park.

2. Where is there yet another, but larger, sandspit in Dorset, originally rather similar to Sandbanks, but now so extensively developed for housing that it is hardly recognisable as a spit? Although it may differs a little in probably having more gravel in parts and its coastline faces more directly east, it has similar wide, sandy beaches, popular with the public. It was temporarily flooded across at the Narrows in the Great Storm of 1824.

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New Cut and the Saltings Strip

New Cut flows out to Shell Bay

New Cut in the Saltings Strip, south of Shell Bay

Behind the First Ridge of Diver (1933) noted that in the northern part there was a strip of saltings, which he referred to as the "Saltings Strip" with the rush Juncus maritimus. He stated that the main strip is separated from the northeast coast by low hillocks of recently blown sand (now the well-established, heather-covered First Ridge and with Zero Ridge seaward of this), and at its southern end runs into the Eastern Lake. The Saltings Strip is probably now characterised by fresh groundwater and is unlikely to be as saline as the name seems to suggest. This is still, though, a marshy slack with rushes. The New Cut now runs through it. This shallow drainage ditch was dug in the winter of 1932-33 for the length of the strip from Eastern Lake to the eastern part of Shell Bay. There is a significant northward flow of freshwater but not to the same extent as the outflow of the Little Sea which enters Shell Bay further west, near the Ferry ramp. At Shell Bay the seaward end of New Cut has been diverted by the development of a new sand dune, as shown in the photograph.

For another "Saltings" location with rushes go to rush-marsh area east of the Little Sea and accessible from Knoll Beach.

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The Little Sea

Little Sea, seen from the west

Little Sea Studland, Dorset, looking northward from the southeastern shore

Little Sea Studland, Dorset, looking southward from the southeastern shore

Most of the shores of the Little Sea are more or less inaccessible and this is good from a point of view of conservation and bird-life. The southeastern shore of the Little Sea is however, accessible in places by a path from Knoll Beach, but it is best that it is not heavily used.

The shore at the southeast end shows a fairly abrupt change from vegetated sand-dunes with heather and bracken to shallow clear and slightly brown water. The shallows at the margin are of sand mostly with land vegetation coming directly to the margin of the lake. In places, though, there some very small sand beaches with drifted vegetation debris. Phragmites grow a short distance out from the shore, perhaps where there is a higher proportion of mud. The sandy shores have large wood ants, and in summer dragonflies, mostly blue, flit around. Out on the lake there is a cormorant or a shag diving for fish and a few seagulls. It is a very quiet place and the footprints of deer show that they come to drink at their "waterhole" here.

Drosera rotundifolia, the insectivorous plant, Sundew, at the acid shores of the Little Sea, South Haven Peninsula, Studland, Dorset

The acidic conditions at the margin of the Little Sea are shown by the presence of the insectivorous plant, Sundew, Drosera rotundifolia which normally lives in nutrient-deficient bogs, and which uses the insects it catches as a source of nitrogen.

Exercise regarding the shores of the Little Sea, Studland, Dorset

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Rush Marsh or Bog, East of the Little Sea

A rush marsh or bog with Juncus, between the Inner Ridge and First Ridge, South Haven Peninsula, Studland, Dorset

A map by Steers (1946) after Diver (1933) of the South Haven Peninsula

If you walk northeast from the southern shores of the Little Sea or instead proceed about 1 km northward from Knoll Beach, you will encounter an interesting Juncus or rush marsh or bog. Look at the map above; this marsh is in the south-pointing reentrant between the First Ridge and the Inner Ridge. Can you find this? It is close to a small hill (a dune) with concrete relics of the Second World War and to some well-developed silver birch trees, unusual in this area.

This rush-marsh was once a low stretch of sand-flats without dunes. These areas have been referred to on old maps as "saltings" and presumably they were once saline. Now, however, well-separated from the sea they probably have fresh groundwater. They are vegetated by clumps of the rush Juncus (probably Juncus maritimus but the species has not been checked). There are more areas like this. See the New Cut and Saltings location.

At the southeastern end of this marsh, next to the path is a bomb crater, fenced off because of deep water. At times this southern end of the Juncusmarsh area may be inaccessible because of swampy ground and small water-courses.

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Knoll Beach

Knoll Beach on a summer's day, Studland, Dorset, view northward

Studland Bay, looking northward from Knoll Beach

Erosion of old dunes at the south side of Knoll Beach

National Trust facilities at Knoll Beach in winter

At Knoll Beach there is a car park, an information centre and a shop and other buildings of the National Trust. There are facilities for school parties. There has been some limited development here over the years and the place is not quite as natural as it once was, but the result is the provision of useful facilities for visitors. The buildings are not obtrusive and fit in well with the scenary. In addition there are associated nature reserves and sign-posted walks. From Knoll Beach there is the long sweep of the beach of Studland Bay northward to the Training Bank. To the south there seems to be some erosion taking place. This is to some extent smoothing out the line of the coast from Middle Beach to Knoll Beach. Some gabions have placed at the shore south of the stretch shown in the photograph to protect against further erosion. Thus this was once a place of sand accretion but is now is one of erosion.

Trees in boggy ground, northeast of Knoll Beach

Inland from just north of Knoll Beach, northeast of the National Trust facilities there is a low area of boggy forest. This is situated a short distance north of the Knoll, the prominant hill, and just east of the road to the ferry. This area was naturally reclaimed from the sea at an early date, and may be in effect an early and now filled part of the Little Sea. Examine the geological map and see if this accords with the distribution of alluvium at the site of the old southern end of the Little Sea.

An aerial view, courtesy of the Channel Coastal Observatory of the area inland from south of Knoll Beach Studland, Dorset, showing an old cliff line

Inland from the south side of Knoll Beach there is an old cliff line (at the edge of the Knoll or Knowle). There was already a small sand spit in front of this in 1585 as shown on the old map. This cliff may not have been undergoing active erosion since about 1500. The sea will reach it again in the future. If you study the maps you can trace this cliff line from Redend Point near Middle Beach round to NE of the Knoll Hotel. The road from the ferry to Studlands probably ascends this cliff.

View of Harry Rocks from Knoll Beach, Studland, Dorset, enlarged

From Knoll Beach the protection given by the Harry Rocks and Foreland peninsula is very obvious. It prevents the strong southwesterly waves driven by the prevailing southwesterly wind from reaching the beach. Wave action is mostly slight and the energy is generally not sufficient to move coarse gravel or boulders.

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Studland Bay, north of Knoll Beach

Studland Beach in winter

Crepidula fornicata and other shells on Studland Beach

Ensis and Ostrea on Studland Beach

The main Studland Bay beach (regarded by some as still part of Knoll Beach) sweeps northward from Knoll Beach to Pilot's Point and the Training Bank. It is a broad sandy beach with relatively few pebbles compared with other beaches in this region. It is much less pebbly than are the beaches at Bournemouth, for example. This is partly because of an a rather limited supply of flint pebbles on this side of Poole Bay, and more importantly because the hinterland consists of abundant blown sand. In places there is some variation. At certain levels high and low on the beach there are lines of shells with some small subangular flint pebbles. The razor shell, Ensis is conspicuous and the cockle shell Cardium (Cerastoderma) edule (or perhaps - C. glaucum?) is very common. The American gastropod Scrobicularia fornicata is always conspicuous in this area. It is an abundant mollusc, not natural to region, which has damaged oyster beds.

Various other bivalves occur and should be looked at closely for identification, preferably without removing them from the beach. The National Trust has published a handout, Studland Information Sheet No. 6, Sea Shells. This is available from the National Trust shop at Knoll Beach. It contains a list of about 58 gastropods (univalves) and bivalves that have been recorded from the beach at Studland Heath National Nature Reserve. They are not illustrated, though, and a colour guide book to British sea-shells would be needed for identification.

An interesting feature shown in one of the photographs above is the red alga from the Maerl beds offshore, shown on a map above and recorded in the Hook Island Study. These are not often found on the beaches in this region. The examples shown were found a few hundred metres north of the Knoll Beach car park. They have also been swept by currents into Durlston Bay, Swanage, and can be found just north of Durlston Head at the low tide level. The occurrence north of Knoll Beach is presumably the result of washing onshore of debris from the northernmost patch of Maerl which has been mapped just offshore from here. The algae are Lithothamnion and Phymatolithon according to the Southampton University diving team which surveyed the sea-floor here.

Other features of interest in this stretch include the presence of much small lignite at the low-tide level on one part of the shore a few hundred yards north of Knoll Beach. This is probably debris reworked from the lignite-bearing Poole Formation. It is not known whether this has been eroded from an offshore exposure (quite likely) or is derived from the lignite bed at Redend Point (some distance away). A complication when looking for lignite is that coal fragments also occur in Studland Bay, particularly the northern part, because coal was once used by fishermen here to weigh down nets or lobster pots.

Also at the low-tide level there are some curious local patches of pebbles. I do not know what is the origin of these. With them are a few exotic rocks, including some limestone and some artificial material such as concrete and brick. Perhaps something was built on the beach here when it was in use for military purposes in the Second World War.

The back of the beach, the junction with the Foredunes warrants study. In places there are some signs of erosion in places, some limited retreat of the beach. This produces a small steep, cliff-like feature. In January, 2003 it was noticed that some sand had blown off the dunes onto the beach, presumably as a result of recent westerly wind.

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Middle Beach, Studland

Middle Beach, Studland from Redend Point

The Redend Sandstone at Redend Point is patchily cemented by iron oxides. It thus varies in hardness and resistance to sea-erosion. In general it forms a promontory against which the sea laps at high tide, as shown in the photograph. Just to the northwest of it is Middle Beach. There is a National Trust car park here and toilets and a cafe in summer. This beach is at the northern limit of the cliff-line and from here northwards the beach is of accumulated sand with sand dunes behind. At one time the cliff-line extended further northwest from here following the break of slope at the back of the huts and continuing on inland to some extent to the Knoll or Knowle. Accretion is not taking place here now and you can see that there are gabions (metal cages containing pebbles) used for sea-defences. Some large limestone blocks have also been placed here. Without this protection the beach would soon cut back to the old cliff-line.

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Tertiary Cliffs - to the South

The Tertiary (Palaeogene) strata are exposed to varying extents in the cliffs from Redend Point southward to the Chalk cliffs. For photographs and details of these please go to the webpage on:

Studland - Tertiary Cliffs.

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6.1 COMPARISON: Coastal Dunes in Semi-Arid Regions

Button Beach, Akrotiri, Cyprus, a sand-spit and dune accumulation resembling the South Haven Peninsula, Studland

Sea-holly and grasses on sand-dunes at Button Beach, Akrotiri, Cyprus

Aeolianite - cemented dunes with cross-bedding at Akrotiri, Cyprus

Developments of sand-spits and of coastal dunes are common in many parts of the world. The South Haven Peninsula is notable for quartz sand which almost completely lacks calcium carbonate. Carbonate-rich beach and dune sands are present on the English coasts at Braunton Burrows, Devon, at Trebetherick Point, Daymer Bay and adjacents areas near Padstow, and at Fistral Bay, Newquay and at Godrevy in Cornwall. They are also present in South Wales and on the West Coast of Ireland. In places dune sands become cemented by calcium carbonate to form eolianite (aeolianite).

In the semi-arid areas of Mediterranean Sea and elsewhere, and in the arid areas of the Arabian Gulf and elsewhere it is very common for coastal dunes to become carbonate-cemented. This is partly the result of high-carbonate content of the beach sand. Carbonate-rich beach sands tend to occur where the sea-water is carbonate-saturated and where abundant shell or ooid (oolite) allochems (particles) are present. The cementation is particularly favoured by the upward movement of calcium carbonate in the soil in such regions of relative aridity. Associated features are caliche or calcrete development and the formation of rhizoconcretions.

In Cyprus, for example, cemented dunes are common. Button Beach, shown above, is a beach resembling the South Haven Peninsula (Daniel is playing with rock pools on eolianite, but the younger dunes northward are not yet firmly-cemented). The dunes are stabilised by vegetation; Mediterranean scrub rather then heather. Older dunes are cemented here and elsewhere on the Akrotiri Peninsula. The cross-bedding in one of these is shown above.

(Note: The photographs of Cyprus have been chosen and modified to show only geological and geomorphological features. They have been photo-edited with some irrelevant non-geological content removed. Resolution is limited by small pixel number and no high-resolution versions exist. The images are copyright and not available for reproduction.)

A common problem encountered by geologists wandering in Mediterranean or Middle Eastern areas is distinguishing eolianite (cemented dunes) from beachrock (cemented beach material). The main indicators are as follows:


1. Absence of pebbles.
2. Cross-bedding is conspicuous but variable, with a lack of regular bedded units.
3. Presence of rhizoconcretions (root concretions of calcium carbonate).
4. The mound-like or ridge-like morphology of dunes may be preserved
5. Cementation by low-Mg calcite.
6. Common caliche-development and calichefication (and calcrete) in the upper metre or so.


1. Pebble layers and/or shell layers present.
2. Seaward dip, with small-scale cross-lamination.
3. Cementation by high-Mg calcite or aragonite.
4. No rhizoconcretions.

Obviously these are guides not fixed rules. Note, also, that it is quite common for beachrock to pass upward into eolianite. Interpretion needs some care. The northern Egyptian coast is particularly good for eolianite developments.

Returning to the subject of the South Haven Peninsula, eolianite cannot form there because of the lack of carbonate in the sands and the relatively heavy rainfall. The dunes therefore have no real resistance to erosion by the sea. On the other hand heather grows at Studland because of the acid soils there. It cannot grow on the calcareous, coastal sand dunes that are common south of Britain.

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The crossing of the Little Sea by Miss Sally Stone in about 1810:

Sally and the Little Sea In about 1810 efforts were made by the Rector to improve the opportunities for women in Swanage by teaching them bonnet-making, so that they no longer had to do the work of donkeys or mules winding capstans in the quarries. "Three strong women were selected" to travel the country with the straw hats and bonnets which had been made, as a consequence, in Swanage. One of these had to get to Cowes, Isle of Wight with a great basket of hats and bonnets. She had to walk to the Little Sea.

"Little Sea is penned back by the Sand Banks; but at certain tides it rushes down over the beach into the sea, in a stream about 29 yards in width, and from 12 to 18 inches in depth... The name of the traveller to the east was Sally Stone. One summer's morning, about six o'clock, our Eastern traveller, Sally, to wit, started off for the Isle of Wight... but when Sally arrived at Little Sea she found that it was running over the beach at a good depth, being in full flood, although at certain periods it would be quite dry. Now when men waded through they first of all took off their boots and stockings, and rolled up their trousers before crossing over; but if a man and a woman happened to meet there, going the same way, the man would gallantly offer to carry the woman across. If the lady proved to be "fat, fair and forty" her accomodating porter would often have to halt when half-way over, put the lady down and take her up better... On this particular occasion Sally was alone. .. She began to prepare for wading by taking off her boots and stockings and pinning up her skirts to a respectable height. She then slung her boots and stockings round her neck, shouldered her basket, and passed over to the other side, and having replaced her footgear and readjusted her dress, she travelled on to the South Haven Inn, where she naturally indulged in such light refreshment as was procurable, bread and cheese and beer, or a drop of "short" as the case may be... "
From here Sally sailed to the Isle of Wight, drinking gin, brandy and punch, capsized in a boat, undressed in the captain's cabin and slept there, was given money by the squire, had some more drink, and returned to Swanage in good spirits with wet straw hats and bonnets unsold. She seems to have enjoyed her adventures - but this is irrelevant to our stories of the Little Sea!

(from Hardy with figure slightly modified from Dawson)

Travelling from Swanage to Poole in Later Victorian Times

Mr. William Masters Hardy, a native of Swanage, reminisced in 1910:

Poole Harbour, Dorset, in Victorian times "I well remember that 50 years ago, when one wanted to go to Poole, which was in those days our London, just as Wareham was our Birmingham, one had to go by the market boat, a little cutter; and when there was no wind it took them seven or eight hours to get there. This was very inconvenient. There was another way to get to Poole - to walk over Studland hill and along the beach to the Sandbanks and ferry. But before one reached this spot on Studland beach one had to pass through what was known as Little Sea, a stream of water running from a little lake behind the Sandbanks and over the beach into the sea. Sometimes it was about 20 yards wide and 18 inches deep. On one occasion a gentleman by the name of Smedmore had to go to Poole to attend a trustee meeting, and dressed in his best broadcloth, he had to walk to Poole. It was high tide, so he got a man named James Horlock to go down as far as Little Sea to carry him across the water. When they arrived at the stream, Mr. Smedmore mounted on Horlock's back and started to cross. When they reached the middle of the stream, where the water was about 18 inches deep, Horlock cried out, "O sir, O sir, please I must put you down and take you up better." Down he dumped him in the water. Mr. Smedmore was an even-tempered gentleman and also a deacon, and not given to bad language, or I fancy that not only the air, but also the water, would have been a different colour. It was certainly most exasperating. Business people should be thankful that these obstacles have surmounted by the introduction of better means of communication - steamers, railways, bicycles, motors, etc."


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7.1 APPENDIX: Notes for Field Leaders

The National Trust

The South Haven Peninsula, Studland belongs to the National Trust who protect it is environmental terms and helpfully make it available for public use, subject to certain rules. Please see the National Trust Studland webpage for more information or contact them for specific enquiries. They have field study facilities and information at Knoll Beach and their headquarters are in Studland Village. Please take care with regard to conservation.

The Sandbanks Ferry

There is good access from the Bournemouth and Poole area via the Sandbanks Ferry. In the winter season it is usually easy and quick to get on and off this car ferry, which also carries buses and minibuses. It is not expensive. At certain times in the winter though the ferry may be stopped for maintenance. In the summer there are large numbers of holiday-makers and you are warned that there may be long queues for the ferry at certain times. An alternative route, which the writer normally uses, is to travel around Poole Harbour via Wareham and the Corfe Castle road. Then turn left for Studland, literally at Corfe Castle and just before the village.

Car Parks

There are the following car parks. You may need to make specific enquiries or check in advance by car regarding the parking of coaches. The road from Studland to South Haven Point and the ferry takes buses:

1. South Haven Point. This is at the east side of the ferry terminal. There are toilets but not always open in the winter. There is some shelter from the rain at the toilet building but not much else in winter. There are informative notice boards and a walkway across the reed marsh. This is the car-park for studying Shell Bay and the northern part of the South Haven Peninsula.

2. Knoll Beach. This is the main National Trust centre for tourists and field parties etc. There is a shop, cafe and toilets (I have found the toilets open in winter). There is also a residential field study centre. Please contact the National Trust for details. This is the best car-park for studying the central and southern part of the South Haven Peninsula, including the dune ridges.

3. Middle Beach at Studland. There is a toilet and a cafe here which may be open at certain times. This is a good place to study coast erosion, and particularly Redcliff Point with Eocene strata (but low tide is needed to go round the point).

4. The National Trust car park adjacent to the Bankes Arms pub in Studland Village. This car-park is a good centre for South Beach (a short walk) or for Harry Rocks and Ballard Point (a longer walk on the cliff top). It is convenient to have the pub adjacent and this is a good place to raise the morale of a party at lunch time on a wet day! Food can be obtained here. There is a public toilet a short distance down the road from the car park and it is usually open. Features nearby include the new doline (swallow-hole), Studland Church and the strange cross carved in Portland Stone from the Isle of Purbeck and including carvings of such unusual topics as the aircraft Concorde. This car park is also a good place to start a walk over Ballard Down to Ballard Cliff and Swanage on the south side of the hill.

5. Elsewhere. There are few other places to park a car conveniently, and it might be difficult for a group of vehicles to stop at other places. You can obtain a good view of the Little Sea from the road from Studland to the ferry, and it would not be difficult to park one or two cars to walk to a viewpoint.


The coast here is microtidal with tidal range generally less than 2 metres. The South Haven Peninsula of sand can be studied in any tide conditions, although a low tide is good to see the shore. There is no major risk on the sand peninsula of being trapped by the tide. Further south Redend Point cannot be rounded unless the tide is very low. However, there is access round by the local lanes a short walk inland will solve the problem. The iron pipes and the lignite bed at Redend Point may be out of reach at high tide, though.

If anyone tries to reach Harry Rocks from the shore then this is a much more serious matter regarding tides and can only be attempted with favourable tide and wave conditions. It is not recommended but may, perhaps, be undertaken by the specialist who needs to study this part of the Chalk. One can easily be cut off by the tide, it is necessary to scramble along close to the cliff which has some threat of falling rocks, and there is some very slippery seaweed in piles which have to be crossed. In addition, sea-gulls may object to the presence of an intruder. It is not possible to travel beyond Harry Rocks. The present writer has only done this two or three times in a half-century.

Swimming is not normally regarded as part of a geological or geographical field trip. Note though that the beach at Studland Bay is gently shelving and not normally hazardous in good weather. At Shell Bay, though, there are strong and dangerous tidal currents.

Bad Weather Conditions

Being far south in England and in a region known for its amount of sunshine, this region generally has good or mild weather. It can be affected by winter storms, though, and in bad conditions a field trip may have to be cancelled. If it does take place then warm, waterproof clothing and sturdy footwear are essential for all participants. Field trips with suitably-dressed and experienced, volunteer adults (i.e. scientific societies) may less of a problem than dealing with students. Those individuals more at risk may opt not to attend and this is sensible. Furthermore, it is not necessary to walk a long distance from a car and anyone encountering difficulties can return. It is important that the field leader is fully informed, so that people do not seem to be missing. Compulsory student trips may not be always be operated easily in bad weather; unless the field leader is very careful they might by chance include some students who are inadequately clothed for the weather or who may be unwell or unfit. However, some well-prepared, well-dressed and well-organised student parties can be seen on the beach in wet weather though without seeming to have any problems.

In terms of exposure to the weather, the South Haven Peninsula is not usually particularly bad. The main Studland beach can be very exposed to strong winds and, in winter, to cold winds from the east. Shell-Bay is in the lee of southerly winds and not too exposed. Middle Beach and South Beach are both quite protected from southwesterly gales. Harry Rocks and Ballard Down are openly exposed.

Specific shelter from the rain may be obtained at the National Trust facilities at Knoll Beach, using the shop, cafe etc. There is a little shelter at South Haven Point, but not much. There is the cafe at Middle Beach if it is open. There is the Banks Arms pub at Studland village. Swanage is not far to the south and has shops, pubs and various tourist attractions. There is an interpretation centre at the Durlston Head country park to south of Swanage town.


As mentioned above, an additional summer complication is the presence of naturists (nudists). These are present in a certain area of central Studland Bay and part of the dunes behind, as controlled and limited by the National Trust . This area has been reduced in size recently and a field party would have to walk for some distance to reach the defined stretch of coast. There are warning notices. There are undercover police patrol to catch undesirable characters who may also visit the area. Geologists should, if possible, visit in Autumn, Winter and Spring when they are very unlikely to encounter nudists or others, and the peninsula is very free of people in general. For more information consult the National Trust .

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I thank Alan Holiday for kindly providing aerial photographs of the South Haven Peninsula that were taken by him. This is much appreciated. I am very grateful to the National Trust for allowing me to reproduce their pamphlet which provides information on the Studland area. In particular I am much obliqed to David Kemp, National Trust, CLV Manager, Corfe Castle and Purbeck, Castle View, Corfe Castle, Wareham. I appreciate the cooperation and help of the National Trust in various respects. I am grateful for the kind participation of various field parties in field work and photography, including those of the Open University Geological Society and the Havant Group WEA. Dawn and Tony Denyer showed me the Oregon Dunes and provided most generous hospitality in the USA for which I am very grateful. Joanna and Ben Bentley made it possible for me to examine the coastal dunes of Cyprus, and their help is much appreciated. The The Channel Coastal Observatory has very helpfully provided aerial photographs, and I particularly thank the Manager - Travis Mason. I much appreciate the advice and help of my daughter, Tonya Loades of Bartley West, Chartered Surveyors.

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Please go to the webpage on Studland and Harry Rocks; Bibliography and References.

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|Studland Peninsula - Poole Harbour Side (new, in prep.) |Home and Contents |Studland - Tertiary Cliffs |Harry Rocks, Ballard Point |Swanage Bay |Studland and Harry Rocks; Bibliography |Sandbanks Peninsula

National Trust - Studland

Copyright © 2014 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 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.